American Water Works Assn.

Characterization of particles in filter effluents.

This report provides an in-depth analysis of inorganic and organic constituents in influent and effluent streams to granular media filters at a variety of water treatment plants across the US and Canada. The report evaluates the effect of factors such as pretreatment schemes, filter designs and operation, and raw water sources on the composition of particles in the filter influent and effluent. In addition to characterizing the material composition, the particles are also characterized according to their size distribution across four defined size classes, from settleable down to dissolved materials and particles in the nanometer size range. Particular attention is focused on the smallest particles sizes, as they represent materials that are invisible to particle sizing and counting instruments commonly employed at water treatment utilities. The report highlights the potential benefits of particle monitoring of filtrate using particle counters, and will aid water suppliers in assessing more stringent standards on turbidity. Brandt is affiliated with the Department of Civil and Environmental Engineering at Rice University. The report lacks a subject index. (Annotation ©2008 Book News Inc. Portland, OR)