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Recent advancements in water treatment

For immediate release, acs news service weekly presspac: january 19, 2022.

Generating clean, safe water is becoming increasingly difficult. Water sources themselves can be contaminated, but in addition, some purification methods can cause unintended harmful byproducts to form. And not all treatment processes are created equal with regard to their ability to remove impurities or pollutants. Below are some recent papers published in ACS journals that report insights into how well water treatment methods work and the quality of the resulting water. Reporters can request free access to these papers by emailing  newsroom@acs.org .

“Drivers of Disinfection Byproduct Cytotoxicity in U.S. Drinking Water: Should Other DBPs Be Considered for Regulation?” Environmental Science & Technology Dec.15, 2021

In this paper, researchers surveyed both conventional and advanced disinfection processes in the U.S., testing the quality of their drinking waters. Treatment plants with advanced removal technologies, such as activated carbon, formed fewer types and lower levels of harmful disinfection byproducts (known as DBPs) in their water. Based on the prevalence and cytotoxicity of haloacetonitriles and iodoacetic acids within some of the treated waters, the researchers recommend that these two groups be considered when forming future water quality regulations.

“Complete System to Generate Clean Water from a Contaminated Water Body by a Handmade Flower-like Light Absorber” ACS Omega Dec. 9, 2021 As a step toward a low-cost water purification technology, researchers crocheted a coated black yarn into a flower-like pattern. When the flower was placed in dirty or salty water, the water wicked up the yarn. Sunlight caused the water to evaporate, leaving the contaminants in the yarn, and a clean vapor condensed and was collected. People in rural locations could easily make this material for desalination or cleaning polluted water, the researchers say.

“Data Analytics Determines Co-occurrence of Odorants in Raw Water and Evaluates Drinking Water Treatment Removal Strategies” Environmental Science & Technology Dec. 2, 2021

Sometimes drinking water smells foul or “off,” even after treatment. In this first-of-its-kind study, researchers identified the major odorants in raw water. They also report that treatment plants using a combination of ozonation and activated carbon remove more of the odor compounds responsible for the stink compared to a conventional process. However, both methods generated some odorants not originally present in the water.

“Self-Powered Water Flow-Triggered Piezocatalytic Generation of Reactive Oxygen Species for Water Purification in Simulated Water Drainage” ACS ES&T Engineering Nov. 23, 2021

Here, researchers harvested energy from the movement of water to break down chemical contaminants. As microscopic sheets of molybdenum disulfide (MoS2) swirled inside a spiral tube filled with dirty water, the MoS2 particles generated electric charges. The charges reacted with water and created reactive oxygen species, which decomposed pollutant compounds, including benzotriazole and antibiotics. The researchers say these self-powered catalysts are a “green” energy resource for water purification.

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Current Water Treatment Technologies: An Introduction

• Reference work entry
• First Online: 11 July 2021
• pp 2033–2066
• Cite this reference work entry

• Na Tian 4 ,
• Yulun Nie 5 ,
• Xike Tian 5 &
• Yanxin Wang 6  

347 Accesses

Water treatment and purification in environmental protection are the worldwide issues to relieve the water shortage. At present, various treatment technologies for drinking water or wastewater have been developed. Hence, in this chapter, we will summarize the available water treatment and purification technologies including their advantages and disadvantages as well as the practical application. The main contents then can be divided into the following parts: Firstly, the purification processes for drinking water are introduced including the efficiency and mechanism of filtration and sedimentation, flocculation, disinfection, and other modern emerging technologies. Secondly, the principles and applications of existed wastewater treatment methods are summarized. Thirdly, the new technologies of water treatment are presented such as water reuse technology, membrane technology, advanced oxidation processes based deep water treatment technologies, etc. We think, by summarizing the recent literature and our preliminary work, the present chapter will give the basic information of various water treatment technologies for readers and further capitalize on these technologies for sustainable water management.

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Petrie B, Barden R, Kasprzyk-Hordern B (2015) A review on emerging contaminants in wastewaters and the environment: current knowledge, understudied areas and recommendations for future monitoring. Water Res 72:3–27

Article   CAS   Google Scholar  

Sorensen JPR, Lapworth DJ, Nkhuwa DCW, Stuart ME, Gooddy DC, Bell RA, Chirwa M, Kabika J, Liemisa M, Chibesa M, Pedley S (2015) Emerging contaminants in urban groundwater sources in Africa. Water Res 72:51–63

Zhang FR, Song YW, Song S, Zhang RJ, Hou WG (2015) Synthesis of magnetite-graphene oxide-layered double hydroxide composites and applications for the removal of Pb(II) and 2,4-dichlorophenoxyacetic acid from aqueous solutions. ACS Appl Mater Interfaces 7:7251–7263

Gupta A, Chauhan VS, Sankararamakrishnan N (2009) Preparation and evaluation of iron-chitosan composites for removal of As(III) and As(V) from arsenic contaminated real life groundwater. Water Res 43:3862–3870

Kong SQ, Wang YX, Zhan HB, Liu ML, Liang LL, Hu QH (2014) Competitive adsorption of humic acid and arsenate on nanoscale iron–manganese binary oxide-loaded zeolite in groundwater. J Geochem Explor 144:220–225

Thong ZW, Han G, Cui Y, Gao J, Chung TS, Chan SY, Wei S (2014) Novel nanofiltration membranes consisting of a sulfonated pentablock copolymer rejection layer for heavy metal removal. Environ Sci Technol 48:13880–13887

Sun YB, Yang SB, Chen Y, Ding CC, Cheng WC, Wang XK (2015) Adsorption and desorption of U(VI) on functionalized graphene oxides: a combined experimental and theoretical study. Environ Sci Technol 49:4255–4262

Yang Y, Ok YS, Kim KH, Kwon EE, Tsang YF (2017) Occurrences and removal of pharmaceuticals and personal care products (PPCPs) in drinking water and water/sewage treatment plants: a review. Sci Total Environ 596–597:303–320

Ortiz M, Raluy RG, Serra L (2007) Life cycle assessment of water treatment technologies: wastewater and water-reuse in a small town. Desalination 204:121–131

Igunnu ET, Chen GZ (2014) Produced water treatment technologies. Int J Low-Carbon Technol 9:157–177

Qu XL, Alvarez PJ, Li QL (2013) Applications of nanotechnology in water and wastewater treatment. Water Res 47:3931–3946

Sonune A, Ghate R (2004) Developments in wastewater treatment methods. Desalination 167:55–63

Ternes TA, Meisenheimer M, Mcdowell D, Sacher F, Brauch HJ, Haist-Gulde B, Preuss G, Wilme U, Zulei-Seibert N (2002) Removal of pharmaceuticals during drinking water treatment. Environ Sci Technol 36:3855–3863

Krasner SW, McGuire MJ, Jacangelo JG, Patania NL, Reagan KM, Aieta EM (1989) The occurrence of disinfection by-products in US drinking water. J Am Water Works Ass 81:41–53

Gunten UV (2003) Ozonation of drinking water: part I. Oxidation kinetics and product formation. Water Res 37:1443–1467

Azimi A, Azari A, Rezakazemi M, Ansarpour M (2017) Removal of heavy metals from industrial wastewaters: a review. ChemBioEng Rev 4:37–59

Article   Google Scholar  

Vymazal J (2014) Constructed wetlands for treatment of industrial wastewaters: a review. Ecol Eng 73:724–751

Bautista P, Mohedano AF, Casas JA, Zazo JA, Rodriguez JJ (2008) An overview of the application of Fenton oxidation to industrial wastewaters treatment. J Chem Technol Biotechnol 83:1323–1338

Moussavi G, Mahmoudi M (2009) Removal of azo and anthraquinone reactive dyes from industrial wastewaters using MgO nanoparticles. J Hazard Mater 168:806–812

Gehrke I, Geiser A, Somborn-Schulz A (2015) Innovations in nanotechnology for water treatment. Nanotechnol Sci Appl 8:1–17

Krzeminski P, Tomei MC, Karaolia P, Langenhoff A, Almeida CMR, Felis E, Gritten F, Andersen HR, Fernandes T, Manaia CM, Rizzo L, Fatta-Kassinos D (2019) Performance of secondary wastewater treatment methods for the removal of contaminants of emerging concern implicated in crop uptake and antibiotic resistance spread: a review. Sci Total Environ 648:1052–1081

Ali I, Peng CS, Khan ZM, Naz I, Sultan M, Ali M, Abbasi IA, Islam T, Ye T (2019) Overview of microbes based fabricated biogenic nanoparticles for water and wastewater treatment. J Environ Manag 230:128–150

Muzammil Anjum RM, Waqas M, Gehany F, Barakat MA (2019) Remediation of wastewater using various nano-materials. Arab J Chem 12:4897–4919

Kim KH, Ihm SK (2011) Heterogeneous catalytic wet air oxidation of refractory organic pollutants in industrial wastewaters: a review. J Hazard Mater 186:16–34

Samaei SM, Gato-Trinidad S, Altaee A (2018) The application of pressure-driven ceramic membrane technology for the treatment of industrial wastewaters – a review. Sep Purif Technol 200:198–220

Chowdhury S, Mazumder MAJ, Al-Attas O, Husain T (2016) Heavy metals in drinking water: occurrences, implications, and future needs in developing countries. Sci Total Environ 569–570:476–488

Garfí M, Cadena E, Sanchez-Ramos D, Ferrer I (2016) Life cycle assessment of drinking water: comparing conventional water treatment, reverse osmosis and mineral water in glass and plastic bottles. J Clean Prod 137:997–1003

Sharma S, Bhattacharya A (2017) Drinking water contamination and treatment techniques. Appl Water Sci 7:1043–1067

Muhamad MS, Salim MR, Lau WJ, Yusop Z (2016) A review on bisphenol A occurrences, health effects and treatment process via membrane technology for drinking water. Environ Sci Pollut Res Int 23:11549–11567

Glaze WH (1987) Drinking-water treatment with ozone. Environ Sci Technol 21:224–230

Sillanpaa M, Ncibi MC, Matilainen A, Vepsalainen M (2018) Removal of natural organic matter in drinking water treatment by coagulation: a comprehensive review. Chemosphere 190:54–71

Moon J, Kang MS, Lim JL, Kim CH, Park HD (2009) Evaluation of a low-pressure membrane filtration for drinking water treatment: pretreatment by coagulation/sedimentation for the MF membrane. Desalination 247:271–284

Hall ER, Monti A, Mohn WW (2010) A comparison of bacterial populations in enhanced biological phosphorus removal processes using membrane filtration or gravity sedimentation for solids-liquid separation. Water Res 44:2703–2714

Martinez-Huitle CA, Brillas E (2008) Electrochemical alternatives for drinking water disinfection. Angew Chem Int Ed 47:1998–2005

Aboulhassan MA, Souabi S, Yaacoubi A, Baudu M (2006) Removal of surfactant from industrial wastewaters by coagulation flocculation process. Int J Environ Sci Technol 3:327–332

Asami T, Katayama H, Torrey JR, Visvanathan C, Furumai H (2016) Evaluation of virus removal efficiency of coagulation-sedimentation and rapid sand filtration processes in a drinking water treatment plant in Bangkok, Thailand. Water Res 101:84–94

Volk C, Bell K, Ibrahim E, Verges D, Amy G, LeChevallier M (2000) Impact of enhanced and optimized coagulation on removal of organic matter and its biodegradable fraction in drinking water. Water Res 34:3247–3257

Sharp EL, Jarvis P, Parsons SA, Jefferson B (2006) Impact of fractional character on the coagulation of NOM. Colloids Surf A Physicochem Eng Asp 286:104–111

Henderson R, Sharp E, Jarvis P, Parsons S, Jefferson B (2006) Identifying the linkage between particle characteristics and understanding coagulation performance. In: Han MY, Park KH, Dockko S (eds) Particle separation 2005 – drinking water treatment. Iwa Publishing, London, pp 31–38

Google Scholar  

Duan JM, Gregory J (2003) Coagulation by hydrolysing metal salts. Adv Colloid Interf Sci 100–102:475–502

Yang C, Gao LL, Wang YX, Tian XK, Komarneni S (2014) Fluoride removal by ordered and disordered mesoporous aluminas. Microporous Mesoporous Mater 197:156–163

Daud Z, Awang H, Latif AAA, Nasir N, Ridzuan MB, Ahmad Z (2015) Suspended solid, color, COD and oil and grease removal from biodiesel wastewater by coagulation and flocculation processes. Procedia Soc Behav Sci 195:2407–2411

Di Bella G, Giustra MG, Freni G (2014) Optimisation of coagulation/flocculation for pre-treatment of high strength and saline wastewater: performance analysis with different coagulant doses. Chem Eng J 254:283–292

Kabdaşlı I, Arslan-Alaton I, Ölmez-Hancı T, Tünay O (2012) Electrocoagulation applications for industrial wastewaters: a critical review. Environ Technol Rev 1:2–45

Jarvis P, Sharp E, Pidou M, Molinder R, Parsons SA, Jefferson B (2012) Comparison of coagulation performance and floc properties using a novel zirconium coagulant against traditional ferric and alum coagulants. Water Res 46:4179–4187

Lu WM, Tung KL, Pan CH, Hwang KJ (1998) The effect of particle sedimentation on gravity filtration. Sep Sci Technol 33:1723–1746

Zhang JN, Lin T, Chen W (2017) Micro-flocculation/sedimentation and ozonation for controlling ultrafiltration membrane fouling in recycling of activated carbon filter backwash water. Chem Eng J 325:160–168

Yim SS, Kwon YD (1997) A unified theory on solid-liquid separation- filtration, expression, sedimentation, filtration by centrifugal force, and cross flow filtration. Korean J Chem Eng 14:354–358

Font R, HernÁNdez A (2000) Filtration with sedimentation: application of Kynchs theorems. Sep Sci Technol 35:183–210

Tiller FM, Hsyung NB (1995) Role of porosity in filtration- XII. Filtration with sedimentation. AICHE J 41:1153–1164

Tiehm A, Herwig V, Neis U (1999) Particle size analysis for improved sedimentation and filtration in waste water treatment. Water Sci Technol 39:99–106

Hawkes JJ, Limaye MS, Coakley WT (1997) Filtration of bacteria and yeast by ultrasound-enhanced sedimentation. J Appl Microbiol 82:39–47

Kato R, Asami T, Utagawa E, Furumai H, Katayama H (2018) Pepper mild mottle virus as a process indicator at drinking water treatment plants employing coagulation-sedimentation, rapid sand filtration, ozonation, and biological activated carbon treatments in Japan. Water Res 132:61–70

Albinana-Gimenez N, Miagostovich MP, Calgua B, Huguet JM, Matia L, Girones R (2009) Analysis of adenoviruses and polyomaviruses quantified by qPCR as indicators of water quality in source and drinking-water treatment plants. Water Res 43:2011–2019

Albinana-Gimenez N, Clemente-Casares P, Calgua B, Huguet JM, Courtois S, Girones R (2009) Comparison of methods for concentrating human adenoviruses, polyomavirus JC and noroviruses in source waters and drinking water using quantitative PCR. J Virol Methods 158:104–109

Haramoto E, Kitajima M, Kishida N, Konno Y, Katayama H, Asami M, Akiba M (2013) Occurrence of pepper mild mottle virus in drinking water sources in Japan. Appl Environ Microbiol 79:7413–7418

Gimbert LJ, Haygarth PM, Beckett R, Worsfold PJ (2005) Comparison of centrifugation and filtration techniques for the size fractionation of colloidal material in soil suspensions using sedimentation field-flow fractionation. Environ Sci Technol 39:1731–1735

Pavlovic I, Perez MR, Barriga C, Ulibarri MA (2009) Adsorption of Cu 2+ , Cd 2+ and Pb 2+ ions by layered double hydroxides intercalated with the chelating agents diethylenetriaminepentaacetate and meso-2,3-dimercaptosuccinate. Appl Clay Sci 43:125–129

Humplik T, Lee J, O’Hern SC, Fellman BA, Baig MA, Hassan SF, Atieh MA, Rahman F, Laoui T, Karnik R (2011) Nanostructured materials for water desalination. Nanotechnology 22:2788–2794

Zevenbergen C, Van Reeuwijk LP, Frapporti G, Louws RJ, Schuiling RD (1996) A simple method for defluoridation of drinking water at village level by adsorption on Ando soil in Kenya. Sci Total Environ 188:225–232

Loganathan P, Vigneswaran S, Kandasamy J, Naidu R (2013) Defluoridation of drinking water using adsorption processes. J Hazard Mater 248–249:1–19

Babi KG, Koumenides KM, Nikolaou AD, Makri CA, Tzoumerkas FK, Lekkas TD (2007) Pilot study of the removal of THMs, HAAs and DOC from drinking water by GAC adsorption. Desalination 210:215–224

Tian XK, Wu QY, Wong KM, Yang C, Wang WW, Wu XN, Wang YX, Zhang SX, Lei Y (2013) A simple technique for the facile synthesis of novel crystalline mesoporous ZrO 2 -Al­ 2 O 3 hierarchical nanostructures with high lead (II) ion absorption ability. Appl Surf Sci 284:412–418

Tian XK, Wang WW, Tian N, Zhou CX, Yang C, Komarneni S (2016) Cr(VI) reduction and immobilization by novel carbonaceous modified magnetic Fe 3 O 4 /halloysite nanohybrid. J Hazard Mater 309:151–156

Mellouk S, Belhakem A, Marouf-Khelifa K, Schott J, Khelifa A (2011) Cu(II) adsorption by halloysites intercalated with sodium acetate. J Colloid Interface Sci 360:716–724

Liu L, Wan YZ, Xie YD, Zhai R, Zhang B, Liu JD (2012) The removal of dye from aqueous solution using alginate-halloysite nanotube beads. Chem Eng J 187:210–216

Tian XK, Wang WW, Wang YX, Komarneni S, Yang C (2015) Polyethylenimine functionalized halloysite nanotubes for efficient removal and fixation of Cr (VI). Microporous Mesoporous Mater 207:46–52

Wang JH, Zhang X, Zhang B, Zhao YF, Zhai R, Liu JD, Chen RF (2010) Rapid adsorption of Cr (VI) on modified halloysite nanotubes. Desalination 259:22–28

Zhao YF, Abdullayev E, Vasiliev A, Lvov Y (2013) Halloysite nanotubule clay for efficient water purification. J Colloid Interface Sci 406:121–129

Alkan M, Çelikçapa S, Demirbaş Ö, Doğan M (2005) Removal of reactive blue 221 and acid blue 62 anionic dyes from aqueous solutions by sepiolite. Dyes Pigments 65:251–259

Brigatti MF, Medici L, Poppi L (1996) Sepiolite and industrial waste-water purification: removal of Zn 2+ and Pb 2+ from aqueous solutions. Appl Clay Sci 11:43–54

Kara M, Yuzer H, Sabah E, Celik MS (2003) Adsorption of cobalt from aqueous solutions onto sepiolite. Water Res 37:224–232

Marjanović V, Lazarević S, Janković-Častvan I, Potkonjak B, Đ Janaćković R (2011) Petrović, Chromium(VI) removal from aqueous solutions using mercaptosilane functionalized sepiolites. Chem Eng J 166:198–206

Kocaoba S (2009) Adsorption of Cd(II), Cr(III) and Mn(II) on natural sepiolite. Desalination 244:24–30

Serratosa JM (1979) Surface properties of fibrous clay minerals (palygorskite and sepiolite). Dev Sedimentol 27:99–109

Galan E (1996) Properties and application of palygorskite-sepiolite clays. Clay Miner 31:443–453

Joussein E, Petit S, Churchman J, Theng B, Righi D, Delvaux B (2005) Halloysite clay minerals-a review. Clay Miner 40:383–426

Du ML, Guo BC, Jia DM (2010) Newly emerging applications of halloysite nanotubes: a review. Polym Int 59:574–582

Belkassa K, Bessaha F, Marouf-Khelifa K, Batonneau-Gener I, Comparot J, Khelifa A (2013) Physicochemical and adsorptive properties of a heat-treated and acid-leached Algerian halloysite. Colloid Surf A 421:26–33

Matusik J (2016) Halloysite for adsorption and pollution remediation. In: Peng Y, Thill A, Faïza B (eds) Developments in clay science. Elsevier, pp 606–627

Tian N, Tian XK, Ma LL, Yang C, Wang YX, Wang ZY, Zhang LD (2015) Well-dispersed magnetic iron oxide nanocrystals on sepiolite nanofibers for arsenic removal. RSC Adv 5:25236–25243

Tian N, Tian XK, Liu XW, Zhou ZX, Yang C, Ma LL, Tian C, Li Y, Wang YX (2016) Facile synthesis of hierarchical dendrite-like structure iron layered double hydroxide nanohybrids for effective arsenic removal. Chem Commun 52:11955–11958

Li Q, Mahendra S, Lyon DY, Brunet L, Liga MV, Li D, Alvarez PJ (2008) Antimicrobial nanomaterials for water disinfection and microbial control: potential applications and implications. Water Res 42:4591–4602

Hua GH, Reckhow DA (2007) Comparison of disinfection byproduct formation from chlorine and alternative disinfectants. Water Res 41:1667–1678

Li XF, Mitch WA (2018) Drinking water disinfection byproducts (DBPs) and human health effects: multidisciplinary challenges and opportunities. Environ Sci Technol 52:1681–1689

Malato S, Fernández-Ibáñez P, Maldonado MI, Blanco J, Gernjak W (2009) Decontamination and disinfection of water by solar photocatalysis: recent overview and trends. Catal Today 147:1–59

Giannakis S, López MIP, Spuhler D, Pérez JAS, Ibáñez PF, Pulgarin C (2016) Solar disinfection is an augmentable, in situ-generated photo-Fenton reaction – part 2: a review of the applications for drinking water and wastewater disinfection. Appl Catal B Environ 198:431–446

Ma SL, Zhan SH, Jia YN, Shi Q, Zhou QX (2016) Enhanced disinfection application of Ag-modified g-C 3 N 4 composite under visible light. Appl Catal B Environ 186:77–87

Kimura SY, Komaki Y, Plewa MJ, Marinas BJ (2013) Chloroacetonitrile and N,2-dichloroacetamide formation from the reaction of chloroacetaldehyde and monochloramine in water. Environ Sci Technol 47:12382–12390

Villanueva CM, Cordier S, Font-Ribera L, Salas LA, Levallois P (2015) Overview of disinfection by-products and associated health effects. Curr Environ Health Rep 2:107–115

Rook JJ (1974) Formation of haloforms during chlorination of natural waters. Water Treat Examinat 23:234–243

Jeong CH, Postigo C, Richardson SD, Simmons JE, Kimura SY, Marinas BJ, Barcelo D, Liang P, Wagner ED, Plewa MJ (2015) Occurrence and comparative toxicity of haloacetaldehyde disinfection byproducts in drinking water. Environ Sci Technol 49:13749–13759

Singer PC (1994) Control of disinfection by-products in drinking water. J Environ Eng 120:727–744

Richardson SD (2003) Disinfection by-products and other emerging contaminants in drinking water. Trends Anal Chem 22:666–684

Simpson KL, Hayes KP (1998) Drinking water disinfection by-products: an Australian perspective. Water Res 32:1522–1528

Williams DT, LeBel GL, Benoit FM (1997) Disinfection by-products in Canadian drinking water. Chemosphere 34:299–316

John DE, Haas CN, Nwachuku N, Gerba CP (2005) Chlorine and ozone disinfection of encephalitozoon intestinalis spores. Water Res 39:2369–2375

Xu P, Janex ML, Savoye P, Cockx A (2002) Wastewater disinfection by ozone: main parameters for process design. Water Res 36:1043–1055

Cho M, Chung H, Yoon J (2003) Disinfection of water containing natural organic matter by using ozone-initiated radical reactions. Appl Environ Microbiol 69:2284–2291

Zeng XK, Wang ZY, Wang G, Gengenbach TR, David T, McCarthy A, Deletic JGY, Zhang XW (2017) Highly dispersed TiO 2 nanocrystals and WO 3 nanorods on reduced graphene oxide: Z-scheme photocatalysis system for accelerated photocatalytic water disinfection. Appl Catal B Environ 218:163–173

Fernández-Ibáñez P, Polo-López MI, Malato S, Wadhwa S, Hamilton JWJ, Dunlop PSM, D’Sa R, Magee E, O’Shea K, Dionysiou DD, Byrne JA (2015) Solar photocatalytic disinfection of water using titanium dioxide graphene composites. Chem Eng J 261:36–44

Wolfe RL (1990) Ultraviolet disinfection of potable water. Environ Sci Technol 24:768–773

Yu JC, Ho WK, Yu JG, Yip H, Wong PK, Zhao JC (2005) Efficient visible-light-induced photocatalytic disinfection on sulfur-doped nanocrystalline titania. Environ Sci Technol 39:1175–1179

Kraft A (2008) Electrochemical water disinfection: a short review. Platin Met Rev 52:177–185

Patermarakis G, Fountoukidis E (1990) Disinfection of water by electrochemical treatment. Water Res 24:1491–1496

Song K, Mohseni M, Taghipour F (2016) Application of ultraviolet light-emitting diodes (UV-LEDs) for water disinfection: a review. Water Res 94:341–349

Kitis M (2004) Disinfection of wastewater with peracetic acid: a review. Environ Int 30:47–55

Blume T, Neis U (2004) Improved wastewater disinfection by ultrasonic pre-treatment. Ultrason Sonochem 11:333–336

Jeong J, Kim C, Yoon J (2009) The effect of electrode material on the generation of oxidants and microbial inactivation in the electrochemical disinfection processes. Water Res 43:895–901

Kerwick MI, Reddy SM, Chamberlain AHL, Holt DM (2005) Electrochemical disinfection, an environmentally acceptable method of drinking water disinfection? Electrochim Acta 50:5270–5277

Huang X, Qu Y, Cid CA, Finke C, Hoffmann MR, Lim K, Jiang SC (2016) Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell. Water Res 92:164–172

Muralikrishna IV, Manickam V (2017) Wastewater treatment technologies. In: Environmental management. Elsevier, pp 249–293

Chapter   Google Scholar  

Amuda OS, Amoo IA (2007) Coagulation/flocculation process and sludge conditioning in beverage industrial wastewater treatment. J Hazard Mater 141:778–783

Dabrowski A, Hubicki Z, Podkoscielny P, Robens E (2004) Selective removal of the heavy metal ions from waters and industrial wastewaters by ion-exchange method. Chemosphere 56:91–106

Atlow SC, Bonadonna-Aparo L, Klibanov AM (1984) Dephenolization of industrial wastewaters catalyzed by polyphenol oxidase. Biotechnol Bioeng 26:599–603

Glaze WH, Kang JW, Chapin DH (1987) The chemistry of water treatment processes involving ozone, hydrogen peroxide and ultraviolet radiation. Ozone Sci Eng 9:335–352

Epa U (2011) Principles of design and operations of wastewater treatment pond systems for plant operators, engineers, and managers. United States Environmental Protection Agency, Office of Research and Development

Tünay O, Kabdasli I, Orhon D, Kolçak S (1997) Ammonia removal by magnesium ammonium phosphate precipitation in industrial wastewaters. Water Sci Technol 36:225–228

Birge WJ, Black JA, Short TM, Westerm AG (1989) A comparative ecological and toxicological investigation of a secondary wastewater treatment plant effluent and its receiving stream. Environ Toxicol Chem 8:437–450

Munkittrick KR, Van Der Kraak GJ, Mcmaster ME, Port CB (1992) Response of hepatic mfo activity and plasma sex steroids to secondary treatment of bleached Kraft pulp mill effluent and mill shutdown. Environ Toxicol Chem 11:1427–1439

Wu Y, Chung A, Tam NFY, Pi N, Wong MH (2008) Constructed mangrove wetland as secondary treatment system for municipal wastewater. Ecol Eng 34:137–146

Ubukata Y, Takii S (1994) Induction ability of excess phosphate accumulation for phosphate removing bacteria. Water Res 28:247–249

Lehman SG, Liu L (2009) Application of ceramic membranes with pre-ozonation for treatment of secondary wastewater effluent. Water Res 43:2020–2028

Lin HJ, Chen JR, Wang FY, Ding LX, Hong HC (2011) Feasibility evaluation of submerged anaerobic membrane bioreactor for municipal secondary wastewater treatment. Desalination 280:120–126

Sarria V, Parra S, Adler N, Péringer P, Benitez N, Pulgarin C (2002) Recent developments in the coupling of photoassisted and aerobic biological processes for the treatment of biorecalcitrant compounds. Catal Today 76:301–315

Wang XJ, Song Y, Mai JS (2008) Combined Fenton oxidation and aerobic biological processes for treating a surfactant wastewater containing abundant sulfate. J Hazard Mater 160:344–348

Rittmann BE (1987) Aerobic biological treatment: water treatment processes. Environ Sci Technol 21(2):128–136

Tomlinson TG, Boon AG, Trotman CNA (1966) Inhibition of nitrification in the activated sludge process of sewage disposal. J Appl Bacteriol 29:266–291

Li B, Zhang T (2010) Biodegradation and adsorption of antibiotics in the activated sludge process. Environ Sci Technol 44:3468–3473

Fuhs GW, Chen M (1975) Microbiological basis of phosphate removal in the activated sludge process for the treatment of wastewater. Microb Ecol 2:119–138

Lin AY, Yu TH, Lateef SK (2009) Removal of pharmaceuticals in secondary wastewater treatment processes in Taiwan. J Hazard Mater 167:1163–1169

Liao BQ, Kraemer JT, Bagley DM (2006) Anaerobic membrane bioreactors: applications and research directions. Crit Rev Environ Sci Technol 36:489–530

Lin HJ, Xie K, Mahendran B, Bagley DM, Leung KT, Liss SN, Liao BQ (2009) Sludge properties and their effects on membrane fouling in submerged anaerobic membrane bioreactors (SAnMBRs). Water Res 43:3827–3837

Zhang XY, Wang ZW, Wu ZC, Lu FH, Tong J, Zang LL (2010) Formation of dynamic membrane in an anaerobic membrane bioreactor for municipal wastewater treatment. Chem Eng J 165:175–183

Lin HJ, Peng W, Zhang MJ, Chen JR, Hong HC, Zhang Y (2013) A review on anaerobic membrane bioreactors: applications, membrane fouling and future perspectives. Desalination 314:169–188

Koivunen J, Siitonen A, Heinonen-Tanski H (2003) Elimination of enteric bacteria in biological-chemical wastewater treatment and tertiary filtration units. Water Res 37:690–698

Gómez M, Plazab F, Garralón G, Pérez J, Gómez MA (2007) A comparative study of tertiary wastewater treatment by physico-chemical-UV process and macrofiltration-ultrafiltration technologies. Desalination 202:369–376

Sérodes JB, Walsh E, Goulet O (2011) Tertiary treatment of municipal wastewater using bioflocculating micro-algae. Can J Civ Eng 18:940–944

Wu J, Yang YS, Lin J (2005) Advanced tertiary treatment of municipal wastewater using raw and modified diatomite. J Hazard Mater 127:196–203

Ince NH (1998) Light-enhanced chemical oxidation for tertiary treatment of municipal landfill leachate. Water Environ Res 70:1161–1169

Vijayalakshmi P, Raju GB, Gnanamani A (2011) Advanced oxidation and electrooxidation as tertiary treatment techniques to improve the purity of tannery wastewater. Ind Eng Chem Res 50:10194–10200

Liu F, Zhao CC, Zhao DF, Liu GH (2008) Tertiary treatment of textile wastewater with combined media biological aerated filter (CMBAF) at different hydraulic loadings and dissolved oxygen concentrations. J Hazard Mater 160:161–167

Wei XC, Viadero RC Jr, Bhojappa S (2008) Phosphorus removal by acid mine drainage sludge from secondary effluents of municipal wastewater treatment plants. Water Res 42:3275–3284

Araña J, Herrera Melián JA, Doña Rodrıguez JM, González Dıaz O, Viera A, Pérez Peña J, Marrero Sosa PM, Espino Jiménez V (2002) TiO 2 -Photocatalysis as a tertiary treatment of naturally treat waste-water. Catal Today 76:279–289

Zhi D, Wang JB, Zhou YY, Luo ZR, Sun YQ, Wan ZH, Luo L, Tsang DCW, Dionysiou DD (2020) Development of ozonation and reactive electrochemical membrane coupled process: enhanced tetracycline mineralization and toxicity reduction. Chem Eng J 383:123149–123158

Viet ND, Cho J, Yoon Y, Jang A (2019) Enhancing the removal efficiency of osmotic membrane bioreactors: a comprehensive review of influencing parameters and hybrid configurations. Chemosphere 236:124363–124381

Hassan M, Olvera-Vargas H, Zhu XP, Zhang B, He YL (2019) Microbial electro-Fenton: an emerging and energy-efficient platform for environmental remediation. J Power Sources 424:220–244

Kamali M, Suhas DP, Costa ME, Capela I, Aminabhavi TM (2019) Sustainability considerations in membrane-based technologies for industrial effluents treatment. Chem Eng J 368:474–494

Rossignol N, Vandanjon L, Jaouen P, Quemeneur F (1999) Membrane technology for the continuous separation microalgae-culture medium-compared performances of cross-flow microfiltration and ultrafiltration. Aquac Eng 20:191–208

Nabeel F, Rasheed T, Bilal M, Iqbal HMN (2019) Supramolecular membranes: a robust platform to develop separation strategies towards water-based applications. Sep Purif Technol 215:441–453

Jacangelo JG, Trussell RR, Watson M (1997) Role of membrane technology in drinking water treatment in the United States. Desalination 113:119–127

Saleem H, Trabzon L, Kilic A, Zaidi SJ (2020) Recent advances in nanofibrous membranes: production and applications in water treatment and desalination. Desalination 478:114178–114218

Khanzada NK, Farid MU, Kharraz JA, Choi J, Tang CY, Nghiem LD, Jang A, An AK (2020) Removal of organic micropollutants using advanced membrane-based water and wastewater treatment: a review. J Membr Sci 598:117672–117709

Madaeni SS (1999) The application of membrane technology for water disinfection. Water Res 33:301–308

Matter CG (2018) Membrane filtration (micro and ultrafiltration) in water purification. Springer International Publishing AG

Yu W, Brown M, Graham NJ (2016) Prevention of PVDF ultrafiltration membrane fouling by coating MnO 2 nanoparticles with ozonation. Sci Rep 6:30144–30156

Yoon J, Amy G, Chung J, Sohn J, Yoon Y (2009) Removal of toxic ions (chromate, arsenate, and perchlorate) using reverse osmosis, nanofiltration, and ultrafiltration membranes. Chemosphere 77:228–235

Kwon Y, Lee DG (2019) Removal of contaminants of emerging concern (CECs) using a membrane bioreactor (MBR): a short review. Global NEST J 21:337–346

CAS   Google Scholar  

Iorhemen OT, Hamza RA, Tay JH (2016) Membrane bioreactor (MBR) Technology for Wastewater Treatment and Reclamation: membrane fouling. Membranes (Basel) 6:33–62

Arefi-Oskoui S, Khataee A, Safarpour M, Orooji Y, Vatanpour V (2019) A review on the applications of ultrasonic technology in membrane bioreactors. Ultrason Sonochem 58:104633–104648

Zhen GY, Pan Y, Lu XQ, Li YY, Zhang ZY, Niu CX, Kumar G, Kobayashi T, Zhao YC, Xu KQ (2019) Anaerobic membrane bioreactor towards biowaste biorefinery and chemical energy harvest: recent progress, membrane fouling and future perspectives. Renew Sust Energ Rev 115:109392–109416

Li KL, Xu LL, Zhang Y, Cao AX, Wang YJ, Huang HO, Wang J (2019) A novel electro-catalytic membrane contactor for improving the efficiency of ozone on wastewater treatment. Appl Catal B Environ 249:316–321

Tang SY, Zhang LX, Peng Y, Liu J, Zhang X, Zhang ZH (2019) Fenton cleaning strategy for ceramic membrane fouling in wastewater treatment. J Environ Sci (China) 85:189–199

Li QL, Kong H, Li P, Shao JH, He YL (2019) Photo-Fenton degradation of amoxicillin via magnetic TiO 2 -graphene oxide-Fe 3 O 4 composite with a submerged magnetic separation membrane photocatalytic reactor (SMSMPR). J Hazard Mater 373:437–446

Chan SHS, Yeong Wu T, Juan JC, Teh CY (2011) Recent developments of metal oxide semiconductors as photocatalysts in advanced oxidation processes (AOPs) for treatment of dye waste-water. J Chem Technol Biotechnol 86:1130–1158

Oturan MA, Aaron JJ (2014) Advanced oxidation processes in water/wastewater treatment: principles and applications. A review. Crit Rev Environ Sci Technol 44:2577–2641

Pignatello JJ, Oliveros E, MacKay A (2006) Advanced oxidation processes for organic contaminant destruction based on the Fenton reaction and related chemistry. Crit Rev Environ Sci Technol 36:1–84

Wang J, Wang S (2016) Removal of pharmaceuticals and personal care products (PPCPs) from wastewater: a review. J Environ Manag 182:620–640

Cheng M, Zeng GM, Huang DL, Lai C, Xu P, Zhang C, Liu Y (2016) Hydroxyl radicals based advanced oxidation processes (AOPs) for remediation of soils contaminated with organic compounds: a review. Chem Eng J 284:582–598

Hu PD, Long MC (2016) Cobalt-catalyzed sulfate radical-based advanced oxidation: a review on heterogeneous catalysts and applications. Appl Catal B Environ 181:103–117

Bethi B, Sonawane SH, Bhanvase BA, Gumfekar SP (2016) Nanomaterials-based advanced oxidation processes for wastewater treatment: a review. Chem Eng Process Process Intensif 109:178–189

Khatri J, Nidheesh PV, Anantha Singh TS, Suresh Kumar M (2018) Advanced oxidation processes based on zero-valent aluminium for treating textile wastewater. Chem Eng J 348:67–73

Guzzella L, Feretti D, Monarca S (2002) Advanced oxidation and adsorption technologies for organic micropollutant removal from lake water used as drinking-water supply. Water Res 36:4307–4318

Clarizia L, Russo D, Di Somma I, Marotta R, Andreozzi R (2017) Homogeneous photo-Fenton processes at near neutral pH: a review. Appl Catal B Environ 209:358–371

Pliego G, Zazo JA, Garcia-Muñoz P, Munoz M, Casas JA, Rodriguez JJ (2015) Trends in the intensification of the Fenton process for wastewater treatment: an overview. Crit Rev Environ Sci Technol 45:2611–2692

Wang W, Huang G, Yu JC, Wong PK (2015) Advances in photocatalytic disinfection of bacteria: development of photocatalysts and mechanisms. J Environ Sci 34:232–247

Tušar NN, Maučec D, Rangus M, Arčon I, Mazaj M, Cotman M, Pintar A, Kaučič V (2012) Manganese functionalized silicate nanoparticles as a Fenton-type catalyst for water purification by advanced oxidation processes (AOP). Adv Funct Mater 22:820–826

Chen LW, Li XC, Zhang J, Fang JY, Huang YM, Wang P, Ma J (2015) Production of hydroxyl radical via the activation of hydrogen peroxide by hydroxylamine. Environ Sci Technol 49:10373–10379

Wang JL, Xu LJ (2012) Advanced oxidation processes for wastewater treatment: formation of hydroxyl radical and application. Crit Rev Environ Sci Technol 42:251–325

Bokare AD, Choi W (2014) Review of iron-free Fenton-like systems for activating H 2 O 2 in advanced oxidation processes. J Hazard Mater 275:121–135

Jin H, Tian XK, Nie YL, Zhou ZX, Yang C, Li Y, Lu LQ (2017) Oxygen vacancy promoted heterogeneous Fenton-like degradation of Ofloxacin at pH 3.2–9.0 by Cu substituted magnetic Fe 3 O 4 @FeOOH Nanocomposite. Environ Sci Technol 51:12699–12706

Dai C, Tian XK, Nie YL, Lin HM, Yang C, Han B, Wang YX (2018) Surface facet of CuFeO 2 nanocatalyst: a key parameter for H 2 O 2 activation in Fenton-like reaction and organic pollutant degradation. Environ Sci Technol 52:6518–6525

Zhou Y, Jiang J, Gao Y, Pang SY, Yang Y, Ma J, Gu J, Li J, Wang Z, Wang LH, Yuan LP, Yang Y (2017) Activation of peroxymonosulfate by phenols: important role of quinone intermediates and involvement of singlet oxygen. Water Res 125:209–218

Wang Z, Bush RT, Sullivan LA, Chen C, Liu J (2014) Selective oxidation of arsenite by peroxymonosulfate with high utilization efficiency of oxidant. Environ Sci Technol 48:3978–3985

Liang C, Huang CF, Mohanty N, Kurakalva RM (2008) A rapid spectrophotometric determination of persulfate anion in ISCO. Chemosphere 73:1540–1543

Huang GX, Wang CY, Yang CW, Guo PC, Yu HQ (2017) Degradation of bisphenol A by peroxymonosulfate catalytically activated with Mn 1.8 Fe 1.2 O 4 nanospheres: synergism between Mn and Fe. Environ Sci Technol 51:12611–12618

Qi CD, Liu XT, Ma J, Lin CY, Li XW, Zhang HJ (2016) Activation of peroxymonosulfate by base: implications for the degradation of organic pollutants. Chemosphere 151:280–288

Zhou Y, Jiang J, Gao Y, Ma J, Pang SY, Li J, Lu XT, Yuan LP (2015) Activation of peroxymonosulfate by benzoquinone: a novel nonradical oxidation process. Environ Sci Technol 49:12941–12950

Tian N, Tian XK, Nie YL, Yang C, Zhou ZX, Li Y (2018) Biogenic manganese oxide: an efficient peroxymonosulfate activation catalyst for tetracycline and phenol degradation in water. Chem Eng J 352:469–476

Tian N, Tian XK, Nie YL, Yang C, Zhou ZX, Li Y (2019) Enhanced 2, 4-dichlorophenol degradation at pH 3-11 by peroxymonosulfate via controlling the reactive oxygen species over Ce substituted 3D Mn 2 O 3 . Chem Eng J 355:448–456

Ciardelli G, Corsi L, Marcucci M (2000) Membrane separation for wastewater reuse in the textile industry. Resour Conserv Recycl 31:189–197

Beavis P, Lundie S (2003) Integrated environmental assessment of tertiary and residuals treatment- LCA in the wastewater industry. Water Sci Technol 47:109–116

Shuval H, Lampert Y, Fattal B (1997) Development of a risk assessment approach for evaluating wastewater reuse standards for agriculture. Water Sci Technol 35:15–20

Levine AD, Asano T (2004) Recovering sustainable water from wastewater. Environ Sci Technol 38:201–208

Meneses M, Pasqualino JC, Castells F (2010) Environmental assessment of urban wastewater reuse: treatment alternatives and applications. Chemosphere 81:266–272

Pasqualino JC, Meneses M, Abella M, Castells F (2009) LCA as a decision support tool for the environmental improvement of the operation of a municipal wastewater treatment plant. Environ Sci Technol 43:3300–3307

Munoz I, Rodriguez A, Rosal R, Fernandez-Alba AR (2009) Life cycle assessment of urban wastewater reuse with ozonation as tertiary treatment: a focus on toxicity-related impacts. Sci Total Environ 407:1245–1256

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Tian, N., Nie, Y., Tian, X., Wang, Y. (2021). Current Water Treatment Technologies: An Introduction. In: Kharissova, O.V., Torres-Martínez, L.M., Kharisov, B.I. (eds) Handbook of Nanomaterials and Nanocomposites for Energy and Environmental Applications. Springer, Cham. https://doi.org/10.1007/978-3-030-36268-3_75

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A new way to swiftly eliminate micropollutants from water

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“Zwitterionic” might not be a word you come across every day, but for Professor Patrick Doyle of the MIT Department of Chemical Engineering, it’s a word that’s central to the technology his group is developing to remove micropollutants from water. Derived from the German word “zwitter,” meaning “hybrid,” “zwitterionic” molecules are those with an equal number of positive and negative charges.

Devashish Gokhale, a PhD student in Doyle’s lab, uses the example of a magnet to describe zwitterionic materials. “On a magnet, you have a north pole and a south pole that stick to each other, and on a zwitterionic molecule, you have a positive charge and a negative charge which stick to each other in a similar way.” Because many inorganic micropollutants and some organic micropollutants are themselves charged, Doyle and his team have been investigating how to deploy zwitterionic molecules to capture micropollutants in water. 

In a new paper in Nature Water , Doyle, Gokhale, and undergraduate student Andre Hamelberg explain how they use zwitterionic hydrogels to sustainably capture both organic and inorganic micropollutants from water with minimal operational complexity. In the past, zwitterionic molecules have been used as coatings on membranes for water treatment because of their non-fouling properties. But in the Doyle group’s system, zwitterionic molecules are used to form the scaffold material, or backbone within the hydrogel — a porous three-dimensional network of polymer chains that contains a significant amount of water. “Zwitterionic molecules have very strong attraction to water compared to other materials which are used to make hydrogels or polymers,” says Gokhale. What’s more, the positive and negative charges on zwitterionic molecules cause the hydrogels to have lower compressibility than what has been commonly observed in hydrogels. This makes for significantly more swollen, robust, and porous hydrogels, which is important for the scale up of the hydrogel-based system for water treatment.

The early stages of this research were supported by a seed grant from MIT’s Abdul Latif Jameel Water and Food Systems Lab (J-WAFS). Doyle’s group is now pursuing commercialization of the platform for both at-home use and industrial scale applications, with support from a J-WAFS Solutions grant.

Seeking a sustainable solution

Micropollutants are chemically diverse materials that can be harmful to human health and the environment, even though they are typically found at low concentrations (micrograms to milligrams per liter) relative to conventional contaminants. Micropollutants can be organic or inorganic and can be naturally-occurring or synthetic. Organic micropollutants are mostly carbon-based molecules and include pesticides and per- and polyfluoroalkyl substances (PFAS), known as “forever chemicals.” Inorganic micropollutants, such as heavy metals like lead and arsenic, tend to be smaller than organic micropollutants. Unfortunately, both organic and inorganic micropollutants are pervasive in the environment.

Many micropollutants come from industrial processes, but the effects of human-induced climate change are also contributing to the environmental spread of micropollutants. Gokhale explains that, in California, for example, fires burn plastic electrical cables and leech micropollutants into natural ecosystems. Doyle adds that “outside of climate change, things like pandemics can spike the number of organic micropollutants in the environment due to high concentrations of pharmaceuticals in wastewater.”

It's no surprise then, that over the past few years micropollutants have become more and more of a concern. These chemicals have garnered attention in the media and led to “significant change in the environmental engineering and regulatory landscape” says Gokhale. In March 2023, the U.S. Environmental Protection Agency (EPA) proposed a strict, federal standard that would regulate six different PFAS chemicals in drinking water. Just last October, the EPA proposed banning the micropollutant trichloroethylene, a cancer-causing chemical that can be found in brake cleaners and other consumer products. And as recently as November, the EPA proposed that water utilities nationwide be required to replace all of their lead pipes to protect the public from lead exposure. Internationally, Gokhale notes the Oslo Paris Convention, whose mission is to protect the marine environment of the northeast Atlantic Ocean, including phasing out the discharge of offshore chemicals from the oil and gas industries. 

With each new, necessary regulation to protect the safety of our water resources, the need for effective water treatment processes grows. Compounding this challenge is the need to make water treatment processes that are sustainable and energy-efficient. 

The benchmark method to treat micropollutants in water is activated carbon. However, making filters with activated carbon is energy-intensive, requiring very high temperatures in large, centralized facilities. Gokhale says approximately “four kilograms of coal are needed to make one kilogram of activated carbon, so you lose a significant amount of carbon dioxide to the environment.” According to the World Economic Forum, global water and wastewater treatment accounts for 5 percent of annual emissions. In the U.S. alone, the EPA reports that drinking water and wastewater systems account for over 45 million tons of greenhouse gas emissions annually.

“We need to develop methods which have smaller climate footprints than methods which are being used industrially today,” says Gokhale.

Supporting a "high-risk" project

In September 2019, Doyle and his lab embarked on an initial project to develop a microparticle-based platform to remove a broad range of micropollutants from water. Doyle’s group had been using hydrogels in pharmaceutical processing to formulate drug molecules into pill format. When he learned about the J-WAFS seed grant opportunity for early-stage research in water and food systems, Doyle realized his pharmaceutical work with hydrogels could be applied to environmental issues like water treatment. “I would never have gotten funding for this project if I went to the NSF [National Science Foundation], because they would just say, ‘you're not a water person.’ But the J-WAFS seed grant offered a way for a high-risk, high-reward kind of project,” Doyle says.

In March 2022, Doyle, Gokhale, and MIT undergraduate Ian Chen published findings from the seed grant work, describing their use of micelles within hydrogels for water treatment. Micelles are spherical structures that form when molecules called surfactants (found in things like soap), come in contact with water or other liquids. The team was able to synthesize micelle-laden hydrogel particles that soak up micropollutants from water like a sponge. Unlike activated carbon, the hydrogel particle system is made from environmentally friendly materials. Furthermore, the system’s materials are made at room temperature, making them exceedingly more sustainable than activated carbon.

Building off the success of the seed grant, Doyle and his team were awarded a J-WAFS Solutions grant in September 2022 to help move their technology from the lab to the market. With this support, the researchers have been able to build, test, and refine pilot-scale prototypes of their hydrogel platform. System iterations during the solutions grant period have included the use of the zwitterionic molecules, a novel advancement from the seed grant work.  

Rapid elimination of micropollutants is of special importance in commercial water treatment processes, where there is a limited amount of time water can spend inside the operational filtration unit. This is referred to as contact time, explains Gokhale. In municipal-scale or industrial-scale water treatment systems, contact times are usually less than 20 minutes and can be as short as five minutes. 

“But as people have been trying to target these emerging micropollutants of concern, they realized they can’t get to sufficiently low concentrations on the same time scales as conventional contaminants,” Gokhale says. “Most technologies focus only on specific molecules or specific classes of molecules. So, you have whole technologies which are focusing only on PFAS, and then you have other technologies for lead and metals. When you start thinking about removing all of these contaminants from water, you end up with designs which have a very large number of unit operations. And that's an issue because you have plants which are in the middle of large cities, and they don't necessarily have space to expand to increase their contact times to efficiently remove multiple micropollutants,” he adds.

Since zwitterionic molecules possess unique properties that confer high porosity, the researchers have been able to engineer a system for quicker uptake of micropollutants from water. Tests show that the hydrogels can eliminate six chemically diverse micropollutants at least 10 times faster than commercial activated carbon. The system is also compatible with a diverse set of materials, making it multifunctional. Micropollutants can bind to many different sites within the hydrogel platform: organic micropollutants bind to the micelles or surfactants while inorganic micropollutants bind to the zwitterionic molecules. Micelles, surfactants, zwitterionic molecules, and other chelating agents can be swapped in and out to essentially tune the system with different functionalities based on the profile of the water being treated. This kind of “plug-and-play” addition of various functional agents does not require a change in the design or synthesis of the hydrogel platform, and adding more functionalities does not take away from existing functionality. In this way, the zwitterionic-based system can rapidly remove multiple contaminants at lower concentrations in a single step, without the need for large, industrial units or capital expenditure. 

Perhaps most importantly, the particles in the Doyle group’s system can be regenerated and used over and over again. By simply soaking the particles in an ethanol bath, they can be washed of micropollutants for indefinite use without loss of efficacy. When activated carbon is used for water treatment, the activated carbon itself becomes contaminated with micropollutants and must be treated as toxic chemical waste and disposed of in special landfills. Over time, micropollutants in landfills will reenter the ecosystem, perpetuating the problem.

Arjav Shah, a PhD-MBA candidate in MIT's Department of Chemical Engineering and the MIT Sloan School of Management, respectively, recently joined the team to lead commercialization efforts. The team has found that the zwitterionic hydrogels could be used in several real-world contexts, ranging from large-scale industrial packed beds to small-scale, portable, off-grid applications — for example, in tablets that could clean water in a canteen — and they have begun piloting the technology through a number of commercialization programs at MIT and in the greater Boston area.

The combined strengths of each member of the team continue to drive the project forward in impactful ways, including undergraduate students like Andre Hamelberg, the third author on the Nature Water paper. Hamelberg is a participant in MIT’s Undergraduate Research Opportunities Program (UROP). Gokhale, who is also a J-WAFS Fellow, provides training and mentorship to Hamelberg and other UROP students in the lab.

“We see this as an educational opportunity,” says Gokhale, noting that the UROP students learn science and chemical engineering through the research they conduct in the lab. The J-WAFS project has also been “a way of getting undergrads interested in water treatment and the more sustainable aspects of chemical engineering,” Gokhale says. He adds that it’s “one of the few projects which goes all the way from designing specific chemistries to building small filters and units and scaling them up and commercializing them. It’s a really good learning opportunity for the undergrads and we're always excited to have them work with us.”

In four years, the technology has been able to grow from an initial idea to a technology with scalable, real-world applications, making it an exemplar J-WAFS project. The fruitful collaboration between J-WAFS and the Doyle lab serves as inspiration for any MIT faculty who may want to apply their research to water or food systems projects.

“The J-WAFS project serves as a way to demystify what a chemical engineer does,” says Doyle. “I think that there's an old idea of chemical engineering as working in just oil and gas. But modern chemical engineering is focused on things which make life and the environment better.”

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Home > Books > Ozonation - New Aspects [Working Title]

Emerging Technologies in Water Treatment: Recent Advances

Submitted: 13 July 2022 Reviewed: 17 November 2022 Published: 03 February 2023

DOI: 10.5772/intechopen.109063

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Ozone, a triatomic oxygen molecule, is a powerful oxidant generated by water electrolysis or produced in situ using the corona discharge method. Typical applications in water treatment involve the disinfection, disposal of virus, bacteria, and hydrogen sulfide removal and are responsible for odorous compounds in septage tanks and oxidation lagoons. Recently, electrocoagulation and cavitation have evolved to increase the efficiency of ozone gas disinfection. Electrocoagulation (EC) permits the sanitation of wastewater, the destruction of oil-water emulsions, and heavy metals present in mining waste and manufacturing industry. EC is useful when traditional disinfection methods using chemical agents or biological treatment is not completely efficient. Using the EC technology proposed by Reingeniería en Saneamiento Ltd., replacement of sacrifice electrodes is not estimated. Cavitation and ozone systems, as beneficial processes in water treatment technology are supported by electroflotation, electrocoagulation, and electrochemistry in urban wastewater plants to accomplish effective solutions in different processes. Along with the chapter, how modular plants can be designed to achieve the correct purification system based on a previous diagnosis of the process is explained. Finally, due to complexity of treatment process, automation need to advance from manual control to programmable logic controllers if control architectures for water treatment system advance in the same way the depuration process is properly controlled.

• electrolysis
• electrocoagulation
• water treatment

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Carlos martín enríquez castro *.

• Food Engineering and Technology Program, TECNM Campus Zacatecas Norte, Río Grande, México

Manuel Pérez Nafarrate

• TRIO3 Innovation Technologies and Reingeniería en Saneamiento Ambiental Ltd. Guadalajara, México

Anuar Manuel Badillo Olvera

• Electromechanical Engineering Program, TECNM Campus Zacatecas Norte, Río Grande, México

César Guzmán Martínez

• Appalachian State University, USA

*Address all correspondence to: [email protected]

1. Introduction

Ozone is a natural gas created from oxygen atoms. The oxygen molecule is made up of two oxygen atoms. These oxygen molecules are broken into atoms by corona discharge during electrical storms or by UV light from the Sun [ 1 ]. Individual oxygen atoms cannot exist alone without reassembling back into diatomic oxygen molecules. During this recombination step, some atoms will regroup into loosely bound triatomic oxygen. This new molecule is called ozone, ozone is a very strong oxidant and an ideal chemical-free purification and disinfectant agent. Ozone is often misdiagnosed as low-altitude pollution [ 2 ]. This could not be farther from the truth. In fact, ozone breaks down pollutants and should be welcomed when it is in the air. The most effective way to produce ozone commercially is through the use of corona discharge [ 3 ].

Ozone is dissolved thirteen times faster in water than oxygen and acts immediately, instead of using chlorine. Several functions such as dispatch of viruses, bacteria, molds, spores, and algae make this chemical agent very efficient [ 4 ]. Plenty of applications in the industry and home are extensive: ozone oxidizes nitrites to nitrates, organic nutrients and hydrogen sulfide are dissolved, color and odor are vanished, BOD can decrease, and dissolved oxygen is increased. Nowadays, it can be inferred that water treatment is the most beneficial.

1.1 How does ozone work?

When ozone is exposed to a bacteria or a virus, it immediately destroys the cell membrane. This happens in less than a second. Ozone is an oxidizing agent and when it encounters any odor molecule, oxidation occurs (chemical combustion) as shown in Figure 1 . Disinfection by triatomic oxygen (ozone) occurs through the rupture of the cell wall. This is a more efficient method than chlorine, which relies on diffusion into cell protoplasm and inactivation of enzymes. An ozone level of 0.4 ppm for four minutes has been shown to kill any bacteria, viruses, mold, and mildew. When the effectiveness of ozone as a disinfectant was measured, there was little or no disinfection up to a certain dose. At higher levels, the disinfectant effect increases. For complete disinfection, excess or residual ozone must be maintained in the solution to ensure that all living microorganisms have been contacted. No antibiotic that is really effective in the field of virus has been discovered yet. There are indications that DNA viruses such as herpes are implicated in human cancers, as they organize the host cell’s genetic material to produce new viruses. Ozone will inactivate viruses on contact, even at very low temperatures and residual concentrations. In the case of polio, just 0.012 ppm kills all viral cells in less than 10 seconds. Mold and mildew are easily controlled by the ozone present in the air and in the water. Giardia and Cryptosporidium cysts are susceptible to ozone but are not affected by normal chlorine levels.

Mechanism of ozone in touch with an electric source to produce pure oxygen. (adapted from www.ozonesolutions.com ).

As can be seen in Figure 2 , ozone reacts with a bacterium, and a cracking process inside the cell structure is initiated [ 1 ]. Ozone penetrates into the periphery of the cell wall [ 2 ]. The ozone penetrates and creates a hole in the bacterial wall [ 3 ]. The ozone molecule in the bacterial cell structure is inserted [ 4 ]. Magnification of the bacterial cell after contact with the ozone molecules [ 5 ]. Destruction of the cell after ozone action. Research investigations to destroy gram-negative and gram-positive bacteria’s have been conducted [ 2 , 3 , 5 ]. A procedure to destroy enterobacterias such as E. coli at 95°F, using ozone, requires an ozone range between 0.1 and 0.5 mg/l and maintaining an adequate redox potential to reach a higher disinfection efficiency [ 6 ].

Detail of ozone action in the bacterial cell. https://my.medklinn.com/knowledge_centre/effect-of-ozone-on-bacteria/ .

The mechanisms of ozone bacterial destruction need to be further elucidated. It is known that the cell enveloped by bacteria are made of polysaccharides and proteins and that in Gram-negative microorganisms, fatty acid alkyl chains and helical lipoproteins are present. In acid-fast bacteria, such as Mycobacterium tuberculosis , on third to one-half of the capsule is formed of complex lipids (esterified mycolic acid, in addition to normal fatty acids), and glycolipids (sulfolipids, lipopolysaccharides, mycosides, and trehalose mycolates). The high lipid content of the cell walls of these ubiquitous bacteria may explain their sensitivity, and eventual demise, subsequent to ozone exposure. Ozone may also penetrate the cellular envelope, directly affecting cytoplasmic integrity, and disrupting any one of numerous levels of its metabolic complexities.

1.2 Characteristics of ozone as a disinfectant agent

The effect of ozone to eliminate pathogens has been corroborated for several decades. Its killing action on bacteria, viruses, fungi, and many species of protozoa serves as the basis for its growing use in disinfecting municipal water supplies in cities around the world. Bacteria are microscopic so-called tiny single-celled creatures that have a primitive structure. They absorb food and release metabolic products, and multiply by division. The body of the bacterium is sealed by a relatively solid cell membrane. Their life processes are controlled by a complex enzyme system. Ozone interferes with the metabolism of bacterial cells, most likely by inhibiting and blocking the functioning of the enzyme control system. A sufficient amount of ozone passes through the cell membrane, and this leads to the destruction of bacteria. Viruses are small, self-contained particles built of crystals and macromolecules. Unlike bacteria, they multiply only within the host cell. Ozone destroys viruses by diffusing through the protein coat in the nucleic acid core, resulting in viral RNA damage. At higher concentrations, ozone destroys the capsid or outer protein shell by oxidation. Indicator bacteria in effluents, namely coliforms and pathogens, such as Salmonella , show a marked sensitivity to ozone inactivity. Other bacterial microorganisms susceptible to the disinfecting properties of ozone include Streptococci, Shigella, Legionella pneumophila, Pseudomonas aerunginosa, Yersinia enterocolitica, Campylobacter jejuni, Mycobacteria, Klebsiella pneumonia , and Escherichia coli [ 1 ]. Ozone destroys both aerobic and, more importantly, anaerobic bacteria, which are primarily responsible for the devastating sequelae of complicated infections, as exemplified by pressure ulcers and gangrene.

Ozone is the most oxidizing agent available to man after fluorine. Thanks to its high oxidizing power, ozone is capable of attacking and destroying all kinds of microorganisms such as bacteria, cysts, virus, algae, spores, and protozoa. Several research papers talking about the importance of these topics have been realized previously [ 1 , 7 , 8 , 9 , 10 ]. Ozone used in combination with other emergent technologies decomposes organic substances including detergents, phenols, pesticides, herbicides, and fertilizers; neutralizes inorganic substances such as ammonia, urea, nitrites, cyanides, and arsenic [ 11 ]. Numerous families of viruses including poliovirus I and II, human rotaviruses, Norwalk virus, Parvoviruses, and hepatitis A and B, among many others, are susceptible to the virucidal actions of ozone. Most research efforts on virucidal effects of ozone have centered upon ozone’s propensity to break apart lipid molecules at sites of multiple bond configuration. Indeed, once the lipid envelope of the virus is fragmented, its DNA or RNA core cannot survive. Non-enveloped viruses (Adenoviridae, Picornaviridae, namely poliovirus, Coxsackie, echovirus, rhinovirus, hepatitis A and E, and Reoviridae (Rotavirus)), have also begun to be studied. Viruses that do not have an envelope are called “naked viruses.” They are constituted of a nucleic acid core (made of DNA or RNA) and a nucleic acid coat, or capsid, made of protein. Ozone, however, aside from its well-recognized action upon unsaturated lipids, can also interact with certain proteins and their constituents, namely amino acids. Indeed, when ozone comes in contact with capsid proteins, protein hydroxides and protein hydroxides and protein hydroperoxides are formed.

Viruses have no protection against oxidative stress. Normal mammalian cells, on the other hand, possess complex systems of enzymes (i.e., superoxide dismutase, catalase, and peroxidase) that tend to ward off the nefarious effects of free radical species and oxidative challenge. It may thus be possible to treat infected tissues with ozone, respecting the homeostasis derived from their natural defenses, while neutralizing offending and attacking pathogens devoid of similar defenses. The enveloped viruses are usually more sensitive to physicochemical challenges than naked virions. Although ozone’s effects upon unsaturated lipids are one of its best-documented biochemical action, ozone is known to interact with proteins, carbohydrates, and nucleic acids. This becomes especially relevant when ozone inactivation of non-enveloped virions is considered. Fungi families inhibited and destroyed by exposure to ozone include Candida, Aspergillus, Histoplasma, Actinomycoses , and Cryptococcus . The walls of fungi are multilayered and are composed of approximately 80% carbohydrates and 10% of proteins and glycoproteins. The presence of many disulfide bonds had been noted, making this a possible site for oxidative inactivation by ozone. In all likelihood, however, ozone has the capacity to diffuse through the fungal wall into the organismic cytoplasm, thus disrupting cellular organelles. Protozoan microorganisms disrupted by ozone include Giardia, Cryptosporidium , and free-living amoebas, namely Acanthamoeba, Hartmonella , and Naegleria . The antiprotozoal action has yet to be elucidated.

2. Effect of ozone in the treatment of industrial effluents

According to Ostman et al. [ 12 ], to reach the scale-up of an adequate ozone treatment system, the following considerations are important: accomplishing the demand for ozone and considering the flow rate on demand, design, and development of all the peripheral equipment necessary to maintain the production process including the ozone generator, pipes and reaction chamber, and the panel control considered can include the instrumentation devices and power unit. Reingeniería en Saneamiento Ambiental Ltd. has evolved in technology transfer offering its products with an uninterrupted improvement philosophy. To increase in the demand for ozone, the concept of modular plants provided in their business proposals is considered. Another point in the prototype design is to recall the primary purpose of the model. In Figure 3 , it is displayed a specific model to comply with the specifications of the construction industry.

Components of a water treatment plant for a housing complex of 20 houses and 100 inhabitants (with TRIO3 permitted authorization).

According to the operational principle of the TRIO3® injector, when pressurized operating water enters the interior of the injector, it is compressed in the injection chamber and changes into a high-velocity jet of water. The increased velocity through the injection chamber results in a decrease in pressure, thus allowing gas (ozone or air) to be drawn through the suction port and entrained in the water stream. As the water stream moves toward the injector outlet, its speed is reduced and it exits at a lower pressure than the injector inlet pressure. TRIO3 has invented and manufactured an injector superior to anything on the market today. The size of the bubbles allows the ozone gas to have full contact with the water and to control the release of the gas. The excellent mass transfer of this injector allows more “work” with less ozone, saving the customer money. As the ozone gas enters the water stream, it is in the form of small “micro-bubbles,” which are aggressively mixed with the water. These “micro-bubbles” provide an exceptionally large surface area on which ozone can be effectively transferred into the water. A large bubble is 20 mm and has a volume of 4.19 cm 3 and a surface area of 12.6 cm 2 . Two hundred and ninety-six small bubbles (3 mm) can be won instead of the big bubble in previous point with a total area of 3.6 cm 2 . This is 6.6 times the area of the large bubble. This smaller bubble has better mass transfer, and the process becomes more efficient.

Table 1 shows the operating parameters using a TRIO3® injector. The measured dissolved oxygen concentration was a 150-gallon tank of water in the TRIO3® injector installed, using a baseline of 4.76 ppm and 56% of purity at 73.4°F. The oxygen concentrator uses air drawn from outside the housing through a Solberg replaceable element coarse particle air filter. The integral compressor passes air through a bed of molecular sieves providing 95 ± 1 % pure oxygen feed gas through the ozone cell. Air passing through the filter is stripped of nitrogen and water vapor to give dry oxygen feed gas. The oxygen concentrator gives a true dew point of −52°C to prevent the formation of HNO 3 (nitric acid) within the ozone cell. Oxygen is regulated for pressure and flow and is set at 6 L/min introduced through stainless steel fittings and Teflon tubing into the ozone cell. The ozone cell is powered by solid-state electronics and is a medium-frequency generator designed to operate at 500 Hz and 50,000 V. In this way, oxygen passing through the ozone cell is converted into ozone. Ozone exits the cell through a stainless steel and ozone-proof line to a stainless steel bulkhead that fits into the bottom of the housing and connects to the blower assembly.

Ozone concentration in the injector using microbubbles.

Average concentration was 6.29 ppm.

2.1 Ozone as a disinfectant agent in municipal waste effluents

Hydrogen sulfide (H 2 S), an acutely toxic substance, is immediately lethal at relatively low concentrations. H 2 S becomes a health and safety hazard when it combines with carbon dioxide and water vapors as it corrodes plant equipment and piping. When shaken it erupts with such speed that levels of toxicity paralyze the lungs. This eruption occurs when stagnant sewage is shaken by loosening a plug. Wastewater contains up to 6000 ppm. Exposures as low as 300 ppm over a 30 min period will render a person unconscious. Exposure to a concentration of 1000 ppm of H2S in air causes paralysis of the respiratory system, cardiac arrest, and death within minutes. H2S is produced by the action of anaerobic sulfur-fixing bacteria on materials containing sulfur. In low concentrations, hydrogen sulfide smells like rotten eggs. At high concentrations, it desensitizes the sense of smell, and in the nose, it is no longer detectable. H2S is colorless, flammable, heavier than air, soluble in water, and extremely toxic.

Research conducted by the National Institute for Occupational Safety and Health (NIOSH) at three municipal wastewater treatment plants resulted in worker health symptoms of shortness of breath, sore throat, eye irritation, nausea, and diarrhea. Area air samples were collected for H 2 S using sensor monitors and data loggers. Hydrogen sulfide concentrations ranged from undetectable to 124 ppm. NIOSH recommended exposure limits for hydrogen sulfide are capped at 10 ppm. This may not be exceeded during any part of the working day. As confirmed by OSHA regulations, 124 ppm H 2 S exposure is immediately dangerous to life or health conditions.

Municipal waste effluents (MWE) are present mainly in a big populated city. MWE includes a combination of aromatic compounds, oily discharges, and food industry waste. MWE are hardly degradable by conventional methods, and due to high toxicity have high COD lectures [ 13 ]. MWE deposited in waste-activated sludges are oxidized using combined methods such as ozone and electrocoagulation [ 14 , 15 ]. Next, a first case study was performed at the Miami Dade County Water and Sewer Department (WASD) and applied in a Corrosion Control Program to implement the inspection and assessment of several pumping stations of potable water.

2.1.1 Introduction

Identifying and rehabilitating corrosion deterioration in the pump stations of WASD. As part of WASD’s corrosion control program, technical personnel inspected approximately 34 pump stations for corrosion damage in recent years under two different projects. As an additional WASD staff performing routine maintenance, 18 pump stations with significant corrosion were also identified. This project provided engineering services for a corrosion inspection and evaluation of the 52 pumping stations. The findings and recommendations are presented in this report.

2.1.2 Objective

The objective of this project was to identify the necessary rehabilitation efforts to repair existing damage and mitigate further corrosion deterioration of each of the pumping stations. A prioritized schedule and preliminary cost estimate for the implementation of recommended corrective actions were also provided.

Inspect all pump stations identified by WASD.

Evaluate the extent of corrosion based on the inspection results.

Identify the necessary measures of rehabilitation and protection against corrosion.

Develop cost estimates at the planning level.

Prepare a prioritized schedule for implementation.

Prepare a report documenting the inspection findings and recommendations.

2.2 Inspection

The severity of structural corrosion (lack of concrete and exposed rebar).

The state of gates, handrails, ventilation, and lighting.

The corrosivity of the atmosphere (levels of hydrogen sulfide).

2.2.1 Selection of pumping stations

An initial list of significant corrosion damage in pump stations identified by the WASD Pump Station Division.

Subsequent inspections by the WASD team revealed additional pumping stations with more severe levels of corrosion.

Pumping stations identified by the staff crew with significant corrosion damage in the framework were classified in the “Pumping Station Odor Survey Project.”

The pumping stations inspected under this project are those believed to have the most severe corrosion problems based on available information.

2.2.2 Other considerations

The general condition of the structure of the dry well, pumps, and electrical components.

Suction or discharge ventilation.

If a dehumidifier is present and working.

If a sump pump is present and working.

Some of the criteria that were evaluated included the Corrosion Description (None, Not Remarkable, Apparent Corrosion) and the Corrosion Classification (Depending on the white deposits caused by salts and minerals as well as the damage caused in the structure). Figure 4 shows a detailed description of the pumping equipment damaged.

Effects of corrosion in pumping stations (WASD Pump Station division permission).

The findings of this investigation show that each pumping station presented different levels of deterioration. Even though none of the pumping stations inspected showed significant corrosion in the dry well, it was noted that a dehumidifier was required, which is essential to remove moisture and prevent a corrosive atmosphere in the dry well. In this way, it was possible to reduce this problem. On the other hand, the levels of hydrogen sulfide were monitored to know the aggressiveness of the atmosphere and the speed at which corrosion occurs inside the wet well. Severe corrosion damage can be expected at stations with levels between 1 and 10 ppm. Therefore, these data in combination with physical evidence provide a reasonable basis for determining the corrosion potential at each station. For example, some stations (PS 44 and PS 516) with moderate corrosion damage recorded hydrogen sulfide levels below 1 ppm on the day of inspection, a moderate level of corrosion, and loss of concrete from the walls, which indicates that these concentrations damage the structure of the pumping equipment due to the effect of the gas. The ozone, used at several concentrations (1, 3, and 5%) allowed the elimination of hydrogen sulfide, taking into account the safety problems that this represented. Regarding this point, it is convenient to point out that the entrance of personnel to the wet well is necessary for many pumping stations to carry out routine maintenance operations, such as cleaning of the bar screens, operation of the gate, and maintenance of pressure sensors.

Wet well level and pump suction bells . The safety of operations and maintenance personnel while performing these tasks was a primary concern in the wet well evaluation. The safety of each pump station was assessed based on the condition of the access ladder, work platform, handrails, and wet vent. Repair or replacement of any of the above. Figure 5 shows the ozone generator used in the experiment.

Ozone generator (gas bust 2000 displayed with TRIO3 permitted authorization).

The second case was developed in Gifford Florida, a facility that TRIO3 had installed and used to demonstrate the effectiveness of removing the odors from a wastewater treatment plant (WWTP). A proposal was suggested to the directive staff of the WWTP to eliminate odors with ozone at a reasonable cost in a 30-day trial.

Two units to prove the ability of ozone were mounted, and a month later three more systems were installed. A main disinfection objective in the workers’ office allowed them to work in a clean and odor-free room. The other two were larger units installed on the septage tank and in the dewatering building. On the facility, on a daily basis, were taken readings of the hydrogen sulfide levels. During these readings/tests, an MDS MINI responder hydrogen sulfide meter was used. The manual reading in the septage tank is shown in Figure 6 .

Readings taken in Septage tank (with TRIO3 permitted authorization).

Lectures taken during the trial were between 130 and 700 ppm of hydrogen sulfide. A properly sized machine as quoted herein eliminated 100% of the hydrogen sulfide and methane. The proposed unit treated all five chambers in the septage tank. Since the hydrogen sulfide is the more powerful odor than the methane second, all odors from this area of the plant ceased. Based on the pilot study conducted, an estimation of the septage tank requirements required a Gas Buster unit (as shown previously in Figure 5 ) sufficient to provide a minimum of 10 pounds per day of ozone. Figure 7 shows the detailed facility monitored.

Septage tank with a gas buster unit installed (with TRIO3 permitted authorization).

The dewatering building is the source of several odorous compounds. Therefore, the removal of the liquids and the composition of the solids are a major source of odors. The chief culprit is again hydrogen sulfide. As treated sewage solids are introduced to the belt press, the liquid in the solids are removed in this facility as shown below in Figure 8 .

Belt press used to treat sewage solids (with TRIO3 permitted authorization).

The proposal of the odor control study proposed by TRIO3 in the sludge thickener tanks was a major issue to aboard. Ozone control system in Florida facility included the design and installation of a cover for the tank and interfaced a gas buster system so as to provide a blanket of ozone between the cover and the sludge. The dome designed is shown in Figure 9 . The reduced loading of the scrubbers with the ozone system enhanced their ability to remove all odors. The loading from the Septage Tanks was virtually zero and the loading from the Dewatering Building was also zero. The scrubber was installed with the addition of ozone to perform as designed.

Sludge thickener facility (with TRIO3 permitted authorization).

2.3 Evolution of water treatment units with different purposes

One of the characteristics present in the process developed by Reingeniería en Saneamiento Ambiental Ltd. around the last 20 years includes the addition of operative modules in order to fulfill the requirements of the process. Figure 10a shows the module installed with ozone and electrochemical oxidation/precipitation unit, reactor tank with measurements of 90 cm width x 1.20 m height. Figure 10b displays a complete PLC console; this rack includes a flocculation tank, aeration tank, ozone generator, power supply, and PLC control display.

Mobile unit provided with ozone generator and electrolysis unit (with TRIO3 permitted authorization).

Ozone molecules reacting with the influent give different qualities of treated water, which can be reached when active compounds (free radicals) react with the polluted mixture of the influent [ 16 ]. Therefore, a high quality treated water depends on the concentration of ozone used in the oxidation process as shown in Figure 11 .

Pictures of influent and the evolution in the quality of water for several effluent samples (with TRIO3 permitted authorization).

3. Innovative technologies in water treatment

3.1 electrocoagulation.

Electrocoagulation (EC) allows the purification of wastewater that has a high content of salts. To carry out the physicochemical operation of electrolysis, it is necessary to dissolve the compounds by means of electrodes provided with iron or aluminum. Due to this electrolysis reaction of water, hydroxyl compounds are generated [ 17 ].

Remotion of heavy metals such as oxides that pass the Toxicity Characteristic Leaching Procedure (TCLP).

EC eliminates successfully suspended and colloidal solids.

EC disrupts oil-in-water emulsions.

Separation of grease, oil, and lubricants.

Extraction and appropriate disposal of organic complexes.

EC remotion effectiveness of bacteria in an effective way.

Destruction of viruses and microorganisms.

Not many studies mention the EC and ozone to depurate wastewater at the industrial level, and most of the research developed under controlled conditions [ 11 , 17 ]. Electrocoagulation is effective when we accomplish the following conditions: first, the device generates an electric charge between particles; the electrical layer between both particles must be strong enough to be repelled and prevent agglomeration. Finally, the flocculation capacity to form flocs is monitored. Flocs deposited at the bottom of the deposit are disposed of. Therefore, EC is possible when the process variables such as pH, impelling force, and aggregation level of the coagulant species are monitored correctly [ 18 ]. A detailed scheme of what happens in the EC process, as shown in Figure 12 , is the following.

Schematic design of electrocoagulation reactor (according to Mohammad Ahmadian design).

The ions produced in excess during EC do not necessarily increase the number of salts in the influent avoiding a higher quantity of the sludge produced.

It is necessary to generate a higher electric activity to eliminate the contaminants effectively, removing them due to the generation of gas bubbles (H 2 and O 2 ) and dragging them to the surface.

A dissolved air flotation clarifier (DAF-type unit) line is installed to increase the flotation efficiency. In electroflocculation, the removal of contaminants is favored because the gas bubbles generated in the system (H 2 and O 2 ) drag them, so they tend to float on the surface.

The different variables involved induce three recurrent procedures but at the same time different from each other, as mentioned in Appendix 1. The theoretical foundation of electrocoagulation is that precipitation takes place at the same time as colloid destabilization. On the other hand, chemical coagulation consists of the formation of sludge due to the union of colloids, forming masses of considerable size, to later separate them from the water by adding more chemicals such as Aluminum Sulfate, Ferric Chloride, among others. The masses of colloids are formed by the contact between the colloids, this is achieved mainly by the movement of the liquid, due to electrical phenomena, such as the presence of ions of opposite charge to that of the colloids, action of hydrogens, and others. It is important to mention that the water is subjected to electrolysis, which is favored by the presence of dissolved salts, which enable the conduction of electricity and are present in all wastewater and industrial water. Due to this, a release of gaseous Hydrogen and Oxygen is produced in their respective electrodes. When these gases rise to the surface, they cause three phenomena: (1) Quick separation of colloids from the electrode, preventing it from getting dirty (cleaning); (2) Dragging of destabilized colloids to the surface forming a cream, allowing not only extraction by classical sedimentation but also by flotation, and; (3) Due to the gas bubbles, ascending and descending currents of the solution are produced, causing a better contact surface, thus causing an increase in the destabilization efficiency. This “spontaneous” agitation avoids “mechanical” agitation (no external agitation needed).

Technical scope of electrocoagulation.

The electrocoagulation process can be defined as the destabilization of suspended or dissolved chemical species present in a solution, product of the application of an electrical potential difference through a cathode–anode system immersed in the water solution to be treated. As a consequence, and during the said electrolytic process, the cationic species produced at the anode enter the solution, reacting with the other species, forming flocs, and precipitating the respective hydroxides. Unlike chemical, coagulation is the origin of the coagulant.

Technical aspects of electrocoagulation operation.

The operating conditions of an electrocoagulation system are highly dependent on the chemical conditions, pH, particle size of the water to be treated, and especially its conductivity. The general treatment of wastewater requires low voltage applications (<50 Volts) with variable amperage, according to the chemical characteristics of the water. Table 2 shows several technical aspects to consider when using electrocoagulation.

Process variables involved in electrocoagulation.

3.2 Comparative analysis of electrocoagulation vs. biological treatment

The electrocoagulation system applied to wastewater, compared to conventional biological systems, requires a smaller surface (between 50 and 60% less).

Electrocoagulation residence times are 10 to 60 s, compared to biological systems that require 12 to 24 h.

They are compact units, easy to operate, with lower energy consumption and sludge production (more compact) than conventional biological systems.

The electrocoagulation cells are made of PVC, or high-density polyethylene and are installed on the ground. Therefore, they do not require major civil works, such as chemical and biological systems.

Investment costs are 50% lower than biological systems.

Electricity consumption per m 3 of treated water, (between $0.01 to $0.05 USD/m 3 ), is less than conventional treatment systems.

They do not use chemical products. They are 100% automatic units, which are used when required, with response times of 10 to 60 s, at their efficiency level.

EC technology is adaptable to different types of Wastewater Treatment Plants.

Electrocoagulation is applied to the mining industry, electroplating, refineries, and foundries, among others. Table 3 shows the percentage of removal of main parameters. More information about EC Technology parameters can be found in Appendix 2.

Percentage of removal of main parameters.

Using ozone, at the outlet of the electrocoagulation treatment plant, an outlet concentration of <50 MPN/100 ml of Total Coliforms will be reached.

3.3 Cavitation as a depurative process in water treatment technology

The cavitation, electrolysis, and ozone system does not require adjuvants in the treatment of wastewater. Hydro cavitation is a recently used technique that has benefited from technological advances in wastewater treatment and is the subject of multiple investigations. Cavitation uses concepts related to the characterization of the formation, growth, and subsequent collapse of activities that generate large amounts of energy, creating hot spots and strong oxidation conditions through the production of hydroxyl radicals [ 19 ]. According to Foster [ 10 ], cavitation, a phenomenon defined as nucleation, involves the growth and implosion of cavities filled with steam or gas, which are achieved by the passage of ultrasound (acoustic cavitation) or by changes in flow and pressure (hydrodynamic cavitation). To develop hydrodynamic cavitation is necessary to modify the geometry of the flow to increase the kinetic energy. The cavitation increases by having a construction of the flow that results in a considerable reduction of the local pressure of the liquid. This change in the pressure of the liquid increases the kinetic energy. Drops in the liquid pressure below its vapor pressure create millions of vapor cavities, and turbulent conditions of varying pressure fields downstream of the construction occur. The lifetime of these cavities is very short (a few microseconds). The cavities finally violently implode and generate high pressures (up to 1000 bar) and very high temperatures (10,000°K). These changes intensify chemical reactions and promote the formation of radicals and their subsequent reactions [ 10 ]. Extreme shear forces generated by cavitation events and shock waves help break down contaminant molecules, especially the complex high molecular weight compounds. The intermediate compounds are more prone to hydroxyl radical attack and biological oxidation, further enhancing the overall rate of degradation and the mineralization of wastewater. Under such extreme conditions, the water molecule inside the cavity becomes OH and H radicals. The OH radicals diffuse into the liquid and react with contaminant molecules, resulting in oxidation and mineralization products [ 20 ]. Applications of this proven technology have been mentioned in cold water [ 21 ], municipal sewage [ 13 , 15 ], industrial wastewater [ 17 ], reuse of winery wastewater, artisan production of wastewater reuse, and any waste that requires removal of organic contaminants (PHC/PAH, dioxin/PCB, pesticides), COD/BOD and reductions in TSS [ 14 ]. A prototype adapted by TRIO3, as shown in Figure 13 , displays the cavitation technology. The schematic diagram proposed by the company, mentioning components in Figure 14 , complies with the technical specifications for water treatment procedures. According to the dimensions established in the equipment, the flow rate is dependent on these specifications as shown in Table 4 .

Water treatment unit provided with cavitation technology ( https://wcponline.com/2023/06/23 ).

Isometric diagram for a water treatment unit provided with cavitation technology. With permission of Bhat et al. (2021). https://www.sciencedirect.com/science/article/abs/pii .

Specifications for the construction of hydro cavitation units.

The variables involved in cavitation process induce three common procedures but are different from each other [ 19 ]. These are: a) electro-flotation, where the gas to drag the contaminants previously conditioned to the surface is used, b) The electrocoagulation-flotation involves the injection of metal ions to agglutinate the pollutant agents dispersed in water, and directing them to the anode and sweeping the generated gas, and c) The electrochemistry operation involves redox reactions used to crack toxic compounds and treated later by biological procedures.

The process variables, above mentioned, relate to the type of contaminant to eliminate (see Appendix 2). Therefore, disinfection is due to anodic oxidation. Reingeniería en Saneamiento Ambiental Ltd. has made an effort to offer ecological Systems based on Allotropic Physical Chemical Technology . Through this ionization system, the molecules made up of two or more elements; dissociate the remaining molecules in their original state as atoms or ions. Thus, it softens the water, stabilizes the pH factor, and eliminates its encrusting capacity [ 7 ], as shown in Figure 15 .

Water deionization process. https://www.freedrinkingwater.com/water-education2/49-water-di-process.htm .

A screen is used for urban sewage to retain macro solids.

A regulator tank with a capacity of 45 m 3 .

A sand trap with the capacity for the same flow.

High-speed flocculation unit. The system will be made up of 32 pieces of equipment, each consisting of four cathode electrodes 1¼” in diameter by 48″ length and two anode electrodes 1″ in diameter by 48″ length made of quality 316 stainless steel. Housed in eight tanks 1.50 m high by 1.00 m wide and 1.00 m length (1500 L each) made of hydraulic PVC schedule 40, with four equipment in each tank.

After the high-speed flocculation process, the water will pass to a hopper-type sedimentation tank, with a capacity of 14,000 L for separation of the sludge generated by this process and later passing to the sludge sump for disposal and the water to the system.

High-Impact Ionization Unit. The system will be made up of 96 pieces of equipment, each consisting of six cathode electrodes of 1¼” diameter by 48″ length and three anode electrodes of 3/4″ in diameter by 48″ long, made of quality 316 stainless steel. Housed in 24 tanks 1.50 m high by 1.00 m wide and 1.00 m long (1500 L each) made of hydraulic PVC schedule 40, depositing four teams in each.

Ozone Disinfection Reactor Tank Unit. The clarified and gauged water goes to the disinfection tank, which has a TriO3® brand Ozone system, in order to eliminate unwanted microorganisms and obtain treated water with the required quality. It has the function, as its name indicates, of disinfecting the water from pathogenic bacteria in humans, such as bacteria, viruses, and protozoa.

Sludge Digester. The excess sludge during the purification process is sent to the digester tank, where it is oxidized (a reduction of 40% of the volatile solids present in the sludge), since at this stage the microorganisms do not receive organic matter as food and they will only be provided with air (oxygen), promoting cannibalism (and at the same time avoiding the generation of odors) thus achieving a decrease in them, which will be ready for dehydration.

Sludge Drying Bed. The sludge previously stabilized in the digester and free of odors is sent to this equipment for drying, thus facilitating its handling and final disposal as a soil improver for green areas.

Because the WWTP proposed by TRIO3 is a modular type, the necessary modules can be increased according to the growth needs of the client. Following, Figures 16 and 17 present a prototype of a WWTP using electroflocculation technology. Figure 18 shows an oxidation lagoon and the disposal of treated water into the sea in the province of Santa Rosa Lambayeque, Peru.

Picture of electroflocculation technology (copyright of Reingeniería en Saneamiento ltd).

Oxidation lagoon and disposal of treated water in the district municipality of Santa Rosa Lambayeque, Peru (copyright of Reingeniería en Saneamiento ltd).

4. Instruments and automation system in wastewater treatment process

In the last decades, the automation engineering of water treatment plants has presented advances that have led to improvements in the operation of the process [ 22 ]. For current plants, effective control is of critical importance, in terms of design, characteristics such as easy operation and maintenance and low operating cost are sought, as well as ensuring the capacity of the plant for the reduction or partial elimination of nutrients [ 23 ].

Due to the complexity of the treatment process, manual control of treatment plants may not provide the level of control necessary to meet all operating specifications. In this sense, in recent years with the rapid development of electronics, it is possible to use different devices such as Programmable Logic Controllers (PLCs), Industrial Computers, and Microcontrollers to carry out process control tasks automatically [ 24 ].

One of the most widely used control architectures for water treatment systems is SCADA (Supervisory Control and Data Acquisition) made up of different communication elements and human–machine interfaces, PLCs, remote terminals, and sensors. It is expected that this technology will soon be able to be adapted to the WTP technology to increase the productivity and automation of their processes. A human–machine interface (HMI) component is present within the SCADA tool, where human operators interact with the information acquired by the system through a browser interface, and also allows them to make decisions not programmed in the automatic system [ 25 ]. Figure 19 illustrates the general architecture of an automated water treatment system.

SCADA hardware architecture for wastewater treatment plant. https://www.semanticscholar.org/paper/06/o1/2023/Wastewater-treatment-plant-SCADA-application .

HMI (Human-Machine Interface). It presents human operators with the information acquired by the system through a browser interface, and also allows them to make decisions not programmed in the automatic system.

Master unit of the SCADA system. It is in charge of acquiring the information collected by the remote stations and implementing the control law.

RTUs (Remote Terminal Units). Automatically collects data and connects directly to process sensors. They function as slave units to the supervisory controllers or to the supervisory control and data acquisition (SCADA) master.

PLC (Programmable Logic Controller). Used for automation of the wastewater treatment process and designed with multiple inputs and outputs. Its programming is in ladder language which is similar to electrical plans, which facilitates the interpretation of the code.

Additionally, the SCADA system has different sensors and transmitters which measure physical variables through different principles and convert them into physical signals for interpretation through the system. In general, PLCs are used in SCADA systems as process control elements, however, there are other alternatives such as Raspberry Pi boards, which can be more useful mainly for mobile treatment units (cavitation treatment) due to their size, energy consumption, and processing capacity [ 3 , 26 ]. Raspberry Pi boards can be considered as microcomputers since they have a microprocessor that works under the ARM architecture and also has a series of digital I/O ports that allow acquiring the signal from the sensors and executing the control law through its Departures. The Raspberry pi must be accompanied by a power system to adjust the voltage and current levels of the board to those required by the process actuators [ 27 ].

5. Conclusions and discussion

There are several technologies in the market for WTP purposes. The electrocoagulation, cavitation, and ozone used separately for industrial purposes and municipal wastewater provides different removal efficiencies. This proposed chapter analyzes the benefits of using ozone for disinfection, deodoration, and adequate treatment of tap water, reuse, and recycling of wastewater. Preliminary studies developed by TRIO3 and Reingeniería en Saneamiento Ltd. demonstrate positive results using these technologies combined. The control of process variables in WWTP mentioned above involves novelty advances in ozone technology. Effective procedures discussed for the optimization of processes require more collaborative research in the usage of ozone.

Acknowledgments

Thanks to TECNM Campus Zacatecas Norte, TRIO3® Food Technologies and Reingeniería en Saneamiento Ambiental Ltd.

Nomenclature

• 1. Enríquez-Castro CM, Pérez-Nafarrate M, Gerardo Rodríguez JE. Innovation in food products using ozone technology: Impact on quality assurance. In: Innovation in the Food Sector through the Valorization of Food and Agro-Food by-Products. London, UK, London, UK: Intech Open; 2021
• 2. Oner ME, Demirci A. Ozone for food decontamination: Theory and applications. Handbook of hygiene control in the food industry. 2016;491-501
• 3. Kim J-G, Ahmed EY, Sandhya D. Application of ozone for enhancing the microbiological safety and quality of foods: A review. Journal of Food Protection. 1999; 62 (9):1071-1087
• 4. Krstović S, Krulj J, Jaksic S, Bocarov-Stancic A, Jajic I, et al. Ozone as decontaminating agent for ground corn containing deoxynivalenol, zearalenone, and ochratoxin a. Cereal Chemistry. 2021; 98 (1):135-143
• 5. Schirrmeister JF, Liebenow AL, Petz K, Wittmer A, Serr A, Hellwig E, et al. New bacterial compositions in root-filled teeth with periradicular lesions. Journal of Endodontics. 2009; 35 (2):169-174
• 6. Asfahl KL, Savin MC. Destruction of Escherichia coli and broad-host-range plasmid DNA in treated wastewater by dissolved ozone disinfection under laboratory and field conditions. Advances in Microbiology. 2012; 2 :1-7
• 7. Wu Z, Shen H, Ondruschka B, Zhang Y, Wang W, Bremner DH. Removal of blue-green algae using the hybrid method of hydrodynamic cavitation and ozonation. Journal of Hazardous Materials. 2012; 235 :152-158
• 8. Jain K, Patel AS, Pardhi VP, Flora SJS. Nanotechnology in wastewater management: A new paradigm towards wastewater treatment. Molecules. 2021; 26 (6):1797
• 9. Nisar MA, Ross KE, Brown MH, Bentham R, Whiley H. Legionella pneumophila and protozoan hosts: Implications for the control of hospital and potable water systems. Pathogens. 2020; 9 (4):286
• 10. Foster J, Sommers BS, Gucker SN, Blankson IM, Adamovski G. Perspectives on the interaction of plasmas with liquid water for water purification. IEEE Transactions on Plasma Science. 2012; 40 (5):1311-1323
• 11. Asaithambi P, Govindararajan R, Yesuf MB, Selvakumar P, Alemayehu E, et al. Enhanced treatment of landfill leachate wastewater using sono (US)-ozone (O3)–electrocoagulation (EC) process: Role of process parameters on color, COD and electrical energy consumption. Process Safety and Environmental Protection. 2020; 142 :212-218
• 12. Östman M, Bjorlenius B, Fick J, Tysklind M. Effect of full-scale ozonation and pilot-scale granular activated carbon on the removal of biocides, antimycotics and antibiotics in a sewage treatment plant. Science of the Total Environment. 2019; 649 :1117-1123
• 13. Li W, Li C, Zhu N, Yuan H, Shen Y. The extent of sludge solubilization allows to estimate the efficacy of ozonation for removal of polycyclic aromatic hydrocarbons (PAHs) in municipal sewage sludge. Journal of Hazardous Materials. 2021; 413 :125404
• 14. Wang J, Zhang X, Li G. Effects of ozonation on soil organic matter of contaminated soil containing residual oil. Journal of Soils and Sediments. 2012; 12 (2):117-127
• 15. Ried A, Mielcke J, Wieland A. The potential use of ozone in municipal wastewater. Ozone: Science & Engineering. 2009; 31 (6):415-421
• 16. Gogate PR, Mededovic-Thagard S, McGuire D, Chapas G, Blackmon J, Cathey R. Hybrid reactor based on combined cavitation and ozonation: From concept to practical reality. Ultrasonics Sonochemistry. 2014; 21 (2):590-598
• 17. Bilińska L, Blus K, Gmurek M, Ledakowicz S. Coupling of electrocoagulation and ozone treatment for textile wastewater reuse. Chemical Engineering Journal. 2019; 358 :992-1001
• 18. Barrera-Díaz CE, Balderas-Hernández P, Bilyeu B. Electrocoagulation: Fundamentals and prospectives. In: Electrochemical water and wastewater treatment. 2018; 61-76
• 19. Čehovin M et al. Hydrodynamic cavitation in combination with the ozone, hydrogen peroxide and the UV-based advanced oxidation processes for the removal of natural organic matter from drinking water. Ultrasonics Sonochemistry. 2017; 37 :394-404
• 20. Bruggeman P, Schram DC. On OH production in water containing atmospheric pressure plasmas. Plasma Sources Science and Technology. 2010; 19 :045025
• 21. Gardoni D, Vailati A, Canziani R. Decay of ozone in water: A review. Ozone: Science & Engineering. 2012; 34 (4):233-242
• 22. Wang R, Jiaqi L, Xianbin GJ. Design and simulation of an ozone catalytic oxidation system based on programmable logic controller. Journal Européen des Systèmes Automatises. 2020; 53 :517-524
• 23. Hong S-W, Choi Y, Kim SJ, Kwon G. Pilot-testing an alternative on-site wastewater treatment system for small communities and its automatic control. Water Science and Technology 2005; 51 (10):101-108
• 24. Manesis SA, Sapidis DJ, King RE. Intelligent control of wastewater treatment plants. Artificial Intelligence in Engineering. 1998; 12 (3):275-281
• 25. Humoreanu B, Nascu I. Wastewater treatment plant SCADA application. In: Proceedings of 2012 IEEE International Conference on Automation, Quality and Testing, Robotics. 2012:575-580
• 26. Hamidi EAZ, Gustiana T, Effendi MR, Hambali PAM. Design and implementation supervisory control and data acquisition (SCADA) of flocculation process of water treatment plant (WTP) using raspberry pi. In: Proceeding of 2019 IEEE 5th International Conference on Wireless and Telematics (ICWT). 2019; 1-5
• 27. Upadhyay D, Sampalli S. SCADA (supervisory control and data acquisition) systems: Vulnerability assessment and security recommendations. Computers & Security. 2020; 89 :101666

© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Turning to nature to improve vital water treatment

by RMIT University

Escalating industrialization, urbanization and climate change in Asia present a significant challenge to maintaining water quality.

In an effort to improve water treatment , RMIT has collaborated in an international team supporting pilot projects in Vietnam, Sri Lanka and the Philippines through an Asia-Pacific Network for Global Change Research project.

Led by RMIT's Professor Jega Jegatheesan, the pilots included the construction of floating wetlands in Can Tho, Vietnam and Kandy, Sri Lanka, green roofs in Ho Chi Minh City and constructed wetland in the Philippines.

This saw 40 students at Can Tho University trained to build and install the structures in two canals, with another 32 early career researchers engaged through hands-on learning across the other sites.

RMIT also provided scientific and methodological guidance for the establishment and replication of a green roof in Ho Chi Minh City for domestic wastewater treatment.

The system using rock, oyster shells and charcoal was set up on the roof of a research center at Ho Chi Minh City University of Technology in Vietnam, another project partner.

Jegatheesan said the project's overall aim was to effectively remove pollutants from water bodies, delivering environmental and communal benefits.

"We developed guidelines to replicate and scale nature-based water treatment solutions," said Jegatheesan.

"Our overall aim was to explore the role nature-based solutions could play in making Southeast Asian cities more liveable and resilient.

"We worked with teams in the Philippines, Sri Lanka, Vietnam, Australia and Spain to make this happen—there was a lot of support all round, which was critical to our success."

RMIT Europe's Nevelina Pachova worked on developing the project's concept and supported its implementation through a series of online and in-person meetings.

"In Europe, nature-based solutions are popular for making cities greener and the use of urban resources more sustainable and circular," she said.

"Many traditional resource management practices in Southeast Asia are de facto nature-based solutions but many have disappeared or remain limited to rural areas.

"So the idea was to discover if and how they can be integrated in making cities better places to live in."

The main goal was to develop solutions suited to local conditions, which Pachova said required the consultation of diverse stakeholders.

The team has now applied for a follow-up project focused on building capacities and engaging people in the design and use of nature-based solutions across the broader range of sites in the region.

Provided by RMIT University

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Overview of Drinking Water Treatment Technologies

On this page:, granular activated carbon, packed tower aeration, multi-stage bubble aeration, anion exchange, cation exchange, biological treatment, reverse osmosis/nanofiltration, adsorptive media.

• Ultraviolet Photolysis and Advanced Oxidation Processes

Caustic Feed

Phosphate feed, nontreatment options, what is granular activated carbon.

Granular activated carbon (GAC) is a porous adsorption media with extremely high internal surface area. GACs are manufactured from a variety of raw materials with porous structures including:

• bituminous coal
• lignite coal
• coconut shells

Physical and/or chemical manufacturing processes are applied to these raw materials to create and/or enlarge pores.  This results in a porous structure with a large surface area per unit mass.

Why is it useful?

GAC is useful for the removal of taste- and odor-producing compounds, natural organic matter, volatile organic compounds (VOCs), synthetic organic compounds and disinfection byproduct precursors. Organic compounds with high molecular weights are readily adsorbable.

Treatment capacities for different contaminants vary depending on the properties of the different GACs, which in turn vary widely depending on the raw materials and manufacturing processes used.

What are the advantages of using GAC?

GAC is a proven technology with high removal efficiencies (up to 99.9%) for many VOCs, including trichloroethylene (TCE) and tetrachloroethylene (PCE). In most cases, GAC can remove target contaminants to concentrations below 1 µg/l. Another advantage is that regenerative carbon beds allow for easy recovery of the adsorption media.

What are the disadvantages of using GAC?

The media has to be removed and replaced or regenerated when GAC capacity is exhausted. In some cases, disposal of the media may require a special hazardous waste handling permit. Other adsorbable contaminants in the water can reduce GAC capacity for a target contaminant.

How can the WBS model for GAC be used?

The work breakdown structure (WBS) model can estimate costs for two types of GAC systems where:

• the GAC bed is contained in pressure vessels in a treatment configuration similar to that used for other adsorption media (for example, activated alumina), referred to as pressure GAC
• the GAC bed is contained in open concrete basins in a treatment configuration similar to that used in the filtration step of conventional or direct filtration, referred to as gravity GAC

The WBS model for GAC includes standard designs to estimate costs for treatment of a number of different contaminants, including atrazine and various VOCs. The WBS model can also be used to estimate the cost of GAC treatment for removal of other contaminants.

To simulate the use of GAC for treatment of other contaminants, users will need to adjust default inputs (for example, bed volumes before breakthrough, bed depth) and, potentially, critical design assumptions (for example, minimum and maximum loading rates).

Where can I find more information on GAC?

The technical report Work Breakdown Structure-Based Cost Model for Granular Activated Carbon Drinking Water Treatment Technologies discusses GAC technology in detail.

What is packed tower aeration?

Aeration processes, in general, transfer contaminants from water to air. Packed tower aeration (PTA) uses towers filled with a packing media designed to mechanically increase the area of water exposed to non-contaminated air. Water falls from the top of the tower through the packing media while a blower forces air upwards through the tower. In the process, volatile contaminants pass from the water into the air.

PTA is useful for removing volatile contaminants including:

• Volatile organic compounds (VOCs)
• Disinfection byproducts
• Hydrogen sulfide
• Carbon dioxide
• Other taste- and odor-producing compounds

The more volatile the contaminant, the more easily PTA will remove it. PTA readily removes the most volatile contaminants, such as vinyl chloride. With sufficient tower height and air flow, PTA can even remove somewhat less volatile contaminants, such as 1,2-dichloroethane.

What are the advantages of using PTA?

PTA is a proven technology and can achieve high removal efficiencies (99 percent or greater) for most VOCs. PTA removal efficiency is independent of starting concentration. Therefore, it can remove most volatile contaminants to concentrations below 1 µg/L. PTA generates no liquid or solid waste residuals for disposal.

What are the disadvantages of using PTA?

Depending on the location and conditions, air quality regulations might require the use of air pollution control devices with PTA, increasing the technology cost. PTA uses tall towers that could be considered unsightly in some communities. Under certain water quality conditions, scaling or fouling of the packing media can occur if precautions are not taken.

How can the WBS model for PTA be used?

The work breakdown structure (WBS) model for PTA includes standard designs to estimate costs for treatment of a number of different contaminants, including methyl tertiary-butyl ether (MTBE) and various VOCs. However, the WBS model can be used to estimate the cost of PTA treatment for removal of other contaminants as well.

To simulate the use of PTA for treatment of other contaminants, users will need to adjust default inputs (for example, Henry’s coefficient, molecular weight) and, potentially, critical design assumptions (for example, minimum and maximum packing height).

Where can I find more information on PTA?

The technical report Work Breakdown Structure-Based Cost Model for Packed Tower Aeration Drinking Water Treatment Technologies discusses PTA technology in detail.

What is multi-stage bubble aeration?

Aeration processes, in general, transfer contaminants from water to air. Multi-stage bubble aeration (MSBA) uses shallow basins that are divided into smaller compartments, or stages, using baffles.

Inside each stage, diffusers (consisting of perforated pipes or porous plates) release small air bubbles that rise through the water. The bubbles and their resulting turbulence cause volatile contaminants to pass from the water into the air.

MSBA is useful for removing volatile contaminants including:

The more volatile the contaminant, the more easily MSBA will remove it. Vendors supply MSBA in skid-mounted, pre-packaged systems that can be particularly suitable for small systems.

What are the advantages of using MSBA?

MSBA is a proven technology. In recent EPA pilot tests, MSBA achieved high removal efficiencies (98 percent to greater than 99 percent) for most VOCs, removing them to concentrations below 1 µg/L. MSBA is a low-profile aeration technology that does not require tall, potentially unsightly towers. MSBA generates no liquid or solid waste residuals for disposal.

What are the disadvantages of using MSBA?

Depending on the location and conditions, air quality regulations might require the use of air pollution control devices with MSBA, increasing the technology cost.

MSBA is less efficient at removing contaminants than packed tower aeration, requiring high air flow rates to remove the most recalcitrant VOCs. Treating large water flows with MSBA can require a large number of basins. This might not be practical for large systems.

How can the WBS model for MSBA be used?

The work breakdown structure (WBS) model for MSBA includes standard designs for the treatment of a number of contaminants, including various VOCs. However, the WBS model can be used to estimate the cost of MSBA treatment for removal of other volatile contaminants as well.

To simulate the use of MSBA for treatment of other contaminants, users will need to adjust default inputs (for example, air-to-water ratio, number of stages) and, potentially, critical design assumptions (for example, maximum air surface intensity).

Where can I find more information on MSBA?

The technical report Work Breakdown Structure-Based Cost Model for Multi-stage Bubble Aeration Drinking Water Treatment Technologies discusses MSBA technology in detail.

What is anion exchange?

In an anion exchange treatment process, water passes through a bed of synthetic resin. Negatively charged contaminants in the water are exchanged with more innocuous negatively charged ions, typically chloride, on the resin’s surface.

Anion exchange is useful for the removal of negatively charged contaminants including arsenic, chromium-6, cyanide, nitrate, perchlorate, per- and polyfluoroalkyl substances (PFAS), sulfate, and uranium.

Treatment capacities for different contaminants vary depending on the properties of the resin used and characteristics of the influent water. Several of vendors manufacture different resins, including those designed to selectively remove specific contaminant ions.​

What are the advantages of using anion exchange?

Anion exchange is a proven technology that can achieve high removal efficiencies (greater than 99 percent) for negatively charged contaminants. When the capacity of the resin is exhausted, it can be regenerated to restore it to its initial condition. The regeneration process uses a saturated solution, usually of sodium chloride (also known as brine). An alternative to regeneration is to dispose of the exhausted resin and replace it with fresh resin. This alternative is often employed when selective resins are used to remove perchlorate or PFAS.

What are the disadvantages of using anion exchange?

The spent regenerant brine is a concentrated solution of the removed contaminants and will be high in dissolved solids and excess regenerant ions (e.g., sodium, chloride). This waste stream will require disposal or discharge. Anion exchange treatment also can lower the pH of the treated water and, therefore, may require post-treatment corrosion control. When replacement with fresh resin is used as an alternative to regeneration, the spent resin, loaded with removed contaminants, will require disposal. In some cases, disposal of the resin may require a special hazardous waste handling permit.

How can the WBS model for anion exchange be used?

The primary work breakdown structure (WBS) model for anion exchange includes standard designs to estimate costs for treatment of arsenic and nitrate. EPA has developed separate WBS models, also available on this page, to estimate costs for treatment of perchlorate and PFAS. In addition, the WBS anion exchange models can be used to estimate the cost of anion exchange treatment for removal of other contaminants.

To simulate the use of anion exchange for treatment of other contaminants, users will need to adjust default inputs (for example, bed volumes before regeneration, bed depth) and, potentially, critical design assumptions (for example, minimum and maximum loading rates).

Where can I find more information on anion exchange?

The technical report Work Breakdown Structure-Based Cost Model for Anion Exchange Drinking Water Treatment discusses anion exchange technology in detail.

What is cation exchange?

In a cation exchange treatment process, water passes through a bed of synthetic resin. Positively charged contaminants in the water are exchanged with more innocuous positively charged ions, typically sodium, on the resin’s surface.

Cation exchange is useful for water softening by removing hardness ions such as calcium and magnesium. It can also remove other positively charged contaminants including barium, radium and strontium.

Treatment capacities for different contaminants vary depending on the properties of the resin used and characteristics of the influent water. A number of vendors manufacture different resins, including those designed to selectively remove specific contaminant ions.​

What are the advantages of using cation exchange?

Cation exchange is a proven technology for water softening and removal of positively charged contaminants. It can achieve high removal efficiencies (greater than 99 percent) for positively charged contaminants. When the capacity of the resin is exhausted, it can be regenerated to restore it to its initial condition. The regeneration process uses a saturated solution, usually of sodium chloride (also known as brine).

What are the disadvantages of using cation exchange?

The spent regenerant brine is a concentrated solution of the removed contaminants and also will be high in dissolved solids and excess regenerant ions (e.g., sodium, chloride). This waste stream will require disposal or discharge.

How can the WBS model for cation exchange be used?

The work breakdown structure (WBS) model for cation exchange includes standard designs for water softening. The same designs may also be appropriate for radium removal. The WBS model can also be used to estimate the cost of cation exchange treatment for removal of other contaminants.

To simulate the use of cation exchange for treatment of other contaminants, users will need to adjust default inputs (for example, bed volumes before regeneration, bed depth) and, potentially, critical design assumptions (for example, minimum and maximum loading rates).

Where can I find more information on cation exchange?

The technical report Work Breakdown Structure-Based Cost Model for Cation Exchange Drinking Water Treatment discusses cation exchange technology in detail.

What is biological treatment?

Biological treatment of drinking water uses indigenous bacteria to remove contaminants. The process has a vessel or basin called a bioreactor that contains the bacteria in a media bed. As contaminated water flows through the bed, the bacteria, in combination with an electron donor and nutrients, react with contaminants to produce biomass and other non-toxic by-products. In this way, the biological treatment chemically “reduces” the contaminant in the water.

Biological treatment is useful for the removal of contaminants including nitrate and perchlorate. Following a startup period, the bacterial population in the water will adapt to consume the target contaminants as long as favorable conditions, such as water temperature and electron donor and nutrient concentrations, are maintained.

What are the advantages of using biological treatment?

Biological treatment can achieve high removals (greater than 90 percent) of nitrate and perchlorate. The process destroys contaminants, as opposed to removing them, and, therefore, does not produce contaminant-laden waste streams. Biological treatment remains effective even in the presence of certain co-occurring contaminants.

What are the disadvantages of using biological treatment?

An active bioreactor will have a continuous growth of biomass that needs to be periodically removed. Although the excess biomass will not be contaminant-laden, it still requires disposal. Also, biological treatment adds soluble microbial organic products and can deplete the oxygen in treated water. Post-treatment processes are needed to control these effects.

How can the WBS model for biological treatment be used?

The work breakdown structure (WBS) model can estimate costs for anoxic biological treatment using three types of bioreactors:

• pressure vessels with a fixed media bed
• open concrete basins with a fixed media bed
• pressure vessels with a fluidized media bed.

The WBS model for biological treatment includes standard designs for perchlorate and nitrate treatment. However, the model can also be used to estimate the cost of biological treatment for the removal of other contaminants.

To simulate the use of biological treatment for other contaminants, users will need to adjust default inputs (e.g., electron donor and nutrient doses) and critical design assumptions (e.g., minimum and maximum loading rates).

Where can I find more information on biological treatment?

The technical report Work Breakdown Structure-Based Cost Model for Biological Drinking Water Treatment discusses the technology in detail.

What are reverse osmosis and nanofiltration?

Reverse osmosis (RO) and nanofiltration (NF) are membrane separation processes that physically remove contaminants from water. These processes force water at high pressure through semi-permeable membranes that prevent the passage of various substances depending on their molecular weight. Treated water, also known as permeate or product water, is the portion of flow that passes through the membrane along with lower molecular weight substances. Water that does not pass through the membrane is known as concentrate or reject and retains the higher molecular weight substances, including many undesirable contaminants.

Why are they useful?

RO and NF are useful for the removal a wide range of contaminants. RO can remove contaminants including many   inorganics, dissolved solids, radionuclides and synthetic organic chemicals. RO can also be used for removing salts from brackish water or sea water. NF is useful for removal of hardness, color and odor compounds, synthetic organic chemicals and some disinfection byproduct precursors.

What are the advantages of using RO and NF?

RO and NF are proven technologies that can achieve high removals of a broad range contaminants at once. They do not selectively target individual contaminants and remain effective for water that contains mixtures of contaminants. The processes do not usually require adjustment based on the specific trace contaminants present.

What are the disadvantages of using RO and NF?

RO and NF reject part of the feed water (15 to 30 percent) that enters the process. This “loss” of water as concentrate can present a problem when water is scarce. Furthermore, this large volume concentrate stream is laden with removed contaminants, salts and dissolved solids and will require discharge or disposal. Also, the high pressures used in these treatment processes can result in significant energy consumption. Pre-treatment processes are frequently required to prevent membrane fouling or plugging. Finally, RO can lower the pH of treated water and, therefore, may require post-treatment corrosion control.

How can the WBS model for RO and NF be used?

The work breakdown structure (WBS) model can estimate costs for either RO or NF. It includes standard designs for feed waters of various quality in terms of gross chemical composition (e.g., salt concentrations). The design parameters typically do not require adjustment to target a specific trace contaminant, other than selecting the appropriate type of membrane (e.g., RO or NF) given the contaminant’s molecular weight and other characteristics.

Where can I find more information on RO and NF?

The technical report Work Breakdown Structure-Based Cost Model for Reverse Osmosis/Nanofiltration Drinking Water Treatment discusses these technologies in detail.

What is adsorptive media?

Adsorptive water treatment technologies involve passing contaminated water through a media bed. The contaminants in the water adsorb to empty pore spaces on the surface of the adsorptive media as the water passes through. Granular activated carbon (GAC), described above, is one type of adsorptive media, but other types exist, including aluminum-based, iron-based, titanium-based, zirconium-based and other types of media.

Adsorptive media treatment is useful for removal of inorganic contaminants including antimony, arsenic, beryllium, fluoride, selenium, thallium, and uranium. The capacity of the media to adsorb different contaminants depends on the specific type of media used, the water chemistry (e.g., pH), and contaminant valence.

What are the advantages of using adsorptive media?

Adsorptive media is a proven technology with high removal efficiencies for certain inorganic contaminants (e.g., up to greater than 99% for arsenic, up to 99% or more for fluoride). When the appropriate media is used in combination with the appropriate water quality conditions (e.g., pH), the process can remove selected target contaminants to concentrations below relevant regulatory limits. Another advantage is that some types of adsorptive media can be regenerated in place after their capacity is exhausted. The regeneration process typically uses an acid wash, followed by a caustic wash.

What are the disadvantages of using adsorptive media?

The media has to be removed and replaced or regenerated when its adsorptive capacity is exhausted. When regeneration is employed, the spent regenerant is a concentrated solution of the removed contaminants and will require disposal or discharge. When replacement with fresh media is used as an alternative to regeneration, the spent media, loaded with removed contaminants, will require disposal. In some cases, disposal of the media may require a special hazardous waste handling permit.

How can the WBS model for adsorptive media be used?

The work breakdown structure (WBS) model can estimate costs for the following combinations of media and target contaminant:

• Conventional activated alumina for removal of arsenic
• Conventional activated alumina for removal of fluoride
• Iron-modified activated alumina (also known as AAFS-50) for removal of arsenic
• Granular ferric oxide (GFO) for removal of arsenic
• Granulated ferric hydroxide (GFH) for removal of arsenic.

The WBS model can also estimate costs for treatment using alternative media and/or other contaminants, if the user provides appropriate assumptions about the media and adjusts default inputs (e.g., bed volumes before breakthrough, bed depth).

The technical report Work Breakdown Structure-Based Cost Model for Adsorptive Media Drinking Water Treatment discusses the technology in detail.

Ultraviolet Photolysis and Advanced Oxidation Processes (UVAOP)

What is ultraviolet photolysis and advanced oxidation.

Ultraviolet (UV) light can be used on its own (in photolysis), or in combination with chemical addition (in UV advanced oxidation), to reduce the concentration of organic contaminants. In UVAOP drinking water treatment, water passes through a reactor vessel equipped with lamps that emit UV light. In photolysis, the contaminants are degraded by the photons emitted by the UV lamps. Advanced oxidation adds chemicals such as hydrogen peroxide (H 2 O 2 ) or chlorine. These chemicals react with the UV light to generate radicals (such as hydroxyl) that in turn oxidize the contaminants.

UVAOP is useful to reduce the concentration of organic micropollutants that may be difficult to address with other technologies including 1,4-dioxane, N-nitrosodimethylamine (NDMA), and methyl tert-butyl ether (MTBE). The process can also be useful for treatment of taste and odor issues. The effectiveness of the process depends on the UV dose, chemical dose (in advanced oxidation), contact time, concentration of the target contaminants, and other water quality parameters (e.g., UV transmittance, presence of radical scavengers).

What are the advantages of using UVAOP?

UVAOP can achieve high removal efficiencies for 1,4-dioxane (up to greater than 99%) and MTBE (greater than 90%). The process destroys contaminants, as opposed to removing them, and therefore, does not produce contaminant-laden waste streams.

What are the disadvantages of using UVAOP?

UVAOP is non-selective and can oxidize non-target organic compounds present in the water. In some cases, this oxidation can increase the potential for formation of disinfection byproducts in the drinking water distribution system. Also, in advanced oxidation, the process will not completely consume the entire dosage of the chemical added. The presence of the excess chemical in the treated water may be of concern. Both of these disadvantages may require post-treatment using a process such as GAC. Finally, operating the UV lamps can consume significant electrical energy and the lamps themselves usually require periodic cleaning and replacement.

How can the WBS model for UVAOP be used?

The work breakdown structure (WBS) model can estimate costs for the following combinations of treatment processes and target contaminant:

• Treatment of 1,4-dioxane using UV and H 2 O 2 (UV/H 2 O 2 )
• Treatment of 1,4-dioxane using UV and chlorine (UV/Cl)
• Treatment of NDMA using direct photolysis.

The WBS model can also estimate costs for treatment of other contaminants by UV/ H 2 O 2 , UV/Cl, or direct photolysis, if the user adjusts default inputs (e.g., UV energy input, oxidant dose).

Where can I find more information on UVAOP?

The technical report Work Breakdown Structure-Based Cost Model for Drinking Water Treatment by Ultraviolet Photolysis and Advanced Oxidation Processes discusses the technology in detail.

What is caustic feed?

Caustic soda, also known as sodium hydroxide (NaOH), is sometimes added to drinking water to raise the water’s pH, making the water less acidic.

Caustic feed can be useful on its own to attain and maintain a desired pH and prevent downstream corrosion in a drinking water distribution system. It can also be useful following treatment processes that lower the pH of water to return the water to its original or more neutral pH. It may also be useful prior to certain treatment processes to optimize the pH of the water feeding those processes.

What are the advantages of using caustic feed?

Caustic soda is a liquid chemical that can rapidly change the pH of water without requiring extensive equipment for feeding and mixing.

What are the disadvantages of using caustic feed?

Concentrated caustic soda is harmful to human skin and therefore requires handling precautions and secondary containment. At higher concentrations, caustic soda will freeze at moderate temperatures (i.e., 50 percent solution freezes at 58 degrees Fahrenheit), so storage tanks may need to be indoors and/or equipped with special heating equipment. This disadvantage can be mitigated by using lower concentration caustic soda.

How can the WBS model for caustic feed be used?

The work breakdown structure (WBS) model can estimate costs for a process to add caustic soda into a water pipeline at an existing drinking water treatment plant. It includes several pre-defined scenarios of starting pH, target pH, and other water quality parameters. It can easily estimate costs for other scenarios if the user adjusts default inputs.

Where can I find more information on caustic feed?

The technical report Work Breakdown Structure-Based Cost Model for Caustic Feed Drinking Water Treatment discusses the technology in detail.

What is phosphate feed?

Phosphate-based chemicals, such as phosphoric acid, zinc orthophosphate, or others, are sometimes added to drinking water to control corrosion in a distribution system.

Phosphate addition is among the treatment strategies for compliance with the federal Lead and Copper Rule.

What are the advantages and disadvantages of using phosphate feed?

Phosphate corrosion control chemicals containing orthophosphate are believed to combine with lead and copper in plumbing materials to form insoluble compounds, thus reducing lead and copper release at the tap. The effectiveness of this process depends on chemical dosage and pH. However, the addition of these chemicals does not permanently eliminate sources of lead and copper release (e.g., service lines). Changes in influent water quality can require re-optimization of corrosion control practices. In addition, different phosphate chemical formulations have different advantages and disadvantages. For example, phosphoric acid is potentially cheaper than zinc orthophosphate, but is a strong acid that can require safety precautions.

How can the WBS model for phosphate feed be used?

The work breakdown structure (WBS) model can estimate costs for a process to add phosphoric acid or zinc orthophosphate into a water pipeline at an existing drinking water treatment plant. It can estimate the cost of phosphate feed using different chemical formulations, if the user provides appropriate inputs for the alternative chemical (e.g., solution strength, density, price).

The technical report Work Breakdown Structure-Based Cost Model for Phosphate Feed Drinking Water Treatment discusses the technology in detail.

What are nontreatment options?

Instead of treating a contaminated water source, nontreatment options replace the source with water that meets applicable drinking water standards. Examples include interconnection with another system and drilling a new well to replace a contaminated one.

Nontreatment can provide a route to compliance with drinking water standards for various contaminants, as long as an alternate water source is available.

What are the advantages of using nontreatment options?

Small water utilities, particularly those that lack financial and/or technical capacity, might be able to use nontreatment approaches to avoid the cost and labor associated with installing and operating new treatment processes.

What are the disadvantages of using nontreatment options?

Interconnection requires a neighboring utility with excess capacity that is willing to sell water to the affected utility. Installation of a new well requires the existence and accessibility of an uncontaminated aquifer.

How can the WBS model for nontreatment options be used?

The work breakdown structure (WBS) model can estimate costs for either of two nontreatment options:

• interconnection with another system
• drilling a new well to replace a contaminated one

Where can I find more information on nontreatment options?

The technical report Work Breakdown Structure-Based Cost Model for Nontreatment Options for Drinking Water Compliance discusses these options in detail.

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• Published: 06 August 2018

Emerging opportunities for nanotechnology to enhance water security

• Pedro J. J. Alvarez 1 ,
• Candace K. Chan 2 ,
• Menachem Elimelech   ORCID: orcid.org/0000-0003-4186-1563 3 ,
• Naomi J. Halas 4 &
• Dino Villagrán 5  

Nature Nanotechnology volume  13 ,  pages 634–641 ( 2018 ) Cite this article

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• Chemical engineering
• Civil engineering
• Environmental, health and safety issues
• Nanoscale materials

No other resource is as necessary for life as water, and providing it universally in a safe, reliable and affordable manner is one of the greatest challenges of the twenty-first century. Here, we consider new opportunities and approaches for the application of nanotechnology to enhance the efficiency and affordability of water treatment and wastewater reuse. Potential development and implementation barriers are discussed along with research needs to overcome them and enhance water security.

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Chen, B. et al. Global land-water nexus: Agricultural land and freshwater use embodied in worldwide supply chains. Sci. Total Environ. 613–614 , 931–943 (2018).

Google Scholar  

Schewe, J. et al. Multimodel assessment of water scarcity under climate change. Proc. Natl Acad. Sci. USA 111 , 3245–3250 (2014).

CAS   Google Scholar  

Coping with Water Scarcity - Challenge of the Twenty-First Century (UN Water, 2007).

Bates, B., Kundzewicz, Z., Wu, S. & Palutikof, J. (eds) Climate Change and Water Technical Paper of the Intergovernmental Panel on Climate Change (IPCC, 2008).

Steffen, W. et al. Planetary boundaries: Guiding human development on a changing planet. Science 347 , 6223 (2105).

UNICEF & WHO. Progress on Sanitation and Drinking Water: 2015 Update and MDG Assessment (UNICEF, 2015).

Prüss‐Ustün, A. et al. Burden of disease from inadequate water, sanitation and hygiene in low‐ and middle‐income settings: a retrospective analysis of data from 145 countries. Trop. Med. Int. Health 19 , 894–905 (2014).

Liu, L. et al. Global, regional, and national causes of child mortality: an updated systematic analysis for 2010 with time trends since 2000. Lancet 379 , 2151–2161 (2012).

Luo, Y. et al. Proliferation of multidrug-resistant New Delhi metallo-β-lactamase genes in municipal wastewater treatment plants in northern China. Environ. Sci. Technol. Lett. 1 , 26–30 (2014).

O’Neill. J. Antimicrobial Resistance: Tackling a Crisis for the Health and Wealth of Nations (The Review on Antimicrobial Resistance, 2014).

Hutton, G. & Haller, L. Evaluation of the Costs and Benefits of Water and Sanitation Improvements at the Global Level (WHO, 2004).

Van Minh, H. & Hung, N. V. Economic aspects of sanitation in developing countries. Environ. Health Insights 5 , S8199 (2011).

Bigas, H. Water Security and the Global Water Agenda: A UN-water Analytical Brief (United Nations University - Institute for Water, Environment and Health, 2013).

Zodrow, K. R. et al. Advanced materials, technologies, and complex systems analyses: Emerging opportunities to enhance urban water security. Environ. Sci. Technol. 51 , 10274–10281 (2017).

Dong, S. Y. et al. Recent developments in heterogeneous photocatalytic water treatment using visible light-responsive photocatalysts: a review. RSC Adv. 5 , 14610–14630 (2015).

Kumar, S. G. & Devi, L. G. Review on modified TiO 2 photocatalysis under UV/visible light: Selected results and related mechanisms on interfacial charge carrier transfer dynamics. J. Phys. Chem. A 115 , 13211–13241 (2011).

Zhang, D. S. et al. Enhanced capacitive deionization performance of graphene/carbon nanotube composites. J. Mater. Chem. 22 , 14696–14704 (2012).

Wang, H. et al. In situ creating interconnected pores across 3D graphene architectures and their application as high performance electrodes for flow-through deionization capacitors. J. Mater. Chem. A 4 , 4908–4919 (2016).

Yang, Y. & Hoffmann, M. R. Synthesis and stabilization of blue-black TiO 2 nanotube arrays for electrochemical oxidant generation and wastewater treatment. Environ. Sci. Technol. 50 , 11888–11894 (2016).

Liu, S. et al. Improved degradation of the aqueous flutriafol using a nanostructure macroporous PbO 2 as reactive electrochemical membrane. Electrochim. Acta 253 , 357–367 (2017).

Radjenovic, J. & Sedlak, D. L. Challenges and opportunities for electrochemical processes as next-generation technologies for the treatment of contaminated water. Environ. Sci. Technol. 49 , 11292–11302 (2015).

Yavuz, C. T. et al. Low-field magnetic separation of monodisperse Fe 3 O 4 nanocrystals. Science 314 , 964–967 (2006).

Farrell, J. W. et al. Arsenic removal by nanoscale magnetite in Guanajuato, Mexico. Environ. Eng. Sci. 31 , 393–402 (2014).

Cooper, A. M., Hristovski, K. D., Moller, T., Westerhoff, P. & Sylvester, P. The effect of carbon type on arsenic and trichloroethylene removal capabilities of iron (hydr)oxide nanoparticle-impregnated granulated activated carbons. J. Hazard. Mater. 183 , 381–388 (2010).

Sylvester, P., Westerhoff, P., Mooller, T., Badruzzaman, M. & Boyd, O. A hybrid sorbent utilizing nanoparticles of hydrous iron oxide for arsenic removal from drinking water. Environ. Eng. Sci. 24 , 104–112 (2007).

Alsbaiee, A. et al. Rapid removal of organic micropollutants from water by a porous β-cyclodextrin polymer. Nature 529 , 190–194 (2015).

Mauter, M. S. et al. The role of nanotechnology in tackling global water challenges. Nat. Sustain. 1 , 166–175 (2018).

Lee, J. et al. Photochemical and antimicrobial properties of novel C 60 derivatives in aqueous systems. Environ. Sci. Technol. 43 , 6604–6610 (2009).

Lee, J. et al. C 60 aminofullerene immobilized on silica as a visible-light-activated photocatalyst. Environ. Sci. Technol. 44 , 9488–9495 (2010).

Lee, C.-G. et al. Porous electrospun fibers embedding TiO 2 for adsorption and photocatalytic degradation of water pollutants. Environ. Sci. Technol. 52 , 4285–4293 (2018).

Wang, F. Hollow anatase TiO 2 octahedrons with exposed high-index {102} facets for improved dye-sensitized photoredox catalysis activity. Inorg. Chem. 57 , 4550–4555 (2018).

Liu, S., Yu, J. & Jaroniec, M. Tunable photocatalytic selectivity of hollow TiO 2 microspheres composed of anatase polyhedra with exposed {001} facets. J. Am. Chem. Soc. 132 , 11914–11916 (2010).

Zhang, R. et al. Antifouling membranes for sustainable water purification: strategies and mechanisms. Chem. Soc. Rev. 45 , 5888–5924 (2016).

Boo, C., Lee, J. & Elimelech, M. Engineering surface energy and nanostructure of microporous films for expanded membrane distillation applications. Environ. Sci. Technol. 50 , 8112–8119 (2016).

Yamani, J. S., Lounsbury, A. W. & Zimmerman, J. B. Towards a selective adsorbent for arsenate and selenite in the presence of phosphate: Assessment of adsorption efficiency, mechanism, and binary separation factors of the chitosan-copper complex. Water Res. 88 , 889–896 (2016).

Dongare, P. D. et al. Nanophotonics-enabled solar membrane distillation for off-grid water purification. Proc. Natl Acad. Sci. USA 114 , 6936–6941 (2017).

Zodrow, K. et al. Polysulfone ultrafiltration membranes impregnated with silver nanoparticles show improved biofouling resistance and virus removal. Water Res. 43 , 715–723 (2009).

Tang, W., He, D., Zhang, C. & Waite, T. D. Optimization of sulfate removal from brackish water by membrane capacitive deionization (MCDI). Water Res. 121 , 302–310 (2017).

Yu, C. Modulating particle adhesion with micro-patterned surfaces. ACS Appl. Mater. Inter. 6 , 8199–8207 (2014).

Werber, J. R., Osuji, C. O. & Elimelech, M. Materials for next-generation desalination and water purification membranes. Nat. Rev. Mater. 1 , 16018 (2016).

Liu, C., Lee, J., Small, C., Ma, J. & Elimelech, M. Comparison of organic fouling resistance of thin-film composite membranes modified by hydrophilic silica nanoparticles and zwitterionic polymer brushes. J. Memb. Sci. 544 , 135–142 (2017).

Ben-Sasson, M., Lu, X., Nejati, S., Jaramillo, H. & Elimelech, M. In situ surface functionalization of reverse osmosis membranes with biocidal copper nanoparticles. Desalination 388 , 1–8 (2016).

Ben-Sasson, M. et al. In situ formation of silver nanoparticles on thin-film composite reverse osmosis membranes for biofouling mitigation. Water Res. 62 , 260–270 (2014).

Lu, X. et al. Enhanced antibacterial activity through the controlled alignment of graphene oxide nanosheets. Proc. Natl Acad. Sci. USA 114 , E9793–E9801 (2017).

Perreault, F., de Faria, A. F., Nejati, S. & Elimelech, M. Antimicrobial properties of graphene oxide nanosheets: Why size matters. ACS Nano 9 , 7226–7236 (2015).

Perreault, F. et al. Biofouling mitigation in forward osmosis using graphene oxide functionalized thin-film composite membranes. Environ. Sci. Technol. 50 , 5840–5848 (2016).

Faria, A. F. et al. Thin-film composite forward osmosis membranes functionalized with graphene oxide–silver nanocomposites for biofouling control. J. Memb. Sci. 525 , 146–156 (2017).

Park, H. B., Kamcev, J., Robeson, L. M., Elimelech, M. & Freeman, B. D. Maximizing the right stuff: The trade-off between membrane permeability and selectivity. Science 356 , eaab0530 (2017).

Werber, J. R., Deshmukh, A. & Elimelech, M. The critical need for increased selectivity, not increased water permeability, for desalination membranes. Environ. Sci. Technol. Lett. 3 , 112–120 (2016).

Brame, J., Long, M. C., Li, Q. L. & Alvarez, P. Trading oxidation power for efficiency: Differential inhibition of photo-generated hydroxyl radicals versus singlet oxygen. Water Res. 60 , 259–266 (2014).

Chong, M. N., Jin, B., Chow, C. W. K. & Saint, C. Recent developments in photocatalytic water treatment technology: A review. Water Res. 44 , 2997–3027 (2010).

Lee, H. & Choi, W. Photocatalytic oxidation of arsenite in TiO 2 suspension: Kinetics and mechanisms. Environ. Sci. Technol. 36 , 3872–3878 (2002).

Tan, T. T. Y., Beydoun, D. & Amal, R. Photocatalytic reduction of Se(VI) in aqueous solutions in UV/TiO 2 system: Importance of optimum ratio of reactants on TiO 2 surface. J. Mol. Catal. A Chem. 202 , 73–85 (2003).

Chenthamarakshan, C. R. & Rajeshwar, K. Heterogeneous photocatalytic reduction of Cr(VI) in UV-irradiated titania suspensions: Effect of protons, ammonium ions, and other interfacial aspects. Langmuir 16 , 2715–2721 (2000).

Doudrick, K., Monzon, O., Mangonon, A., Hristovski, K. & Westerhoff, P. Nitrate reduction in water wsing commercial titanium dioxide photocatalysts (P25, P90, and Hombikat UV100). J. Environ. Eng. 138 , 852–861 (2012).

Li, L. L. et al. Enhanced biofilm penetration for microbial control by polyvalent phages conjugated with magnetic colloidal nanoparticle clusters (CNCs). Environ. Sci. Nano 4 , 1817–1826 (2017).

Jabbari, V., Veleta, J. M., Zarei-Chaleshtori, M., Gardea-Torresdey, J. & Villagran, D. Green synthesis of magnetic MOF@GO and MOF@CNT hybrid nanocomposites with high adsorption capacity towards organic pollutants. Chem. Eng. J. 304 , 774–783 (2016).

Fu, Y., Wang, J. Y., Liu, Q. X. & Zeng, H. B. Water-dispersible magnetic nanoparticle-graphene oxide composites for selenium removal. Carbon 77 , 710–721 (2014).

Su, H., Ye, Z. B., Hmidi, N. & Subramanian, R. Carbon nanosphere-iron oxide nanocomposites as high-capacity adsorbents for arsenic removal. RSC Adv. 7 , 36138–36148 (2017).

Bagbi, Y., Sarswat, A., Mohan, D., Pandey, A. & Solanki, P. R. Lead and chromium adsorption from water using L-cysteine functionalized magnetite (Fe 3 O 4 ) nanoparticles. Sci. Rep. 7 , 7672 (2017).

Neumann, O. et al. Solar vapor generation enabled by nanoparticles. ACS Nano 7 , 42–49 (2013).

Hogan, N. J. et al. Nanoparticles heat through light localization. Nano Lett. 14 , 4640–4645 (2014).

Ghasemi, H. et al. Solar steam generation by heat localization. Nat. Commun. 5 , 4449 (2014).

Zhou, L. et al. 3D self-assembly of aluminium nanoparticles for plasmon-enhanced solar desalination. Nat. Photon. 10 , 393–398 (2016).

Kashyap, V. et al. A flexible anti-clogging graphite film for scalable solar desalination by heat localization. J. Mater. Chem. A 5 , 15227–15234 (2017).

Hua, M. et al. Heavy metal removal from water/wastewater by nanosized metal oxides: A review. J. Hazard. Mater. 211 , 317–331 (2012).

Torrent, J., Barron, V. & Schwertmann, U. Phosphate adsorption and desorption by goethites differing in crystal morphology. Soil Sci. Soc. Am. J. 54 , 1007–1012 (1990).

Waychunas, G. A., Kim, C. S. & Banfield, J. F. Nanoparticulate iron oxide minerals in soils and sediments: unique properties and contaminant scavenging mechanisms. J. Nanopart. Res. 7 , 409–433 (2005).

Lounsbury, A. W., Yamani, J. S., Johnston, C. P., Larese-Casanova, P. & Zimmerman, J. B. The role of counter ions in nano-hematite synthesis: Implications for surface area and selenium adsorption capacity. J. Hazard. Mater. 310 , 117–124 (2016).

Chen, X. B., Liu, L., Yu, P. Y. & Mao, S. S. Increasing solar absorption for photocatalysis with black hydrogenated titanium dioxide nanocrystals. Science 331 , 746–750 (2011).

Swearer, D. F. et al. Heterometallic antenna-reactor complexes for photocatalysis. Proc. Natl Acad. Sci. USA 113 , 8916–8920 (2016).

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Acknowledgements

This work was supported by the National Science Foundation Engineering Research Center on Nanotechnology-Enabled Water Treatment (EEC-1449500).

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Pedro J. J. Alvarez

Materials Science and Engineering, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA

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Menachem Elimelech

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Alvarez, P.J.J., Chan, C.K., Elimelech, M. et al. Emerging opportunities for nanotechnology to enhance water security. Nature Nanotech 13 , 634–641 (2018). https://doi.org/10.1038/s41565-018-0203-2

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DOI : https://doi.org/10.1038/s41565-018-0203-2

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Watershed moment: Atlantic First Nations Water Authority partners with Dalhousie to deliver world‑class water treatment

Andrew Riley - April 24, 2024

The Atlantic First Nations Water Authority (AFNWA) made history in 2018 by incorporating as the first Indigenous-owned and -led water utility in Canada. It was a significant step for First Nations in the region toward self-determination and control of the resource that is central to the health of their communities and protection of the environment.

Now, a new $4.3 million NSERC Alliance-Mitacs Accelerate Grant will support a partnership between the AFNWA and Dalhousie University to help the organization in its mission to deliver world-class drinking water and treatment guided by Indigenous knowledge and values. 

The new partnership will support the AFNWA in improving the quality and sustainability of community infrastructure, strengthening safety and risk management, and engaging community members to ensure they are informed and empowered.

Underpinning the priorities of the partnership is a plan to train a new generation of Indigenous and non-Indigenous engineers and other professionals to ensure the water authority’s long-term success. This will include 20 graduate and postdoctoral research trainees, 15 undergraduate interns, and 35 First Nations high school students in Mi'kmaq and Wolastoqey communities.

Chief Wilbert Marshall, chair of the AFNWA’s board of directors says, “Training students, with a focus on recruiting and training Indigenous students, will help build a strong foundation and set the AFNWA up for long-term success.” He adds that new opportunities for First Nations students for training and employment will also be beneficial to communities they serve.

Taking control

Since late 2022, 12 of the 34 First Nations communities in Atlantic Canada joined the AFNWA, with two more expected to join this year. In the process of establishing the authority, it quickly became apparent that the infrastructure the organization would assume responsibility for suffered from serious deficiencies – the result of decades of chronic underfunding, says James MacKinnon, the AFNWA’s director of engagement and government relations.

“Before the AFNWA, Indigenous peoples’ water and wastewater systems were operated and managed by the individual bands relying on Indigenous Services Canada for annual funding for maintenance and infrastructure upgrades. However, the funding fell far short of the resources needed,” says MacKinnon, who also notes that the short-term funding model made long-term planning extremely difficult.

By bringing First Nations together under the auspice of the AFNWA, it obtained dependable funding based on 10-year cycles that allowed them to consider strategic investments in infrastructure and staffing. With this support in place, the new organization’s board of directors, comprised of member Chiefs and technical experts from Indigenous organizations, approached long-time partner Dalhousie to help chart the path forward.

A natural choice

“The AFNWA recognized early on that they were going to be a leader in this space, but that partnering with an academic institution could provide strategic support and training of Indigenous and non-Indigenous engineers to help ameliorate gaps and address long-standing inequities,” says Dr. Megan Fuller, the director of research for the AFNWA at Dalhousie’s Centre for Water Resources Studies.

Dalhousie was the natural choice, she says, since it already had a long-established relationship with the First Nations focused on water safety. The connection was made through the work of Dr. Graham Gagnon, who leads Dal’s Centre for Water Resource Studies and who has been an advocate for the improvement of Indigenous water services in Nova Scotia for more than a decade.

Dr. Gagnon is the lead researcher on the partnership from the Dalhousie side. He is joined by Dr. Amina Stoddart, Dal’s Canada Research Chair in Wastewater Treatment Technology and Surveillance, who will play a key role in helping the AFNWA assess new infrastructure and process requirements. Dr. Chad Walker will join from Dalhousie’s School of Planning to support the AFNWA’s development of Indigenous-led governance and community engagement.

A pipeline of talent

In addition to building new education and training pathways for Indigenous students, the partnership will create a course at Dalhousie focused on integrating Indigenous Ways Knowing into traditional engineering curriculum. Guided by the AFNWA’s Elders Advisory Lodge – the First Nations Elders and knowledge holders who advise the AFNWA’s board – Dalhousie is creating a program that will empower students to see their work through an Indigenous lens. Known as Two-Eyed Seeing or Etuaptmumk, the course’s content will help students see their work from an Indigenous perspective and combine it with western knowledge to enhance their learning.

“This will be the first class of its kind and I want students to take away everything they can,” says Elder Methilda Knockwood-Snache, chair of the AFNWA’s Elders Advisory Lodge. “The concept of Two-Eyed Seeing – seeing western science and traditional Indigenous knowledge as equals – is much needed for youth to understand where they came from and have pride in who they are. This class will teach new perspectives and allow students to work together and be the change we want to see. This type of work is the work I live for.”

Once graduate students have the necessary background in Two-Eyed Seeing, Dr. Fuller says they will take leading roles in helping to answer high priority research questions the AFNWA wants to address. This includes contending with how best to improve outdated and inadequate drinking and wastewater treatment systems.

“There are 10 years of capital upgrades that are coming down the pike for these communities. So, Dal’s Centre for Water Resource Studies and the Indigenous and non-Indigenous trainees associated with this work are going to think about what good treatment looks like and what treatment processes should be employed, so that investments can be made to ensure drinking water is safe and clean for everyone,” says Dr. Fuller

Students will also support the AFNWA’s corrosion control program, a process that is commonly conducted in municipalities across Nova Scotia and New Brunswick to limit lead exposure through drinking water.

“It's not something that the federal government has prioritized in the past,” says Dr. Fuller. “So, we now can go through and deal with the lead problems that may be found to be occurring in these individual residences for the first time.”

‘LED-ing’ the way

Dr. Gagnon says that beyond best practice, Dalhousie’s partnership with the AFNWA will help the First Nations take a global lead in the treatment of wastewater. Currently much of the world’s wastewater is treated using UV lamps that rely on toxic mercury vapor to generate their light.

As part of the partnership, Dal researchers and students will conduct a pilot study with the AFNWA focused on the implementation of UV light emitting diodes (LEDs). The technology has the power to disinfect without the risk of mercury escaping into water systems, while also consuming significantly less energy.

“It's very exciting because the AFNWA is essentially going to be leading the water community in North America in this trial,” says Dr. Gagnon. “It's based on principles and values that they have in terms of sustainability. And it's very exciting for us to be a part of this study, guided by their strong vision and values, to make advances that matter.”

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A new coating method in mRNA engineering points the way to advanced therapies

Medicine can help to treat certain illnesses, e.g., antibiotics can help overcome infections, but a new, promising field of medicine involves providing our body with the "blueprint" for how to defeat illnesses on its own.

mRNA therapeutics is the delivery of messenger RNA (mRNA) molecules into the body, which the cellular machinery can use to make specific proteins. The field is rapidly advancing, especially because mRNA vaccines proved successful against COVID-19. However, the delivery of these engineered mRNAs to a specific organ has proved challenging.

Now, a team at Tokyo Medical and Dental University (TMDU) has shown that coating the engineered mRNAs with a molecule called polyethylene glycol, or PEG, allows their delivery selectively to the spleen.

To understand this achievement, let's first discuss how mRNA therapeutics has worked until now. Engineered mRNAs have been packaged into structures called "polyplexes" for delivery into the body. The polyplex structures allow mRNAs to remain stable while outside cells and to be released in a controlled manner once inside cells. Once inside, the mRNAs are used by cellular machinery to produce proteins that are naturally dysfunctional or absent.

Without modification, the polyplexes tend to accumulate in the lungs, as after injection into the blood they rapidly stick to each other and surrounding proteins and cells and become lodged in the lung's blood vessels. Treating polyplexes with PEG, a process called "PEGylation," prevents them from sticking together; however, applying PEG in a controlled, consistent manner to the polyplex surface is very difficult.

The team at TMDU has developed a new method of PEGylation, where the mRNAs are hybridized to PEG molecules before the polyplexes are formed. Using this method, almost all the PEG strands mixed into the reaction become bound to the polyplexes, allowing much greater control over the final amount of PEG on the polyplex surface.

Using a mouse model, the team found that the quantities and lengths of the PEG molecules significantly affected how well the mRNA therapy worked. A small number of short PEG molecules prevented accumulation of the engineered mRNAs in the lungs, facilitating effective delivery to the spleen. This approach has demonstrated utility in mRNA vaccines.

"Our novel method allows fine tuning of the amount of PEGylation of mRNA polyplexes," explains senior author Dr. Satoshi Uchida, "which in turn allows control of the physicochemical properties of the polyplexes, and thus their biological functionalities."

mRNA technology has wide-ranging potential for treating many diseases that have previously been considered incurable, as well as for the development of novel cancer treatments and vaccines. The development of this innovative technique paves the way for significant advances in the therapeutic use of mRNA polyplexes, with far-reaching potential consequences for human health.

• COVID and SARS
• Medical Topics
• Gene Therapy
• Biotechnology and Bioengineering
• Biotechnology
• Molecular Biology
• Nature of Water
• Organic Chemistry
• Biochemistry
• Biopharmaceutical
• Prostate cancer
• Stem cell treatments
• Monoclonal antibody therapy
• Chemotherapy
• Polyethylene

Story Source:

Materials provided by Tokyo Medical and Dental University . Note: Content may be edited for style and length.

Journal Reference :

• Miki Suzuki, Yuki Mochida, Mao Hori, Akimasa Hayashi, Kazuko Toh, Theofilus A. Tockary, Xueying Liu, Victor Marx, Hidetomo Yokoo, Kanjiro Miyata, Makoto Oba, Satoshi Uchida. Poly(ethylene Glycol) (PEG)–OligoRNA Hybridization to mRNA Enables Fine‐Tuned Polyplex PEGylation for Spleen‐Targeted mRNA Delivery . Small Science , 2024; DOI: 10.1002/smsc.202300258

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Strange & offbeat.

The fluoride fight: Data shows more US cities, towns remove fluoride from drinking water

Fluoride, the tooth health-boosting mineral that conjures images of dentists' offices for many, has been a standard additive to municipal water sources since the 1940s.

Naturally occurring in water, soil, plants, rocks and even the air, fluoride was discovered as a useful tool for preventing cavities and tooth decay by the late 1930s. In 1945, Grand Rapids, Michigan became the first city to fluoridate its community water, adjusting existing levels in the supply to the therapeutic 1.0 parts-per-million (ppm).

Since then, the levels have been adjusted to a maximum of 0.7 ppm or 0.7  milligrams  of fluoride per liter of water which is considered optimal for preventing tooth decay.

According to the U.S. Centers for Disease Control and Prevention (CDC), 72.7% of the U.S. population on a community water source received fluoridated water as of 2020. This percentage has remained relatively consistent since 2008, according to CDC data, fluctuating between 72.4% at the lowest and 74.6% at the highest.

Last week, KFF Health reported that as the fluoride bans proliferate, the issue has divided communities.

While the CDC maintains that fluoridated water is both safe and cost-effective, questions as to potential hazards introduced by water fluoridation have existed as long as the practice has been popular.

Fluoride divide: As bans spread, fluoride in drinking water divides communities across the US

Communities concerned about fluoride risks

The potential for fluoride toxicity does technically exist, for example, but would require consuming an amount of fluoridated water that would kill a human via water intoxication before the amount of fluoride could become harmful or deadly, according to the Cleveland Clinic.

Other arguments have included a theorized connection between fluoridated water and increased cancer risk, a topic studied extensively. According to the National Cancer Institute , the most recent population-based studies found no evidence of an association between fluoride in drinking water and an increased risk of bone cancer, though past results have been mixed.

Other topics have been explored as science has evolved, including the impact of fluoride consumption on pregnancy, arthritis, IQ, and kidney disease. Again, results have been mixed and scientists say more research needs to be done to come to any strong conclusions.

Is fluoridated water still needed in the modern age?

Some have begun to speculate about the need for fluoridated water with so many dental hygiene products now available in stores. Detractors argue that there is no need to add more of the compound on top of what naturally occurs in water and that distributing it via drinking water is an imprecise and uncontrolled way of dosing residents.

The CDC says, however, that while hygiene products can help reduce tooth decay, the greatest protection comes when they are used in tandem with fluoridated water. Still, groups across the U.S. have taken up the cause of getting fluoride removed or banned from community water, saying the consumption of the mineral should be an individual choice.

Currently, a federal case in the California courts could change the practice, forcing the Environmental Protection Agency (EPA) to regulate or ban the use of fluoride in drinking water nationwide.

U.S. communities implement bans on fluoridated water

The Flouride Action Network, an anti-fluoride group, has tracked the ongoing battle in U.S. communities. As of 2023, the network says, more than 240 communities in the world have rejected the use of fluoridated water since 2010, more than 170 of which are in the U.S.

Some of these communities, like Weston, Georgia, have as few as 80 affected residents. Others, however, like Portland, Oregon have roughly 900,000.

According to the Flouride Action Network data, the overall number of U.S. residents not receiving fluoridated water after a community rejection, rule or ban went into place has steadily increased since 2010, with large gains between 2010 and 2014, followed by a less dramatic but still upward trend.

4.2 million Americans lived in communities without fluoridated water last year

In January 2011, the U.S. Department of Health and Human Services (HHS) announced plans to reduce the recommended fluoride level in drinking water, saying the U.S. has seen increased incidences of dental fluorosis in children, a tooth condition that can occur when exposed to too much fluoride, prompting some existing detractors to double down on their beliefs about fluoridated water.

Several official agencies acknowledged the increased consumption of fluoride through other means beyond water at this time, citing this fact as another reason for reducing the levels in drinking water.

In 2015, federal recommendations were simplified to make 0.7 pm the standard level at which fluoride should be present in community water.

According to the Flouride Action Network data, more than 4.2 million Americans lived in a community without fluoridated water in 2023, up from just 219,900 in 2010.

Not all states agree on fluoride

Some areas of the U.S. have been more aggressive than others in riding its community waters of added fluoride. The Fluoride Action Network data reported 16 states without any bans or removals of fluoridated water on record.

The rest of the states saw varying levels of rejection, with some like Alaska, Arizona, Idaho, Kansas, Louisana, Maine, Maryland, Montana, New Mexico, North Carolina, Ohio, Oregon, South Carolina, Vermont, West Virginia and Wyoming only reporting one or two counties in which fluoride had been removed from water.

Other states, however, like Pennsylvania, California, Florida, Tenessee, Missouri, and Wisconsin had well over five counties reporting such bans or removals. Pennsylvania had the most with 17 counties containing 647,232 residents, followed by Tennessee with 15 counties and Missouri with 10.

Others, like Oregon, New Mexico and Kansas had higher overall populations affected by a lack of fluoride in drinking water despite few counties participating; Oregon, for example, had 914,120 people represented by only two counties.

The fluoride fight continues

As Americans wait out the conclusion of the California case, it appears fluoride will remain a community issue.

The decision to omit added fluoride from community water is often made at local government assemblies and via a vote among sometimes hyperlocal government lines, meaning one community may make a decision that the bordering one does not.

While official health agencies have reaffirmed the assertion that fluoride continues to be safe, effective and even necessary, the movement's growth indicates what was once considered a fringe opinion has become more mainstream.

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