Ecotoxicity Assessment of Four Oxidizing Agents for Remediation of BTEXs-Contaminated Soil

In this investigation, four classical chemical oxidizing agents—hydrogen peroxide (H 2 O 2 ), Fenton reagent, sodium persulfate (Na 2 S 2 O 8 ), and potassium permanganate (KMnO 4 )—were employed to remediate soils contaminated with BTEXs (benzene, toluene, ethylbenzene, and xylene). Simultaneously, ecotoxicity assays were integrated to comprehensively evaluate the consequences of the remediation efforts. The various oxidizing agents demonstrated efficient removal of BTEXs from the soil at appropriate concentrations. Post-remediation ecotoxicity evaluations indicated that H 2 O 2 and KMnO 4 treatments had the least phytotoxic effects on soil. On the contrary, high doses of Fenton and Na 2 S 2 O 8 treatments significantly increased the phytotoxicity of the soil. Each of the four oxidative interventions led to a reduced survival rate among earthworms, with a particularly pronounced effect observed at high concentrations of Na 2 S 2 O 8 . The oxidation of water-soluble substances in the soil by Fenton and Na 2 S 2 O 8 exerted a significant inhibitory impact on the luminous intensity of luminescent bacteria. Conversely, the remediation with KMnO 4 substantially alleviated the aquatic biotoxicity of soil leachate. This deleterious effect was mitigated by the application of low concentrations of H 2 O 2 and Fenton. However, the utilization of KMnO 4 resulted in a significant reduction in the diversity of soil microbial communities. Graphical Abstract