饮用水中双氯芬酸钠的电化学膜滤法去除工艺

Technological Process of Diclofenac Sodium Removal in Drinking Water by Electrochemical Membrane Filtration(EMF)

采用电化学膜滤法(EMF)对饮用水中的有机微污染物——双氯芬酸钠(DCFNa)进行去除,考察了外加电压、初始浓度对EMF去除饮用水中DCFNa的影响。研究结果表明:EMF对DCFNa的去除以间接氧化作用为主,反应过程中生成了大量的活性氧化物质(ROS)物质;在批次试验条件下,其降解过程符合伪一级反应动力学模型,随着外加电压的增大,其降解速率增大,而在低初始浓度条件(0.1～2.0 mg/L)下,初始浓度对EMF去除DCFNa的影响较小,当初始浓度增加至10 mg/L时,降解效果出现下降趋势。研究进一步考察了不同运行方式及膜通量对EMF去除DCFNa效果的影响。结果表明,在不同的运行方式条件下,循环流优于批次试验优于连续流,且EMF对DCFNa的去除率随着膜通量的增加而降低。在初始电压为2.5 V、膜通量为30 L/(m^2·h)时,连续流试验4 h后,DCFNa的去除率达到89.2%。

Electrochemical membrane filtration (EMF) process was used for the removal of diclofenac sodium (DCFNa) in drinking water. The effects of applied voltage and initial concentration on DCFNa removal from drinking water were investigated. The results showed that the removal of DCFNa by EMF process was owe to the indirect oxidation, and a large amount of reactive oxygen species (ROS) was generated in the process. In batch experiments, degradation process fit well with a pseudo first-order kinetics model, and with the increase of applied voltage, the degradation rate increased. When initial concentration was low (0.1~2.0 mg/L), initial DCFNa concentration showed insignificant effects on DCFNa removal by EMF process. However, when initial concentration increased to 10 mg/L, the degradation ratio declined. The effect of different operation modes on the removal of DCFNa by EMF were furtherly investigated. The results showed that the degradation efficiency of circulation flow mode was higher than that of batch experiments and continuous flow mode. The results of membrane flux experiments showed that the removal rate of DCFNa decreased with the increase of membrane flux. When applied voltage was 2.5 V with membrane flux of 30 L/(m 2 ·h), DCFNa removal rate reached 89.2% after 4 h reaction by continuous flow mode.