Bactericidal activity of Ag nanoparticle-impregnated fibreglass for water disinfection

Abstract

A new bactericidal system composed of fibreglass impregnated with silver (Ag) nanoparticles was developed and tested. Silver content, particle size and distribution were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The antibacterial effectiveness was evaluated against Escherichia coli (E. coli, ATCC 29055). The minimum inhibitory loading was determined to be less than 1.8 wt% of silver nanoparticles per gram of fibreglass. In a 1 h immersion test, using a 0.1 mg fibreglass mat ml 21 , with 2.9 wt% loading of silver nanoparticles completely disinfected 100 ml of 10 6 CFU ml 21 of E. coli, dramatically outperforming activated carbon fibres impregnated with silver. Inactivation rate studies of 0.05 mg fibreglass mat ml 21 (Ag 1.8 wt%) with 10 12 CFU E. coli displayed a 7 log reduction in 5 minutes. The activation and reuse of fibreglass (Ag 4.3 wt%) maintained its full effectiveness after two cycles of use and thermal regeneration at 3508C.

Removal of Escherichia coli and Faecal Coliforms from Surface Water and Groundwater by Household Water Treatment Devices/Systems: A Sustainable Solution for Improving Water Quality in Rural Communities of the Southern African Development Community Region

“…It is also possible that the removal efficiency could have been enhanced by the AgNO 3 that was embedded in the clay during the manufacturing process. The longer disinfection capacity of the SIPP could be attributed to the presence of the silver ion since independent studies have corroborated the effect of Ag in a water purification application, irrespective of substrate [47,48,49,50]. Silver has bacteriostatic properties and inactivates bacteria by disrupting the disulphide bonds of proteins in the cell membrane or by inhibiting DNA replication [23,44,51].…”

Removal of waterborne bacteria from surface water and groundwater by cost-effective household water treatment systems (HWTS): A sustainable solution for improving water quality in rural communities of Africa

“…It is also possible that the silver nano-particles, which are embedded within the clay during manufacturing, contribute to high pathogen-removal efficiency (Michen et al, 2011). Previous studies have reported the effect of Ag in a water-purification application, irrespective of substrate and have revealed that Ag ions have antiviral and bacteriostatic properties (Nangmenyi et al, 2009;Michen et al, 2012). A study by Momba and co-authors (2010b) revealed that only the Ag-impregnated pot was significantly more effective in removing E. coli, compared to the control pot that had not been impregnated with AgNO 3 .…”

Antibacterial Effect of Colloidal Solutions of Silver Nanoparticles on Microorganisms of Cereal Crops

“…The potential of AgNP for drinking-water disinfection is currently being extensively explored, principally in conjunction with filtration. The medium or matrix utilised for the nanoparticles varies widely and includes coating on polyurethane foams (Jain and Pradeep, 2005), fibreglass (Nangmenyi et al, 2009), copolymer beads (Gangadharan et al, 2010), polystyrene resin beads , alginate composite beads (Lin et al, 2013), ceramic (Lv et al, 2009), titiania (Liu et al, 2012), activated carbon composite incorporating magnetite (Valušová et al, 2012) and bacterial carriers (De Gusseme et al, 2010, 2011. As the focus here is on the efficacy of silver in water disinfection, only studies where this can be distinguished from, say, the filtration effect have been considered below.…”