Effects of water quality parameters on the release of silver nanoparticles from a ceramic surface using a quartz crystal microbalance.
Michael Stewart, Angela R. Bielefeldt, Elisabeth Mansfield, R S. Summers, Joseph N. Ryan
Ceramic water filters are used in many developing countries as a household water treatment technology, often produced locally using regionally-available materials, and constructed in various forms (i.e., as discs, candles, or pots) that all rely on similar mechanisms of filtration and disinfection. A common production technique involves application of an anti-microbial, colloidal silver coating to the porous ceramic filter. The silver coating has shown improvements in microbial log reduction values over uncoated ceramic filters both in the laboratory and in the field. However, a more complete understanding of the silver coating requires knowledge of specific characteristics of the colloidal silver solution, including particle size, composition, and charge, and to understand how these characteristics affect silver particle deposition, anti-microbial activity, and potential optimization of the silver coating. Additionally, as water passes through the ceramic filter, the silver coating will release from the ceramic surface, decreasing the disinfection effectiveness of the filter by reducing the presence of silver. In this investigation, a colloidal silver solution was prepared according to procedures recommended for ceramic pot filter production. The colloidal silver solution was then characterized for particle size distribution, trace contaminants, and zeta potential. Silver nanoparticles were adsorbed onto representative ceramic surfaces and assessed with a quartz crystal microbalance, which monitored silver release from the surface. Experiments were conducted to determine the effects of several water quality parameters, including pH, turbidity, ionic strength, and natural organic matter, on the release of silver nanoparticles from representative ceramic surfaces. The most significant release was caused by waters containing sodium hypochlorite, suggesting that cleaning of silver-containing ceramic filters should be performed with caution.
WQTC 2010 - Water Quality Technology Conference proceedings
, Bielefeldt, A.
, Mansfield, E.
, Summers, R.
and Ryan, J.
Effects of water quality parameters on the release of silver nanoparticles from a ceramic surface using a quartz crystal microbalance., WQTC 2010 - Water Quality Technology Conference proceedings, Savannah, GA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=906596
(Accessed December 8, 2023)