Silver‐embedded granular activated carbon as an antibacterial medium for water purification

Abstract

Silver (Ag) particle embedded granular activated carbon (GAC) was made for the first time to assess its ability in inhibiting the growth of Escherichia coli (E. coli), a water-borne bacterial pathogen. Ag-GAC was made by impregnating GAC with AgNO 3 and then reducing it to metallic Ag. Plate assay showed slight inhibition of E. coli, even with Ag-GAC prepared from 0.005 mol L −1 AgNO 3 , but this and shake flask tests showed a conspicuous effect only for higher concentrations of 0.1-1 mol L −1 AgNO 3 . Flow tests further indicated that Ag-GAC made from 1.0 mol L −1 AgNO 3 caused a desirable three orders of reduction in E. coli number concentration in less than 30 s. An optimum of 9-10.5 wt% of embedded Ag in the final Ag-GAC product was necessary for the requisite complete inhibition of E. coli, killing bacteria in the contact-mode for up to 350 L of flowing water. These results prove that Ag-GAC possesses antibacterial properties and can be used for disinfection to produce potable quality water.

Inorganic engineered nanoparticles in drinking water treatment: a critical review

“…279,280,281 The high specific surface area provided by nanoparticles and the fact they can penetrate deeper and thus can purify water from pathogens such as bacteria, fungi and viruses, 282 triggered the development of nanoscale research in this direction. 207,279,284,285,286,287,288,289,290,291,292,293,294,295,296 In this section, we review the proposed mechanisms for the excellent antimicrobial activity of Ag nanoparticles and recent advances made toward the development of various Ag nanoparticle-based products for drinking water purification. For example, Ag nanoparticles have been extensively used in biomedical products for wound dressing, treatment of burns and bacterial infections, diagnostics and surgery.…”

“…207,279,280,284,285,286,287,288,289,290,291,292,293,294,296,297,303 Among all, ceramic materials have been widely used as support material for low-cost point-of-use water purification as they are relatively cheap and easy to prepare. In order to develop such products, Ag nanoparticles have been incorporated into robust and porous supports, including paper, ceramics, biopolymers, calcium carbonate and carbon.…”

Nanoparticles in the Water Cycle

“…Hence, the antibacterial effects of Ag nanoparticles have been investigated in several studies Yoon et al, 2008). A reduction of three orders of magnitude was observed for the number of E. coli investigated with silver-embedded granular activated carbon whereas no inhibition of microbial growth occurred when GAC was used alone (Bandyopadhyaya et al, 2008). In addition to silver, antibacterial activities of nanoparticles have also been found for Cu, ZnO, CeO 2 or CNTs Yoon et al, 2008;.…”

Zinc-sulphate-heptahydrate coated activated carbon for microbe removal from stormwater

“…doi: 10.2166/wst.2012.342 One way of improving WSUD designs is to introduce a microcide or coating to the filtration material. There are several different filtration materials that are commonly used, with granular activated carbon (GAC) frequently employed due to its porous nature, high adsorption rate and large surface area (Pal et al 2006;Bandyopadhyaya et al 2008). Most of the microcides which are currently being tested are metal-based coatings such as copper acetylacetonate, zinc-sulphate-heptahydrate, silver nitrate, aluminium hydroxychloride and ferric chloride.…”