TREATMENT OF CLAM PROCESSING WASTEWATERS BY MEANS OF UPFLOW ANAEROBICSLUDGE BLANKET TECHNOLOGY

The ability of upflow anaerobic sludge blanket (UASB) technology to tr eat wastewaters from a mechanical shucking, clam processing facility w as evaluated. Both batch and continuous flow studies were performed at approx. 32 degrees C to evaluate the effects of varying organic loadi ng rate (OLR), hydraulic residence time (HRT), NaCl level, and nutrien t additions. Among the parameters measured were biochemical oxygen dem and (BOD,), chemical oxygen demand (GOD), total suspended solids (TSS) , various nutrients and gas production. The UASB system proved to be e ffective, accomplishing soluble BOD,, soluble GOD, and TSS removals of 87, 83 and 83%, respectively, under the best conditions considered (a verage OLR = 13.8 g COD/1/d and average HRT = 3 h). The average conver sion of wastewater organics to methane was in the area of 80 parts per thousand. Sodium levels at and about 5250 mg/l significantly impacted on the performance of the UASB.