The degradation of municipal solid waste incineration leachate by UV/persulfate and UV/H2O2 processes: The different selectivity of SO4•- and •OH

In this work, the different selectivity of SO 4 •- and • OH towards municipal solid waste incineration leachates (MSWILs) was studied by a comparative study of UV/persulfate (PS) and UV/H 2 O 2 . Results showed SO 4 •- preferentially mineralized carbon atoms of higher average oxidation state, while • OH showed a two-stage mechanism of partial oxidation and mineralization successively. Electron spin resonance (ESR) analysis showed SO 4 •- had superior selectivity towards MSWILs than • OH, and Fe(II) would significantly affect the selectivity via forming Fe-MSWILs complex. As the consequence, Fe(II) showed slightly negative effect on UV/PS, but greatly enhanced the performance of UV/H 2 O 2 /Fe(II). High concentration of Cl - affected the degradation of non-fluorescent substances by UV/PS, while SO 4 2 - and NO 3 - showed no effect. In contrast, anions showed no effect on UV/H 2 O 2 . In addition, • OH preferentially attacked large molecules, but SO 4 •- showed no selectivity. This study further revealed the selectivity of SO 4 •- and • OH in the treatment of hypersaline wastewater, and provided theoretical support for the development of targeted technology .