슬러지순환비가 MBR시스템의 처리성능에 미치는 영향

초록

Membrane bioreactor (MBR) technology has gained prominence due to its advantages, including superior effluent quality, precise control over solids and hydraulic retention times, and reduced volume and footprint. MBRs have been operated with long solids retention times to maintain high biomass concentrations, reduce solids production, and minimize reactor volume. A pilot-scale plant experiment was conducted using an anoxic selector and aerobic MBR (ANO-MBR) system with a hydraulic retention time of 6 hours to enhance the existing anaerobic-anoxic-oxic activated sludge processes. This study aimed to evaluate the system’s performance in treating domestic wastewater with the following characteristics: pH 6.9±0.5, BOD 145.2±31.5 mg/L, COD 93.4±21.4 mg/L, SS 132.6±43.1 mg/L, and T-N 34.363±10.063 mg/L. The MBR was submerged with two plate-type membrane modules with an adequate pore size of 0.4 ﾵm. Consequently, the substrate remaining ratio decreased as the returned sludge ratio from the MBR to the anoxic reactor increased. Notably, the substrate remaining ratio at returned sludge ratios of <1.5Q was 3-13% lower than that at >2.0Q. An increased returned sludge ratio for the MBR ledto higher permeate flux and lower transmembrane pressure (TMP). Specifically, TMP was 30% higher at returned sludge ratios of <1.5Q compared to >2.0Q. This reduction in TMP was attributed to decreased particulate matter and viscosity in the mixed liqueur of the MBR, resulting from a reduction in mixed liqueur suspended solids.

키워드