7/1/2001 - 6/30/2003
- Paul McGinley, UW-Stevens Point
New regulations and a greater understanding of the health effects of arsenic exposure will lead many water suppliers to consider reducing arsenic concentrations in their drinking water. Concurrent iron and arsenic removal may provide an opportunity for many small water systems to simultaneously address a significant aesthetic water quality problem and provide risk reduction from arsenic exposure. Unfortunately, current information on arsenic removal does not provide a clear discussion of the limitations and advantages of concurrent arsenic and iron removal particularly for small groundwater systems using conventional, low-residence time, oxidation/filtration systems. This research examined combined iron and arsenic removal, and in particular, arsenic removal during the oxidation and precipitation of iron followed by pressure filtration in short residence time systems. This project had two primary objectives. The first was to evaluate the likely utility of iron removal as a means to reduce arsenic concentrations in Wisconsin public water supplies. The second was to provide a detailed laboratory and field demonstration of iron and arsenic removal that was directed towards identification of kinetic and speciation concerns for oxidation/direct filtration processes.