Treatment of tofu liquid waste using anaerobic-aerobic biofilm aeration system to reduce pollution

Background: Tofu derived from processed soybeans is popular among the public, but its production has an unfavourable effect. After all, it produces liquid waste that causes quite high pollution because it contains quite high organic components. The present study aimed to reduce the content of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and ammonia (NH3) in the liquid waste of a tofu factory. The scope of this research is limited to reducing the content of BOD, COD, and NH3 using an anaerobic-aerobic biofilm aeration system. Methods: This is an experimental study with a pre-post test only design and one group post-test design. The study population in this study is the tofu industry, and the sample in this study is partly water from the tofu waste. Sample examination was carried out at the Regional Health Laboratory of Jambi province, Indonesia. Results: The results showed a decrease in BOD, COD, and NH3 after passing through a tofu waste treatment machine using anaerobic and aerobic biofilms with BOD, COD, and ammonia values of 64.6%, 49.6%, and 79.8%, respectively. Tofu waste treatment using anaerobic and aerobic biofilms can lower the temperature and increase the pH of the waste. Conclusion: On the surface of the bioball used, the growth of the biofilm was found, and to increase the ability of the equipment, an initial treatment, such as filtration and sedimentation of waste, and reducing acidity with the help of quicklime was needed.