| Polycyclic aromatic hydrocarbons(PAHs) is a kind of hydrocarbons, its molecular structure contains two or more aromatic rings. Widespread in the environment, it transfers and accumulates in the soil-plant system, and has great impacts on ecosystem and human health. Through the research on the characteristics and affecting factors of PAHs on the camphor tree root-soil interface, this paper discussed the migration and transformation of the PAHs in the plant-soil system, which provided a scientific basis for plant Repair of persistent organic pollutants. The results showed that:Distribution patterns of the mass fractions ofΣPAHs on root-soil interface of camphor tree showed:non-rhizosphere soil> rhizosphere> root; The highest concentration of single species of PAHs is PHE(0.5076mg.kg" 0.4206mg.kg-1 and 0.2887mg.kg-1), the lowest concentration of single species of PAHs on root-soil interface are different, the lowest concentration compound in non-rhizosphere soil is the BghiP (0.0008 mg.kg-1), and the lowest concentration compound in rhizosphere soil compound is IcdP (0.0004mg.kg-1), the lowest concentration compound in the roots is BaP (0.0017mg.kg-1)The maximum of the mass fractions of EPAHs in non-rhizosphere soil and rootsΣPAHs were in April (1.96830mg.kg-1 and 1.1088mg.kg-1), The maximum of the mass fractions of EPAHs in rhizosphere soil was in July (1.9462mg.kg-1), but the minimum of the mass fractions ofΣPAHs in non-rhizosphere soil, rhizosphere soil and roots were in October (0.1501 mg.kg-1,0.1011mg.kg-1 and 0.2292 mg.kg-1); the highest rate of PAHs detected in non-rhizosphere soil and rhizosphere soil were in July, the highest rate of PAHs detected in root was January. PAHs concentration in spring and summer higher than autumn and winter.Distribution patterns of the mass fractions ofΣPAHs and each component content of PAH in 0-20cm soil layer showed:rhizosphere soil (1.1843 mg.kg-1)> rhizosphere soil (1.0541 mg.kg-1)> root (0.6848 mg.kg-1), distribution patterns of the mass fractions ofΣPAHs and each component content of PAH in 21-40cm soil layer showed:non-rhizosphere soil(1.4057 mg.kg-1)> rhizosphere(1.2173mg.kg-1)> root(0.6715mg.kg-1), distribution patterns of the mass fractions ofΣPAHs and each component content of PAH in 41-60cm soil layer showed:non-rhizosphere soil (1.1900mg.kg-1)> rhizosphere (0.9062 mg.kg-1)> root (0.6018 mg.kg-1)Vertical distribution pattern of the mass fractions ofΣPAHs and each component content of PAH on Root-soil interface is:with increasing soil depth, the mass fractions of PAHs in the way significantly decreased.The correlative analysis shows it is significantly negative correlated between Actinomyces and PAHs in non-rhizosphere soil, while the correlations between Bacteria,Fungi and PAHs fail to meet the significant level. In rhizosphere soil, it is significantly negative correlated between Fungi,Actinomyces and PAHs. And it is significantly negative correlated between Bacteria,Actinomyces and PAHs.The correlative analysis shows it is significantly positive correlated between Catalase activities,Phosphatase activities and PAHs in non-rhizosphere soil, while the correlation between Polyphenol oxidase activities and PAHs fail to meet the significant level. In rhizosphere soil, It is showed that it is significantly positive correlated between Catalase activities, Polyphenol oxidase activities and PAHs, while correlations between Phosphatase activities and PAH don't meet the significant level. The correlative analysis shows it is positively correlated between PAHs and soil organic matter, soil organic matter in the soil influenced the distribution of PAHs strongly. |
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