广西黎塘岩溶区富含铁锰结核土元素迁移特征

发布时间：2019-02-17 14:20

【摘要】：【目的】研究广西黎塘岩溶区土壤富含铁锰结核背景下元素含量与迁移特征,为富含铁锰结核土的有效修复提供理论依据。【方法】选择具有代表性的未受农业耕作影响的富含铁锰结核土为试验样地,其成土母岩为碳酸盐岩,以成土母岩为碎屑岩的土壤为对照,分层采集剖面A(0~35 cm)、B层(35 cm)土壤及对应岩石样品,测定土壤、岩石氧化物及重金属元素含量。【结果】广西黎塘岩溶区土壤主要是Si、Al和Fe的氧化物,三者之和在土壤剖面A、B层的平均含量分别占总量的86.32%和86.30%;广西黎塘岩溶区土壤的SiO_2和Fe_2O_3含量均低于对照,而Al_2O_3、Ca O和Mg O含量高于对照。广西黎塘岩溶区土壤Cd、Pb和Zn含量顺序为ZnPbCd,其中剖面A层Cd和Pb平均含量均超过B层,而Zn平均含量低于B层,剖面A、B层Cd、Pb和Zn平均含量均已超过广西土壤元素背景值及成土母岩为碎屑岩的土壤,未超过土壤环境质量二级标准值。广西黎塘岩溶区土壤以高硅铝系数、低盐基总量淋溶系数为特征,土壤剖面B层风化淋溶强度高于A层,风化淋溶程度整体上高于碎屑岩成土。土壤烧失量(LOI)与SiO_2含量、Al_2O_3含量、硅铝率、盐基总量淋溶系数的相关系数分别为-0.8063、0.7091、-0.8570和-0.2923,土壤剖面A、B层Ca、Mg元素及B层的Cd元素发生了亏损,其他元素均表现为富集或强烈富集。【结论】成土母岩为碳酸盐岩的土壤氧化物、重金属含量、风化淋溶强度、迁移特征等与成土母岩为碎屑岩的土壤具有差异,铁锰结核的存在已造成重金属元素在土壤中的积累并具有潜在污染。
[Abstract]:[objective] to study the characteristics of element content and migration in soils rich in ferromanganese nodules in the karst area of Litang, Guangxi, China. [methods] the representative iron-manganese nodule soil, which is not affected by agricultural cultivation, is selected as the experimental sample and its parent rock is carbonate rock. The soil samples of A (0 ~ 35 cm), B) layer (35 cm) and corresponding rock samples were collected in stratified section A (0 ~ 35 cm), B), and the soil was determined by using the soil of parent rock as clastic rock as a control. [results] in the karst area of Litang, Guangxi, the soil was mainly composed of Si,Al and Fe oxides, the average contents of which were 86.32% and 86.30%, respectively. The contents of SiO_2 and Fe_2O_3 in the soils of the karst area of Litang in Guangxi were lower than those of the control, while the contents of Al_2O_3,Ca O and Mg O were higher than those of the control. The sequence of soil Cd,Pb and Zn content in Litang karst area of Guangxi is ZnPbCd,. The average content of Cd and Pb in section A is higher than that in layer B, but the average content of Zn is lower than that in layer B. Cd, in section A is lower than that in layer B. The average contents of Pb and Zn have exceeded the background value of soil elements in Guangxi and the clastic rock of the parent rock of the soil, not exceeding the secondary standard value of soil environmental quality. The soil in Litang karst area of Guangxi is characterized by high Si-Al coefficient and total leaching coefficient of low base. The weathering leaching intensity of layer B is higher than that of layer A, and the degree of weathering leaching is higher than that of clastic rock as a whole. The correlation coefficients between (LOI) and SiO_2 content, Al_2O_3 content, Si / Al content, total leaching coefficient of base were -0.8063 ~ 3 ~ 0.7091 ~ 0.8570 and -0.2923, respectively. The elements of Mg and Cd in layer B are depleted, and the other elements are enriched or strongly enriched. [conclusion] the parent rocks are carbonate rocks, the content of heavy metals, the strength of weathering and leaching. The characteristics of migration are different from those of clastic rocks, and the existence of ferromanganese nodules has resulted in the accumulation of heavy metals in the soil and potential pollution.
【作者单位】：中国地质科学院岩溶地质研究所/国土资源部广西壮族自治区岩溶动力学重点实验室;
【基金】：国家自然科学基金项目(41502332) 广西自然科学基金项目(2015GXNSFBA139198)
【分类号】：S153

【相似文献】