Abstract:

The resistance distribution and fouling mechanism of kaolin dynamic membrane in treating wastewater were studied.Based on flux measurement and calculation, the ratio and change of diversified resistances under different operation conditions were made clear, the resistance of dynamic membrane was controlled by in-pore blockage and fouling layer on the dynamic membrane.The total resistance and the ratio of diversified resistances changed with the increase of cross-flow velocity.The classical theory about membrane pollution was used to analyze fouling mechanism of the dynamic membrane,and the following conclusions were reached that particles clogged pores or bridged the pore entrances in the first 10 minutes of filtration, then particles were brought up to the surface, and deposited on the surface of the dynamic membrane.The filtrate flux fitted the cake filtration model when cross-flow velocity was small.Moderately high velocity was advantageous for reducing filtration resistance.

Key words:

高岭土, 动态膜, 错流过滤, 阻力分布, 污染机理

摘要：

对高岭土动态膜处理污水过程中膜污染阻力分布及膜污染机理进行了研究。通过测定和计算得知不同操作条件下各部分阻力的比例及其变化情况。动态膜过滤污水的阻力主要由动态膜膜孔堵塞阻力和膜面污染层阻力所控制。随着错流速度的增大，总阻力减小，各部分阻力的比例有所变化，但动态膜膜孔堵塞阻力和膜面污染层阻力依然占主导地位。利用传统膜过滤时有关膜污染的堵塞模型和滤饼过滤模型对动态膜处理污水时的实验数据进行分析，结果表明，动态膜过滤污水过程中，过滤初期约10 min左右，污染以膜的微孔堵塞为主，此后，膜的污染情况因操作条件不同而有所差异，影响最显著因素为错流速度，当错流速度较小时，膜的污染以膜面沉积污染物为主，符合滤饼过滤模型。适当提高错流速度有利于减小过滤阻力。

关键词:

高岭土, 动态膜, 错流过滤, 阻力分布, 污染机理