Efficient activation of oxone by pyrite for the degradation of propanil: Kinetics and degradation pathway

Pyrite (FeS2) is an abundant sulfide-associated iron mineral that exists in the earth. In this study, the pyrite/oxone process was demonstrated to be an effective approach for the catalytic degradation of propanil, where more than 90% decay ([propanil](0) = 0.01 mM) was achieved within 15 min. Typically, the effects of various experimental parameters, including catalyst loading, oxone dosage, propanil concentration, and initial solution pH, were examined. Two optimal reaction pH values were observed at pH 9.1 and pH 2.9. The generated SO4 - and OH were verified to be the dominant reactive radicals and primarily responsible for the propanil degradation. Both Fe(II) regeneration and sulfur conversion play an important role in oxone activation mechanism and effectively aid the catalytic activity of pyrite. Different co-existing natural water constituents exert dissimilar effects on the pyrite/oxone process. Additionally, the reusability test of pyrite exhibited a reasonable catalytic activity. The pyrite/oxone process was proven efficient in terms of propanil mineralization. A series of reaction intermediates was detected via four major degradation pathways. Overall, the pyrite/oxone process could be a promising approach for the removal of organic compounds in water.

Automated summary

The study demonstrated that the pyrite/oxone process is an efficient method for the degradation of propanil, with more than 90% decay achieved within 15 minutes. The generated SO4- and OH were found to be the dominant reactive radicals, with optimal reaction pH values observed at pH 9.1 and pH 2.9. The Fe(II) regeneration and sulfur conversion play important roles in the oxone activation mechanism. Co-existing natural water constituents have differing effects on the pyrite/oxone process, and the process shows promise for organic compound removal in water.