title: Silver nanoparticle-doped zirconia capillaries for enhanced bacterial filtration.
abstract: Membrane clogging and biofilm formation are the most serious problems during water filtration. Silver nanoparticle (Agnano) coatings on filtration membranes can prevent bacterial adhesion and the initiation of biofilm formation. In this study, Agnano are immobilized via direct reduction on porous zirconia capillary membranes to generate a nanocomposite material combining the advantages of ceramics being chemically, thermally and mechanically stable with nanosilver, an efficient broadband bactericide for water decontamination. The filtration of bacterial suspensions of the fecal contaminant Escherichia coli reveals highly efficient bacterial retention capacities of the capillaries of 8 log reduction values, fulfilling the requirements on safe drinking water according to the U.S. Environmental Protection Agency. Maximum bacterial loading capacities of the capillary membranes are determined to be 3×10(9)bacterialcells/750mm(2) capillary surface until back flushing is recommendable. The immobilized Agnano remain accessible and exhibit strong bactericidal properties by killing retained bacteria up to maximum bacterial loads of 6×10(8)bacterialcells/750mm(2) capillary surface and the regenerated membranes regain filtration efficiencies of 95-100%. Silver release is moderate as only 0.8% of the initial silver loading is leached during a three-day filtration experiment leading to average silver contaminant levels of 100μg/L.
authors.affiliation: Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Wehling
authors.affiliation: Department Sustainable Chemistry, Center for Environmental Research and Sustainable Technology, University of Bremen, Leobener Str. UFT, 28359 Bremen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Köser
authors.affiliation: Institute for Technical Chemistry, Leibniz University of Hanover, Callinstr. 5, 30167 Hanover, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Lindner
authors.affiliation: Institute for Technical Chemistry, Leibniz University of Hanover, Callinstr. 5, 30167 Hanover, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lüder
authors.affiliation: Institute for Technical Chemistry, Leibniz University of Hanover, Callinstr. 5, 30167 Hanover, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Beutel
authors.affiliation: Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany. Electronic address: stephen.kroll@uni-bremen.de.
authors.forename: Stephen
authors.initials: S
authors.lastname: Kroll
authors.affiliation: Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
authors.forename: Kurosch
authors.initials: K
authors.lastname: Rezwan
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D002516:Ceramics; D004867:Equipment Design; D004926:Escherichia coli / Q000187:drug effects; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D008567:Membranes, Artificial; D012834:Silver; D015040:Zirconium; C028541:zirconium oxide
keywords: Bactericide membrane surface; Ceramic capillary membrane; Immobilized silver nanoparticles; Macroporous; Silver leaching