Tofu Acidic Wastewater Treatment by Anaerobic Fixed Bed Reactor Using Bamboo as Biofilm Carrier

摘要

Wastewater from tofu processing, primarily generated during acid coagulation process has high organic concentration and low pH. Since many industries discharge the wastewater without any treatment, hence will cause environmental problem in Indonesia. In this study, single stage continuous anaerobic degradation of tofu processing wastewater by using fixed bed reactor (FBR) compared with Upflow anaerobic sludge blanket (UASB) was examined by 230 days continuous operation. Cut bamboos as biofilm carrier were packed randomly in FBR. Continuous feeding was gradually increased from OLR of 3.3 to 5.0 kg COD/m~3 .day and then decreased to 4.3 kg COD/m~3 .day. FBR showed better performance at COD load 4.3 kg COD/m~3 .day, the highest TOC removal efficiency 95% and methane gas yield 0.56 L/g TOC-removed was achieved. The UASB reactor achieved better performance for 98 days and then the treatment function was stopped due to the decreased in pH. Microbial community were analyzed. Hydrogenotrophic methanogens belonging to family Methanobacteriaceae were the most dominant archaea, while the family Cloacamonaceae and Porphyromonadaceae were the most common bacteria, suggesting that hydrogenotrophic methanogenesis with the syntrophic oxidation of volatile fatty acids (VFAs) was a major route of methane formation for tofu processing wastewater treatment.