【作者】 高扬；

【导师】 周培；

【作者基本信息】 上海交通大学 ， 环境工程， 2010， 博士

【摘要】 开展崇明岛生态环境修复和整治对上海市未来发展具有重要的战略意义,围垦土地的环境修复可以有效地缓解农业中耕地使用的压力,又可以保证农产品免受污染,不仅体现以人为本的科学发展观,而且研究成果可为环境资源的可持续发展提供有力的技术保证。本研究以崇明岛冲积土壤为研究对象,分析不同土地利用方式下土壤重金属污染及相关酶活性与微生物群落结构特征,并通过室内模拟实验研究重金属复合污染下土壤生态毒理效应以及如何减轻重金属危害,最后利用从重金属污染地筛选出的两株耐重金属Pb和Cd的真菌并联合螯合剂添加到土壤中以提高植物累积土壤重金属效率。研究主要结论如下:1.崇明岛冲积土壤高重金属含量的区域主要集中在中部,土壤Ni和Cr的含量在西部长江下游冲积沙区较高;工业用地对土壤重金属含量影响显著,而商业用地则不然,东部农田和湿地区域土壤中的重金属含量较低;Pb、Zn、Cu、Cd这4种重金属应作为重点防治对象,着重控制Pb和Cd污染,崇明岛西部应重点监测Ni和Cr污染。2.利用随机扩增多态性DNA(RAPD)的分子检测方法发现:不同土地利用方式下崇明岛土壤的总DNA多态性条带呈显著差异,其多态性条带数量大小顺序为:农业用地>商业用地>工业用地>湿地;农业土壤的总DNA相似性系数显著高于其他土地利用类型,湿地与工业土壤DNA基因相似性要低于其他土地利用类型;不同土地利用方式下崇明岛土壤酶的活性主要由中部的镇中心以及居民和工业区向东部的东滩湿地和西部以及北沿农场逐渐降低,并且随土层深度增加,土壤酶高活性的区域逐渐减小。3.通过模拟实验发现:单一Pb污染对土壤呼吸强度和酶活性的影响要小于单一Cd污染及Cd、Pb复合污染,种植龙葵及玉米等作物有助于提高土壤微生物活性和土壤酶活性;单一Pb和Cd、Pb复合污染下土壤DNA的多态性条带要多于单一Cd污染;种植龙葵及玉米等作物在不同程度上提高了土壤DNA的多态性以及基因丰富度;不同栽培方式对脲酶、磷酸酶等土壤酶活性释放作用的大小顺序为:混合栽培>单一栽培>未栽培植物。4.通过不同植物对比研究发现:重金属超富集植物龙葵的超氧化物歧化酶(SOD)、丙二醛(MDA)、酸溶性硫醇化合物(TAST)、总谷胱甘肽(GSH)和植物鳌合肽(PC)随土壤重金属毒性系数增加呈逐渐增加或减小的趋势;SOD、MDA、TAST、GSH和PC与土壤中的重金属毒性系数呈多元回归关系(R2> 0.95);SOD、TAST和PC的相关酶基因在超富集植物抗氧化防御系统中显著表达,TAST和PC在不同超积累与非超积累植物体内对重金属胁迫的响应机制不同。5.利用生物联合技术修复Cd、Pb复合污染的研究中发现:添加柠檬酸或具有耐铅功能的绿色木霉菌(Hypocrea virens)及耐镉功能的淡紫拟青霉菌(Paecilomyces lilacinus)能显著能提高30-45%龙葵生物量;不同重金属浓度处理下龙葵生物量的大小顺序:柠檬酸与微生物联合添加>添加柠檬酸>添加微生物>空白>未添加酸或微生物菌处理;柠檬酸和微生物两者联合添加将提高30%Cd的累积量,不同处理下龙葵对Cd的累积大小顺序为:柠檬酸与微生物联合添加>添加微生物>添加柠檬酸>未添加酸或微生物菌处理;龙葵对Pb无显著的超积累特征,Pb主要集中在根部累积,茎和叶累积率较低,而添加筛选的具有耐铅功能的绿色木霉菌及耐镉功能的淡紫拟青霉菌有助于显著提高龙葵对Pb的积累,但添加柠檬酸反而降低龙葵对Pb的积累。更多还原

【Abstract】 Development of ecological environmental remediation and repair on reclaimed land has strategical meaning, which can effectively allivieate useness pressure of agricultural land and avoid pollution on agricultural product, and from which it embody scientific development view based on human and provide maintance logistics for environmental resource’s sustainable development. This study take reclaimed land in Chongming Island as subject investigated, and research on heavy metal pollution and microbe community characteristic under different land use, and then through pot-culture simulated experiment, study on soil ecological molecule toxicological effect and improve soil health under heavy metal combined pollution. At last, two strain fungi which can tolerate Cd and Pb isolated from heavy metal polluted soil combined with chelate are applied to heavy metal polluted soil in order to improve phytoextraction efficiency. The main conclusion as follow:1. The highest heavy metal polluted areas of the Chongming Island are centralized in middle part of Chongming Island, and high Ni and Cr pollution in the western Chongming Island is the alluvial area of Yangtse River; the effect of industrial land use on heavy metal content in soil is significant, whereas the effect of commercial land on heavy metal pollution isn’t observed, and eastern farmland and wetland are at low heavy metal index; Pb, Zn, Cu and Cd must be considered as key controlled object, in which must emphasize on controlling Pb and Cd pollution and Ni and Cr pollution in western Chongming Island.2. The soil DNA polymorphism bands under different land use is different, and the order of which is: agricultural land > commercial land > industrial land > wetland; the gene similarity of agricultural soil is significantly higher than that of other land use, and the gene similarity of wetland and industrial land are lower; the spatial evolving characteristic of soil enzyme and organic matter under different land use in Chongming Island follow gradually decreasing order : industrial and commercial land→agricultural land→wetland, and wetland reversely disclose soil health evolving process.3. Soil respiration and enzyme activity is higher under single Pb treatment than under single Cd and combined pollution, and plant is helpful to improve soil microbe and enzyme activity; soil gene polymorphism bands are higher under single Pb and combined pollution than under single Cd pollution; plant will improve soil gene polymorphism bands and richness and the order of improving soil enzyme activity under different culture manners is: mixed planting> monoculture> unplanted treatment.4. superoxide dismutase (SOD), malondialdehyde (MDA), total acid soluable thiol (TAST), total glutathione (GSH) and phytochelatins (PC) of hyperaccumulator change with heavy metal toxicity coefficient and significantly relate with heavy metal toxicity coefficient (y= a+bx+cx2, R2>0.95); SOD, TAST and PC of hyperaccumulator significantly express under heavy metal stress, and the detoxification function of TAST and PC in different plant is different.5. Addition of critic acid or microbe can enhance 30-45% Solanum nigrum. L biomass under Cd and Pb combined pollution, and the order of biomass under different treatment is: combined application> addition of critic acid > addition of microbe > control > no addition of critic acid or microbe; combined addition of critic acid and microbe can enhance 30% Cd accumulation in plant, and the order of transfer coefficient for Cd is: combined application> addition of microbe > addition of critic acid > control > no addition of critic acid or microbe; Solanum nigrum. L don’t show significantly hyperaccumulating characteristic on Pb, and Pb accumulation is centralized on root and the item and leaf in Solanum nigrum. L is at low extraction coefficient; additions of microbe significantly enhance Pb accumulation on plant and addition of critic acid decreases Pb accumulation reversely.更多还原