title: Silver-modified clinoptilolite for the removal of Escherichia coli and heavy metals from aqueous solutions.
abstract: This paper investigates the potential of using the silver antibacterial properties combined with the metal ion exchange characteristics of silver-modified clinoptilolite to produce a treatment system capable of removing both contaminants from aqueous streams. The results have shown that silver-modified clinoptilolite is capable of completely eliminating Escherichia coli after 30-min contact time demonstrating its effectiveness as a disinfectant. Systems containing both E. coli and metals exhibited 100 % E. coli reduction after 15-min contact time and maximum metal adsorption removal efficiencies of 97, 98, and 99 % for Pb(2+), Cd(2+), and Zn(2+) respectively after 60 min; 0.182-0.266 mg/g of metal ions were adsorbed by the zeolites in the single- and mixed-metal-containing solutions. Nonmodified clinoptilolite showed no antibacterial properties. This study demonstrated that silver-modified clinoptilolite exhibited high disinfection and heavy metal removal efficiencies and consequently could provide an effective combined treatment system for the removal of E. coli and metals from contaminated water streams.
authors.affiliation: Department of Civil and Environmental Engineering, University of Surrey, Guildford, Surrey, UK, l.akhigbe@surrey.ac.uk.
authors.forename: Lulu
authors.initials: L
authors.lastname: Akhigbe
authors.forename: Sabeha
authors.initials: S
authors.lastname: Ouki
authors.forename: Devendra
authors.initials: D
authors.lastname: Saroj
authors.forename: Xiang Min
authors.initials: XM
authors.lastname: Lim
mesh_terms: D000327:Adsorption; D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D019216:Metals, Heavy / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning; D012834:Silver / Q000737:chemistry*; D014873:Water Pollutants / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction; D017641:Zeolites / Q000737:chemistry*
chemical_list: D019216:Metals, Heavy; D014873:Water Pollutants; C083175:clinoptilolite; D017641:Zeolites; D012834:Silver
references.citation: Appl Environ Microbiol. 2008 Apr;74(7):2171-8
references.pmid: 18245232
references.citation: J Colloid Interface Sci. 2006 Dec 1;304(1):21-8
references.pmid: 16989853
references.citation: J Hazard Mater. 2012 Jan 30;201-202:260-4
references.pmid: 22178285
references.citation: Bioresour Technol. 2012 Aug;117:86-91
references.pmid: 22609718
references.citation: J Biomed Mater Res. 2000 Dec 15;52(4):662-8
references.pmid: 11033548
references.citation: J Environ Manage. 2008 Sep;88(4):853-63
references.pmid: 17573181
references.citation: J Hazard Mater. 2008 Jun 30;155(1-2):385-92
references.pmid: 18262351
references.citation: Adv Colloid Interface Sci. 2011 Feb 17;162(1-2):39-58
references.pmid: 21272842
references.citation: J Hazard Mater. 2007 Jul 19;146(1-2):362-71
references.pmid: 17261347
references.citation: J Colloid Interface Sci. 2004 Dec 15;280(2):309-14
references.pmid: 15533402
references.citation: Int J Nanomedicine. 2011;6:581-90
references.pmid: 21674015
references.citation: Int J Nanomedicine. 2011;6:331-41
references.pmid: 21383858
references.citation: Appl Microbiol Biotechnol. 1999 Jun;51(6):730-50
references.pmid: 10422221
references.citation: Nat Rev Microbiol. 2013 Jun;11(6):371-84
references.pmid: 23669886
references.citation: Appl Environ Microbiol. 2003 Jul;69(7):4278-81
references.pmid: 12839814
references.citation: Trends Biochem Sci. 1998 Apr;23(4):143-8
references.pmid: 9584618
references.citation: J Appl Microbiol. 2008 May;104(5):1516-24
references.pmid: 18179543
references.citation: Rev Environ Contam Toxicol. 2007;191:23-45
references.pmid: 17708071
references.citation: Environ Sci Pollut Res Int. 2012 Jul;19(6):2285-90
references.pmid: 22252384
references.citation: Water Res. 2002 Jun;36(11):2784-92
references.pmid: 12146866