Enantioselective degradation of dufulin pesticide in water: Uptake, thermodynamics, and kinetics studies

Kudzu (Pueraria thunbergiana) plant extract impregnated sediments were used for abiotic and biotic uptakes and biodegradation. The optimized conditions were 25 mu g L-1 concentration, 7 days for abiotic uptake and 56 days for biotic uptake and biodegradation, dose 2 g L-1, 7 pH, and 35 degrees C temperature. The amount removed of dufulin was 32.6% in abiotic conditions while these were 90% in the case of biotic uptake and biodegradation. Enantioselective biodegradation indicated that S-(+)-enantiomer degraded faster (90%) than R-(-)-enantiomer (87%). The data for abiotic and biotic uptakes and biodegradation followed well Langmuir, thermodynamics, and kinetics models. All these processes followed pseudo first-order kinetics. It was observed that biodegradation was three times responsible for dufulin removal than simple sorption uptake (abiotic and biotic). The abiotic and biotic uptakes and biodegradation were quite fast and endothermic nature. The developed method may be used to remove the racemic and enantiomeric dufulin in water.