Abstract |
Alkaline hydrolysis half-lives, based on second-order alkaline hydrolysis rate constants, for carbaryl, propham (IPC), and chlorpropham (CIPC) at pH 9 (27 degrees) are 0.15>1 x 10 to the 4th power days, and >1 x 10 to the 4th power days, respectively. The direct photolysis half-life for carbaryl in sunlight is 6.6 days in distilled water. Calculated minimum half-lives for the direct photolysis of IPC and CIPC in a clear water body near the surface are 254 and 121 days, respectively. Half-lives, based on second-order fungal rate constants, for the IPC and CIPC are calculated under given conditions. Kinetic data on hydrolysis, photolysis, and biolysis are employed as a basis for comparison of the relative importance of these three degradation processes. |