PVDF超滤膜应用于工业废水处理的膜污染形成与控制

The Formation and Control of Membrane Fouling Occurred in the Ultra-Filtration Process of PVDF Membranes Applied for Industrial Wastewater Treatment Plant

通过对南水水质净化厂PVDF超滤膜在生产过程中出现的膜污染现象进行分析,判断污染物质主要成分为碳酸钙。污染成因是进厂水的p H、碱度以及生产中使用的混凝剂PAC钙离子含量偏高。通过一系列的实验,采用了"氨基磺酸+次氯酸钠+EDTA-2Na"的联合清洗方法对污染物进行了清洗;并通过更换混凝剂类型、加强膜系统的日常清洗维护等途径,使得该膜污染现象得到了根本控制,从而在不进行工艺改造、不提高运行成本的前提下,实现了膜系统的稳定运行。

According to the analysis of PVDF ultra-filtration membrane fouling in wastewater treatment process of the Nanshui water quality purification plant, the main pollutant was calcium carbonate. The high pH and alkalinity of the wastewater and the large amount of the calcium ion in the coagulant PAC used could be the primary reason to induce fouling. Based on a series of experiments, the combined cleaning method of＇sulfamic acid ＋ sodium hypochlorite ＋ EDTA-2Na＇ was used to clean the pollutant. Meanwhile, the membrane fouling was controlled by changing the type of coagulant and strengthening the daily membrane cleaning and maintenance. Thus the stable operation of membrane system was achieved without technology improvement and operating cost increase.