PMID- 12487310
OWN - NLM
STAT- MEDLINE
DCOM- 20030411
LR  - 20190714
IS  - 0013-936X (Print)
IS  - 0013-936X (Linking)
VI  - 36
IP  - 22
DP  - 2002 Nov 15
TI  - The influence of vertical sorbed phase transport on the fate of organic chemicals 
      in surface soils.
PG  - 4860-7
AB  - Gaseous exchange between surface soil and the atmosphere is an important process 
      in the environmental fate of many chemicals. It was hypothesized that this 
      process is influenced by vertical transport of chemicals sorbed to soil 
      particles. Vertical sorbed phase transport in surface soils occurs by many 
      processes such as bioturbation, cryoturbation, and erosion into cracks formed by 
      soil drying. The solution of the advection/diffusion equation proposed by Jury et 
      al. to describe organic chemical fate in a uniformly contaminated surface soil 
      was modified to include vertical sorbed phase transport This process was modeled 
      using a sorbed phase diffusion coefficient, the value of which was derived from 
      soil carbon mass balances in the literature. The effective diffusivity of the 
      chemical in a typical soil was greater in the modified model than in the model 
      without sorbed phase transport for compounds with log K(OW) > 2 and log K(OA) > 
      6. Within this chemical partitioning space, the rate of volatilization from the 
      surface soil was larger in the modified model than in the original model by up to 
      a factor of 65. The volatilization rate was insensitive to the value of the 
      sorbed phase diffusion coefficient throughout much of this chemical partitioning 
      space, indicating that the surface soil layer was essentially well-mixed and that 
      the mass transfer coefficient was determined by diffusion through the atmospheric 
      boundary layer only. When this process was included in a non-steady-state 
      regional multimedia chemical fate model running with a generic emissions scenario 
      to air, the predicted soil concentrations increased by upto a factor of 
      25,whilethe air concentrations decreased by as much as a factor of approximately 
      3. Vertical sorbed phase transport in the soil thus has a major impact on 
      predicted air and soil concentrations, the state of equilibrium, and the 
      direction and magnitude of the chemical flux between air and soil. It is a key 
      process influencing the environmental fate of persistent organic pollutants 
      (POPs).
FAU - McLachlan, Michael S
AU  - McLachlan MS
AD  - Baltic Sea Research Institute, Seestrasse 15, D-18119 Rostock, Germany. 
      michael.mclachlan@io-warnemuende.de
FAU - Czub, Gertje
AU  - Czub G
FAU - Wania, Frank
AU  - Wania F
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Environ Sci Technol
JT  - Environmental science & technology
JID - 0213155
RN  - 0 (Air Pollutants)
RN  - 0 (Soil Pollutants)
RN  - 7440-44-0 (Carbon)
SB  - IM
MH  - Adsorption
MH  - Air Movements
MH  - Air Pollutants/*analysis
MH  - Carbon/chemistry
MH  - *Models, Theoretical
MH  - Soil Pollutants/*analysis
MH  - Volatilization
EDAT- 2002/12/19 04:00
MHDA- 2003/04/12 05:00
CRDT- 2002/12/19 04:00
PHST- 2002/12/19 04:00 [pubmed]
PHST- 2003/04/12 05:00 [medline]
PHST- 2002/12/19 04:00 [entrez]
AID - 10.1021/es025662y [doi]
PST - ppublish
SO  - Environ Sci Technol. 2002 Nov 15;36(22):4860-7. doi: 10.1021/es025662y.