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

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.

Key words:Fe/Cu catalytic reduction; halogenated disinfection byproducts; trichloroacetic acid; drinking water