Soil-air partitioning is an important diffusive process that affects the environmental fate of organic compounds and human health. In this review, factors affecting the soil-air partitioning of polychlorinated bipheny...Soil-air partitioning is an important diffusive process that affects the environmental fate of organic compounds and human health. In this review, factors affecting the soil-air partitioning of polychlorinated biphenyls(PCBs) and total dichloro-diphenyl-trichloroethanes(p,p'- and o,p'- isomers of DDT, DDD, and DDE) are discussed. Hydrophobicity is an important factor that influences soil-air partition coefficients(KSA), and its effect can be explained through enthalpy of phase change for soil-air partitioning transfer(ΔHSA). For more hydrophobic compounds, a sharp increase in the KSA of PCBs and organochlorines can be seen in the early aging period. During the aging period, the temperature has a significant effect on the more hydrophobic organic compounds. The content and properties of soil organic matter influence the KSA of the target compounds. Generally, KSA decreases with increasing relative humidity in soils. The linear trend between KSA and temperature(T) changes at 0 °C. Freezing the air or soil in experiments would change the research results. On the basis of factors influencing soil-air partitioning, a multipleparameter(T, organic carbon fraction(fOC), and octanol-air partition coefficient(KOA)) model is put forward to predict the KSA values for PCBs and total DDTs.展开更多
基金supported by the National Natural Science Foundation of China (No. 41172223)the Fundamental Research Funds for the Central Universities (No. 2652012089)the Commonwealth and Environmental Protection Project of the Ministry of Environmental Protection of the People’s Republic of China (No. 201209053)
文摘Soil-air partitioning is an important diffusive process that affects the environmental fate of organic compounds and human health. In this review, factors affecting the soil-air partitioning of polychlorinated biphenyls(PCBs) and total dichloro-diphenyl-trichloroethanes(p,p'- and o,p'- isomers of DDT, DDD, and DDE) are discussed. Hydrophobicity is an important factor that influences soil-air partition coefficients(KSA), and its effect can be explained through enthalpy of phase change for soil-air partitioning transfer(ΔHSA). For more hydrophobic compounds, a sharp increase in the KSA of PCBs and organochlorines can be seen in the early aging period. During the aging period, the temperature has a significant effect on the more hydrophobic organic compounds. The content and properties of soil organic matter influence the KSA of the target compounds. Generally, KSA decreases with increasing relative humidity in soils. The linear trend between KSA and temperature(T) changes at 0 °C. Freezing the air or soil in experiments would change the research results. On the basis of factors influencing soil-air partitioning, a multipleparameter(T, organic carbon fraction(fOC), and octanol-air partition coefficient(KOA)) model is put forward to predict the KSA values for PCBs and total DDTs.
