New treatment of stabilized leachate by ozone/Fenton in the advanced oxidation process

Ozonation, combined with the Fenton process (O3/H2O2/Fe2+), was used to treat matured landfill leachate. The effectiveness of the Fenton molar ratio, Fenton concentration, pH variance, and reaction time were evaluated under optimum operational conditions. The optimum removal values of chemical oxygen demand (COD), color, and NH3–N were found to be 65%, 98%, and 12%, respectively, for 90 min of ozonation using a Fenton molar ratio of 1 at a Fenton concentration of 0.05 mol L−1 (1700 mg/L) H2O2 and 0.05 mol L−1 (2800 mg/L) Fe2+ at pH 7. The maximum removal of NH3–N was 19% at 150 min. The ozone consumption for COD removal was 0.63 kg O3/kg COD. To evaluate the effectiveness, the results obtained in the treatment of stabilized leachate were compared with those obtained from other treatment processes, such as ozone alone, Fenton reaction alone, as well as combined Fenton and ozone. The combined method (i.e., O3/H2O2/Fe2+) achieved higher removal efficiencies for COD, color, and NH3–N compared with other studied applications.

► Ozone and Fenton in AOPs was used to treat stabilized landfill leachate.
► Effectiveness of Fenton concentration, pH variance, and reaction time were evaluated.
► The optimum removal values of COD, color, and NH3–N were 65%, 98%, and 12%, respectively.
► Ozone consumption for COD removal was 0.63 kg O3/kg COD.
► O3/H2O2/Fe2+ is more efficient in leachate treatment compared with ozone, Fenton, and combined Fenton and ozone techniques.