State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China and Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China E-mail:
College of Civil Engineering, Huaqiao University, Jimei District, Xiamen 361021, China.
Water Sci Technol. 2021 Mar;83(5):1005-1016. doi: 10.2166/wst.2021.037.
Powered Activated Carbon - Membrane Bioreactors (PAC-MBRs) have been used with good results for slightly polluted water treatment. Our batch experiments showed that the transmembrane pressure of a PAC-MBR was 25% less than that of a MBR in one period of test, which indicated that PAC did help control the fouling in MBRs. Based on this observation, several mechanisms of membrane fouling of MBRs and PAC-MBRs were investigated to have some insight into how PAC brought a positive impact. The total resistances decreased by 60% and different resistances were redistributed after adding PAC. The dominant one changed from filtration resistance to cake resistance. These smaller cake resistances resulted from the PAC because, showing in the scanning electron microscopy pictures, it made the cake layer looser and rougher than that on a normal membrane. Meanwhile, the analysis of the membrane eluent showed that the addition of PAC changed the microbial species and its metabolites on the membrane and effectively reduced the adsorption of hydrophilic organic molecules on the membrane surface. Additionally, PAC prevented polypeptide compounds from being trapped inside the pores of membranes, so the cake on the PAC-MBR contaminated membrane surface was easier to scrape off. In the test of cleaning methods, alkaline cleaning removed the most organics from contaminated membranes to restore membrane performance.
粉末活性炭 - 膜生物反应器（PAC-MBR）已被成功应用于轻度污染的水处理。我们的批处理实验表明，在一个测试周期内，PAC-MBR 的跨膜压力比 MBR 低 25%，这表明 PAC 有助于控制 MBR 中的污染。基于这一观察，我们研究了 MBR 和 PAC-MBR 的膜污染的几种机制，以深入了解 PAC 带来的积极影响。添加 PAC 后，总阻力降低了 60%，不同阻力重新分布。主导阻力从过滤阻力变为滤饼阻力。这些较小的滤饼阻力是由于 PAC 造成的，从扫描电子显微镜图片可以看出，它使滤饼层比正常膜更疏松和粗糙。同时，对膜洗脱液的分析表明，PAC 的添加改变了膜上微生物的种类及其代谢物，并有效减少了膜表面上亲水性有机分子的吸附。此外，PAC 阻止了多肽化合物被困在膜孔内，因此 PAC-MBR 污染膜表面上的滤饼更容易刮除。在清洗方法的测试中，碱性清洗去除了污染膜上的大部分有机物，恢复了膜的性能。
