Analysis of reduction of COD (Chemical Oxygen Demand) levels in tofu waste using activated sludge method

This study aims to reduce COD (Chemical Oxygen Demand) levels in tofu waste using activated sludge. The method used to conduct this experiment is to use the fermentation method by grouping the tofu dregs samples into three groups. Then the tofu dregs sample was added with 1:3 activated sludge and incubated for two days, four days, and six days. The results showed that samples with an incubation period of 2 days had effectiveness in reducing COD levels in tofu waste as much as52.3%; during the incubation period of 4 days can reduce COD levels by 75.5%, and during the incubation period for six days have 79.8% effectiveness in reducing COD levels. A significant increase in the decrease in COD levels on the sixth day indicates that the microbes in activated sludge can multiply optimally to decompose waste and reduce COD levels optimally. In addition, the incubation time on the sixth day of the nutrients required by microbes increased, thereby increasing microbial activity. So it can be concluded that the incubation process of tofu dregs with activated sludge for six days is effective in reducing COD levels and can overcome environmental pollution problems.