KINETIC ASSESSMENT OF THE EFFECT OF CARBAMATE INSECTICIDES ON ANAEROBIC TRANSFORMATION OF COSUBSTRATE REACTIONS

This study reports on the biokinetics of the effects of carbamate inse cticides on co-substrate inhibition in unacclimated anaerobic cultures . Results of the experiments carried out in this study showed that car bofuran and aldicarb were not toxic to co-substrate transformation rea ctions. Carbaryl was moderately toxic towards unacclimated cultures by inhibiting both ethanol and acetate conversion reactions. An increase in carbaryl concentration produced a decrease in the maximum specific substrate utilization rate (k) and the half-saturation coefficient (K -s) for the ethanol conversion reaction, and a decrease in the maximum specific substrate utilization rate (k) and an increase in the half-s aturation coefficient (K-s) for the acetate conversion reaction. The e xperimental program also indicated that carbaryl was converted to 1-na phthol in the reactors and 1-naphthol was more toxic to the co-substra te transformation reactions than the parent insecticide.