平板陶瓷膜处理油田采出水运行控制优化及膜污染机理

Operation control optimization and membrane fouling mechanism of flat-sheet ceramic membrane treating oilfield produced water

陶瓷膜凭借其机械强度高、化学稳定性好等优点,近年来在油田采出水处理领域得到了广泛的应用。针对陶瓷膜处理油田采出水膜污染控制这一核心问题,采用小试实验与模型分析相结合的方法,深入开展了陶瓷膜处理系统运行控制优化的研究,结合微观表征,阐明了陶瓷膜处理油田采出水膜污染机理。结果表明,陶瓷膜处理油田采出水最佳运行控制工况为:初始膜通量80 L·(m^(2)·h)^(-1),过滤时间10 min,反冲洗时间30 s,曝气强度3 L·min^(-1);此条件下陶瓷膜可保持平均膜通量27.82 L·(m^(2)·h)^(-1)。原水和污染层的表征结果表明,胺类或酰胺类、烃类、羧酸类、芳香族、醇类等有机物化合物是造成陶瓷膜污染的主要有机物,Si、Fe、Ca、Mg、Ba等无机盐离子也是膜污染的重要组成部分;过滤过程中膜孔内阻力和凝胶层阻力对陶瓷膜膜污染形成起主导作用。

Ceramic membrane has been widely used in the field of oilfield produced water treatment in recent years because of its high mechanical strength,good chemical stability and other advantages.Aiming at the core issue of membrane pollution control in oilfield produced water treatment by ceramic membrane,the small-scale experiment and model analysis were used to deeply conduct the optimization research on the operation control of ceramic membrane treatment system.Combined with microscopic characterization,the membrane pollution mechanism in oilfield produced water treatment by ceramic membrane was clarified.The results showed that the optimal operating control conditions for oilfield produced water treatment by ceramic membrane were:initial membrane flux of 80 L·(m^(2)·h)^(-1),filtering time of 10 min,backwashing time of 30 s,aeration intensity of 3 L·min^(-1).Under above conditions,the ceramic membrane could maintain an average membrane flux of27.82 L·(m^(2)·h)^(-1).The characterization results of raw water and pollution layer showed that amine or amide,hydrocarbon,carboxylic acid,aromatic,alcohol and other organic compounds were the main organics causing ceramic membrane pollution,and inorganic salt ions such as Si,Fe,Ca,Mg,Ba were also important components of membrane pollution;In the filtration process,both the resistances in the membrane pore and in the gel layer play a leading role in the formation of ceramic membrane fouling.