STUDY ON DEGRADATION OF HUMIC ACIDS BY UV/O3/H2O2 PROCESS

As one of the major disinfection by-products, humic acids are hazardous to natural water bodies. In this study, we investigated the removal of low concentrations of humic acids by UV, O-3, H2O2 and UV/O-3/H2O2 process. The parameters, such as reaction time, humic acid concentration and solution pH were investigated. The results showed that, with humic acid concentration of 20 mg/L, the best ozone output was 190 mg/h. The optimal UV lamp's power was 15 W, with H2O2 concentration of 20 mg/L, a reaction time of 10 min, pH of 8.5, UV254 and TOC removal was 89.33% and 30.89%, respectively. From the experimental results, we can know that pH does not show a high influence on the removal rate. The concentrations of organics and aromaticity, after being processed by UV/O-3/H2O2 method, were analyzed. The process of oxidation, was inferred by ultraviolet spectrum and Fourier transform infrared (FT-IR) analysis. The results showed that after UV/O-3/H2O2 treatment, the molecular weight of humic acid and unsaturated bonds decreased while small molecules of aldehydes, ketones and acids increased.