Removal of organic pollutants from tofu-processing wastewater through anaerobic treatment process with short hydraulic retention time

Abstract

Anaerobic digestion of tofu-processing wastewater was carried out in batch and continuous systems. The performance of a continuous system was investigated at the hydraulic retention time of 10 days and the organic loading rate of 0.752 kg/m3 day. Anaerobic digestion operated in the continuous system generated higher bi-ogas yield (123 mL/g VS) compared with the batch system (43 mL/g VS). The assessment of biodegradation efficiency showed that a continuous reactor had higher VS reduction (76%) in comparison with the batch reactor, which only had 57% VS reduction. The results of the current study also revealed that anaerobic digestion applied for treating the tofu-processing wastewater could recover pH culture from the acidic condition (pH 5) into the level close to the neutral condition (pH 6.6). The current study is highly significant for the development of applied technology for protecting environment.