Heavy metals in the soil of mining areas have become a primary source of pollution, which could cause deleterious health effects in people exposed through soil-plant systems via multi-pathways. A long-term field experiment under natural conditions was carried out to explore the distribution characteristic and migration law of heavy metals in a soil-wheat system of a mining area in Xuzhou. According to the second level standard of environmental quality standards for soils of China (GB 15618-1995), 30.8 g of CrCl3·6H2O, 8.3 g of Pb(CH3COO)2·3H2O, and 16.5 g of ZnSO4·7H2O were added into the soil of three experimental sites, respectively. The other experimental site with no additional compounds was used as the control site. The Cr, Pb, and Zn concentrations in the soil-wheat system were counted and their corresponding migration models were constructed. From 2014 to 2017, the mean concentrations of Cr (49.09 mg·kg−1), Pb (20.08 mg·kg−1), and Zn (39.11 mg·kg−1) in the soil of the addition sites were higher than that of the control site. The mean concentrations of Cr, Pb, and Zn in wheat of the addition sites were greater than that of the control site with the values of 3.29, 0.06, and 29 mg·kg−1. In comparison, the Cr, Pb, and Zn concentrations in the soil of all experimental sites were lower than the second level standard of environmental quality standards for soils of China (GB 15618-1995), whereas the Cr concentration exceeded its corresponding soil background value of Xuzhou in 2017. The Pb concentration in soil of the addition site was greater than its corresponding background value from 2014 to 2016. The Pb and Zn concentrations in wheat of all experimental sites were lower than the national hygienic standard for grains of China (GB2715-2005) and the national guidelines for cereals of China (NY 861-2004), but the Cr concentration significantly exceeded the national guidelines for cereals of China (NY 861-2004). By constructing the Identical-Discrepant-Contrary (IDC) gray connection models, the result showed that there was a non-linear relationship of Cr, Pb, and Zn concentrations in the soil-wheat system, and the absolute values of most correlation coefficients were lower than 0.5 and the values of greyness were more than 0.5. The curvilinear regression models could not reflect the relationship of Cr, Pb, and Zn concentrations in the soil-wheat system with the regression coefficient values far less than 1. Due to the values of regression coefficient being close to 1, this study suggested that the allocation estimation models could be used for simulating the Cr, Pb, and Zn migration in the soil-wheat system of a mining area in Xuzhou.
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机译：矿区土壤中的重金属已成为主要的污染源，可能通过多种途径对通过土壤植物系统暴露的人们造成有害的健康影响。进行了自然条件下的长期野外试验，以探索徐州某矿区土壤-小麦系统中重金属的分布特征和迁移规律。根据《中国土壤环境质量二级标准》（GB 15618-1995），向其中添加了30.8 g CrCl3·6H2O，8.3 g Pb（CH3COO）2·3H2O和16.5 g ZnSO4·7H2O。三个实验点的土壤。没有其他化合物的另一个实验位点用作对照位点。计算了土壤-小麦系统中的Cr，Pb和Zn浓度，并建立了相应的迁移模型。 2014年至2017年，铬（49.09 mg·kg −1 ），铅（20.08 mg·kg −1 ）和锌（39.11 mg·kg）的平均浓度添加部位土壤中的 −1 ）高于对照部位。添加部位小麦中Cr，Pb和Zn的平均浓度高于对照部位，分别为3.29、0.06和29 mg·kg -1 。相比之下，所有实验点土壤中的铬，铅和锌的浓度均低于中国土壤环境质量标准的二级标准（GB 15618-1995），而铬的浓度则超过了其相应的土壤本底值。在2017年达到徐州市的标准.2014年至2016年添加地点土壤中的Pb浓度高于其相应的背景值。所有实验地点小麦中的Pb和Zn浓度均低于中国谷物的国家卫生标准（GB2715 -2005）和中国谷物国家指南（NY 861-2004），但是Cr的含量大大超过了中国谷物国家指南（NY 861-2004）。通过建立同等差异灰色关联模型，结果表明土壤-小麦系统中Cr，Pb和Zn的浓度存在非线性关系，且大多数相关系数的绝对值<数学xmlns：mml =“ http://www.w3.org/1998/Math/MathML” id =“ mm1”溢出=“ scroll”> r < / mrow> 小于0.5，并且灰度值展开▼
