AWWA WQTC50455

Treatment at four full-scale washwater reclamation plants (WWRPs) ranging in size from 11 to 43 million gallons per day (MGD) was optimized based on the results from previous bench- and pilot-scale evaluations. Turbidity, particle count, and aerobic spore measurements were used to evaluate the teatment at these plants under current and optimized coagulant conditions. Cryptosporidium levels in the WWRP influents and effluents were monitored, and the impact of the recycle streams upon the drinking water treatment plant was evaluated. The degree of improvement under optimized treatment conditions was plant-dependent. WWRP effluent total particle counts dropped by 16-73 percent (595-4,300 particles/mL) and turbidity decreased by 15-69 percent (0.21-1.78 ntu) under optimized coagulant conditions. Little difference was observed in aerobic spore measurements under optimized treatment conditions because of their low concentrations in the WWRP effluents throughout the study. Cryptosporidium oocysts were not detected in the WWRP influents or effluents with either of the two analytical methods employed - the Information Collection Rule and Method 1622. The impact of the recycle stream on treatment plant influent water quality varied at each location, depending on source water quality; however, little impact was observed overall. Includes 13 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

01/01/1999

File Size:

1 file , 470 KB