ABSTRACT
The n-butyl ester of 2,4-dichlorophenoxyacetic acid (2,4-D) has been primarily released to the atmosphere during spraying operations in its use as a herbicide on cereal and other crops and aquatic weeds. The oxygen uptake of n-butyl 2,4-D was considerably higher than controls after 2 days when incubated with sewage seed. The adsorption of the n-butyl ester of 2,4-D to several Canadian prairie soils was attempted using slurries in a batch and soil column experiments. The sorbed amounts were very small, as is evidenced by the fact that 8.77 g of bentonite, 13.33 g of illite, or 42.73 g of kaolinite are required to reduce the concentration of butyl 2,4-D from 3 to 2 mg/L. The adsorption of butyl ester of 2,4-D to flocculated humic acid is stronger than the free acid and the adsorption follows Freundlich isotherm pattern with a slope of 0.97. 2,4-D and its derivatives can be absorbed via the oral, dermal, and inhalation routes.
