Remediation of organophosphorus pesticide polluted soil using persulfate oxidation activated by microwave

Contaminated sites from pesticide industry have attracted global concern due to the characteristics of organic pollution with high concentrations and complete loss of habitat conditions. Remediation of organophosphorus pesticide polluted soil using microwave-activated persulfate (MW/PS) oxidation was investigated in this study, with parathion as the representative pesticide. Approximately 90 % of parathion was degraded after 90 min of MW/PS oxidation treatment, which was superior to those by single PS or MW treatment. Relatively greater performances for parathion degradation were obtained in a relatively larger PS dosage, higher microwave temperature, and lower organic matter content. Appropriate soil moisture favored parathion degradation in soil. SO4.(-),.OH, O-2.(-), and O-1(2) generated in the MW/PS system all contributed to parathion degradation. Multiple spectroscopy analyses indicated that P-O and P=S bonds in parathion were destroyed after MW/PS oxidation, accompanied by generation of hydroxylated and carbonylated byproducts. The soil safety after parathion degradation was assessed via model prediction. Furthermore, MW/PS oxidation also exhibited great performance for degradation of other organophosphorus pesticides, including ethion, phorate, and terbufos.

Automated summary

The study found that using microwave-activated persulfate (MW/PS) oxidation can effectively degrade organophosphorus pesticides like parathion in contaminated soil. The oxidation products generated in the MW/PS system play a crucial role in the degradation of organophosphorus pesticides. Suitable treatment conditions include larger persulfate dosage, higher microwave temperature, and appropriate soil moisture.