Characterization of foulants in air-sparged side-stream tubular membranes used in a municipal wastewater membrane bioreactor
Characterization of foulants in air-sparged side-stream tubular membranes used in a municipal wastewater membrane bioreactor
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城市废水膜生物反应器中使用的空气喷射侧流管式膜中污染物的表征
DOI：
10.1016/j.seppur.2012.03.027
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发表时间：
2012
影响因子：
8.6
通讯作者：
Y.
中科院分区：
文献类型：
--
作者：
Hoque;A.;Kimura;K.;Miyoshi;T.;Yamato;N.;Watanabe;Y.
膜生物反应器（MBR）由于其自身的优势，在过去的十年中受到了广泛的关注，但其操作尚未得到优化。近年来，气相侧流mbr （asmbr）因克服了浸没式mbr清洗膜组件困难等缺点而备受关注。膜反应器的广泛应用受到膜污染相关问题的限制，asmbr也不例外。ASMBR膜表面的水力条件与浸没式MBR膜表面的水力条件不同，这种差异会影响污染物的特性。本研究的目的是确定在现有城市污水处理厂运行的中试规模ASMBR的污染物特性。圆柱形膜组件垂直安装在ASMBR中，每个组件可容纳约100个膜管。在第一个实验中，研究了在水平截面上不同管道位置的污染物的差异。无论管在膜组件中的位置如何，污染物的特性都没有显著差异。第一个实验还表明，从ASMBR中使用的管状膜中提取的污物中腐殖质物质占主导地位，而据报道，在浸没式mbr中，污物中亲水物质如多糖/蛋白质占主导地位。在接下来的实验中，将一个微小的中空纤维膜模块浸入ASMBR的反应池中，以过滤共享的生物质悬浮液，并直接比较不同MBR配置（即充气侧流与浸入式）中的污染物特性。从ASMBR的管状膜中提取的污染物中腐殖质物质占主导地位，而从浸入式中空纤维膜中提取的污染物中亲水有机物占主导地位。我们假设两种构型的水力条件不同导致了杂质含量的差异。本研究的结果表明，处理膜污染的有效措施取决于MBR的配置。
Membrane bioreactors (MBRs) have become very attractive during the past decade owing to their advantages, although MBR operation has not been optimized yet. Recently, air-sparged side-stream MBRs (ASMBRs) have received much attention because they can overcome the drawbacks of submerged MBRs such as the difficulty of cleaning membrane modules. Widespread application of MBRs has been limited by problems associated with membrane fouling, and ASMBRs are not exceptions. Hydraulic conditions on the membrane surface used in an ASMBR are different from those in a submerged MBR, and this difference affects the characteristics of foulants. The aim of this study was to determine foulant characteristics in a pilot-scale ASMBR operated at an existing municipal wastewater treatment plant. Cylindrical membrane modules holding about 100 membrane tubes each were installed vertically in the ASMBR. Differences of foulants depending on tube positions in the horizontal cross section were investigated in the first experiment. There were no significant differences in the foulant characteristics regardless of the tube positions in the membrane module. This first experiment also showed that humic substances were dominant in the foulants extracted from the tubular membranes used in the ASMBR, whereas hydrophilic substances such as polysaccharides/proteins were reportedly dominant in foulants in the case of submerged MBRs. In the following experiment, a tiny hollow-fiber membrane module was submerged in the ASMBR’s reaction tank to filter the shared biomass suspension and enable direct comparison of foulant characteristics in different MBR configurations (i.e., air-sparged side-stream versus submerged). Humic substances were again found to be dominant in foulants extracted from the ASMBR’s tubular membranes, whereas hydrophilic organic matter was dominant in foulants extracted from the submerged hollow-fiber membranes. We hypothesize that different hydraulic conditions in the two configurations brought about the difference in foulants. The results obtained in this study suggest that effective measures to address membrane fouling will differ depending on the MBR configuration.