MBR반응조내의 수리학적 거동이 막여과에 미치는 영향

초록

The purpose of this study is to investigate the effects of hydraulic behavior on membrane fouling and filtration in an aerobic membrane bioreactor (MBR). Aeration as hydraulic behavior parameter is required in an aerobic MBRs for providing dissolved oxygen (DO) to microbes, making the sludge flocs in a suspended state and mitigating membrane fouling. Membrane stirring-cell (effective volume of 500 mL) was used as an aerobic MBR which was filled with real mixed liquor suspended solid (MLSS, <7000 mg/L) taken from real activated sludge tank. When applying stirring rate (<600 rpm) for MBR, a high stirring rate and low MLSS concentration have achieved a relative low TMP build-up. Permeate flux of membrane decreased with the increase of MLSS concentration, whereas it increased with the increase of stirring rate. This indicates that a high hydraulic shear force on the surface of membrane due to rapid stirring rate results in the mitigation of membrane fouling due to detachment of particulate and dissolved organic matter generated from sludge. The above results indicate that a suitable hydraulic shear force and MLSS level in an aerobic MBR should be considered to be cost-effective operation of an aerobic MBR due to the mitigation of membrane fouling.

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