Exploring the sorption and degradation dynamics of validamycin-A in agricultural soils for environmental management

Validamycin A (VA) is one of the antibiotics that have been utilized in agriculture in Asia; nevertheless, there haven't been many investigations on what happens to VA in soil. The rate at which pesticides are adsorbed into the soil must be determined, since their usage in agriculture is growing. In order to accomplish this, the current study investigated the sorption and degradation of VA in ten distinct soil samples via batch equilibrium studies while maintaining strict laboratory controls. In thermodynamic analysis with a C-type curve, the negative values of Gibbs free energy (ΔG) are thoroughly evaluated using both linear and Freundlich models. These values vary from - 16.8 to - 22.2 kJ/mol. Impact of temperature (18, 23, and 30 °C) and pH (5, 7, and 9) on the degradation of this antibiotic in soil was also scrutinized. Our findings demonstrated that, as a result of enhanced microbial activity at higher temperatures, VA deteriorated more quickly at 23 °C and 30 °C than at 18 °C. In comparison to lower pH values, the VA removal efficiencies with sample-4 was significantly greater at pH 7.4 (92.9%) and pH 9 (97.4%). Moreover, first order reaction kinetics were followed in the degradation of VA. The results demonstrated that VA bound to the selected soils, resulting in medium to low persistence as demonstrated by degradation values. In summary, this study provides important information regarding the behavior and fate of VA in different types of soil, information that might be useful in developing workable management strategies and environmental risk assessments.