Ozonation for remediation of pesticide-contaminated soils at field scale

This work is the first ever study under field conditions for the removal of different classes of pesticides from soil using ozonation as a remediation technique. Initial assays were conducted with three different soil matrices to assess the effectiveness of the methodology under lab conditions. Field scale experiments were carried out on plots located in a greenhouse during the winter of 2020. The polluted soil was exposed to different treatments to test the effect of the mode of ozone application on pesticide degradation (S: polyethylene film covering, SOS: polyethylene film + surface ozone application, SOD: polyethylene film + deep application, SODS: polyethylene film + dual application, and C: no treatment). Ozonation impact was also assessed by variations on physical-chemical characteristics of the soil. Higher degradation was detected in ozonized soils, particularly in the SODS treatment, where ozone was dually applied on the surface and deep. During monitoring of remediation experiments, 15 of the main transformation products (TPs) were found. The results suggest that ozonation has favourable prospects to be considered a credible alternative technology for remediation of pesticide polluted soils.