Improved fenton method to remove recalcitrant organics in landfill leachate

Sanitary landfill leachate is usually treated with biological process followed by FeCl₃ coagulation, but the effluent still contains high concentration of COD. The Fenton method can substitute for chemical coagulation to improve the removal of recalcitrant organics. Instead of using the traditional Fenton method and FeCl₃ coagulation, we investigated a two-stage Fenton process and Fenton method with PAC, in which MW chromatography was used to evaluate the fraction of organic removal in detail. We have found that the Fenton method could remove low molecular weight fractions better than FeCl₃; evidently, the two-stage Fenton method is better than a one-stage for a higher requirement of COD removal, and carbon adsorption can remove oxidation-resistant organics efficiently. The proper combination of two-stage Fenton with carbon adsorption can satisfy the COD effluent standards.