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 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.