摘要
为掌握金矿区尾渣堆积对土壤环境的影响,以重金属元素Cr、Ni和As为研究对象,设置与尾渣堆不同距离采样点,采集了不同剖面深度的土壤样品,采用单因子污染指数法和内梅罗综合污染指数法对研究区土壤重金属污染程度进行评价。同时,在采样点采集了芦苇、茵陈蒿、铁杆蒿和针茅等典型土著植物样品,测定并计算了各植物样品的重金属富集和转移系数,探明了3种重金属在植物不同组织中的累积和再分配情况。结果表明:以陕西土壤元素背景值为标准,在距离尾渣堆30m和50m范围内,污染等级为轻度。以GB 15618—2018土壤污染风险筛选值为标准,Cr、Ni、As无污染。尾渣中Ni、As含量随采样深度的增加而增大,在距尾渣堆10m处的As在表层0~10cm含量显著高于10~30cm含量的现象。0~30m范围内,Ni和As平均含量与尾渣堆距离显著相关(p<0.05)。芦苇、铁杆蒿和针茅根部对Cr、Ni,铁杆蒿和针茅对As的吸附累积能力较强。
To fully understand and evaluate the impact of chromium,nickel,and arsenic on the surrounding soil pollution in tailings from gold ore dressings,soil samples were collected at different depths near an abandoned concentrating mill in a gold mining area.By examining the chromium,nickel,and arsenic contents in the soil samples,the degree of chromium,nickel,and arsenic pollution over the soil profile was analyzed by Single factor index method and Nemerow index evalution method at different sampling points.Meanwhile,typical plant samples,including Bulrush(Phragmites communis),Capillary Wormwood(Artemisia capillaris),Artemisia annua(Artemisia gmelinii)and Stipa(Stipa capillata Linn.)were collected at the soil sampling point.The chromium,nickel,and arsenic contents were determined in the aboveground and belowground organs,and the enrichment and transfer coefficients of each plant sample were calculated.The results showed that:based on Shaanxi soil element background values,the pollution level is mild within a range of 30 mand 50 mfrom the tailings pile.The content of nickel and arsenic in tailings increased with the increasing of soil depth.While,the content of arsenic at 0~10 cm in the surface layer was significantly higher than that of 10~30 cm at a distance of 10 mfrom the tailings pile.In the range of 0~30 m,the average contents of nickel and arsenic were significantly related to the distance of tailings heap(p<0.05).For chromium,nickel,and arsenic,Artemisia annua and Stipashould be chosen as the right plant,because of the ability of heavy metal accumulation efficiency.In addition,Bulrush also have a certain accumulation capacity for chromium and nickel.
作者
卢楠
李刚
罗玉虎
LU Nan;LI Gang;LUO Yuhu(Shaanxi Land Engineering Construction Group Co.,Ltd.,Xi'an 710075,China;Shaanxi Key Laboratory of Land Consolidation,Xi'an 710061,China;Key Laboratory of Degraded and Unused Land Consolidation Engineering,the Ministry of Natural Resources,Xi'an 710075,China;Shaanxi Land Consolidation Engineering Technology Research Center,Xi'an 710075,China;Institute of Land Engineering and Technology,Shaanxi Land Engineering Construction Group Co.,Ltd.,Xi'an 710075,China)
基金
陕西省土地工程建设集团内部科研项目(DJNY2019-18)
陕西省土地整治重点实验室开放基金项目(2018-JC16,2018-JC17,2019-JC04).
关键词
尾矿渣
重金属污染
植物调查
富集
转移
tailing slag
heavy metal pollution
plant survey
enrichment
migration
