Advanced oxidation process of mature landfill leachate containing ferrous ion

Advanced Oxidation Process by means of Fenton-like process was performed to treat mature landfill leachate containing 0.0069 M of Ferrous iron. Hydrogen peroxide was added to promote the oxidation of leachate at specific Fe²⁺/H₂O₂ molar ratio, and conducted at pH 3 and pH 4 in completely stirred batch operated for 240 min. The highest removal of organic measured as COD was 97%, achieved at Fe²⁺/H₂O₂ molar ratio of 1:5 and pH 3. Although the presence of chloride ions interfere the oxidation process, the removal of COD was obviously affected at the molar ratio of 1:15 and 1:20 at both pH, whereas the other molar ratios were unclear due to possible generation of intermediate species. While pH 3 was preferable for the Fenton-like process, neutralisation/ precipitation at pH 7 and/or pH 8 was required as polishing treatment of the effluents. This may limit the application of Fenton-like process for alkaline leachate treatment.