膜蒸馏用于气田采出水的深度处理

采用自制聚丙烯中空纤维疏水膜,开展了内压式真空膜蒸馏处理某气田采出水的实验研究,考察了膜通量、脱盐率、产水电导率及产水水质等随运行时间的变化,针对实验后期出现的膜污染情况对膜蒸馏浓水除硬后进行二段膜蒸馏,再对出水进一步做催化臭氧氧化处理。实验结果表明：105 h后,废水中各离子浓度随着废水的浓缩而急剧升高,同时废水的高硬度造成膜堵塞,产生膜污染;除硬后去除了膜结垢污染,改善了膜疏水性能,膜通量恢复到初始膜通量的73%;膜蒸馏出水经催化臭氧氧化处理后,出水COD、TOC和ρ（NH₄⁺-N）分别为49 mg/L、6.5 mg/L和11.0 mg/L,满足回用要求。

Membrane distillation technology for advanced treatment of gas field produced water

The experimental study was carried out on the treatment of gas field produced water by internal pressure vacuum membrane distillation with the self-made polypropylene hollow fiber hydrophobic membrane. The variation of membrane flux,desalinization ratio,electrical conductivity and water quality with running time were investigated. The membrane distillation concentrated water was treated to remove minerals to alleviate the membrane fouling in the later stage of the experiment,and then the effluent was subjected to two-stage membrane distillation and catalytic ozone oxidation. The experimental results show that：After 105 h,the concentration of various ions in the wastewater increases sharply with the concentration process and the high hardness of the wastewater caused membrane clogging and membrane fouling;After minerals removal,the membrane fouling is prevented,the hydrophobicity of membrane is improved,and the membrane flux is recovered to 73% of the initial value;The membrane distillation effluent is treated by catalytic ozone oxidation,and the COD,TOC and ρ（NH₄⁺-N）of the effluent are 49 mg/L,6.5 mg/L and 11.0 mg/L,respectively,which can meet the requirements for reuse.