青岛市新兴工业园区土壤重金属污染特征

Heavy metals pollution characteristics of soil in a new industrial district of Qingdao city

为研究青岛市新兴工业园区土壤重金属污染的特征,2019年5月在该工业园的边角、钢厂内等采集表层土壤样品32个和3条受人为因素扰动较少的剖面土壤样品29个,化验分析其中的重金属As、Cd、Cr、Cu、Hg、Ni、Pb、Zn。在此基础上,运用统计分析和潜在生态危害指数(potential ecological risk index,RI)法等对其重金属进行评价。结果表明:表层土壤重金属As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的平均质量比分别为6.200、0.183、52.400、15.000、0.038、21.000、33.300、68.100 mg/kg,其中Cd、Hg、Pb、Zn高于青岛市土壤背景值;高值区多呈点状分布,其中Cd、Cu、Pb、Zn位于钢厂钢材堆放处,As位于轮胎厂外,而Hg则位于化工厂外,且Hg是青岛市土壤背景值的20倍;Cu、Cr、Ni之间相关性较强,Cd、Pb、Zn之间相关性也较强,而As、Hg与其他重金属之间的相关性较弱;钢厂外剖面土壤重金属受人为因素影响不明显,而化工厂外剖面Cd、Cr、Pb、Zn、Hg、Cu和距离化工厂500 m的剖面Hg、Pb受人为因素影响明显;Hg是土壤重金属的主要潜在生态危害因子,其次为Cd,严重污染主要集中在局部地区,需要进一步加强监测与控制,防止其对土壤生态造成危害。

In order to study the heavy metals pollution characteristics of soil in a new industrial district of Qingdao,some soil samples were collected in May 2019,such as 32 surface soil samples which were located in the corner or side of industrial district and in the steel plant etc,and 29 soil samples in 3 profiles which were less affected by human factor.And the contents of As,Cd,Cr,Cu,Hg,Ni,Pb and Zn were analyzed in these soil samples.Based on the test results,the heavy metals in these soil samples were analyzed by the methods of statistical analysis and the potential ecological risk index(RI).The results show that the average content concentrations are 6.200 mg/kg of As,0.183 mg/kg of Cd,52.400 mg/kg of Cr,15.000 mg/kg of Cu,0.038 mg/kg of Hg,21.000 mg/kg of Ni,33.300 mg/kg of Pb,68.100 mg/kg of Zn.Among them,Cd,Hg,Pb and Zn are higher than those of soil background at Qingdao.The distribution of high value areas of heavy metals in surface soil are mostly punctiform.Among them,Cd,Cu,Pb and Zn are located in steel stacking place of the steel plant,and As were located outside the tire plant.Moreover,Hg are located outside the chemical plant,and the maximum content concentrations of Hg is 20 times of soil background at Qingdao.There is a significant correlation between Cu,Cr and Ni in the surface soil.In addition,there is also a significant correlation between Cd,Pb and Zn.In contrast,there is a poor correlation between As,Hg with other heavy metals.The heavy metals of soil in the profile outside the steel plant are not affected by human factors.However,the heavy metals of soil in the other profile are obviously affected by human factors.For example,it was found that Cd,Cr,Pb,Zn,Hg,Cu in the profile outside the chemical plant and Hg,Pb in the profile 500 meters away from the chemical plant,and Hg was the main potential ecological risk of heavy metals in soils,the second was Cd.Serious pollution of heavy metals in soil is mainly concentrated in some areas,so it is necessary to further strengthen its monitoring and control to prevent damaging the soil ecology.