PMID- 14998036
OWN - NLM
STAT- MEDLINE
DCOM- 20040421
LR  - 20190714
IS  - 0013-936X (Print)
IS  - 0013-936X (Linking)
VI  - 38
IP  - 4
DP  - 2004 Feb 15
TI  - Remediation of methyl iodide in aqueous solution and soils amended with thiourea.
PG  - 1188-94
AB  - Methyl iodide (MeI) is considered a very promising fumigant alternative to methyl 
      bromide (MeBr) for controlling soil-borne pests. Because atmospheric emission of 
      highly volatile fumigants contributes to air pollution, feasible strategies to 
      reduce emissions are urgently needed. In this study, thiourea (a nitrification 
      inhibitor) was shown to accelerate the degradation of MeI in soil and water. In 
      aqueous solution, the reaction between MeI and thiourea was independent of pH, 
      although the rate of MeI hydrolysis increased in alkaline solution. Substantial 
      increases in the rate of MeI dissipation were observed in thiourea-amended soils. 
      Transformation of MeI by thiourea in aqueous solution was by a single chemical 
      reaction process, while MeI degradation in thiourea-amended soil apparently 
      involved a catalytic mechanism. The electron delocalization between the thiourea 
      molecule and the surfaces of soil particles is energetically favorable and would 
      increase the nucleophilic reactivity of the thiono group toward MeI, resulting in 
      an enhancement of the dissipation rate. The soil half-life for MeI was reduced 
      from >300 h for unamended soils to only a few hours in soil or sand amended with 
      thiourea at a 2:1 molar ratio (thiourea:MeI). The MeI transformation rate in 
      thiourea-amended soil increased with increasing soil temperature and decreasing 
      soil moisture. Therefore, spraying thiourea on the soil surface to form a 
      "reactive surface barrier" may be an effective and innovative strategy for 
      controlling fumigant emissions to the atmosphere and for improving environmental 
      protection.
FAU - Zheng, Wei
AU  - Zheng W
AD  - USDA-ARS, Soil Physics and Pesticides Research Unit, George E. Brown Jr. Salinity 
      Laboratory, Riverside, California 92507, USA.
FAU - Papiernik, Sharon K
AU  - Papiernik SK
FAU - Guo, Mingxin
AU  - Guo M
FAU - Yates, Scott R
AU  - Yates SR
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Environ Sci Technol
JT  - Environmental science & technology
JID - 0213155
RN  - 0 (Hydrocarbons, Iodinated)
RN  - 0 (Indicators and Reagents)
RN  - 0 (Soil Pollutants)
RN  - DAT010ZJSR (methyl iodide)
RN  - GYV9AM2QAG (Thiourea)
SB  - IM
MH  - Air Pollution/*prevention & control
MH  - Catalysis
MH  - Fumigation
MH  - Hydrocarbons, Iodinated/*analysis/*chemistry
MH  - Indicators and Reagents/*chemistry
MH  - Soil Pollutants
MH  - Temperature
MH  - Thiourea/*chemistry
MH  - Volatilization
EDAT- 2004/03/05 05:00
MHDA- 2004/04/22 05:00
CRDT- 2004/03/05 05:00
PHST- 2004/03/05 05:00 [pubmed]
PHST- 2004/04/22 05:00 [medline]
PHST- 2004/03/05 05:00 [entrez]
AID - 10.1021/es034149x [doi]
PST - ppublish
SO  - Environ Sci Technol. 2004 Feb 15;38(4):1188-94. doi: 10.1021/es034149x.