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Nanotechnology-Enabled Point-of-Use (POU) Filters for Drinking Water Disinfection

  • Lok R. PokhrelEmail author
  • Rebecca L. Dean
  • Zachary L. Jacobs
  • William B. Burrows
Chapter

Abstract

Nanotechnology-incorporated low-cost materials for household point-of-use (POU) water treatment systems may confer better protection to public health due to potential removal of microbial pathogens (bacteria and viruses) from drinking water supplies and could serve as a sustainable complementary option to the conventional communal water treatment methods that are in use today.

Notes

Acknowledgments

We would like to thank Byron Pash for the assistance with literature review on NACF. This work is funded by East Carolina University (grant # 111101 to LRP).

References

  1. 1.
    Achakulwisut P, Mickley LJ, Anenberg SC (2018) Drought-sensitivity of fine dust in the US Southwest: implications for air quality and public health under future climate change. Environ Res Lett 13(5).  https://doi.org/10.1088/1748-9326/aabf20
  2. 2.
    Adie DB, Igboro SB, Daouda N (2013) Determination of the filter potential of Luffa sponge (Luffa aegyptiaca) in water quality analysis. Am Int J Contemp Med 3(3):117–123Google Scholar
  3. 3.
    Ahmed F, Lalia BS, Kochkodan V, Hilal N, Hashaikeh R (2016) Electrically conductive polymeric membranes for fouling prevention and detection: a review. Desalination 391:1–15.  https://doi.org/10.1016/j.desal.2016.01.030CrossRefGoogle Scholar
  4. 4.
    Alexander JW (2009) History of the medicinal use of silver. Surg Infect 10(3):289–292.  https://doi.org/10.1089/sur.2008.9941CrossRefGoogle Scholar
  5. 5.
    Amin MT, Alazba AA, Manzoor U (2014) A review of removal of pollutants from water/wastewater using different types of nanomaterials. Adv Mater Sci Eng 2014:24.  https://doi.org/10.1155/2014/825910CrossRefGoogle Scholar
  6. 6.
    Ammonium persulfate A3678 (2018) Millipore Sigma. Retrieved from: https://www.sigmaaldrich.com/catalog/product/sigma/a3678?lang=en®ion=US
  7. 7.
    Arakha M, Pal S, Samantarrai D, Panigrahi TK, Mallick BC et al (2015) Antimicrobial activity of iron oxide nanoparticle upon modulation of nanoparticle-bacteria interface. Nat Sci Rep 5:14813, 1–12.  https://doi.org/10.1038/srep14813CrossRefGoogle Scholar
  8. 8.
    Bhatnagar A, Hogland W, Marques M, Sillanpää M (2013) An overview of the modification methods of activated carbon for its water treatment applications. Chem Eng J 219:499–511.  https://doi.org/10.1016/j.cej.2012.12.038CrossRefGoogle Scholar
  9. 9.
    Bielefeldt AR, Kowalski K, Summers SR (2009) Bacterial treatment effectiveness of point-of-use ceramic water filters. Water Res 43:3559–3565.  https://doi.org/10.1016/j.watres.2009.04.047CrossRefGoogle Scholar
  10. 10.
    Bishoge OK, Zhang L, Suntu SL, Jin H, Zewde AA, Qi Z (2018) Remediation of water and wastewater by using engineered nanomaterials: a review. J Environ Sci Health A 53(6):537–554.  https://doi.org/10.1080/10934529.2018.1424991CrossRefGoogle Scholar
  11. 11.
    Bottone EJ, Perez AA II, Oeser JL (1994) Loofah sponges as reservoirs and vehicles in the transmission of potentially pathogenic bacterial species to human skin. J Clin Microbiol 32(2):469–472Google Scholar
  12. 12.
    Bruins MR, Kapil S, Oegme FW (2000) Microbial resistance to metals in the environment. Epidemiol Environ Saf 45(3):196–207Google Scholar
  13. 13.
    Carnegie Mellon University (CMU) (2016) Super-absorbing polymer powder. Leonard Gelfand Center. Retrieved from: https://www.cmu.edu/gelfand/education/k12-teachers/polymers/polymer-and-absorption/super-absorb-powder.html
  14. 14.
    CDC (2016) Global water, sanitation, and hygiene (WASH). Retrieved from: http://www.cdc.gov/healthywater/global/wash_statistics.html
  15. 15.
    CDC (2016) Disinfection by-products. Retrieved from: https://www.cdc.gov/safewater/chlorination-byproducts.html
  16. 16.
    Chaturvedi A, Bajpai AK, Bajpai J (2014) Preparation and characterization of poly(vinyl alcohol) cryogel-silver nanocomposites and evaluation of blood compatibility, cytotoxicity, and antimicrobial behaviors. Soc Plast Eng 1–15. https://onlinelibrary.wiley.com/doi/epdf/10.1002/pc.23108  https://doi.org/10.1002/pc.2310
  17. 17.
    Dankovich TA (2014) Microwave-assisted incorporation of silver nanoparticles in paper for point-of-use water purification. Environ Sci Nano 1:367–378.  https://doi.org/10.1039/c4en00067fCrossRefGoogle Scholar
  18. 18.
    Davis J (2014) Commercial sponge gourd production. NC State Cooperative Extension Resources. Retrieved from: http://content.ces.ncsu.edu/commercial-luffa-sponge-gourd-production/
  19. 19.
    Doungmanee P (2016) The nexus of agricultural water use and economic development level. Kasetsart J Soc Sci 37(1):38–45.  https://doi.org/10.1016/j.kjss.2016.01.008CrossRefGoogle Scholar
  20. 20.
    C2ES (2018) Drought and climate change. Retrieved from https://www.c2es.org/content/drought-and-climate-change/
  21. 21.
    Duan W, Chen G, Chen C, Sanghvi R, Iddya A et al (2017) Electrochemical removal of hexavalent chromium using electrically conducting carbon nanotube/polymer composite ultrafiltration membranes. J Membr Sci 531:160–171CrossRefGoogle Scholar
  22. 22.
    Dudchenko AV, Rolf J, Russell K, Duan W, Jassby D (2014) Organic fouling inhibition on electrically conducting carbon nanotube− polyvinyl alcohol composite ultrafiltration membranes. J Membr Sci 468:1–10CrossRefGoogle Scholar
  23. 23.
    Ehdaie B, Krause C, Smith JA (2014) Porous ceramic tablet embedded with silver Nanopatches for low-cost point-of-use water purification. Environ Sci Technol 48:13901–13908.  https://doi.org/10.1021/es503534cCrossRefGoogle Scholar
  24. 24.
  25. 25.
    EPA (2017) National Primary Drinking Water Regulations (PDWRs). United States Environmental Protection Agency. Retrieved from: https://www.epa.gov/dwregdev/drinking-water-regulations-and-contaminants#Secondary
  26. 26.
    Eshed L, Yaron S, Dosoretz CG (2008) Effect of permeate drag force on the development of a biofouling layer in pressure-driven membrane separation system. Appl Environ Microbiol 74:7338–7347.  https://doi.org/10.1128/AEM.00631-08CrossRefGoogle Scholar
  27. 27.
    Fewtrell L (2014) Silver: water disinfection and toxicity. Centre for Research into Environment and Health. Retrieved from: http://www.who.int/water_sanitation_health/dwq/chemicals/Silver_water_disinfection_toxicity_2014V2.pdf
  28. 28.
    Fiume MZ (2002) Final report on the safety assessment of acrylate copolymers and 33 related cosmetic ingredients. Int J Toxicol 21:1–50Google Scholar
  29. 29.
    Gehrke I, Geiser A, Somborn-Schulz A (2015) Innovations in nanotechnology for water treatment. Nanotechnol Sci Appl.  https://doi.org/10.2147/NSA.S43773
  30. 30.
    Han J, Fu J, Schoch RB (2008) Molecular sieving using nanofilters: past, present and future. Lab Chip 8(1):23–33.  https://doi.org/10.1039//b714128aCrossRefGoogle Scholar
  31. 31.
    He Y, Ingudam S, Reed S, Gehring A, Strobaugh TP, Irwin P (2016) Study on the mechanism of antibacterial action of magnesium oxide nanoparticles against foodborne pathogens. J Nanobiotechnol 14(5):1–9Google Scholar
  32. 32.
    Hulsheger H, Potel J, Niemann E-G (1981) Killing of bacteria with electric pulses of high field strength. Radiat Environ Biophys 20:53–65CrossRefGoogle Scholar
  33. 33.
    International Water Management Institute (2017) Regions. CGIAR Research Center. Retrieved from: http://www.iwmi.cgiar.org/regions/
  34. 34.
    Jain P, Pradeep T (2005) Potential of silver nanoparticle-coated polyurethane foam as an antimicrobial water filter. Biotechnol Bioeng 90(1):59–63.  https://doi.org/10.1002/bit.20368CrossRefGoogle Scholar
  35. 35.
    Kallman EN, Oyanedel-Craver VA, Smith JA (2011) Ceramic filters impregnated with silver nanoparticles for point-of-use water treatment in rural Guatemala. J Environ Eng 137:407–415.  https://doi.org/10.1061/(ASCE)EE.1943-7870.0000330CrossRefGoogle Scholar
  36. 36.
    Kang X, Kuga S, Wang C, Zhao Y, Wu M, Huang Y (2018) Green preparation of cellulose nanocrystal and its application. ACS Sustain Chem Eng 6(3):2954–2960.  https://doi.org/10.1021/acssuschemeng.7b02363CrossRefGoogle Scholar
  37. 37.
    Khan ST, Malik A (2019) Engineered nanomaterials for water decontamination and purification: from lab to products. J Hazard Mater 363:295–308.  https://doi.org/10.1016/j.jhazmat.2018.09.091CrossRefGoogle Scholar
  38. 38.
    Kim JS, Kuk E, Yu KN, Kim J, Park SJ, Lee HJ et al (2007) Antimicrobial effects of silver nanoparticles. Nanomedicine 3:95–101.  https://doi.org/10.1016/j.nano.2006.12.001CrossRefGoogle Scholar
  39. 39.
    Kiruba VSA, Selvakumar PM, Dakshinamurthy A (2015) Biocidal nano-silver reinforced activated charcoal in water treatment. Synth Reactivity Inorg Met-Org Nano-Metal Chem 45(10):1570–1575.  https://doi.org/10.1080/15533174.2013.865221CrossRefGoogle Scholar
  40. 40.
    Kobayashi N, Izumi H, Morimoto Y (2017) Review of toxicity studies of carbon nanotubes. J Occup Health 59(5):394–407CrossRefGoogle Scholar
  41. 41.
    Kumar A, Mishra R, Reinwald Y, Bhat S (2010) Cryogels: freezing unveiled by thawing. Mater Today 13(11):42–44.  https://doi.org/10.1016/S1369-7021(10)70202-9CrossRefGoogle Scholar
  42. 42.
    Li H, Chen Q, Zhao J, Urmila K (2015) Enhancing the antimicrobial activity of natural extraction using the synthetic ultrasmall metal nanoparticles. Nat Sci Rep 5:1103, 1–13.  https://doi.org/10.1038/srep11033CrossRefGoogle Scholar
  43. 43.
    Linley E, Denyer SP, McDonnell G, Simons C, Maillard J-Y (2012) Use of hydrogen peroxide as a biocide: new consideration of its mechanism of biocidal action. J Antimicrob Chemother 67:1589–1596.  https://doi.org/10.1093/jac/dks129CrossRefGoogle Scholar
  44. 44.
    Liu Y, He L, Mustapha A, Li H, Hu ZQ, Lin M (2009) Antibacterial activities of zinc oxide nanoparticles against E. coli 0157:H7. J Appl Microbiol 107:1193–1201.  https://doi.org/10.1111/j.1365-2672.2009.04303.xCrossRefGoogle Scholar
  45. 45.
    Loo S, Fane AG, Lim T, Krantz WB, Liang Y, Liu X, Hu X (2013) Superabsorbent cryogels decorated with silver nanoparticles as a novel water technology for point-of-use disinfection. Environ Sci Technol 47:9363–9371.  https://doi.org/10.1021/es401219sCrossRefGoogle Scholar
  46. 46.
    Loo S, Krantz WB, Fane AG, Hu X, Lim T (2015) Effect of synthesis routes on the properties and bactericidal activity of cryogels incorporated with silver nanoparticles. RSC Adv 5:44626CrossRefGoogle Scholar
  47. 47.
    Lozinsky VI, Galaev IY, Plieva FM, Savina IN, Jungvid H, Mattiasson B (2003) Polymeric cryogels as promising materials in biotechnological interest. Trends Biotechnol 21(10):445–451.  https://doi.org/10.1016/j.tibtech.2003.08.002CrossRefGoogle Scholar
  48. 48.
    Mac Mahon J, Gill LW (2018) Sustainability of novel water treatment technologies in developing countries: lessons learned from research trials on a pilot continuous flow solar water disinfection system in rural Kenya. Dev Eng 3:47–59.  https://doi.org/10.1016/j.deveng.2018.01.003CrossRefGoogle Scholar
  49. 49.
    Madaeni S, Molaeipour S (2010) Investigation of filtration capability of conductive composite membrane in separation of protein from water. Ionics 16:75–80CrossRefGoogle Scholar
  50. 50.
    Manttari M, Pihlajamaki A, Nystrom M (2006) Effect of pH on hydrophilicity and charge and their effect on the filtration efficiency of NF membranes at different pH. J Membr Sci 280:311–320CrossRefGoogle Scholar
  51. 51.
    McGuire MJ, Blute NK, Qin G, Kavounas P, Froelich D, Fong L (2007) Hexavalent chromium removal using anion exchange and reduction with coagulation and filtration. Water Res. Found. Proj. #3167, p 140Google Scholar
  52. 52.
    Meng Y, Lai Y, Jiang X, Zhao Q (2013) Silver nanoparticles decorated filter paper via self-sacrificing reduction for membrane extraction surface-enhanced Raman spectroscopy detection. Analyst 133:2090–2095.  https://doi.org/10.1039/c3an36485bCrossRefGoogle Scholar
  53. 53.
    Metreveli G, Wågberg L, Emmoth E, Belák S, Strømme M, Mihranyan A (2014) A size-exclusion nanocellulose filter paper for virus removal. Adv Healthc Mater 3(10):1546–1550.  https://doi.org/10.1002/adhm.201300641CrossRefGoogle Scholar
  54. 54.
    Mohmood I, Lopes CB, Lopes I, Ahmad I, Duarte AC, Pereira E (2013) Nanoscale materials and their use in water contaminants removal – a review. Environ Sci Pollut Res 20(3):1239–1260.  https://doi.org/10.1007/s11356-012-1415-xCrossRefGoogle Scholar
  55. 55.
    Mollahosseini A, Rahimpour A, Jahamshahi M, Peyravi M, Khavarpour M (2012) The effect of silver nanoparticle size on performance and antibacteriality of polysulfone ultrafiltration membrane. Desalination 306:41–50CrossRefGoogle Scholar
  56. 56.
    Morones JR, Elechiguerra JL, Camacho A, Holt K, Kouri JB, Ramirez JT, Yacaman MJ (2005) The bactericidal effect of silver nanoparticles. Nanotechnology 16(10):2346–2353.  https://doi.org/10.1088/0957-4484/16/10/059CrossRefGoogle Scholar
  57. 57.
    Mostafavi ST, Mehrnia MR, Rashidi AM (2009) Preparation of nanofilter from carbon nanotubes for application in virus removal from water. Desalination 238:271–280.  https://doi.org/10.1016/j.desal.2008.02.018CrossRefGoogle Scholar
  58. 58.
    Munshi AD, Behera TK, Sureja AK, Kumar R (2011) Occurrence and preliminary characterization of gynoecious ridge gourd [Luffa acutangula (L.) Roxb.] in a natural population. Cucurbit Genet Coop Rep 33:57–59. Retrieved from: http://cuke.hort.ncsu.edu/cgc/cgc3334/cgc3334-18.pdfGoogle Scholar
  59. 59.
    NASA (2018) Global climate change. https://climate.nasa.gov/effects/
  60. 60.
    Nata IF, Wu TM, Chen JK, Lee CK (2014) A chitin nanofibril reinforced multifunctional monolith poly(vinyl alcohol) cryogel. R Soc Chem 2:4108–4113.  https://doi.org/10.1039/c4tb00175cCrossRefGoogle Scholar
  61. 61.
    National Academy of Sciences (2002) Small wonders, endless frontiers: a review of the national nanotechnology initiative. National Academy Press. Retrieved from: https://www.nap.edu/read/10395/chapter/1
  62. 62.
    Nover DM, McKenzie ER, Joshi G, Fleenor WE (2013) Assessment of colloidal silver impregnated ceramic bricks for small-scale drinking water treatment applications. Int J Serv Learn Eng 8(1):18–35. ISSN 1555-9033Google Scholar
  63. 63.
    Oboh I, Aluyor E, Audu T (2009) Post-treatment of produced water before discharge using Luffa cylindrica. Leonardo Electron J Pract Technol 14:57–64Google Scholar
  64. 64.
    Odian G (2004) Introduction. In: Principles of polymerization, 4th edn. Wiley, Hoboken, pp 1–37Google Scholar
  65. 65.
    Oyetayo FL, Oyetayo VO, Ajewole V (2007) Phytochemical profile and antibacterial properties of the seed and leaf of the Luffa plant (Luffa cylindrica). J Pharmacol Toxicol 2:586–589.  https://doi.org/10.3923/jpt.2007.586.589CrossRefGoogle Scholar
  66. 66.
    Partap S, Kumar A, Sharma NK, Jha KK (2012) Luffa cylindrica: an important medicinal plant. J Nat Prod Plant Resour 2(1):127–134. ISSN: 2231-3184Google Scholar
  67. 67.
    Phong NTP, Thanh NVK, Phuong PH (2009) Fabrication of antibacterial water filter by coating silver nanoparticles on polyurethane foams. J Phys Conf Ser 187:1–8.  https://doi.org/10.1088/1742-6596/187/1/012079CrossRefGoogle Scholar
  68. 68.
    Poland CA, Duffin R, Kinloch I, Maynard A, Wallace WA et al (2008) Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenicity in a pilot study. Nat Nanotechnol 3(7):423–428.  https://doi.org/10.1038/nnano.2008.111CrossRefGoogle Scholar
  69. 69.
    Polyurethanes (2017) University of York: the essential chemistry industry online. Retrieved from: http://www.essentialchemicalindustry.org/polymers/polyurethane.html
  70. 70.
    Pooi CK, Ng HY (2018) Review of low-cost point-of-use water treatment systems for developing communities. Nat Partn J Clean Water 1(1):1–8.  https://doi.org/10.1038/s41545-018-0011-0CrossRefGoogle Scholar
  71. 71.
    Project on Emerging Nanotechnologies (PEN) (2018). http://www.nanotechproject.org/cpi/
  72. 72.
    Prüss-Ustün A, Bos R, Gore F, Bartram J (2008) Safer water, better health. World Health Organization, Geneva. https://apps.who.int/iris/bitstream/handle/10665/43840/9789241596435_eng.pdf
  73. 73.
    Raffi M, Hussain F, Bhatti TM, Akhter JI, Hameed A, Hasan MM (2008) Antibacterial characterization of silver nanoparticles against E. coli ATCC-15224. J Mater Sci Technol 24(2):192–196Google Scholar
  74. 74.
    Rahaman MS, Vecitis CD, Elimelech M (2011) Electrochemical carbon-nanotube filter performance removal and inactivation in the presence of natural organic matter. Environ Sci Technol 46:1556–1564CrossRefGoogle Scholar
  75. 75.
    Ren D, Smith JA (2013) Retention and transport of silver nanoparticles in a ceramic porous medium used for point-of-use water treatment. Environ Sci Technol 47:3825–3832.  https://doi.org/10.1021/es4000752CrossRefGoogle Scholar
  76. 76.
    Ren D, Colosi LM, Smith JA (2013) Evaluating the sustainability of ceramic filters for point-of-use drinking water treatment. Environ Sci Technol 47:11206–11213.  https://doi.org/10.1021/es4026084CrossRefGoogle Scholar
  77. 77.
    Rodriguez-Narvaez OM, Peralta-Hernandez JM, Goonetilleke A, Bandala ER (2017) Treatment technologies for emerging contaminants in water: a review. Chem Eng J 323:361–380CrossRefGoogle Scholar
  78. 78.
    Russell JR, Huang J, Anand P, Kucera K, Sandoval AG, Dantzler KW et al (2011) Biodegradation of polyester polyurethane by endophytic fungi. Appl Environ Microbiol 77(17):6076–6084.  https://doi.org/10.1128/AEM.00521-11CrossRefGoogle Scholar
  79. 79.
    Ronen Y, Duan W, Wheeldon I, Walker S, Jassby D (2015) Microbial attachment inhibition through low-voltage electrochemical reactions on electrically conducting membranes. Environ Sci Technol 49:12741–12750CrossRefGoogle Scholar
  80. 80.
    Shaheed A, Templeton MR, Matthews RL, Triparhi SR, Bhattarai K (2009) Disinfection of waterborne coliform bacteria using Luffa cylindrica fruit and seed extracts. Environ Technol 30(13):1435–1440.  https://doi.org/10.1080/09593330903193485CrossRefGoogle Scholar
  81. 81.
    Shi G, Rouabhia M, Wang Z, Dao L, Zhang Z (2004) A novel electrically conductive and biodegradable composite made of polypyrrole nanoparticles and polylactide. Biotmaterials 25:2477–2488.  https://doi.org/10.1016/j.biomaterials.2003.09.032CrossRefGoogle Scholar
  82. 82.
    Simonis JJ, Basson AK (2012) Manufacturing a low-cost ceramic water filter and filter system for the elimination of common pathogenic bacteria. Phys Chem Earth 50(52):269–276CrossRefGoogle Scholar
  83. 83.
    Siqueira G, Bras J, Dufresne A (2010) Luffa as a cellulose source. Bioresources 5(2):727–740Google Scholar
  84. 84.
    Sodium acrylate 408220 (2018) Millipore Sigma. Retrieved from https://www.sigmaaldrich.com/catalog/product/aldrich/408220?lang=en®ion=US
  85. 85.
    Tabish TA, Pranjol JI, Hayat H, Rahat AAM, Abdullah TM, Whatmore JL, Zhang S (2017) In vitro toxic effects of reduced graphene oxide nanosheets on lung cancer cells. Nanotechnology 28(50):504001.  https://doi.org/10.1088/1361-6528/aa95a8CrossRefGoogle Scholar
  86. 86.
    UNESCO (2013) Facts and figures. UN Water World Day 2013. Retrieved from: http://www.unwater.org/water-cooperation-2013/water-cooperation/facts-and-figures/en/
  87. 87.
    UNICEF (2015) Progress on sanitation and drinking water: 2015 update and MDG assessment. (WHO). Retrieved from https://data.unicef.org/wp-content/uploads/2015/12/Progress-on-Sanitation-and-Drinking-Water_234.pdf
  88. 88.
    United Nations (n.d.) Water and climate change. Retrieved from http://www.unwater.org/water-facts/climate-change/
  89. 89.
    Ungur G, Hrůza J (2017) Modified polyurethane nanofibers as antibacterial filters for air and water purification. RSC Adv 7(78):49177–49187.  https://doi.org/10.1039/C7RA06317BCrossRefGoogle Scholar
  90. 90.
    Van der Bruggen B, Mänttäri M, Nyström M (2008) Drawbacks of applying nanofiltration and how to avoid them: a review. Sep Purif Technol 63:251–263.  https://doi.org/10.1016/j.seppur.2008.05.010CrossRefGoogle Scholar
  91. 91.
    Vecitis CD, Schnoor MH, Rahaman MS, Schiffman JD, Elimelech M (2011) Electrochemical multiwalled carbon nanotube filter for viral and bacterial removal and inactivation. Environ Sci Technol 45(8):3672–3679CrossRefGoogle Scholar
  92. 92.
    Voisin H, Bergström L, Liu P, Mathew AP (2017) Nanocellulose-based materials for water purification. Nanomaterials (Basel, Switzerland) 7(3):57.  https://doi.org/10.3390/nano7030057CrossRefGoogle Scholar
  93. 93.
    Wallace G, Spinks G (2007) Conducting polymers – bridging the bionic interface. Soft Matter 3:665–671.  https://doi.org/10.1039/b618204fCrossRefGoogle Scholar
  94. 94.
    Wandera D, Wickramasinghe SR, Husson SM (2010) Stimuli-responsive membranes. J Membr Sci 357:6–35CrossRefGoogle Scholar
  95. 95.
    Water Quality Association (2013) Silver. Water Quality Association. Retrieved from: https://www.wqa.org/Portals/0/Technical/Technical%20Fact%20Sheets/2015_Silver.pdf
  96. 96.
    WHO (2002) The world health report 2002 – reducing risks, promoting healthy life. Retrieved from: http://www.who.int/whr/2002/en/whr02_en.pdf?ua=1
  97. 97.
    WHO (2014) Silver in drinking water. Available at: https://www.who.int/water_sanitation_health/dwq/chemicals/silver.pdf
  98. 98.
    Zhang Q, Beirne S, Shu K, Esrafilzadeh D, Huang X-F, Wallace GG (2018) Electrical stimulation with a conductive polymer promotes neurite outgrowth and synaptogenesis in primary cortical neurons in 3D. Sci Rep 8:9855.  https://doi.org/10.1038/s41598-018-27784-5CrossRefGoogle Scholar
  99. 99.
    Zhao L, Deng J, Sun P, Liu J, Ji Y, Nakada N et al (2018) Nanomaterials for treating emerging contaminants in water by adsorption and photocatalysis: systematic review and bibliometric analysis. Sci Total Environ 627:1253–1263CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Lok R. Pokhrel
    • 1
    • 2
    Email author
  • Rebecca L. Dean
    • 1
  • Zachary L. Jacobs
    • 3
  • William B. Burrows
    • 1
  1. 1.Department of Public Health, The Brody School of MedicineEast Carolina UniversityGreenvilleUSA
  2. 2.Department of Health Education and Promotion, Environmental Health Program, College of Health and Human PerformanceEast Carolina UniversityGreenvilleUSA
  3. 3.School of LawUniversity of California-BerkeleyBerkeleyUSA

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