Partition Theory-Based Bioconcentration Of Chlorinated Benzenes In The Soil-Plant System

The main pathways by which organic pollutants enter plants, factors influencing bioconcentration in plant, and the corresponding model were reviewed in this paper. In addition, the content and significance in our research were also proposed.A new method of determination CBs in plant and soil was developed on basis of literature, and the new method was time-saving and simple.Season vegetables and tea trees with 40-year lives were chosen as representative of plant, the distribution of the four CBs (m-DCB o-DCB p-DCB 1,2,4-TCB) between soil-plant system were analyzed and the bioconcentration of CBs in plants and seeds was also discussed in light of partition-limited model.The result showed that mi-DCB o-DCB and 1,2,4-TCB existed in the soil-plant system, and m-DCB>o-DCB> 1,2,4-TCB. The range of concentration in soil was 2~53 ug/kg, calculated in dry weight, and 2~50ug/kg, calculated in wet weight in plant. The concentration of CBs in the different vegetable part was root>leaf>stem (with the exception that for radish and carrot, leaf>stem>root), and root>stem> leaf for tea tree.The range of BCF (bioconcentration factor) in plant was 0.1 ~ 48, and BCFSeed>BCFtea tree>BCFvegetable. For BCF(lip) (lipid normalized bioconcentration factor), koW> BCF(lip)root> BCF(lip)stem> BCF(lip)leaf in vegetables, Kow=BCF(lip)root=BCF(lip)Stem> BCF(lip)leaf in tea tree, Kow=BCF(lip)seedsds in seeds. The range of logBCF (lip) in plant was 1.5~3.9, which was lower than logkow.Bioconcentration of CBs in plant was applicable for partition-limited model, which showed that absorbing CBs by root is the main pathway in which CBs enter plant. The quasi-equilibrium factor (apt) was apt rot>apt 茎>apt 叶,apt DCB >aptTCBBioconcentration of CBs in plant is related to Kow, lipid content, and the age of this plant.