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Environ Sci Technol

Title:		"Reducing 1,3-dichloropropene emissions from soil columns amended with thiourea"
Author(s):		Zheng W; Yates SR; Papiernik SK; Wang Q;
Address:		"Department of Environmental Sciences, University of California, Riverside, California 92521, USA. wzheng@ussl.ars.usda.gov"
Journal Title:		Environ Sci Technol
Year:		2006
Volume:		40
Issue:		7
Page Number:		2402 - 2407
DOI:		10.1021/es051889s
ISSN/ISBN:		0013-936X (Print) 0013-936X (Linking)
Abstract:		"Soil fumigants are becoming an important source of volatile organic compounds (VOCs) in air, especially in some agricultural areas. In this study, we used thiourea to construct a reactive surface barrier (RSB) at the soil surface for reducing 1,3-dichloropropene (1,3-D) volatilization. The agrochemical thiourea could rapidly transform volatile 1,3-D to nonvolatile products via an SN2 nucleophilic substitution reaction. A catalytic mechanism in thiourea-amended soil facilitated the conversion process. A packed soil column system was employed to investigate the emissions and distribution of 1,3-D and optimize the original fumigant emission-reduction strategy. Volatilization of 1,3-D from the soil surface was significantly reduced in columns amended with a thiourea RSB compared with that of bare soil. Volatilization flux and cumulative emissions decreased with increasing thiourea application rate and increasing fumigation depth in packed soil columns. Surface amendment with the RSB did not affect the subsurface distribution of 1,3-D in the soil profile. Combined application of a thiourea RSB and plastic tarps had a synergetic effect in emission control and could eliminate the relatively high fumigant flux that occurs upon tarp disruption. Therefore, this reduced-risk practice was very effective in reducing atmospheric emissions of VOCs from soil treatment with halogenated fumigants"
Keywords:		"Allyl Compounds/*chemistry Catalysis Hydrocarbons, Chlorinated Soil/*analysis Thiourea/*chemistry;"
Notes:		"MedlineZheng, Wei Yates, Scott R Papiernik, Sharon K Wang, Qiquan eng 2006/05/02 Environ Sci Technol. 2006 Apr 1; 40(7):2402-7. doi: 10.1021/es051889s"