Performance of combined persulfate/aluminum sulfate for landfill leachate treatment

Abstract

Although landfilling is still the most suitable method for solid waste disposal, generation of large quantity of leachate is still considered as one of the main environmental problem. Efficient treatment of leachate is required prior to final discharge. Persulfate (S2O82−) recently used for leachate oxidation, the oxidation potential of persulfate can be improved by activate and initiate sulfate radical. The current data aimed to evaluate the performance of utilizing Al2SO4 reagent for activation of persulfate to treat landfill leachate. The data on chemical oxygen demand (COD), color, and NH3–H removals at different setting of the persulfate, Al2SO4 dosages, pH, and reaction time were collected using a central composite design (CCD) were measured to identify the optimum operating conditions. A total of 30 experiments were performed, the optimum conditions for S2O82−/Al2SO4 oxidation process was obtained. Quadratic models for chemical oxygen demand (COD), color, and NH3–H removals were significant with p-value < 0.0001. The experimental results were in agreement with the optimum results for COD and NH3–N removal rates to be 67%, 81%, and 48%, respectively). The results obtained in leachate treatment were compared with those from other treatment processes, such as S2O82− only and Al2SO4 only, to evaluate its effectiveness. The combined method (i.e., /S2O82−/Al2SO4) showed higher removal efficiency for COD, color, and NH3–N compared with other studied applications.