含单宁酸模拟废水对反渗透膜的污染研究

Study on RO membrane fouling by simulated wastewater containing tannic acid

通过改变单宁酸溶液浓度、pH值等参数以及与不同金属离子的协同反应,考察了单宁酸物质对反渗透膜的污染而引发的膜性能的变化过程。试验结果表明,单宁酸的质量浓度为50 mg/L的高浓度与4、10 mg/L的低浓度引发膜通量下降的规律不同;pH值越高,膜污染越慢;K+、Na+、Mg2+、Ca2+与单宁酸协同作用时产生的膜污染程度依次加剧,其中单宁酸溶液中存在Mg2+、Ca2+时的污染速率远大于K+、Na+。

The variation of RO membrane characteristics caused by the pollution of tannic acid matter was investigated through changing the tannic acid solution concentration,pH value and some other parameters and carrying out the concerted reaction with different metal ions.The results of the test showed that,when the tannic acid mass concentrations was as high as 50 mg/L or as low as 4 and 10 mg/L respectively,the rules of membrane flux decline were different.The higher the pH value was,the slower the membrane fouling would be;during the concerted reaction,the situation of membrane fouling was aggravated successively with the existence of K＋、Na＋、Mg2＋、Ca2＋ in tannic acid solution,and the speed of membrane fouling in tannic acid solution containing Mg2＋ and Ca2＋ was much faster than that in the solution containing K＋ and Na＋.