Navigating Imidacloprid Insecticide's Destiny: Sorption and Degradation Aspects in Varied Ecological Zones

Abstract

Sorption profoundly influences the destiny and behavior of agrochemicals in soil and water. The goal of the current study is to use the batch equilibrium technique to examine the adsorption–desorption behavior of the neonicotinoid pesticide imidacloprid in 10 distinct types of Pakistani soils (Ss1–Ss10). Adsorption coefficients (K_d) and associated parameters were assessed using the batch equilibrium approach. The findings showed that the best fit to the experimental data was given by the Freundlich isotherm. In view of this, the Ss6 depicted the highest adsorption coefficient (K_d) value (13.30 µg/mL), followed by Ss7 and Ss8. The positive correlation between K_d and soil organic matter decided it as a major affecting parameter for high adsorption. Negative Gibbs free energy values exhibited the weaker physio-sorption between soil and imidacloprid molecules. Minimum half-lives recorded in photolytic and biodegradative experiments were 247 and 28 days, respectively showing the persisting nature of imidacloprid. Results indicated that imidacloprid had a moderate to strong binding to the chosen soils, resulting in increased persistence and less breakdown. Work currently being done can be expanded to further optimize these impermissible methods to provide workable solutions for cleaning up the environment using natural means.