Fermentation wastewater treatment in a membrane bioreactor

Performance of highly concentrated activated sludge in high strength fermentation wastewater treatment coupled with rotary disk type UF membrane is reported. The maximum MLSS and MLVSS concentrations obtained in this study were 15.2 g l(-1) and 13.0 g l(-1), respectively. The performances of TOC and NH4-N removals were quite well. Most of the soluble organic matters in fermentation wastewater were readily biodegradable. Nitrification increased quickly and varied between 60%-100%. However, denitrification was around 20% throughout the experiment. A series of batch culture tests showed that the maximum specific nitrification rates (SNR) slightly decreased, on the contrary, the maximum specific denitrification rates (SDNR) slightly increased. The actual SNR were between 0.5 and 1.0 mgN gMLVSS(-1) hr(-1) and the actual SDNR were lower than 0.5 mgN gMLVSS(-1) hr(-1) as this process was operated under continuous aeration condition. In addition, specific activities of sludge estimated by INT-dehydrogenase activity were almost maintained the same, however, the volumetric activities of sludge increased significantly with the increase of MLVSS concentration. As a result, it can be inferred that this process is suitable for the treatment of fermentation wastewater.