多环芳烃在土壤-蔬菜界面上的迁移与积累特征

Characters of Soil-Vegetable Transfer and Accumulation of Polycyclic Aromatic Hydrocarbons

研究了南京市工业区周边污染农田土壤中16种优先控制的多环芳烃(PAHs)污染物由土壤向蔬菜迁移的特征及其在蔬菜体内的积累规律.结果表明,蔬菜体内PAHs的浓度与其生长土壤环境中PAHs的浓度呈正相关关系,且土壤中PAHs的浓度显著高于生长在该土壤上的蔬菜根和茎叶组织中的浓度(p<0.05),根中PAHs的浓度显著高于茎叶组织中的浓度(p<0.05).蔬菜根中低环PAHs与PAHs总浓度的比值(∑LMW-PAHs∑PAHs)显著高于其土壤中相应的比例(p<0.05).与高环PAHs(HMW-PAHs)相比,LMW-PAHs易被蔬菜根部吸收,表现出较高的生物有效性.生长在同种污染土壤中的4种叶菜类蔬菜体内PAHs的浓度差异不显著,即这4种蔬菜吸收积累PAHs的差异较小.

The transfer and accumulation of polycyclic aromatic hydrocarbons （PAHs） from aged contaminated agricultural soil to vegetable was studied. The results show that the positive correlation between the PAHs concentrations in tested vegetables and those in the corresponding soils is present. The PAHs concentrations in contaminated soils are significantly （p 〈 0.05 ） higher than that in roots, stems and leaves of vegetables, and the PAHs concentrations in roots are also significantly （p 〈 0.05） higher than that in stems and leaves .The ratio of sum of low molecular weight PAHs to total PAHs concentrations （ ∑ LMW-PAHs/ ∑ PAHs） in polluted vegetable roots is higher than that in corresponding soils （p 〈 0.05）, and LMW-PAHs are more easily accumulated in vegetable roots than HMW-PAHs （high molecular weitht PAHs）. The distinction of PAHs concentrations among the four selected leafy ,vegetables in the same tested soils does not aehieve the significant level.