水稻根系对多环芳烃的吸着与吸收

采集了天津市宝坻和新立2地的水稻根系样品及同期当地的空气、灌溉水和田间土壤样品.将水稻根分为节根和侧根2部分,并采用连续提取方法将根系中的多环芳烃分为3种形态:根表弱吸着态、根表强吸着态和根内吸收态.结果表明:2样点根系中多环芳烃含量存在显著差异;节根和侧根中的多环芳烃含量存在显著差异;被根吸收的部分约占多环芳烃总量的60%左右.比表面和脂含量是影响水稻根系化合物浓度的主要参数.

Sorption and Absorption of PAHs to Rice Roots

Intact rice roots,ambient air,soil and irrigation water samples were collected from two sites at Baodi and Xinli,Tianjin.The rice roots were separated into nodal roots and lateral roots,which were extracted individually using a three-step sequential extraction procedure to measure the sorbed,strongly sorbed and interior adsorbed fractions.The results show that remarkable difference of PAH contents between the samples from the two sites and relatively higher PAH contents in the lateral roots than those in the nodal roots,around 60% of the total PAHs detected were those absorbed in the root tissues.Specific surface area and lipid content of the roots are main factors influencing PAH contents.