[Photochemical degradation of landfill leachate facilitated by combined schwertmannite and H2O2].

It is practically important that high concentrations of organic pollutants in landfill leachate were degraded by a rapid and efficient approach. The influence of operating conditions such as schwertmannite dosage, V(H2O2)/m (schwertmannite) ratio on the degradation efficiency of color, TOC and COD contents of landfill leachate, was investigated by using the schwertmannite/H2O2/UV process. It was demonstrated that the color, TOC and COD removal efficiencies increased significantly with the increase in schwertmannite dosage, and then were approximately stable. However, COD removal efficiency declined because of the presence of the residual H2O2 when V (H2O2)/m (schwertmannite) was greater than 2, and the best removal efficiency of COD was 44.9%. Furthermore, high-intensity ultraviolet was more conducive to eliminate pollutants through photochemical oxidation with schwertmannite/H2O2. The color, TOC and COD removal efficiencies were 90.0%, 78.8% and 52.6% respectively after 2.5 hours of photochemical degradation, with UV-500 W under optimal initial pH = 2.5; meanwhile, this study found that it was beneficial to the photochemical degradation of leachate at room temperature via the schwertmannite/H2O2/UV process, and COD removal efficiency declined gradually when the temperature was higher than 25 degrees C. Controlled trials showed that the schwertmannite/H2O2 method was conducive to the removal of color compared with the traditional homogeneous Fenton reaction.