Silver Dissolution and Release from Ceramic Water Filters

Abstract

Application of silver nanoparticles (nAg) or silver nitrate (AgNO3) has been shown to improve the microbiological efficacy of ceramic water filters used for household water treatment. Silver release, however, can lead to undesirable health effects and reduced filter effectiveness over time. The objectives of this study were to evaluate the contribution of nanoparticle detachment, dissolution, and cation exchange to silver elution, and to estimate silver retention under different influent water chemistries. Dissolved silver (Ag(+)) and nAg release from filter disks painted with 0.03 mg/g casein-coated nAg or AgNO3 were measured as a function of pH (5-9), ionic strength (1-50 mM), and cation species (Na(+), Ca(2+), Mg(2+)). Silver elution was controlled by dissolution as Ag(+) and subsequent cation exchange reactions regardless of the applied silver form. Effluent silver levels fell below the drinking water standard (0.1 mg/L) after flushing with 30-42 pore volumes of pH 7, 10 mM NaNO3 at pH 7. When the influent water was at pH 5, contained divalent cations or 50 mM NaNO3, silver concentrations were 5-10 times above the standard. Our findings support regular filter replacement and indicate that saline, hard, or acidic waters should be avoided to minimize effluent silver concentrations and preserve silver treatment integrity.

Antibacterial and catalytic activities of biosynthesized silver nanoparticles prepared by using an aqueous extract of green coffee bean as a reducing agent

“…12,13 Thus, there is an increased interest in using biodegradable and biocompatible reducing agents to prepare AgNPs. Over the last decade, polysaccharide-based biopolymers such as alginate, starch, and chitosan [14][15][16] have been used as green alternatives [17][18][19][20] to conventional agents due to their low-cost, nontoxicity, and environment-friendly properties. In most cases, the chemical dispersants used for controlling the growth of metallic nanoparticles were replaced by these biopolymers due to their low-toxicity to animal cells.…”

Application de l'impression 3D à l'élaboration de filtres en céramique pouvant servir au traitement de l'eau au point d'utilisation

“…Dans un premier temps, l'objectif était de définir les volumes d'eau (solvant) à utiliser afin de pouvoir effectuer l'extrusion de la pâte de façon efficace. les différentes granulométries de coques de riz ont été définis en se basant sur les travaux de différents auteurs dans la littérature (Bielefeldt et al, 2010;Kallman et al, 2011;Ren and Smith 2013;Mittelman et al, 2015).…”

Human Intestinal Tissue Explant Exposure to Silver Nanoparticles Reveals Sex Dependent Alterations in Inflammatory Responses and Epithelial Cell Permeability

“…AgNPs can have considerable activity against bacteria, fungi, and even some viruses [1][2][3][4][5][6] making them attractive to companies interested in manufacturing products with food safety or sanitary bene ts. A variety of consumer products now contain AgNPs, including food contact materials [7][8][9], clothing and personal care products [10,11] dietary supplements [12], and water lters [13,14]. Additionally, many studies have shown that simulated use of AgNPs-containing consumer products can result in AgNPs release from these products into the environment [7,8,10,11,15].…”