Fe/Cu催化还原去除饮用水消毒副产物三氯乙酸

Removal of Halogenated Disinfection By-products Trichloroacetic Acid by Fe/Cu Catalytic Reduction in Drinking Water

摘要:

以高致癌风险的饮用水卤化消毒副产物（halogenated disinfection by-products, HDBPs）三氯乙酸（TCAA）为去除目标物，研究了Fe/Cu催化还原去除TCAA的效果，包括Fe/Cu质量比、Fe/Cu混合物投加量、pH、有机物浓度和摇床转速等因素对Fe/Cu催化还原去除TCAA的影响。结果表明，Fe/Cu能够有效脱除TCAA，Fe/Cu质量比为10:1时的TCAA去除效果最佳；Fe/Cu最佳投加量为30 g•L-1；Fe/Cu还原脱氯去除TCAA最佳pH值在4到8之间；有机物浓度对Fe/Cu还原脱氯存在负面影响；在摇床转速、反应时间、投加量、pH值和UV254分别为200 r•min-1, 160 min, 30 g•L-1, 6.82和0.117 cm-1的条件下，Fe/Cu催化还原对TCAA的去除率达到97.39％，并且Cu未被消耗，外扩散Fe/Cu催化还原反应的影响可以忽略，Fe/Cu对TCAA的催化还原脱氯降解过程符合拟一级反应。

Abstract:

Trichloroacetic acid (TCAA) which has relatively high concentration and carcinogenic risk, one of the most common disinfection by-products (DBPs) in drinking water, seriously endangers the physical health of mankind and eco-environment. Zero-valent iron (ZVI) reductive process had been used in water treatment extensively such as removal of THMs by ZVI. However, little information is available about the removal of TCAA by low-cost Fe/Cu catalytic reduction technology. Some factors affecting removal of TCAA by Fe/Cu catalytic reduction were studied including the impact of Fe/Cu mass ratio, Fe/Cu dosage, pH, organic matter concentration, and rotate speed on removing TCAA. The results show that Fe/Cu catalytic reduction was effective against TCAA in drinking water. The optimum Fe/Cu mass ratio, dosage and pH range were 10:1, 60g and 4~8 respectively. The organic matter affects the removal of TCAA by Fe/Cu catalytic reduction in negative way. 97.39% of TCAA can be effectively removed by Fe/Cu catalytic reduction on the condition that rotate speed of shaker, reaction time, Fe/Cu dosage, pH and UV254 were 200 r/min, 160 min, 60 g, 6.82 and 0.117 cm-1. The influence of external diffusion on Fe/Cu catalytic reductive reaction may be neglected. The degradation process of TCAA by Fe/Cu catalytic reduction was consistent with pseudo first order reaction.