Biodegradation Of Chiral Napropamide, Metolachlor And Its Active Isomer Dulegold

Chiral pesticides are widely used for agriculture all over the world. Enantiomers of chiral compounds behave differently in biochemical processes. Therefore, the effects and the environmental fate of the enantiomers of chiral pollutants need to be investigated separately.The velocity of oxygen, pH and temperature were studied in this paper in the cultivation of microorganisms. It was showed that microorganisms were sensitivity to velocity of oxygen, pH and temperature. The optimum condition is velocity 1401/h, pH 7.0 and temperature 30 . As many organisms were oxygenated when velocity of oxygen was up to 1401/h, velocity of oxygen was chosen as 1201/h in the experinment.The enantioselectivity biodegradation of napropamide, metolachlor and DoluGold were studied in this paper. An analytical method was established using HPLC chiral OD-RH column for determining residues enantiomers of the pesticides in water. The enantiomers of Napropamide was completely separated, the resolution was up to 1.65. The enantiomers of metolachlor was separated into three peaks with both resolution of 1.05 and DuleGold was also separated into two peaks with resolution of 0.98.The enantioselectivity biodegradation of Napropamide were found. The first-peak enantiomer was degraded faster than the second. The enantioselectivity biodegradation of Metolachlor and DuleGold were not obvious. Napropamide Biodegradation rate was dependent on the adding concentration.The higher the adding concentration was, the lower the biodegradation was. The degradation dynamic of Napropamide, Metolachlor and Dule Gold were studied. The degradation kinetics follow the first kinetics Ct=C0e"kt. Four strains isolated from nature were proved to be quite effective in biodegradation of metolachlor.