Degradation of 1,3-Dichloropropene (1,3-D) in Soils with Different Histories of Field Applications of 1,3-D

Laboratory experiments were conducted to determine the mineralization rates of 1,3-dichloropropene (1,3-D) in surface and subsurface soil samples collected from three sites in Florida with different histories of 1,3-D exposure. Mineralization rates of uniformly labeled ¹⁴C-1,3-D in surface and subsurface samples collected from two of the three sites, one of which was treated with 1,3-D only once and the other which had not been treated with the chemical for 5 years, were similar to the corresponding samples collected from untreated plots, and the rates generally decreased with soil depth. Initial mineralization rates in surface and subsurface samples collected from the site that had repeatedly been treated with 1,3-D at least 6 of the past 12 years were more rapid than those in either the corresponding untreated samples or in samples collected from the two other sites. Not only were the initial mineralization rates in soil samples collected from this site greater, but also the disappearance rates of cis- and trans-l,3-D were greater than in the corresponding untreated samples. Trans-1,3-D was degraded much more rapidly in the enhanced soil than was the cis- form. In addition, no or little trans-3-chloroallyl alcohol (CAA), the hydrolysis product of trans-l,3-D, was formed; large amounts of cis-3-CAA, the hydrolysis product of cis-1,3-D, were detected. This suggest that biological hydrolysis is responsible for the hydrolysis of trans-l,3-D to trans-3-CAA in enhanced soil and chemical hydrolysis is responsible for the hydrolysis of cis- and trans-l,3-D to 3-CAA in nonenhanced soil.