AWWA WQTC62495

This slide presentation outlines chlorine dioxide characteristics and its applications in water treatment. The methods for pilot and full-scale studies are outlined and include: Water supply consisting of a shallow reservoir with moderate total organic carbon (TOC), warm temperatures and the raw water chlorophyll-a generally is 20 ¿¿¿¿¿¿¿¿ 30 µg/L; preliminary batch experiments consisted of nine runs using 1-gal containers with samples collected over a 2 hour period; and, plug-flow experiments consisting of six runs using pilot facility, detention time was 2 hours with results similar to batch phase. Results showed that ClO₂ consistently reduced living algae concentrations, as measured by chlorophyll-a, in raw water by 100 percent (13 of 15 trials). In addition to algae removal, CT credit was also obtained (TOC-dependent). It was determined that ClO₂ can be used effectively for both pre-oxidation and primary disinfection without exceeding chlorite MCL. Includes tables, figures.