Zn,Pb,Cd,Cu在淮南新庄孜煤矿矸石山附近土壤和作物中分布特征

摘要

采用电感耦合等离子体发射光谱仪(ICP-OES)对淮南新庄孜煤矿矸石山周边土壤、黄豆、水稻中Zn,Pb,Cd,Cu进行了测试,分析了其含量分布特征.结果表明:矿区土壤呈碱性,土壤中Zn,Pb含量在深度为20～40 cm最高,分别为43.08,15.61 mg·kg-1,但均低于淮南市土壤背景值,表层土壤(0～20 cm)中Cd含量(0.124mg·kg-1)最高,深部土壤(20～40 cm)中Cu含量(24.27mg·kg-1)最高,分别超淮南市土壤背景值106.76％,0.46％；土壤中Zn,Pb,Cd,Cu含量随土壤深度变化不显著,表层土壤中Zn,Pb含量均在距矸石山一定距离后达峰值,推测可能由煤矸石山产生的粉尘颗粒物随大气迁移造成.通过土壤中重金属含量对土壤中理化性质的逐步回归分析表明:总磷对土壤Zn,Cd含量影响较大,有机质对土壤Pb,Cu含量影响较大.Cd主要分布在黄豆和水稻的根部,Zn较易向黄豆和水稻地上部分迁移.黄豆和水稻地上部Zn富集系数较高,其叶、壳、籽中重金属富集能力大小为Zn＞Cu＞Cd＞Pb.Pb在水稻籽实中达0.52 mg· kg-1(干重),超国家食品中铅限量卫生标准1.3倍,水稻籽实中较高的Pb含量可能对食用此稻米人群产生一定膳食风险.%Samples of soils and crops were collected around Xinzhungzi Coal Mine waste rock pile by theintercept method. The concentrations of Zn, Pb, Cd, Cu in the soils and crops were analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). The results showed that the soil is alkaline, and the max concentrations of Zn, Pb in the soils are 43. 08 mg ? Kg"1 and 15. 61 mg ? Kg"1 at the depth of 20~40 cm, which are below the background values of Huainan soil. The concentrations of Cd and Cu in the soil with the depths of 0-20 cm and 20~40 cm, respectively, are the highest and 106. 76% and 0.46% higher than the background value of Huainan soil. The concentrations of Zn, Pb, Cd, Cu are incorrelate with the depth of soil. The Zn and Pb in the top soil (0~20 cm) reach their peak values at a distance away from the coal mine spoil, which may be caused by the grain from the burst of coal mine spoil transported by the wind. The stepwise regression analysis indicated that total P affects the concentrations of Zn and Pb in soil, and organic matter affects the concentrations of Pb and Cu in soil. Cd accumulates in the roots of soybean and rice, while Zn transports into the aerial parts of the two plants. The enrichments of Zn in the aerial parts of soybean and rice are much higher. The order of Zn, Pb, Cd, Cu enrichments in the leaf, hull and seed of soybean and rice is Zn>Cu>Cd>Pb. The max value of Pb in the grain of rice is 0. 52 mg ? Kg"1 (dry weight), 1. 3 times higher than the national food hygiene standard. The risk from the Pb in the seed of rice should not be overlooked.