紫湖溪流域重金属污染风险与植物富集特征  

Heavy metals pollution risk and characteristics of plant accumulation along Zihu River

作　　者：陈勤[1] 沈羽[1] 方炎明[1] 严靖[1] 李萍萍[1] 张开梅[1] 

机构地区：[1]南京林业大学森林资源与环境学院,南京210037

出　　处：《农业工程学报》2014年第14期198-205,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(31370666;31200233);江苏高校优势学科建设工程资助项目(PAPD);"十一五"国家科技支撑计划(2008BAC39B01;2008BAC39B06);江苏高校协同创新计划~~

摘　　要：土壤重金属污染已成为当今农业与环境领域关注的热点。为揭示紫湖溪流域重金属(As、Cd、Cr、Cu、Mn、Ni、Pb和Zn)污染状况,该研究测定与分析了紫湖溪水体、河底淤泥和河岸土壤以及9种河岸植物的重金属含量,利用污染指数法系统评估其污染状况,进而筛选出具有富集与修复重金属污染潜力的植物。结果表明,紫湖溪水体中Cd与Mn严重超标;河底淤泥中Cd、Zn和Cu污染严重,重金属潜在生态风险:Zn>Cd>Cu>Pb>As>Ni>Cr>Mn;河岸土壤受污水与底泥泛滥影响,土壤重金属间呈显著正相关性,其中,Cd、Zn和Cu重度污染;9种优势植物对重金属的选择性吸收导致其对Cd、Cr和Pb的富集系数(BCF,bioconcentration factor)偏低,转移系数(TF,translocation factor)均小于1,表现出根部囤积型特征。早熟禾、灰绿藜和枸杞对重金属的吸收具有抵抗性,湿地生态型植物水花生与猫爪草对富集重金属具有独特优势,构树对多种重金属较强的富集与转移能力暗示了该木本植物在重金属修复技术领域的巨大应用前景。Heavy metal pollution in the soil of farmland is regarded as serious threats to agricultural production environment in China. Zihu River is located in Nanjing, Jiangsu, China. The source of Zihu River is the purple mountain, a famous local mountain. The pollution problem of Zihu River has aroused public concerns because of heavy metal contamination caused by sewage. To investigate and assess the situation of heavy metal pollution of Zihu River region, concentrations of heavy metals including As, Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined and analyzed for brook water, the soil from river silt and riverbank, as well as for the riverbank plants of nine species. These species include Trifolium repens, Alternanthera philoxeroides, Chenopodium glaucum, Commelina communis, Ranunculus ternatus, Poa annua, Ligustrum lucidum, Lycium chinense, Broussonetia papyrifera. An assessment of heavy-metal contamination was conducted by means of pollution index （Pi）. Such data may provide information for screening of heavy metal accumulator, and for phytoremediation of heavy metals. The results indicated that serious contamination of Cd and Mn was found in the brook water, the concentrations for Cd and Mn were 0.003 mg/L and 0.124 mg/L, respectively. Among the heavy metals in the soil from the river silt, contamination of Zn, Cd and Cu was serious based on the Pi values （18.89, 8.53 and 6.25, respectively）, with the order of potential ecological risk as：Zn〉Cd〉Cu〉Pb〉As〉Ni〉 Cr〉Mn. Pearson correlation analysis showed a significantly （p 〈 0.05） positive correlation among concentrations of heavy metals in the riparian soil, which indicated that they were mainly polluted by sewage and silt. High concentrations of Cd, Zn and Cu were investigated from the soil of the riverbank based on the Pi values （3.68, 3.61 and 3.41, respectively）. The bioconcentration factor （BFs） to Cd, Cr and Pb were quite lower among all the nine species due probably to the selective absorption of the plants. Because Pb is tox

关 键 词：重金属 污染 土壤 水体 底泥 污染指数 富集与转移 植物修复 

分 类 号：X53[环境科学与工程—环境工程]