Remediation of pesticides in commercial farm soils by solarization and ozonation techniques.

Soil contamination by pesticides is a growing environmental problem. Even though nowadays numerous soil remediation technologies are available, most of them have not been tested at field scale. This study attempts to demonstrate the efficiency of solarization-ozonation techniques for the removal of twelve pesticides at full scale. Initial solarization and ozonation trials were conducted in plots located in a greenhouse using freshly and aged contaminated soils under controlled pilot conditions. The combination of solarization and ozonation treatment was efficient for all the studied pesticides both in freshly and in aged contaminated soils, being the lower degradation values found for the second type. This low removal suggests that the increase of pesticides' adsorption on soil resulting from ageing decreases their availability. Once the essays were carried out at pilot scale, the solarization-ozonation applicability was evaluated in a commercial farm soil. This trial was carried out in a greenhouse whose soil had previously been contaminated with some of the pesticides studied. A significant degradation (53.8%) was observed after 40 days of treatment. Pesticides' main metabolites were identified during the different remediation experiments. In addition, the cost of the combined solarization and ozonation technology was evaluated. Finally, our results suggest that this combination of techniques could be considered a promising technology to degrade pesticides in soil.

Remediation of triazole, anilinopyrimidine, strobilurin and neonicotinoid pesticides in polluted soil using ozonation and solarization.

This study aimed to investigate the effectiveness of ozonation and solarization techniques for the removal of different types of pesticides from soil during the summer season. The effect of two experimental parameters (temperature and ozone application mode) on the pesticide degradation was evaluated. The results showed that solarization (S), solarization with surface ozonation (SOS), and solarization with deep ozonation (SOD) enhanced pesticide degradation rates in comparison with the control (untreated soil, C). The triazole, anilinopyrimidine, strobilurin and neonicotinoid pesticides showed similar behaviour under S and SOS conditions. The highest decrease was found in SOD, indicating the significant effect of temperature and ozone application mode on the efficiency of the ozonation treatment. Thus, a higher soil temperature and a longer accumulated time at high temperature in treatments S, SOS and SOD were observed due to solarization process. In addition, the removal efficiency was enhanced with exposure time. Finally, the main 15 transformation products were identified during SOD treatment. The results suggest that solarization combined with ozonation techniques allows decontamination of soil containing pesticide residues.