Agrochemical 2-chloro-2',6'-diethyl-N-methoxymethylacetanilide tranformative and sorptive demeanor in agriculturally significant pedospheric environs

ABSTRACT

Environmental fate of herbicide, Alachlor was evaluated by closely imitating the natural pedosphere through multifarious experiments such as; adsorption, desorption, hydrolysis, photo-degradation and biodegradation. Ten heterogeneous and agriculturally significant soils were utilised for these experiments. Sorption experiments, performed through batch equilibrium method indicated Alachlor distribution ranging from 12 µg ml⁻¹ to 75 µg ml⁻¹. Soil physicochemical characteristics highly influenced the sorption process, indicating an overall weaker physisorption and an exothermic reaction reflected via negative values for Gibbs free energy. Degradation assays were performed for the determination of the impact of biotic and abiotic constraints on Alachlor dissipation. UV-visible spectrophotometry and GC-MS were utilised to analyse Alachlor treated soil samples following extraction at fixed intervals. First-order reaction kinetics were applied on Alachlor degradation. Lowest half-life in hydrolysis, photo-degradation and biodegradation was 2.2, 1.5 and 0.5 days, respectively, while the highest was 5.7, 2.5 and 1.7 days, respectively. Highest transformation percentages attained by hydrolysis, photo-degradation and biodegradation were 96.7%, 99.7% and 99.9%, respectively. Results depicted mediocre binding and less persistence of Alachlor to the soils whilst being exceedingly vulnerable to transformation paths.

KEYWORDS:

• Herbicide
• fate
• hydrolysis
• photo-degradation
• biodegradation

Disclosure statement

No potential conflict of interest was reported by the authors.

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