Monitoring of MBR fouling properties by filtration resistance and zeta potential measured for both filtration and backwashing directions
Monitoring of MBR fouling properties by filtration resistance and zeta potential measured for both filtration and backwashing directions
复制标题
通过在过滤和反冲洗方向上测量的过滤阻力和 zeta 电位来监测 MBR 污垢特性
DOI：
10.1016/j.memsci.2023.121550
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发表时间：
2023
影响因子：
9.5
通讯作者：
Kenji Wakui
中科院分区：
文献类型：
--
作者：
Gagandeep Kaur;Kazuho Nakamura;Kentaro Ogawa;Kenji Wakui
膜生物反应器（MBR）作为一种有前途的、可持续发展的技术，在未来将有很高的需求。为了在线监测污垢状态，使工艺更经济，开发了基于过滤方向和反冲洗方向过滤性能差异的新型污垢监测指标。在实验室规模的MBR中，使用孔径为0.2 μm的氧化铝管式微滤膜，通过直接目视观察过滤表面、过滤阻力和两个方向的zeta电位来监测模块堵塞和污染特性。通过目测确定了避免泥饼堵塞的膜组件流道最佳间隙尺寸为5 mm。过滤方向的过滤阻力RF在运行后期急剧增加，而反冲洗方向的过滤阻力RB在整个运行过程中逐渐增加。在一个模型中，泥饼的行为就像一个“止回阀”，这说明了RF和RB之间的差异。利用串联模型对污染膜的清洗实验结果进行分析，也支持了泥饼行为模型，表明泥饼阻力Rcake对膜的清洗效果起主导作用，对RB无影响。分析还表明，Rcake和大分子吸附阻力Radsorption是判断污垢状态的重要因素，可以通过运行中易于监测的RF和RB来评价，而无需进行清洗实验。zeta电位也依赖于测量方向，并表现出下降的趋势，随着过滤阻力的增加。
Membrane Bioreactor (MBR) being the promising and sustainable technology, will be highly in demand in future. To monitor the inline status of fouling, in order to make the process more economical, novel fouling monitoring indexes based on the differences in filtration properties between the filtration direction and backwashing direction were developed. The module clogging and fouling properties were monitored by direct visual observation of filtration surface, filtration resistance and zeta potential for both directions in a lab scale MBR using alumina tubular microfiltration membrane having pore size of 0.2 μm. The optimal clearance size of flow channel in membrane module for avoiding clogging by sludge cake was determined at 5 mm by the visual observation. The filtration resistance for filtration direction,RF, increased steeply in later stage of operation while that for backwashing direction,RB, showed a gradual increasing throughout operation. This difference betweenRFandRBwas elucidated by a model where the sludge cake behaves like a “check valve”. The analysis of cleaning experiments of fouled membrane with the resistance in series model also supported the model of the sludge cake behavior and showed that the resistance caused by sludge cake,Rcake, dominatedRFand had no impact onRB. This analysis also showed thatRcakeand the resistance caused by macromolecule adsorption,Radsorption, which are important factors for recognizing fouling status, can be evaluated fromRFandRB, which are easy to monitor during operation, without cleaning experiments. The zeta potential also depended on the measurement direction and showed a decreasing trend with the increase in filtration resistance.