摘要:The characteristics of the sauce industrial wastewater is high organic degradable materials, it requires adequate treatment in order to process wastewater is technically and economically feasible. The main treatment to remove high content of organic material is anaerobic process. The presence of a preservative agent in wastewater would lead to disruption of the growth of micro-organisms. Slow the growth of anaerobic bacteria require a solids residence time (solid retention time, SRT) period in anaerobic reactors. This research is to observe the effect of input COD with constant sludge height to the removal of COD. Main equipment process of anaerobic reactor is baffled reactor. Activated sludge used are obtained from the tofu and tempe wastewater treatment unit in Semarang while synthetic wastewater was obtained from dissolution of preservative material product (Del monte sauce). The control parameter was: pH, alkalinity, the ratio of COD: N: P, baffled configuration, wastewater flow rate (20 L/day), addition of micro-nutrient and height of suldge. The variable of reseach was initial COD input. The observed response is: COD removal and pH. The total COD removal for low organic loading (2369.7 mg COD/L) is 80.36 to 98.03 % and for high organic loading (7334 mg COD/L) is 98.15.