MIEX-UF耦合工艺控制膜污染的行为及机理研究

Study on Behavior and Mechanism of MIEX-UF Coupling Process in Controlling Membrane Fouling

以HA、BSA和SA模拟典型膜污染物,对比分析了一体式和分体式两种MIEX-UF耦合工艺在减缓膜污染方面的性能差异。结果表明对任何一种典型污染物来说,一体式MIEX-UF工艺减缓膜污染的效果都远远强于分体式MIEX-UF工艺。机理分析证明,即使MIEX对BSA的吸附去除高达91.4%,吸附也不是一体式MIEX-UF工艺减缓膜污染的最主要因素。尽管污染物的性质会影响一体式工艺中三种膜污染减缓机制的相对贡献比例,但MIEX与污染物间更强亲和力带来的动态膜效应始终是一体式MIEX-UF工艺减缓膜污染的最主要因素。污染物与MIEX间亲和力越强,一体式工艺对其造成的膜污染的减缓效果就越显著。因此,当以提高膜污染控制性能为目的时,在一体式吸附-UF工艺中吸附剂的选择更应该关注其与污染物间亲和力而不是吸附剂的吸附能力。

Using HA,BSA and SA to simulate typical membrane pollutants,and the performance in reducing membrane fouling between the integrated and separated processes of MIEX-UF were compared.The results show that for membrane fouling caused by any typical pollutant,the integrated MIEX-UF process is far more effective in mitigating membrane fouling than the separated MIEX-UF process.Further analysis suggested that MIEX adsorption is not the most important factor in mitigating membrane fouling in the integrated MIEX-UF process even if MIEX adsorbs BSA as high as 91.4%.Although the nature of pollutants will affect the relative contribution ratios of the three fouling mitigation mechanisms in the integrated process,the dynamic layer effect caused by the stronger affinity between MIEX and pollutants is always the most important factor in mitigating membrane fouling in the integrated process.The stronger the affinity between the pollutant and MIEX,the more significant the mitigation effect in membrane fouling by the integrated process.Therefore,to improve the membrane fouling control performance of the integrated adsorption-UF process,more attention should be paid to the affinity between adsorbent and pollutants rather than its adsorption capacity when selecting adsorbents.