不同生物炭对铅锌矿尾矿重金属污染土壤修复效果的研究
发布时间：2018-08-17 16:47
【摘要】：随着城市化、工业化的不断发展,土壤重金属污染不断加剧。作为新型环境功能材料,生物炭具有独特的性质,可以通过静电吸附、离子交换、表面络合和共沉淀等方式有效降低土壤重金属的活性和毒性,起到修复土壤的作用。然而,目前关于生物炭的研究多数集中于选取单一原料在不同温度下制备而成的生物炭对重金属的钝化效果和可能作用机制方面,而将不同原料比例混合制备生物炭的研究鲜有报道。现有研究表明,水稻秸秆制备的生物炭比表面积较大；猪粪制备的生物炭灰分含量高,pH也较高,但其本身含有的重金属使其存在一定的环境风险。本研究以水稻秸秆和猪粪两种生物质材料为对象,设置水稻秸秆和猪粪质量比为1：0、3：1、1：1、1：3和0：1,在400℃C下制备生物炭,探讨不同生物炭的基本理化性质和其对铅锌矿尾矿土壤pH、电导率、可溶性有机碳等的影响以及对土壤重金属铅、锌、铜、镉有效性和不同形态的变化趋势以及对植物生长和吸收土壤重金属的影响,探讨生物炭在铅锌矿尾矿重金属超标土壤修复方面的作用潜力。主要结论如下：(1)生物炭基本元素组成、理化性质和表面特性与原材料性质密切相关。生物炭产率、灰分、重金属Zn、Pb、Cu总量均随猪粪添加比例的增加而增加,生物炭含水率、pH值、EC值、含碳和总K含量则随水稻秸秆添加比例的增加而增加。水稻秸秆生物炭(R)和猪粪生物炭(M)比表面积和总孔容由小到大依次为RR3M1R1M3R1M1M,猪粪生物炭比表面积为3.462 m2/g。(2)通过培养试验研究不同生物炭对土壤pH、EC和对重金属有效态的影响。结果表明,五种生物炭均能够提高土壤pH值和EC,且都随添加量的增加而增加。在同一添加水平下,生物炭提高土壤pH的能力随猪粪比例的增加而增加；生物炭对EC值提高作用的强度随水稻秸秆比例的增加而增加。相关分析表明,重金属Zn、Pb、Cd、Cu有效态含量与土壤pH值、EC值、DOC含量呈显性负相关。生物炭对不同重金属的钝化效果与生物炭类型和土壤理化性质相关。(3)通过盆栽试验研究不同生物炭对青菜生长及对重金属吸收的影响。结果表明,生物炭能增加土壤DOC含量,不同类型生物炭之间存在明显差异。施用生物炭显著提高青菜生物量,猪粪生物炭对青菜地上部增产效果最显著；生物炭显著减少青菜对土壤中重金属的吸收,其中秸秆生物炭在减少青菜根系吸收重金属上效果最为显著。相关分析表明,青菜地上部Zn、Pb、Cd、Cu含量均与土壤pH呈显著负相关关系,Zn、Pb、Cu含量与土壤EC呈显著负相关关系,而青菜地下部Zn、Pb、Cd、Cu含量则与土壤pH值、EC值、DOC含量及Zn、Pb、 Cd、Cu有效态含量均呈显著相关关系。
[Abstract]:With the development of urbanization and industrialization, heavy metal pollution in soil is becoming more and more serious. As a new environmental functional material, biochar has unique properties, which can effectively reduce the activity and toxicity of heavy metals in soil by electrostatic adsorption, ion exchange, surface complexation and coprecipitation, and play a role in soil remediation. However, most of the current studies on biochar focus on the passivation effect and possible mechanism of heavy metals prepared from biochar prepared from a single raw material at different temperatures. However, there are few reports on the preparation of biochar by mixing different raw materials. The existing studies show that the specific surface area of biological carbon prepared by rice straw is large, and the content of carbon ash in pig manure is high and pH is high, but the heavy metals contained in it lead to a certain environmental risk. In this study, two kinds of biomass materials, rice straw and pig manure, were used to prepare biochar at 400 鈩，
本文编号：2188281
[Abstract]:With the development of urbanization and industrialization, heavy metal pollution in soil is becoming more and more serious. As a new environmental functional material, biochar has unique properties, which can effectively reduce the activity and toxicity of heavy metals in soil by electrostatic adsorption, ion exchange, surface complexation and coprecipitation, and play a role in soil remediation. However, most of the current studies on biochar focus on the passivation effect and possible mechanism of heavy metals prepared from biochar prepared from a single raw material at different temperatures. However, there are few reports on the preparation of biochar by mixing different raw materials. The existing studies show that the specific surface area of biological carbon prepared by rice straw is large, and the content of carbon ash in pig manure is high and pH is high, but the heavy metals contained in it lead to a certain environmental risk. In this study, two kinds of biomass materials, rice straw and pig manure, were used to prepare biochar at 400 鈩，
本文编号：2188281
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