3 YEARS OF FULL-SCALE CAPTOR(R) PROCESS OPERATION AT MOUNDSVILLE WWTP

Three years of full-scale operation of the Captor(R) process had been completed at the Moundsville/Glen Dale Wastewater Treatment Plant (WWT P) treating a design flow of 8706 m(3)/d (2.3 mgd). The Captor(R) proc ess applied a combination of attached and suspended growth processes b y adding polyurethane foam media to activated sludge process, raising the equivalent MLSS concentration. The Captor(R) system was designed a s a separate front portion of the activated sludge process, with one t hird of the total HRT of the activated sludge process. The suspended M LSS in the Captor basin was around 900-1700 mg/L and the equivalent me dia based attached MLSS was maintained at 6,500-12,000 mg/L. It has be en found that soluble CBOD5 removal, nitrification and partial denitri fication occurred simultaneously in the Captor basin. The influent loa dings to the Captor chamber were at 100-130 mg/L of soluble BOD5, 20-3 0 mg/L NH3-N, and 50-70 mg/L of TSS at flow rates of 5678-10031 m(3)/d (1.5-2.65 mgd). Over the last three years, 95% soluble CBOD5 removal, 70-90% nitrification and 40-60% denitrification were achieved at an H RT of 50-90 minutes in the Captor chamber. The plant effluent characte ristics consistently met 2-4 mg/L of CBOD5, 1-4 mg/L of TSS, and 2-4 m g/L of Ammonia at low temperatures of 12 degrees C-15 degrees C. The H RTs were 2.5-5 hours for secondary aeration with a sludge age of 3-5 d ays for the activated sludge portion.