膜处理单元保安过滤器污堵原因及清洗恢复试验

Experiment on Fouling Reasons and Cleaning Recovery of Membrane Treatment Unit Security Filter

宁夏某化工厂矿井水膜处理单元保安过滤器在运行中出现了压差上升过快、滤芯更换频繁问题,严重影响后端反渗透系统的高效稳定运行,对污堵滤芯进行了碱洗,清洗效果较差。为确定污堵原因,对过滤器进水水质及滤芯上污染物成分进行了系统分析,判断预处理工段投加的聚铝絮凝剂首先在滤芯上发生沉积,后续金属离子(Ca^(2+)、Si^(2+)等)、有机污染析出附着在絮凝剂层上形成混合污染物,最终造成滤芯彻底污堵。通过开展清洗试验制定了有效的清洗方案,清洗后上线的滤芯运行状况良好,为水处理工程中滤芯的污堵原因及清洗恢复研究提供了系统、可行的思路指导。

During the operation of the security filter of mine water membrane treatment unit in a chemical plant in Ningxia,the fast rise of differential pressure and the frequent replacement of filter element affected the efficient and stable operation of the back-end reverse osmosis system.The cleaning effect is poor by alkali washing on the fouling filter element.In order to determine the cause of fouling,the influent water quality and the pollutant composition on thefilter element were systematically analyzed.It was judged that the polyaluminum flocculant added in the pretreatment section first deposited on the filter element,and the subsequent metal ion(Ca^(2+),Si^(2+),et al)and organic pollution precipitated and adhered to the flocculant layer to form mixed pollutants,which eventually caused the filter element to be completely fouling.Through the cleaning test,an effective cleaning scheme was developed.The filter element on the line after cleaning was in good condition,which provided a systematic and feasible advise for the study about the cause of fouling and cleaning recovery of the filter element in the water treatment project.