Department of Civil and Environmental Engineering, University of Alberta , Edmonton, Alberta, CanadaT6G 2W2.
Environ Sci Technol. 2012 Mar 6;46(5):2877-84. doi: 10.1021/es203813s. Epub 2012 Feb 23.
Membrane filtration is an effective reclamation option for oil sands process-affected water (OSPW). However, fresh OSPWs contain suspended solids and inorganic constituents in suspended and dissolved forms that can severely foul membranes. Pretreatment of OSPW with coagulation-flocculation (CF) was investigated to determine the effects of different coagulant aids (anionic, cationic, and nonionic polymers) on membrane surface properties and fouling. Our results showed that CF pretreatment effectively enhanced nanofiltration (NF) and reverse osmosis (RO) membrane permeate flux and salt rejection ratio through reducing membrane fouling. It was shown that coagulants and coagulant aids applied to OSPW feedwater can affect membrane physicochemical properties (surface hydrophilicity, zeta potential, and morphology), membrane performance, and the fouling indexes. Membrane rejection of ionic species increased significantly with the inclusion of an anionic coagulant aid and slightly with a cationic coagulant aid. Among three coagulant aids tested, anionic coagulant aids led to the most enhanced membrane performance through increasing membrane surface negativity and decreasing the formation of a fouling layer. Conversely, although cationic coagulant aids were the most effective in reducing OSPW turbidity, the application of cationic coagulant aids promoted the adsorption of foulants on membrane surfaces.
膜过滤是一种有效的油砂加工废水（OSPW）回收方法。然而，新鲜的 OSPW 含有悬浮固体和以悬浮和溶解形式存在的无机成分，这些成分会严重污染膜。本研究采用混凝-絮凝（CF）预处理 OSPW，以确定不同助凝剂（阴离子、阳离子和非离子聚合物）对膜表面性质和污染的影响。结果表明，CF 预处理通过减少膜污染，有效地提高了纳滤（NF）和反渗透（RO）膜的渗透通量和盐截留率。结果表明，施加于 OSPW 给水中的混凝剂和助凝剂会影响膜的物理化学性质（表面亲水性、动电位和形态）、膜性能和污染指数。带负电荷的阴离子助凝剂会显著提高膜对离子物质的截留率，而阳离子助凝剂则略有提高。在测试的三种助凝剂中，阴离子助凝剂通过增加膜表面的负电性和减少污染层的形成，使膜性能得到最大程度的提高。相反，尽管阳离子助凝剂在降低 OSPW 浊度方面最有效，但阳离子助凝剂的应用会促进污染物在膜表面的吸附。
