Correlation of pesticide ecotoxicity with clay mineral dispersion effect on adsorption and ozonation – An approach through impact assessment on Lemna minor

An unprecedented approach allowed correlating the pesticide fate in clay-containing media under air exposure with their ecotoxicity. This constitutes the novelty of this work and involves the study of the toxicity of ozonized pesticide-containing waters towards an aquatic plant, Lemna minor. The behavior of diazinon (DAZ) and atrazine (ATR) in natural clay-containing media was simulated in plant growth media fulfilling the Swedish Institute for Standards (SIS) containing Na+ and Fe2+-exchanged montmorillonite (Mt). The exchangeable cation was found to influence the pesticide ozonation and toxicity towards Lemna minor. Pesticide interactions appear to promote high catalytic surface through a compromise between low pH and high Mt dispersion. These results provide valuable findings for predicting pesticide ecotoxicity according to their natural oxidative degradation in the host clay suspension.