包头公园土壤重金属形态分布特征及环境意义  

Speciation Distribution Characteristics and Environmental Significance for Heavy Metals in the Topsoil of Baotou Parks

作　　者：王贵[1] 丛艳静[1] 曹霞[1] 

机构地区：[1]包头师范学院资源与环境学院,内蒙古包头014030

出　　处：《西北农业学报》2007年第6期273-276,共4页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：内蒙古自然科学基金资助项目(200508010610);包头市科技局资助项目(2006R2002-5)

摘　　要：选取包头市区4个有代表性公园分别采集表层土样,测定重金属含量。结果显示,重金属富集非常明显。Cu、Zn、Pb和Cd的含量分别是内蒙古土壤均值的2.9、6.2、2.1和4.9倍;全国土壤几何平均值的1.2、4.4、1.9和2.4倍。相对于北京公园土壤,包头公园土壤Pb含量略低,Zn、Cu和Cd含量分别是北京公园土壤均值的3.7、1.2和1.5倍。重金属富集程度依次为Zn>Cu>Pb>Cd。采用Tessier的五步连续提取法,测定了土壤中重金属各形态含量水平。结果表明,重金属大都以有机结合态和残留态形式存在,有效态含量低,生物可利用性小。Zn的可交换态和碳酸盐结合态占总量的11%,具有一定的生物有效性和潜在生态危害性。Top soil samples were collected in four selected parks of Baotou city, heavy metal concentrations were measured. Results showed that heavy metal accumulation was obviously. Cu, Zn, Pb and Cd contents were 2.9, 6.2, 2.1 and 4.9 times of the mean values of Inner Mongolia background; and 1.2, 4.4, 1.9 and 2.4 times of the mean values of national background respectively. Pb content was lower, compared with the values of Beijing park soils, but Cu, Zn, and Cd contents were 3.7, 1.2 and 1.5 times higher. Speciation distributions revealed, that the heavy metals mainly existed in organ ic and residual states with no obvious environmental significance. Only Zn indicated some bioavailabili ty and potential ecological risks slightly, because of its higher values in carbonate and exchangeable states which was about 11% to the total.

关 键 词：包头 土壤 重金属 形态 生物有效性 

分 类 号：X53[环境科学与工程—环境工程]