Heterogeneous activation of peroxymonosulfate by natural chalcopyrite for efficient remediation of groundwater polluted by aged landfill leachate

Abstract

Natural chalcopyrite (NCP) was used as a low-cost and efficient activator of peroxymonosulfate (PMS) to repair groundwater polluted by aged landfill leachate. The optimal remediation effect of polluted groundwater was achieved at pH 8, PMS concentration 25 mM and NCP dosage 10 g/L via response surface method. The excellent performance of NCP was mainly Fe3+/Fe2+ and Cu2+/Cu+ cycles promoted by sulfur species, which was investigated via XPS analysis. Furthermore, the transformation of SO4•─, •OH and O2•─ were clarified by quenching experiments and ESR. The conversion of organics was revealed by UV–vis spectra and three-dimensional fluorescence spectra. Moreover, the toxicity of polluted groundwater after remediation was significantly reduced through the growth of Chlorella pyrenoidosa. Finally, the flowing experiment using NCP/sand column showed that NCP could effectively activate PMS and thereby restore polluted groundwater.