1. State Key Laboratory of Separation Membranes and Membrane Processes Tiangong University Tianjin 300387 P. R. China
2. School of Environmental Science and EngineeringTiangong University Tianjin 300387 P. R. China
3. Oil Production Plant No. 2, PetroChina Changqing Oilfield Company Qingyang 745100 P. R. China
4. School of Material Science and EngineeringTiangong University Tianjin 300387 P. R. China
5. School of Chemistry and Chemical EngineeringTiangong University Tianjin 300387 P. R. China