Remediation of atrazine-polluted soil using dielectric barrier discharge plasma and biochar sequential batch experimental technology

Abstract

Dielectric barrier discharge (DBD)-biochar sequential batch experimental technology was employed to degrade atrazine (ATZ) in soil. The hydrophilicity, particle size and instability of soil particles increased after DBD treatment, which contributed to the exposure of residual ATZ in the soil. Meanwhile, the subsequent introduction of biochar compensated for the shortcomings of sole DBD treatment (e.g. increased soil sparseness and pH, enhanced the living environment of microorganisms). The ATZ removal efficiency in air discharge reached 66.1 % after 10 min of DBD treatment and 30 min of biochar adsorption, and the energy yield was 4.2 times higher than that of sole DBD treatment. The functional active species in ATZ degradation were confirmed to be oxygen-containing reactive species. ATZ degradation mechanisms were proposed, including dealkylation, dechloro-hydroxylation, alkylic-hydroxylation, alkylic-oxidation, olefinization and deamino-hydroxylation reactions. Hence, the study demonstrated an environmentally friendly technology for effective ATZ degradation while improving the fertility of soil with no chemical injections.