| Recent years,with the development of the polymer flooding enhanced oil recovery technology, a large number of polymer-contained wastewater was produced during the domestic oil extraction. Due to the presence of the polymer in the oily wastewater, it increased the difficulty for the produced water treatment. As for its simplicity and high separation efficiency, membrane separation technology becomes a new candidate for polymer-containing wastewater treatment. However, the membrane is susceptible to be contaminated, which severely restricts the application of membrane separation technology. Accordingly, block polyether F127, tree like block polyether PePE, nano zinc oxide particles were added into the casting solution and the PES/F127, PES/PePE, PES/ZnO composite membrane were prepared to improve the hydrophilic and make an excellent antifouling performance when the modified membrane was used for simulated wastewater containing polymer.In the research, PES membrane was prepared under strictly controlled conditions including pre-evaporation temperature and coagulation temperature etc. Aattenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD) are used for the analysis of the component of the complex membrane. In addition, the modified PES/F127 composite membrane, PES/PePE composite membrane, PES/ZnO composite membrane were analyzed by field aemission scanning electron microscope (SEM) to evaluate the micro structure, synchronous integrated thermal analyzer was used to achieve the thermal stability of the complex membrane. Water contact angle was employed to measure the hydrophilic of the membrane surface. The porosity and water uptake capacity were used to evaluate the pore structure of the ultrafiltration membrane. The water flux was evaluated by ultrafiltration test. Polymer-contained wastewater flux and determination of COD were tested to characterize the separation performance of the membrane. The pure water flux recovery was used to characterize the anti-pollution properties of the composite membrane.The results showed that the water contact angle of the PES/F127 complex membrane decreased to 68.9°, PES/PePE complex membrane decreased to 73.8°, compared with PES membrane (84.8°) with block polyether addition of 20 wt%. Significantly, hydrophilicity of the composite membrane surface was improved. In addition, the water flux of the PES/F127 complex membrane and PES/PePE complex membrane both reached the maximum, when the addition of the block polyether was 20 wt%. The values are 172.0 L/m2·h and 267.5 L/m2·h respectively. Obviously, the permeability of the PES membrane has been significantly improved. When the addition of the nano ZnO particles was 8wt%, the water contact angle decreased to 76°, reduced by 18% and the hydrophilic of the composite membrane surface has been improved. The water flux reached the maximum by 197.5 L/m2·h, with the nano ZnO particles of 4wt%. Compared with PES membrane, the water flux of the PES/ZnO membrane increased 121%. In addition, simulated wastewater separation performance test show that the anti-pollution fouling performance of the composite membranes has been improved significantly compared with PES membrane. |
