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值、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，m(Fe)∶m(Cu)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4~8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 is used in water treatment extensively for the removal of THMs by ZVI.However,little information is available on the removal of TCAA by lowcost Fe/Cu catalytic reduction technology.Some factors affecting the 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 can effectively remove TCAA from drinking water.The optimum Fe/Cu mass ratio,is 10:1,the dosage 30 g·L-1,and the pH between 4~8.The organic matter affects the removal of TCAA by Fe/Cu catalytic reduction in a negative way.97.39% of TCAA can be effectively removed by Fe/Cu catalytic reduction on the condition that the rotate speed of shaker is 200 r·min-1,the reaction time 160 min,Fe/Cu dosage 30 g·L-1,pH6.82 and UV254 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 is consistent with pseudo first order reaction.