Papermaking industry discharges a huge amount of effluent and recycling of processed water with membrane technology has become predominate treatment protocol. In this study, poly(vinylidene fluoride) (PVDF) ultrafiltration membrane was employed to treat the effluent of secondary sedimentation tank from a paper mill. The results of 600 -hs continuous running showed that the PVDF membrane was seriously fouled with increased surface roughness during the filtrating process. Characterization of the fouled PVDF membrane revealed that pore blockage and cake deposition were the main fouling mechanism. The foulants in the pores were mainly oxygen-contained organics, and the foulants on the surface were mainly metal complexes and large particle. Wastewater analysis indicated the co-existence of PVA (1.0 mg/L) and Ca²⁺ (16.7 mg/L) in the secondary effluent. Pores blocking mechanism was caused by strong adheresion of PVA-217 and cake deposition mechanism was induced with macromolecular complexes of calcium ions bonding to PVA-217. The results obtained in this study demonstrated the fouling mechanism in the secondary effluent treatment. The understanding could help to find a feasible chemical method to clean the fouled polymeric membrane with washing agents as NaClO, NaOH and HCl in steps.

造纸工业排放大量废水，利用膜技术回收处理后的水已成为主要的处理方案。在这项研究中，聚偏二氟乙烯（PVDF）超滤膜被用于处理造纸厂二级沉淀池的废水。600小时连续运行的结果表明，在过滤过程中PVDF膜严重结垢，表面粗糙度增加。结垢的PVDF膜的表征表明，孔堵塞和滤饼沉积是主要的结垢机理。孔中的污垢主要是含氧有机物，表面的污垢主要是金属配合物和大颗粒。废水分析表明，PVA（1.0 mg / L）和Ca ²⁺共存（16.7 mg / L）在次要废水中。毛孔阻塞机制是由于PVA-217的强粘附性引起的，而结块的沉积机理是由钙离子与PVA-217结合的高分子复合物引起的。这项研究获得的结果证明了二级污水处理中的结垢机理。这种理解可能有助于找到一种可行的化学方法，以逐步洗涤诸如NaClO，NaOH和HCl之类的清洗剂来清洁聚合物膜。