Correlation of EPS content in activated sludge at different sludge retention times with membrane fouling phenomena
Correlation of EPS content in activated sludge at different sludge retention times with membrane fouling phenomena
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DOI：
10.1016/j.watres.2007.10.026
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发表时间：
2008-03-01
期刊：
影响因子：
12.8
通讯作者：
Hollender, Juliane
中科院分区：
文献类型：
--
作者：
Al-Halbouni, Djamila;Traber, Jacqueline;Hollender, Juliane
在这项研究中，活性污泥特性的膜生物反应器（MBR）的膜污染方面进行了研究，两个中试厂和一个全面的工厂处理城市污水。对于全规模的MBR，与污泥絮体结合的胞外聚合物（EPS）的浓度显示出具有季节性变化，从夏季的17 mg g（-1）干物质（DM）到冬季的51 mg（g DM）（-1），这与较冷季节丝状菌的增加有关。因此，它是在中试规模的MBR与不同的污泥停留时间（SRT）是否不同的EPS含量和相应的污泥性质影响膜污染。发现来自具有低SRT（23 d）的中试MBR的活性污泥具有较差的过滤性、沉降性和脱水性。EPS提取物的光度分析以及LC-OCD测量表明，其含有比在较高SRT（40 d）的污泥显著更高浓度的絮凝体结合的EPS。膜上的污染层的形成，通过SEM-EDX以及EPS提取物的光度分析表征，在较低的SRT下更明显，其中与较高SRT下的膜相比，蛋白质的沉积EPS浓度高40倍，碳水化合物的沉积EPS浓度高5倍。絮体结合的EPS和金属建议发挥作用，在全规模的MBR的污染过程中，这是证实了中试规模的研究。然而，尽管不同的污泥性质，膜的渗透性被发现是相似的。(c)2007爱思唯尔有限公司保留所有权利。
In this study, activated sludge characteristics were studied with regard to membrane fouling in membrane bioreactors (MBRs) for two pilot plants and one full-scale plant treating municipal wastewater. For the full-scale MBR, concentrations of extracellular polymeric substances (EPS) bound to sludge floes were shown to have seasonal variations from as low as 17 mg g(-1) dry matter (DM) in summer up to 51 mg (g DM)(-1) in winter, which correlated with an increased occurrence of filamentous bacteria in the colder season. Therefore, it was investigated at pilot-scale MBRs with different sludge retention times (SRTs) whether different EPS contents and corresponding sludge properties influence membrane fouling. Activated sludge from the pilot MBR with low SRT (23 d) was found to have worse filterability, settleability and dewaterability Photometric analysis of EPS extracts as well as LC-OCD measurements showed that it contained significantly higher concentrations of floc-bound EPS than sludge at higher SRT (40 d) The formation of fouling layers on the membranes, characterised by SEM-EDX as well as photometric analysis of EPS extracts, was more distinct at lower SRT where concentrations of deposited EPS were 40-fold higher for proteins and 5-fold higher for carbohydrates compared with the membrane at higher SRT. Floc-bound EPS and metals were suggested to play a role in the fouling process at the full-scale MBR and this was confirmed by the pilot-scale study. However, despite the different sludge properties, the permeability of membranes was found to be similar. (c) 2007 Elsevier Ltd. All rights reserved.