Activation of persulfate using an industrial iron-rich sludge as an efficient nanocatalyst for landfill leachate treatment

Abstract

In this research, the performance of nanomaterials obtained from the converter sludge (CS) of Esfahan Steel Company, Iran was investigated for the activation of persulfate (PS). The experiments were conducted on real and synthetic leachates. CS showed high catalytic activity for removal of chemical oxygen demand COD and NH3 because of its high iron oxide content. The effects of pH, CS dosage, and PS/COD ratio, temperature, and reaction time on the removal of COD and NH3 were evaluated to optimize operational conditions (pH 2, CS dosage: 1.2 g L−1, PS/COD: 4, and reaction time: 60 min). Maximum COD and NH3 removal efficiencies were 73.56 and 63.87%, respectively. Finally, the optimized process was applied for treatment of a real leachate sample. Although the treated leachate was not suitable to discharge into the environment, an increase in the 5-day biochemical oxygen demand (BOD5) and biodegradability (BOD5/COD) of leachate after treatment indicated that the effluent can be biologically treated. As a consequence, it can be combined with sewage or can be returned to the landfill.