AWWA WQTC50364

As drinking water facilities strive to improve the quality of their product, an increasing amount of attention is being focussed on filter performance. Instrumentation of relatively high sophistication, viz. particle counters, are commonly being employed in an attempt to quantify, and thereby help in further improving filter effluent quality. Particle counters typically used in the drinking water industry, are however, limited to examining particles greater than 2 microns in size. While this is a reasonable size range when used as a surrogate detection method for cryptosporidium and giardia, it is not necessarily the most appropriate size range for best quantifying filter operation. We describe a laser nephelometer designed to be sensitive to sub-micron particles and compare data produced by it to particle counts on several filter cycles, examining features such as ripening, steady state operation, and breakthrough. Includes 2 references, figures.