Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system

Abstract

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system is described. Both uptake and degradation processes of (-)-o,p-DDT were slightly higher than (+)-o,p-DDT enantiomer. The optimized parameters for uptake were 7.0 μg L−1 concentration of o,p-DDT, 60 min contact time, 5.0 pH, 6.0 g L−1 amount of reverine sediment and 25 °C temperature. The maximum degradation of both (-)- and (+)-o,p-DDT was obtained with 16 days, 0.4 μg L−1 concentration of o,p-DDT, pH 7 and 35 °C temperature. Both uptake and degraded process followed first order rate reaction. Thermodynamic parameters indicated exothermic nature of uptake and degradation processes. Both uptake and degradation were slightly higher for (-)-enantiomer in comparison to (+)-enantiomer of o,p-DDT. It was concluded that both uptake and degradation processes are responsible for the removal of o,p-DDT from nature but uptake plays a crucial role. The percentage degradations of (-)- and (+)-o,p-DDT were 30.1 and 29.5, respectively. This study may be useful to manage o,p-DDT contamination of our earth's ecosystem.