Guo Wei, Fu Rui-ying, Zhao Ren-xin, Zhao Wen-jing, Guo Jiang-yuan, Zhang Jun
College of Environment and Resources, Inner Mongolia University, Hohhot 010021, China.
Huan Jing Ke Xue. 2013 May;34(5):1895-900.
The pollution status and distribution characteristic of rare earth elements in soil were analyzed around Bayan Obo mining area and Baotou tailing reservoir located in Inner Mongolia grassland ecosystem, aiming at grasping the overall situation of grassland ecosystem pollution caused by rare earth elements and providing basic information as well as theoretical basis. The results indicated that seven rare earth elements in soils from different directions of Baotou tailing reservoir accumulated to a certain extent compared to the soil background value of Inner Mongolia. The pollution degree was Ce > La > Nd > Pr > Sm > Y > Eu. Within 50 m from the edge of tailing reservoir, soil rare earth contamination was the most serious, with the concentrations of La, Ce, Pr, Nd, Sm, Eu and Y reaching 11,45.0 mg x kg(-1), 23,636.0 mg x kg(-1), 4568.16 mg x kg(-1) , 6855.51 mg x kg(-1), 582.18 mg x kg(-1), 94.21 mg x kg(-1)), and 136.25 mg x kg(-1), respectively. Owing to the dominant wind direction of northwest, soils from the southeast were contaminated most seriously. For Bayan Obo mining area, the concentrations of seven rare earth elements in soil from the mining area were significantly higher than those of other areas investigated, with the concentrations of La, Ce, Pr, Nd, Sm, Eu and Y reaching 3112.56 mg x kg(-1), 7142.12 mg x kg(-1), 1467.12 mg x kg(-1), 2552.80 mg x kg(-1), 210.80 mg x kg(-1), 36.20 mg x kg(-1) and 63.22 mg x kg(-1), respectively. The soils of six areas of Bayan Obo mining area were all contaminated by rare earth elements, and the contamination degree was in the order of mining area > outside the dump > east side of the railway > the dump > outside the urban area > west side of the railway. Besides, the transportation of rare earth ore led to the soil rare earth contamination along the railway, and the distribution characteristic of rare earth elements in soils along the railway was affected by the dominant wind direction of northwest. Baotou tailing reservoir and Bayan Obo mining area had the same contamination characteristic, and the concentrations of rare earth elements were in accordance with those in the tailings. The health and stabilization of local grassland ecosystem are being threatened by excessive soil rare earth elements.
分析了内蒙古草原生态系统中白云鄂博矿区及包头尾矿库周边土壤中稀土元素的污染状况及分布特征，旨在掌握稀土元素对草原生态系统污染的整体情况，为其提供基础资料和理论依据。结果表明，包头尾矿库不同方向土壤中的7种稀土元素相较于内蒙古土壤背景值均有一定程度的累积。污染程度为Ce＞La＞Nd＞Pr＞Sm＞Y＞Eu。在距尾矿库边缘50 m范围内，土壤稀土污染最为严重，La、Ce、Pr、Nd、Sm、Eu和Y的含量分别达到1145.0 mg·kg⁻¹、23636.0 mg·kg⁻¹、4568.16 mg·kg⁻¹、6855.51 mg·kg⁻¹、582.18 mg·kg⁻¹、94.21 mg·kg⁻¹和136.25 mg·kg⁻¹。由于主导风向为西北风，东南部土壤污染最为严重。对于白云鄂博矿区，矿区土壤中7种稀土元素含量显著高于其他调查区域，La、Ce、Pr、Nd、Sm、Eu和Y的含量分别达到3112.56 mg·kg⁻¹、7142.12 mg·kg⁻¹、1467.12 mg·kg⁻¹、2552.80 mg·kg⁻¹、210.80 mg·kg⁻¹、36.20 mg·kg⁻¹和63.22 mg·kg⁻¹。白云鄂博矿区6个区域的土壤均受到稀土元素污染，污染程度依次为矿区＞排土场外部＞铁路东侧＞排土场＞市区外部＞铁路西侧。此外，稀土矿的运输导致铁路沿线土壤稀土污染，铁路沿线土壤中稀土元素的分布特征受西北风主导风向影响。包头尾矿库和白云鄂博矿区具有相同的污染特征，土壤中稀土元素含量与尾矿中的含量一致。土壤中稀土元素超标正威胁着当地草原生态系统 的健康与稳定。
