摘要
为探明岩溶区矿石冶炼场地土壤重金属的垂向分布特征及影响因素,以林口废弃硫铁矿冶炼厂为例,分析了厂区及附近耕地、林地和灌草地土壤纵剖面上Pb、Zn、Cd的全量和有效态含量及与土壤有机质、pH的相关关系。结果表明：不同土地利用类型土壤中Pb、Zn含量普遍低于土壤环境质量二级标准,耕地和灌草地中Cd全量和有效态含量都大于二级标准且在表层富集,耕地表层土壤Cd全量为4.61mg/kg,约为三级标准的5倍,贵州农业土壤背景值的19倍,污染较重,不适于耕种;重金属总的纵向迁移能力表现为Cd〉Pb〉Zn,但在不同土地利用类型土壤中存在一些差异;土壤pH与各重金属有效态都表现出较显著的负线性相关性,相关系数为0.291~0.957,岩溶地区偏碱性的土壤环境可阻碍重金属向下迁移;有机质与有效态Pb和有效态Cd存在显著的正线性相关关系,相关系数达0.5以上,较高的有机质含量可显著增加Pb和Cd的有效态含量。
Total Pb,Zn and Cu content,effective state content and relations between soil organic matter,pH and effective state content in soil profiles of Linkou abandoned pyrite smelting factory,nearby farmland,woodland and shrub-grass land were analyzed to explore vertical distribution characteristics of soil heavy metals and its influence factors in karst ore smelting areas.Results：Pb and Zn content in soils of different land utilization types are lower than the secondary standard of National Soil Environmental Quality generally.Total Cd and its effective state content in soils of farmland and shrub-grass land both are higher than the secondary standard of National Soil Environmental Quality and Cd is rich in the topsoil.Total Cd content in topsoil of farmland is 4.61 mg/kg,about five times that of the third standard of National Soil Environmental Quality and 19 times that of Guizhou Soil Background value,which indicates the heavily polluted farmland is unsuitable for cultivation.Total vertical transfer capacity of heavy metals is Cd Pb Zn but there are some differences among different land utilization types.Soil pH is negatively correlated to effective state content of different heavy metals and the correlation coefficient is 0.291~0.957 and the soil environment with slightly alkaline in karst area hinders downward transfer of heavy metals.Soil organic matter content positively correlates to the content of effective Pb and effective Cd significantly and the correlation coefficient reaches above 0.5,which indicates higher organic matter content can increase Pb and Cd content in soil significantly.
出处
《贵州农业科学》
CAS
2015年第12期90-94,99,共6页
Guizhou Agricultural Sciences
基金
中国地质科学院岩溶地质研究所基本科研业务专项资金项目"林口硫铁矿区水-土环境中重金属迁移转化规律研究"(121237128100259)
关键词
岩溶区
土壤重金属
有效态
迁移能力
重污染
垂向分布
karst
soil heavy metal
effective state
Heavy pollution
transfer capacit
vertical distri bution
