Advanced treatment of landfill leachate by ultraviolet catalytic persulfate

To study the treatment characteristics of leachate biochemical effluent from refuse incineration plant, the effects of advanced treatment of landfill leachate by ultraviolet (UV) system, single persulfate (PS) system and ultraviolet/persulfate (UV/PS) system were compared. The results showed that the removal efficiency of UV/PS system was better than that of the other two systems. When the initial concentration of humic acid was 200mg/L, the dosage of PS was 25mmol/L, and the initial pH value was 4, the maximum removal rate of UV254 was 89.62%, the maximum removal rate of TOC was 76.17%. The effects of temperature, initial pH value and dosage ratio of chemicals on the treatment of leachate by UV/PS process were studied. It's found that the treatment effect was good. The optimal conditions were as follows: temperature 35°C, pH value 4, dosing ratio 2, running for 24h, the maximum removal rate of COD was 82.64%, and the maximum treatment efficiency of TOC was 66.69%. At the same time, the removal ability of the system was in accordance with the pseudo-second-order kinetic equation. This paper can provide reference for advanced treatment of leachate in waste incineration plant. © 2021, Editorial Board of China Environmental Science. All right reserved.