改性聚四氟乙烯膜在油田含油污水处理中的动电现象

ELECTROKINETIC PHENOMENA OF MODIFIED POLYTETRAFLUOROETHYLENE MEMBRANES IN OILY SEWAGE FROM OIL FIELD

对油田含油污水中不同孔径的改性聚四氟乙烯膜的流动电位进行了实验研究。根据Helmholtz-Smoluchowski方程计算出改性聚四氟乙烯膜的微孔表面zeta电位,并对油田含油污水中悬浮颗粒的zeta电位进行了测定。结果表明,改性聚四氟乙烯膜面带有负电荷,表面zeta电位稳定在-20 mV左右,对膜孔径及温度、流量等操作条件的依赖性不强。而污水中悬浮颗粒zeta电位也为负值。由于膜面电荷的作用,使膜具有更强的截留悬浮物颗粒及抗污染能力。

The electrokinetic phenomena of modified polytetrafluoroethylene membranes in the oily sewage from oil field were investigated by using streaming potential method, The zeta potential of the membrane in the oily sewage was calculated on the basis of Helmholtz-Smoluchowski equation. The zeta potential of the particulates suspended in oily sewage was also determined. The experimental and calculation results showed that the membrane was charged negatively, whose zeta potentials maintain at - 20 mV around. The aperture of membranes, the temperature and the filtration flux had little influence on the streaming potential and the zeta potential of the membrane. Also the suspended particulates in the oily sewage were charged negatively. The membranes have strong ability withholding the suspended particulates and powerful anti pollution competence because of the role of the charges on the membranes.