因含聚污水黏度大、流动性差、油类物质黏附性强,采用超滤膜对其进行处理时,油类物质极易在膜表面吸附进而铺展造成严重的膜污染.针对此,设计合成了同时具备亲水及低表面能疏油链段的聚乙二醇-聚甲基丙烯酸三氟乙酯(PEG-PTFMA)两亲改性剂,并采用共混-非溶剂诱导的相转化法制备了PES/PEG-PTFMA抗污染超滤膜.3次循环超滤实验表明,处理含聚污水时,改性PES超滤膜具备良好的抗污染及自清洁性能,与未改性膜相比,通量衰减率从88.0%降低至36.7%,简单水力清洗后通量恢复率从18.0%增高至99.0%以上,同时超滤膜还具备优良的截留性能,产水含油量可由初始的230 mg/L下降至几乎为0 mg/L,固体悬浮物的含量也从50 mg/L下降至约3 mg/L,均低于油田回注水水质指标要求.亲水及低表面能含氟链段在表面的富集显著提高了膜的亲水性及疏油性,从而赋予了膜优良的抗污染能力以及水力清洗时的污染释放自清洁能力.
Due to the high viscosity, poor fluidity and strong adhesion of oil, the polymer-containing wastewater is easily being adsorbed and spreading on the surface of the ultrafiltration membrane, causing serious membrane fouling problems. In this paper, an amphiphilic modifier with both hydrophilic and low surface energy oleophobic segments, polyethylene glycol-polytrifluoroethyl methacrylate(PEG-PTFMA), was designed and synthesized. The antifouling PES/PEG-PTFMA ultrafiltration membranes were fabricated by blending modification methods. The three-cycle ultrafiltration experiments showed that the modified PES ultrafiltration membrane owned superior anti-fouling performance when treated with polymer-containing wastewater. Compared with the unmodified membrane, the flux decay rate decreased from 88.0% to 36.7%. After simple hydraulic cleaning, the flux recovery rate increased from 18.0% to above 99.0%. At the same time, the ultrafiltration membrane also possessed excellent retention performance. The oil content was reduced from the initial 230 mg/L to almost 0 mg/L, and the solid suspension content was reduced from 50 mg/L to about 3 mg/L, which were all lower than the oilfield refill water quality requirements. The enrichment of the hydrophilic and low surface energy fluorine-containing segments on the surface significantly improved the hydrophilicity and oleophobicity of the membrane, thereby imparting excellent anti-fouling ability and self-cleaning ability of pollution during hydraulic cleaning to the membrane.
Membrane Science and Technology