title: Polychlorinated biphenyls in alfalfa: Accumulation, sorption and speciation in different plant parts.
abstract: The accumulation, chemical speciation and distribution of polychlorinated biphenyls (PCBs) were investigated in various parts of alfalfa. Moreover, the adsorption characteristics for PCB 28 by alfalfa and the influencing factors of the adsorption characteristics were studied. There were different degrees of PCB accumulation in alfalfa roots, root nodules and shoots. The decreasing order of the accumulation of PCBs in plant tissues was root nodules > roots > shoots, and the decreasing order of the total PCB contents was roots > shoots > root nodules, indicating that the roots were the main sink for PCB accumulation. There were three modes of PCB speciation in alfalfa roots and root nodules, comprising strong sorption (78%) and weak sorption (19%) on tissue surfaces and absorption within tissues (2%). The adsorption isotherms of PCB 28 indicate that the adsorption capacities of root nodules and shoots were both significantly higher than that of the roots. Both lipids and carbohydrates, and especially lipids, affected the PCB adsorption capacities of the tissues. These results may help in the elucidation of the mechanisms of sorption and accumulation of PCBs in the plants and their main influencing factors and thus contribute to the development of phytoremediation technologies for PCB-contaminated soils.
authors.affiliation: a Key Laboratory of Soil Environment and Pollution Remediation , Institute of Soil Science, Chinese Academy of Sciences , Nanjing , China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Teng
authors.affiliation: a Key Laboratory of Soil Environment and Pollution Remediation , Institute of Soil Science, Chinese Academy of Sciences , Nanjing , China.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Sun
authors.affiliation: a Key Laboratory of Soil Environment and Pollution Remediation , Institute of Soil Science, Chinese Academy of Sciences , Nanjing , China.
authors.forename: Lingjia
authors.initials: L
authors.lastname: Zhu
authors.affiliation: a Key Laboratory of Soil Environment and Pollution Remediation , Institute of Soil Science, Chinese Academy of Sciences , Nanjing , China.
authors.forename: Peter
authors.initials: P
authors.lastname: Christie
authors.affiliation: a Key Laboratory of Soil Environment and Pollution Remediation , Institute of Soil Science, Chinese Academy of Sciences , Nanjing , China.|b Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences , Yantai , China.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Luo
mesh_terms: D001673:Biodegradation, Environmental; D000455:Medicago sativa; D018517:Plant Roots; D011078:Polychlorinated Biphenyls / Q000737:chemistry* / Q000493:pharmacokinetics; D012989:Soil Pollutants / Q000737:chemistry* / Q000493:pharmacokinetics
chemical_list: D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls
keywords: accumulation; alfalfa; polychlorinated biphenyls; sorption; speciation