Determination and Comprehensive Evaluation of Heavy Metal Pollution of Farmland Soil in a Uranium Mining Area
-
摘要: 以某大型铀矿采矿区、冶炼厂、尾矿坝及周边农田土壤五种重金属元素含量实测值为基础数据,对矿区农田土壤重金属污染状况采用改进的内梅罗综合污染指数法、地质累积指数法及潜在生态风险指数法进行综合分析评价,并通过相关性综合分析、主成分分析及聚类分析方法探究农田土壤五种重金属污染物的来源。结果表明,三个采样区农田土壤中镉、铬、铅和铜的污染严重程度:尾矿坝 > 冶炼厂 > 采矿区,放射性元素铀的污染严重程度:冶炼厂 > 尾矿坝 > 采矿区;研究区重金属污染严重,其重金属污染来源的关键因素是铀。该综合评价结果为铀矿区周边农田土壤中重金属污染的科学治理提供重要理论依据。Abstract: According to the measured data of the contents of five heavy metal elements from a large uranium mining area, a smelting plant, a tailings dam and the surrounding farmland, we used the improved Nemerow comprehensive pollution index method, the geological accumulation index method and the potential ecological risk index method to comprehensively analyze and evaluate the heavy metal pollution situation in the farmland soil of the mining area. We also studied the sources of the five heavy metal pollutants from the farmland soil through correlation comprehensive analysis, principal component analysis and cluster analysis methods. The results show that the pollution levels of cadmium, chromium, lead and copper from the farmland soil of the three sampling areas show this order: tailing dam > smelting plant > mining area, and the pollution levels of radioactive element uranium show this order: smelting plant > tailing dam > mining area. Now it is clear that the heavy metal pollution in the study area is very serious and the heavy metal pollution’s main source is uranium. The comprehensive evaluation results could provide an important theoretical basis for the scientific management of heavy metal pollution in farmland soil around the uranium mining area.
-
Key words:
- Uranium mining area /
- Farmland soil /
- Heavy metal /
- Risk assessment /
- Source of pollution
-
表 1 农田土壤重金属含量(n = 135) (单位:mg kg −1)
Table 1. Heavy metal content in farmland soil (n = 135) (unit: mg kg −1)
采样区
Sampling area污染元素
Heavy metal elementPb Cd Cr Cu U 采矿区 127.7 9.91 75.31 115.0 15.32 水冶厂 172.1 10.48 114.1 148.5 21.37 尾矿坝 231.2 11.94 170.4 225.2 18.05 均值 179 10.78 120 163 18.25 CV 0.25 0.08 0.33 0.29 0.14 矿区所在省土壤背景值 37.28 0.10 25.90 18.77 4.40 国家土壤环境质量Ⅱ标准 250 0.3 150 50 空白 表 2 农田土壤重金属相关性
Table 2. Correlation of heavy metals in farmland soil
重金属元素
Heavy metal elementPb Cd Cr Cu U Pb 1 Cd 0.759 1 Cr 0.182 0.045 1 Cu 0.312 0.912* 0.483 1 U 0.116 0.999* 0.998* 0.28 1 注:* 表示显著相关。 表 3 农田土壤重金属含量的总方差解释
Table 3. Total variance explanation of heavy metal content in farmland soils
因子
Factor初始特征值
Initial eigenvalue提取后特征值
Feature value after extraction旋转后特征值
Eigenvalue after rotation特征值
Eigenvalues解释方差(%)
Explain
variance累积方差(%)
Cumulative
variance特征值
Eigenvalues解释方差(%)
Explain
variance累积方差(%)
Cumulative
variance特征值
Eigenvalues解释方差(%)
Explain
variance累积方差(%)
Cumulative
variance1 0.049 52.528 52.528 0.049 52.528 52.528 0.045 48.586 48.586 2 0.034 36.902 89.430 0.034 36.902 89.430 0.038 40.845 89.430 3 0.006 6.364 95.794 4 0.003 3.111 98.905 5 0.001 1.095 100.00 表 4 农田土壤重金属含量的主成份分析载荷矩阵表
Table 4. Principal component analysis of heavy metal content in farmland soils
元素
Element主成分因子
Principal component factor旋转后主成分因子
Principal component factor after rotation1 2 1 2 Pb 0.579 −0.051 −0.527 0.247 Cd −0.034 −0.047 0.006 −0.058 Cr 0.157 0.213 −0.029 0.263 Cu 0.663 0.747 −0.198 0.979 U −0.840 0.540 0.998 0.045 表 5 农田土壤重金属改进的内梅罗综合污染指数
Table 5. Nemero Comprehensive Pollution Index after Improvement of Heavy Metals in Farmland Soils
采样区
Sampling areaPb Cd Cr Cu U P总 污染等级
Pollution class采矿区 0.043 49.05 0.4 3.08 6.78 36.24 重度污染 冶炼厂 0.63 51.9 0.71 4.15 10.54 38.27 重度污染 尾矿坝 0.94 29.2 1.16 6.61 8.48 43.67 重度污染 平均值 0.67 53.4 0.76 4.62 8.60 39.4 重度污染 表 6 农田土壤重金属地质累积指数
Table 6. Geological accumulation index of heavy metals in farmland soil
采样区
Sampling areaPb Cd Cr Cu U 采矿区 1.2(2) 6.07(6) 0.96(1) 2.04(3) 1.22(2) 冶炼厂 1.63(2) 6.15(6) 1.56(2) 2.41(3) 1.7(2) 尾矿坝 2.09(3) 6.34(6) 2.14(3) 3.01(4) 1.46(2) 平均值 1.68(2) 6.19(6) 1.63(2) 2.54(3) 1.47(2) 表 7 农田土壤重金属潜在生态风险指数
Table 7. Potential ecological risk index of heavy metals in farmland soil
采样区
Sampling area潜在生态危害指数
Potential ecological risk indexRI 风险程度
Degree of riskPb Cd Cr Cu U 采矿区 17.12(Ⅰ) 2973(Ⅴ) 5.82(Ⅰ) 306.4(Ⅳ) 69.64(Ⅱ) 3372 强危害 冶炼厂 23.08(Ⅰ) 3144(Ⅴ) 8.81(Ⅰ) 395.6(Ⅴ) 97.14(Ⅲ) 3668.63 强危害 尾矿坝 31.81(Ⅰ) 3582(Ⅴ) 13.16(Ⅰ) 599.9(Ⅴ) 82.05(Ⅲ) 4308.97 强危害 平均值 24.01(Ⅰ) 3234(Ⅴ) 9.27(Ⅰ) 434.2(Ⅴ) 82.95(Ⅲ) 3784.43 强危害 -
[1] 刘平辉, 魏长帅, 张淑梅, 等. 华东某铀矿区水稻土放射性核素铀污染评价[J]. 土壤通报, 2014, 45(6): 1517 − 1521. [2] Zhang Jingru, Li Huizhen, Zhou Yongzhang, et. Bioavailability and soil-to-crop transfer of heavy metals in farmland soils: A case study in the Pearl River Delta, South China[J]. Environmental Pollution, 2018, 235: 710 − 719. doi: 10.1016/j.envpol.2017.12.106 [3] Yefeng Jiang, Yingcong Ye, Xi Guo. Spatiotemporal variation of soil heavy metals in farmland influenced by human activities in the Poyang Lake region, China[J]. Catena, 2019, 176: 79 − 288. [4] 史新杰, 李 卓, 庄文化, 等. 土壤中水分和镉供应量对油菜器官中镉分布特征的影响[J]. 核农学报, 2019, 33(02): 389 − 397. [5] 朱业安. 铀矿土壤重金属污染与超富集植物累积特征研究[D]. 南昌: 东华理工大学, 2013. [6] 黄德娟, 朱业安, 刘庆成, 等. 某铀矿山环境土壤重金属污染评价[J]. 金属矿山, 2013, (01): 146 − 150. doi: 10.3969/j.issn.1001-1250.2013.01.041 [7] 王籼铂, 李义连, 逯 雨, 等. 电热板消解不同酸体系对土壤中6种重金属元素测定的影响研究[J]. 安全与环境工程, 2019, 26(04): 56 − 60. [8] 曹 灿. ICP-AES法测定蔬菜和土壤中As、Cd、Pb、Cr、Zn及污染程度评价的研究[D]. 长沙: 中南大学, 2012. [9] 徐友宁, 柯海玲, 赵阿宁, 等. 小秦岭某金矿区农田土壤重金属污染评价[J]. 土壤通报, 2007, (04): 732 − 736. doi: 10.3321/j.issn:0564-3945.2007.04.024 [10] 郭 琼. 基于SPSS软件的主成份分析法探析—榆次区土地生态系统健康评价[J]. 山西农业大学学报(自然科学版), 2012, 32(1): 58 − 62. [11] 杨忠平, 卢文喜, 刘新荣, 等. 长春市城区表层土壤重金属污染来源解析[J]. 城市环境与城市生态, 2009, 22(5): 29 − 33. [12] 张云菲, 孜比布拉•司马义, 杨胜田, 等. 农田土壤重金属污染特征, 生态风险评价和来源分析[J]. 江苏农业科学, 2020, 48(4): 266 − 272. [13] 贾振邦, 周 华, 赵智杰, 等. 应用地积累指数法评价太子河沉积物中重金属污染[J]. 北京大学学报(自然科学版), 2000, (04): 525 − 530. [14] 李超奎, 王利东, 李 吟, 等. 土壤重金属污染评价方法研究进展[J]. 矿产与地质, 2011, 25(2): 172 − 176. doi: 10.3969/j.issn.1001-5663.2011.02.017