【作者】 吴明文；

【导师】 张超兰； 何冰； 骆东奇；

【作者基本信息】 广西大学 ， 植物营养学， 2007， 硕士

【摘要】 目前，土壤受重金属污染程度越来越严重，土壤重金属污染治理研究已经成为当前国内外的热点科学问题和前沿科研领域。近年来出现的植物修复技术由于成本低、效果好、不破坏环境等优点，正成为农业和环境科学领域研究和开发的热点，而植物修复的关键是找到重金属超富集植物。本课题对广西南丹部分尾矿区的土壤及优势植物进行调查研究，分析土壤及部分优势植物的重金属含量，从中筛选出胜红蓟、醉鱼草和野苎麻这三种植物进行盆栽试验，进一步验证它们在植物修复实践中的应用前景。具体研究结果如下：(1)各尾矿区土壤以酸性为主，土壤多属于复合型污染，尤其是Cd—Zn—Pb复合型污染。在所有被调查的尾矿区土壤样点都有不同程度的镉污染，尾矿区土壤以Cd—Zn—Pb复合污染型为主。各样点具体污染类型是1、4和9号样点为Cd污染型；3号样点为Cd—Zn复合污染型；2、7、8和13号样点为Cd—Zn—Pb复合污染型；5、10和11号样点为Cd—Zn—Pb—Ni复合型污染；12号样点为Cu—Cd—Zn—Pb复合型污染。由此可见12个尾矿区都有Cd污染；9个尾矿区有Zn污染；8个尾矿区有Pb污染；3个尾矿区有Ni污染；1个尾矿区有Cu污染。其中5号尾矿区样点的Cd、Zn和Ni污染最严重。(2)在所有被调查的样点上，共采集21个科的33种优势植物，其中以菊科(Composotae)的优势植物最多，达6种，其次是茄科(So／anaceae)，有3种，荨麻科(Urticaceae)，蓼科(Polygonaceae)，豆科(Fabaceae)，禾本科(Cramineae)和杜鹃科(Ericaceae)各2种，其余14科各有1种。野外调查显示：植物地上部Zn和Pb含量最高的是苎麻(2974.25mg／kg和583.85mg／kg)，Ni含量最高的是何首乌(157.93mg／kg)，Cd含量最高的是胜红蓟(131.50mg／kg)，Cu含量最高的是商陆(61.24mg／kg)。表明胜红蓟对Cd表现较强的富集能力，具有植物修复前景的植物还有醉鱼草，商陆和土荆芥。(3)胜红蓟对Cd有较强的富集能力。野外调查显示：胜红蓟叶部Cd的含量最高可大131.50mg／kg；在盆栽条件下其地上部Cd含量也达到83.82mg／kg，表现出对Cd的累积特性。有关胜红蓟吸收累积Cd的内在机制还需要进一步研究。(4)醉鱼草对Pb有较大的富集能力。野外调查发现，在重金属Pb污染非常严重的5号样点，醉鱼草长势良好，而且形成优势植物，说明其耐胁迫能力很强。调查同时发现醉鱼草地上部Pb含量达348.25mg／kg，盆栽实验其地上部Pb含量最高达289.94mg／kg。无论是野外调查还是盆栽试验均表明醉鱼草是一种耐Pb胁迫并具有Pb富集能力的植物。(5)盆栽试验表明：在土壤2条件下野苎麻对Zn和Pb有较强的吸收值。更多还原

【Abstract】 At present, heavy metal pollution is more and more serious. Phytoremediation mayoffer a new solution of this problem. Finding out a series of ideal hyperaccumulators isthe main groundwork of phytoremediation. The soils and dominant plants wereinvestigated at some mine tailing area of Nandan County in Guangxi Province. Theheavy metal concentrations of dominant species and associated soils were analyzed. Andthen Ageratum conyzoides, Buddleja lindleyana and Boehmeria frutescensvar viridulawere identified by soil pot experiment. The major results were summarized as follows:(1) The soils were investigated at some mine tailing area of Nandan County inGuangxi Province, the results showed that acid soil dominated mine tailing area. Andthe soils mainly belong to combined pollution, especially Cd—Zn—Pb combinedpollution. Concretely, 1st、4th and 9th sample point is Cd pollution; 3rd sample point isCd—Zn combined pollution; 2nd、7th、8th and 13th sample point is Cd—Zn—Pbcombined pollution; 5th、10th and 11th sample point is Cd—Zn—Pb—Ni combinedpollution; 12th sample point is Cu—Cd—Zn—Pb combined pollution. The 5th samplepoint pollution by Cd, Zn and Ni was the most serious.(2) There were 33 species of dominant plants belonging to 21 families wereinvestigated. Among them, Compositae was the family with most species, its 6; andSolanaceae had 3; Urticaceae, Polygonaceae, Fabaceae, Cramineae and Ericaceaef had 2 respectively and the others had only 1. The investigation showed that the plantof the highest Zn and Pb in shoots is Boehemeria nivea(2974.25mg/kg、583.85mg/kg), theplant of the highest concentration of Ni in shoots was Polygonum multiflorm(157.93mg/kg), the plant of the highest concentration of Cd in shoots was Ageratumconyzoides(131.50mg/kg), the plant of the highest concentration of Cu is Phytolaccaacinosa (61.24mg/kg)。And also showed that Ageratum conyzoides, Phytolacca acinosa,Chenopodium ambrosioides, and Buddleja lindleyana Fort, could be useful inphytoremediation.(3) Ageratum conyzoides had strong accumulation capability of Cd. The fieldinvestigation showed that the concentration of Cd in leaf of Ageratum conyzoides was131.50mg/kg. Soil pot experiment showed that Ageratum conyzoides’ shoot had highconcentration Cd (83.82mg/kg) growing in the soil 2.(4) Buddleja lindleyana Fort had strong accumulation capability of Pb, especiallygrow in the soil 2. The result agreed with the investigating conclusion.(5) Boehmeria frutescensvar viridula had strong accumulation capability of Pb andZn when growing in the soil 2.更多还原