锌冶炼渣堆场优势植物的重金属累积特征研究  

Accumulation of Heavy Metals by Dominant Plants in Zinc Smelting Slag Field

作　　者：朱光旭[1] 肖化云[1] 郭庆军[2] 张忠义[1,3] ZHU Guangxu;XIAO Huayun;GUO Qingjun;ZHANG Zhongyi(State Key Laboratory of Environmental Geochemistry//Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China;Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences,Beijing 100101, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院地球化学研究所//环境地球化学国家重点实验室,贵州贵阳550081 [2]中国科学院地理科学与资源研究所环境修复中心,北京110011 [3]中国科学院大学,北京100049

出　　处：《生态环境学报》2016年第8期1395-1400,共6页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(41425014);中国博士后科学基金项目(2015M582578);国家高技术研究发展计划项目(2013AA06A211-2);国家重点基础研究发展计划项目(2014CB238906)

摘　　要：金属冶炼废渣未经处理露天堆存,经降雨和地表水的冲刷及风扬扩散,重金属会进入周围土壤和地下水,严重威胁周边自然生态环境和人体健康。以黔西北某锌冶炼厂的废渣堆场为研究对象,通过实地调查分析废渣堆场土壤和18种优势植物的重金属含量,研究优势植物对重金属的吸收、转运和富集特征,筛选出适应该地区生态修复的先锋植物。结果表明,该场地土壤Cd、Pb、Zn、Cu、Cr和Ni存在不同程度超标,以Cd、Pb、Zn污染最为严重,三者平均含量分别是贵州省土壤背景值的48、311、141倍。废渣场土壤受有效态Cd污染的风险较大,其生物有效性系数为49.12%。调查的优势植物均能适应废渣堆重金属元素较高的环境,对重金属具有一定的耐性。所有植物对重金属的吸收虽然都没有达到超临界植物规定的临界值,但植物体的重金属含量都远远超过了正常范围,且不同植物对重金属的吸收和蓄积特征不同。其中,鬼针草Bidens pilosa L.和土荆芥Chenopodium ambrosioides L.对Cd、Pb、Zn的吸收量大、运输能力强,且覆盖率高、生物量较大,对复合重金属具有一定的耐性,可以作为该地区生态恢复中的先锋物种。根据优势植物对重金属的富集和转运特征,研究区优势植物可分别富集型(如马刺蓟Cirsium monocephalum、蒲公英Taraxacum mongolicum Hand.-Mazz.和土荆芥Chenopodium ambrosioides L.)、根部囤积型(如牛筋草Eleusine indica(L.)Gaertn.、车前草Plantago asiatica L.和节节草Equisetum ramosissimum Desf)和规避型(如红花酢浆草Oxalis articulata Savigny)等3种类型。Heavy metals from untreated metal smelting slag in the open field can be leached into soils and groundwater by rainfall,runoff and wind blowing, which generates a significant risk to the ecological environment and human health. A field investigation onthe content of heavy metals in soils and 18 kinds of dominant plants at one zinc smelting slag site in Northwestern Guizhou Provincewas carried out. The absorption and accumulation characteristics of heavy metals between plants and soils were compared, and thepioneer plants for ecosystem restoration of the area were selected. The results revealed that the soils of the smelting slag field havebeen polluted by heavy metals in varying degrees. The average concentration of Zn, Cr, Cd, Pb, Cu and Ni was 14 017.81, 149.00,31.41, 10 948.75, 323.89 and 68.33 mg·kg-1, respectively. The concentration of Cd, Pb, and Zn was 48, 311 and 114 times of theirrespective background value in Guizhou Province. According to the available heavy metal contents, 49.12% available mass fractionof Cd if of very high risk to the environment. The dominant plants can adapt to the unfavorable edaphic conditions of smelting slagfield and were tolerant to heavy metals. The concentrations of Cd, Pb and Zn in all the analyzed plants exceeded the normal ranges,but had not reached the level for hyperaccumulators. There were great variations of metal uptake and accumulation among differentplant species. Among the dominant plants, Bidens pilosa L. and Chenopodium ambrosioides L. had large biomass, and had goodaccumulation of Cd, Pb and Zn. Thus, Bidens pilosa L. and Chenopodium ambrosioides L. can be used as pioneer plants forrevegetation and phytoremediation in the study area. There were great variations of metal uptake and accumulation among differentplant species. According to the metal accumulation in the plant shoots and roots, the dominant plants were classified into three types:the accumulator, e.g. Cirsium monocephalum, Taraxacum mongolicum Hand.-Mazz. and Chenopodium ambrosioides L.; the rootcom

关 键 词：优势植物 冶炼渣场 重金属污染 植物修复 黔西北 

分 类 号：X173[环境科学与工程—环境科学]