The effectiveness of cod reduction in tofu waste using active mud and oxygenation methods

Abstract

Tofu waste is a byproduct of tofu processing that cannot be just thrown away as it can pollute the waters. In this study, a laboratory-scale test was carried out on tofu waste produced from tofu factories in the Cirebon area. In this tofu waste treatment, activated sludge was used where the waste water was put into an anaerobic reactor with various incubation times. The reduction of COD (Chemical Oxygen Demand) for tofu wastewater treatment was carried out using the K2Cr2O7 oxidizer and anaerobic reactor with an insulated reactor. Afterwards, the anaerobic effluent was collected into the aerobic reactor using broken bricks. Experiment variations were carried out in anaerobic reactors, namely: sludge variation (1/2 and 1/3) and residence time variations, namely: 2 days, 4 days and 6 days. Measurements were taken at 3 points, namely: influent, anaerobic effluent and aerobic effluent. Based on the research, the highest decrease in anaerobic efficiency was 68.8% in the condition of ½ sludge volume and 2 days residence time. As for the aerobic efficiency, it was 48.9% in the conditions of 1/3 sludge volume and 6 days residence time. Meanwhile, the highest decrease in COD levels was 79.4% in the swab condition as much as 1/3 in the 6-day incubation time.