title: Polysulfone ultrafiltration membranes impregnated with silver nanoparticles show improved biofouling resistance and virus removal.
abstract: Biofouling and virus penetration are two significant obstacles in water treatment membrane filtration. Biofouling reduces membrane permeability, increases energy costs, and decreases the lifetime of membranes. In order to effectively remove viruses, nanofiltration or reverse osmosis (both high energy filtration schemes) must be used. Thus, there is an urgent demand for low pressure membranes with anti-biofouling and antiviral properties. The antibacterial properties of silver are well known, and silver nanoparticles (nAg) are now incorporated into a wide variety of consumer products for microbial control. In this study, nAg incorporated into polysulfone ultrafiltration membranes (nAg-PSf) exhibited antimicrobial properties towards a variety of bacteria, including Escherichia coli K12 and Pseudomonas mendocina KR1, and the MS2 bacteriophage. Nanosilver incorporation also increased membrane hydrophilicity, reducing the potential for other types of membrane fouling. XPS analysis indicated a significant loss of silver from the membrane surface after a relatively short filtration period (0.4 L/cm2) even though ICP analysis of digested membrane material showed that 90% of the added silver remained in the membrane. This silver loss resulted in a significant loss of antibacterial and antiviral activity. Thus, successful fabrication of nAg-impregnated membranes needs to allow for the release of sufficient silver ions for microbial control while preventing a rapid depletion of silver.
authors.affiliation: Department of Civil and Environmental Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Zodrow
authors.forename: Léna
authors.initials: L
authors.lastname: Brunet
authors.forename: Shaily
authors.initials: S
authors.lastname: Mahendra
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Anna
authors.initials: A
authors.lastname: Zhang
authors.forename: Qilin
authors.initials: Q
authors.lastname: Li
authors.forename: Pedro J J
authors.initials: PJ
authors.lastname: Alvarez
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000998:Antiviral Agents / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D052918:Environmental Restoration and Remediation / Q000379:methods*; D004926:Escherichia coli / Q000187:drug effects; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry*; D044203:Pseudomonas mendocina / Q000187:drug effects / Q000502:physiology; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology; D013057:Spectrum Analysis; D013450:Sulfones / Q000737:chemistry*; D013535:Suspensions; D014462:Ultrafiltration; D014780:Viruses / Q000187:drug effects / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D000998:Antiviral Agents; D008567:Membranes, Artificial; D011108:Polymers; D013450:Sulfones; D013535:Suspensions; C017662:polysulfone P 1700; D012834:Silver