Abstract: Cellulose triacetate based membranes for forward osmosis were prepared by immersion precipitation. The polymer solution consisted of cellulose triacetate as the membrane material，1,4-dioxane and acetone as solvent，methanol and lactic acid as additives. Casting composition and preparation conditions—1,4-dioxane/acetone ratio，lactic acid content，evaporation time，casting thickness and annealing temperature—were tested for their effects on membrane performance. The optimized membrane showed 14.10L/(m2?h) water flux and 0.031mol/(m2?h) reverse solute flux using a feed solution of pure water and draw solution of 0.56mol/L CaCl2. When 0.1mol/L NaCl was used as the feed solution and 4mol/L glucose was used as the draw solution，water flux was above 5L/(m2?h) and rejection for NaCl was above 99%. The optimized membrane had a more hydrophilic surface，higher water flux，higher salt resistance and better membrane performance than the HTI membrane.

Key words: forward osmosis, membranes, separation, selectivity, cellulose triacetate

摘要： 以三乙酸纤维素（CTA）为膜材料，1,4-二氧六环、丙酮为溶剂，甲醇、乳酸为添加剂，采用相转换法制备了三乙酸纤维素正渗透膜。研究了不同1,4-二氧六环/丙酮配比、添加剂乳酸含量、挥发时间、膜厚度、热处理温度条件下正渗透膜性能的变化规律。研究表明，当采用纯水为原料液，0.56mol/L CaCl2为汲取液时，优化制备的CTA正渗透膜的水通量达到14.10L/(m2?h)，溶质反扩散量为0.031mol/(m2?h)；采用0.1mol/L NaCl为原料液，4mol/L葡萄糖为汲取液时，优化制备的CTA正渗透膜的水通量保持在5L/(m2?h)以上，对NaCl的截留率大于99%。CTA正渗透膜相比于HTI膜，具有较高的亲水性、水通量、截留率，稳定性更好。

关键词: 正渗透, 膜, 分离, 选择性, 三乙酸纤维素