|
|
seeKSpace >
环境与生态科学开放知识资源 >
网络开放学术资源 >
Please use this identifier to cite or link to this item:
http://hdl.handle.net/2239/31271
|
| Title: | Dechlorination of chloropicrin and 1,3-dichloropropene by hydrogen sulfide species: redox and nucleophilic substitution reactions. |
| Authors: | Zheng, W.
Yates, S.R.
Papiernik, S.K.
Guo, M.
Gan, J.
USDA, ARS |
| Keywords: | nucleophilic substitution reactions
hydrogen sulfide species
1,3-dichloropropene
chloropicrin
dechlorination
hydrogen sulfide
aqueous solutions
fumigants
redox reactions |
| Issue Date: | 17-Oct-2007 |
| Description: | The chlorinated fumigants chloropicrin (trichloronitromethane) and 1,3-dichloropropene (1,3-D) are extensively used in agricultural production for the control of soilborne pests. The reaction of these two fumigants with hydrogen sulfide species (H2S and HS(-)) was examined in well-defined anoxic aqueous solutions. Chloropicrin underwent an extremely rapid redox reaction in the hydrogen sulfide solution. Transformation products indicated reductive dechlorination of chloropicrin by hydrogen sulfide species to produce dichloro- and chloronitromethane. The transformation of chloropicrin in hydrogen sulfide solution significantly increased with increasing pH, indicating that H2S is less reactive toward chloropicrin than HS(-) is. For both 1,3-D isomers, kinetics and transformation products analysis revealed that the reaction between 1,3-D and hydrogen sulfide species is an S(N)2 nucleophilic substitution process, in which the chlorine at C3 of 1,3-D is substituted by the sulfur nucleophile to form corresponding mercaptans. The 50% disappearance time (DT50) of 1,3-D decreased with increasing hydrogen sulfide species concentration at a constant pH. Transformation of 1,3-D was more rapid at high pH, suggesting that the reactivity of hydrogen sulfide species in the experimental system stems primarily from HS(-). Because of the relatively low smell threshold values and potential environmental persistence of organic sulfur products yielded by the reaction of 1,3-D and HS(-), the effects of reduced sulfide species should be considered in the development of alternative fumigation practices, especially in the integrated application of sulfur-containing fertilizers. |
| URI: | http://seekspace.resip.ac.cn/handle/2239/31271 |
| Other Identifiers: | http://seekspace.resip.ac.cn/handle/10113/641 |
| Appears in Collections: | 网络开放学术资源
|
Files in This Item:
There are no files associated with this item.
|
All items in DSpace are protected by copyright, with all rights reserved.
|
