抄録
Synthetic wastewater was treated in a bench scale Submerged Membrane Activated Sludge Process (SMASP) unit at different operating conditions (SRT and BOD loading) to study the behavior of change in suction pressure and filtration resistance. It was observed that the influence of SRT and BOD loading on stabilized MLSS was significantly high. At long SRT (500 d) and low BOD loading (≤0.5 kg/m3·d), the organic metabolism was good and the supernatant TOC was low in the bioreactor throughout the operation. Accumulation of unconverted organic matters and metabolites increased the suction pressure rapidly and the operation was unstabilized. At long SRT (500d) and low BOD loading (≤0.5 kg/m3·d), low and steady suction pressure and filtration resistance were observed for long time. At short SRT (≤90d), both clogging and cake resistance were almost equally responsible to develop high filtration resistance. On the other hand, high MLSS concentration (>20000 mg/L) produced high cake resistance at long SRT (500 d) and high BOD loading (0.6 kg/m3·d). Cake resistance was increased with an increase of mass of adhered sludge on the membrane surface. At long SRT (500d) and low BOD loading (≤0.5 kg/m3·d), the adhered sludge quantity was less and the cake resistance was minimized.
