Effect of Sludge Retention Time on Membrane Bio‐Fouling Intensity in a Submerged Membrane Bioreactor
Effect of Sludge Retention Time on Membrane Bio‐Fouling Intensity in a Submerged Membrane Bioreactor
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DOI：
10.1080/01496390600683647
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发表时间：
2006-06
影响因子：
2.8
通讯作者：
Jinsong Zhang;Chua Hwee Chuan;Ji-ti Zhou;A. Fane
中科院分区：
文献类型：
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作者：
Jinsong Zhang;Chua Hwee Chuan;Ji-ti Zhou;A. Fane
浸没式膜生物反应器（sMBR）在城市和工业废水处理中得到越来越多的应用。污泥滞留时间（SRT）是MBR的一个重要运行参数，它影响污泥的生物学特性，从而影响膜污染。在配备KUBOTA平板膜的30 L浸没式MBR中，进行了短SRT（10天）和中等SRT（30天）的井控运行。在稳定运行时，混合液悬浮物（MLSS）在SRT 10和30天分别稳定在约5-6 g/L和8.5-10 g/L。DGGE谱显示，随着SRT的延长，优势菌群发生了变化。srt 10d和30d时，可溶性微生物生成物（SMP）分别为9.3 mg/L和5.4 mg/L。在相同的有机负载速率下，两种srt下从絮凝体和上清液中提取的细胞外聚合物（EPS）总量基本不变。然而，SRT 10天的上清液中多糖浓度比SRT 30天的上清液中多糖浓度高约100%。生物量的黏度随SRT的延长而增加，而两种SRT的平均空气诱导水速度估计相似。通量阶跃试验结果表明，各通量阶跃下，SRT 10天的膜污染率（dTMP/dt）均高于30天。同样，在恒定通量为20 L/m2·h的长期实验运行中，SRT 10天的膜污染明显比30天更严重。这表明污染受SMP和多糖浓度的影响比MLSS更大。
Abstract The submerged membrane bioreactor (sMBR) is being increasingly applied for municipal and industrial wastewater treatment. This paper examines the role of sludge retention time (SRT), an important operating parameter of the MBR as it affects the biological characteristics of the sludge and therefore influences membrane fouling. Well controlled runs were carried out at short SRT (10days) and moderate SRT (30days) in a 30 L submerged MBR equipped with KUBOTA flat‐sheet membranes. At steady operation, the mixed liquor suspended solids (MLSS) stabilized at approximately 5–6 g/L and 8.5–10 g/L for SRT 10 and 30days respectively. The DGGE profiles suggested a shift in the dominant bacterial community with the prolonged SRT. The soluble microbial products (SMP) were 9.3 mg/L and 5.4 mg/L at the SRTs of 10days and 30days respectively. The total amount of extracellular polymeric substance (EPS) extracted from the floc and the supernatant was approximately constant at the two SRTs under the same organic loading rate. However, the polysaccharide concentration in the supernatant was about 100% higher for the SRT of 10days than that for 30days. The viscosity of the biomass increased with the prolonged SRT, while the estimated average air induced water velocity was similar for the two SRTs. The results of flux stepping tests showed that the membrane fouling rate (dTMP/dt) at SRT 10days was always higher than that at 30days at each flux step. Similarly, long term experimental runs at a constant flux of 20 L/m2·h clearly showed more severe membrane fouling for the SRT of 10days than that at 30days. This implies that fouling is more influenced by the concentration of SMP and Polysaccharides than the MLSS.