Heterogeneous degradation of stabilized landfill leachate using persulfate activation by CuFe2O4 nanocatalyst: an experimental investigation

Landfill leachate, is a contaminated liquid consisted of different toxic and hazardous pollutants which could penetrate the ground and reach the groundwater, leading to the soil and water resources pollution. Hence, it is regarded as a substantial risk to the environment. Accordingly, in this work, a sustainable and efficacious sulfate radical-based oxidation approach using persulfate and heterogeneous magnetic CuFe2O4 nanocatalyst was suggested to treat municipal stabilized landfill leachate. In this study, CuFe2O4 catalyst was synthesized through the straightforward sonochemical co-precipitation method, and it was characterized by FTIR, EDX, VSM, XRD, and TEM analysis techniques. The dominant mechanism of the degradation process was discussed in detail, and the influence of various operating conditions such as pH, persulfate dosage and catalyst loading was investigated on the treatment performance of the process based on COD, ammonia-nitrogen (NH3-N) and color removal efficiencies. Under optimized condition (pH = 2, persulfate amount = 5 g/L and catalyst dosage = 1.5 g/L), the treatment process showed acceptable efficiency removals (COD, NH3-N and color removal efficiencies of 57%, 71%, and 63%, respectively). Moreover, performance of the current system was compared with performances of distinct persulfate-based and CuFe2O4-based treatment systems. The reusability of the catalyst was also evaluated over the sequential treatment runs, and the catalyst showed high reactivity over four repeated cycles. To prove the capability of the treatment process in pollutants degradation ATR-FTIR analysis of the leachate samples before and after the oxidation process was conducted, and the results showed that aromatic compounds were converted to aliphatic components after the oxidation.