Landfill leachate treatment with Mn and Ce oxides impregnated GAC–ozone treatment process

Abstract

Abstract Mn and Ce oxides impregnated granular activated carbons (MnCe-ACs) with ozone process (MnCe-AC/O 3 ) are developed in this research for the treatment of landfill leachate. Most of the landfills fail to meet the COD discharge limit (200 mg/L) in Taiwan due to the high contents of humic acids (HAs) in leachates. Experimental results indicate that MnCe-AC/O 3 processes could effectively remove HA, COD and TOC from landfill leachate. Parameters affecting the HAs removal efficiencies, such as types of MnCe-AC, pH, Cu(II), salts and t -butanol are investigated. In general, the removal efficiencies are in the order of MnCe-AC/O 3 > GAC/O 3 > O 3 > MnCe-AC > GAC. MnCe-AC can be used for at least four cycles without significant reduction in performance. The main removal mechanisms of HAs by the MnCe-AC/O 3 processes involved hydroxyl radicals based on the addition of t -butanol experiments. Liquid film diffusion model is the best fitted model for the MnCe-AC/O 3 process. In conclusion, the MnCe-AC/O 3 process can effectively remove organic compounds in landfill leachate to meet the requirement of COD discharge limit with minimal amount of sludge production.