Submitted to: American Chemical Society National Meeting
Publication Type: Proceedings
Publication Acceptance Date: July 20, 2002
Publication Date: August 1, 2002
Repository URL: http://www.ars.usda.gov/SP2UserFiles/Place/53102000/pdf_pubs/P1854.pdf
Citation: Zheng, W., Papiernik, S.K., Guo, M., Yates, S.R. 2002. Competitive degradation between fumigants chloropicrin and 1,3-dichloropropene in soils. Proceedings of Division of Environmental Chemistry, American Chemical Society National Meeting, Aug. 18-22, 2002, Boston, MA. 42(2):65-68. Technical Abstract: The current scientific opinion that methyl bromide contributes significantly to the depletion of stratospheric ozone has led to research on developing better management practices and identifying chemical alternatives to methyl bromide. 1,3-Dichloropropene (1,3-D) formulated with chloropicrin (CP) has been considered a practical alternative fumigant and such mixtures have been developed as commercial formulations. Generally, soil chemical and biological conditions influence the rate of fumigant degradation in soil. Previous research has focused on characterizing abiotic and biotic transformation of a single fumigant compound in soil, and little information exists regarding the effect of fumigant mixtures on the degradation rate. In this study, we determined the rate of degradation of 1,3-D and CP separately and as mixtures and evaluated possible competitive abiotic and biotic degradation in soils. Overall, the first-order rate constant (k) of CP was not influenced considerably when it was applied with 1,3-D in fresh soils, but competitive degradation was observed in autoclaved soils. No significant difference in the k of cis-1,3-D was observed with and without CP; however, the k of trans-1,3-D was decreased when CP was applied to fresh soils. Competitive degradation was also observed in soils amended with nucleophilic compounds such as ammonium thiosulfate.