基于Donnan dialysis原理,在无外加电压作用下采用阳离子交换膜分离去除原水中的Cu2+,研究原水中可能出现的无机颗粒物,有机物质,EDTA酸、氨水、Fe3+、表面活性剂等对阳离子交换膜分离去除cu2+效果的影响,研究表明:原水中添加二氧化硅、腐殖酸、EDTA酸、氨水、Fe3+、表面活性剂等物质,在长时间运行后均会对离子交换膜去除cu2+有不同程度的影响;二氧化硅和非离子表面活性剂等污染物不会和膜及Cu2+发生物理化学反应,对膜去除cu2+效果影响较小,相比空白样。Cu2+去除率下降约4%;氨水、阴离子表面活性剂等会导致Cu2+发生沉淀反应,腐殖酸会吸附cu2+,使原水中游离态cu2+浓度显著降低约50%;EDTA酸、氨水、阴离子表面活性剂等会与cu2+形成络合物。对去除cu+有严重影响,相比空白样,cu+去除率分别下降约100%(EDTA酸)、78%(氨水)、56%(阴离子表面活性剂);阳离子表面活性剂存在时,其会大量占据膜内空间,Cu2+基本无去除;Fe3+在弱酸性或中性水中会水解生成氢氧化铁胶体,对去除cu2+有一定影响,相比空白样,Cu2+去除率下降约12%。
Baesd on Donnan dialysis mechanism, copper ion separation and removing experiments in raw water using exchange membrane was conducted under voltage free condition. The copper ion removing effects of cation exchange membrane cuased by various potential pollutants in raw water such as inorganic particles, organic matters, EDTA acid, ammonia, ferric ion and surfacatant etc, were studied. The results showed that upon addition any one of the above pollutants to raw water, would influence on the copper ions removing effects more or less after a long time operation procedure. To pollutants with no physical and chemical interaction with copper ion and membrane, such as silica and non-ionic surfactant, there were little influences on the copper ion separation of the cation exchange membrane and theCu2+ removal decreased only by about 4% compared to that of blank control experiments; Cu2+ could be precipitated by ammonia and anionic surfaceactive agent, or adsorbed by humic acid which made the concentration of free Cu2+ in the solution reduce by about 50%; While to pollutants which could form complex compounds with Cu2+, serious effects on Cu2+ removal efficiency were observed.' For EDTA acid, ammonia and anionic surfaceactive agent, the Cu2+ removal effects decreased by approximately 100%, 78% and 56% respectively; Cationic surfactants may occupy a lot of space of film render Cu2+ remove difficulty; ferric ion easily hydrolyzed into iron hydroxide colloids in weak acid or neutral solution induced Cu2+ removal effect decreased to certain extend, by about 12% compared to the blank.