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

• Eight types of Mn and Ce oxides impregnated GAC (MnCe-ACs) are developed.
• Liquid film diffusion model is the best fitted model for MnCe-AC/O3 process.
• MnCe-AC can be used for at least four cycles.
• MnCe-AC/O3 can effectively remove organic compounds in landfill leachate.

Mn and Ce oxides impregnated granular activated carbons (MnCe-ACs) with ozone process (MnCe-AC/O3) 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/O3 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/O3 > GAC/O3 > O3 > 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/O3 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/O3 process. In conclusion, the MnCe-AC/O3 process can effectively remove organic compounds in landfill leachate to meet the requirement of COD discharge limit with minimal amount of sludge production.

Figure optionsDownload as PowerPoint slideRemoval of HA, TOC and COD of landfill leachate by various treatment processes.