Nanoparticles (NPs) are manufactured in a wide range of industries and their application for consumer products is increasing.  Questions have been raised whether they can be removed by traditional water treatment procedure once they are released into surface or groundwater. This study aims at: (1) investigating the potential retention and transport of NPs in sand filters at water treatment facilities (WTF); (2) exploring the role of dispersant and capping agents, which are commonly added during the manufacturing of NPs, (3) understanding the influence of biofilm in a biological filtration media, which covers the surface of the sand surface in the filtration system. Three types of commonly used NPs, CeO2, TiO2 and Ag were studied with bare surface and in the presence of surfactant.  Filter sand and water from prefiltration stage of WTF were obtained. The water was collected prior to the sand filter and was characterized in terms of pH, total organic carbon, conductivity, turbidity, phosphate, sulfate and nitrate. The stability of different NPs was investigated by studying the particle size distribution with time and the EMP/Zeta potential in water. NPs Breakthrough was obtained from column studies with three different sand surfaces to investigate role of sand surface and biofilm. All the experiments were conducted using NPs with and without surfactant and the stabilization mechanism of surfactant was discussed. The data was used to build a predictive computational fluid dynamic model that has practical significance to evaluate the interaction of NPs and the traditional sand filtration system in WTFs.

Transport and the retention of nanoparticles in sand filters in municipal water treatment facilities: The role of surface active agents and filter sand biofilm

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.