无锡市土壤重金属富集的梯度效应与来源差异  

The Sources and Gradient Effect of Soil Heavy Metal Concentrations in Wuxi City

作　　者：李建国[1] 濮励杰[1,2] 廖启林[3] 朱明[1] 刘丽丽[4] 张丽芳[5] 王琪琪[1] 戴小清[1] 

机构地区：[1]南京大学地理与海洋科学学院,江苏南京210023 [2]国土资源部海岸带开发与保护重点实验室,江苏南京210023 [3]江苏省地质调查研究院,江苏南京210018 [4]清华大学国家环境保护环境微生物利用与安全控制重点实验室,北京100084 [5]南京财经大学公共管理学院,江苏南京210046

出　　处：《地理科学》2014年第4期496-504,共9页Scientia Geographica Sinica

基　　金：国家自然科学基金项目(41230751;41201180;41101547);南京大学研究生科研创新基金(2012CL14);国家基础科学人才培养基金(J1103408)资助

摘　　要：人类活动引起的土壤重金属富集已经成为区域主要的环境风险。通过对无锡市主城区表层土壤大面积的采样（1957个），运用空间分析和多元统计工具，对无锡市土壤重金属富集的空间特征及其来源进行分析，结果表明：①无锡市土壤As、Cu、Hg、Pb和zn空间变异受人类活动的影响明显，均超出当地的土壤背景值，而Hg已经超过国家土壤环境健康二级标准阈值，成为无锡市最主要的土壤重金属污染因子；②研究区土壤重金属含量随着建设用地距离的增加，呈逐渐下降的趋势，表现出明显的距离梯度特征；③基于不同梯度表现，将无锡土壤重金属分为2种典型距离梯度区间1（0～10km）和区间2（10～16km），区间1土壤重金属富集主要受人类活动的影响明显，而区间2受自然和人为双重因素的影响；④土壤自然特性（CEC、pH和P）与土壤重金属含量（Co、Cu、Fe和Zn）的富集存在显著的正相关关系；⑤无锡市人类活动对于土壤重金属富集的影响范围在10km左右，本研究的现实意义在于为重金属污染土壤分区治理提供帮助，即对于0～10km区域内的土壤可以通过以提高土地利用效率、降低废弃物排放等为主的工程措施来解决；而在10～16km区间则采用以超富集植物修复等为主的生态措施来解决。Heavy metals pollution in soil has become an important environmental hazard. At present, anthropo- genic activities were the main sources attributing to soil heavy metal pollution. A total of 1957 surface soil sam- ples （0-20 cm） were collected in urban district of Wuxi, and spatial feature and sources of the soil pollution of heavy metals were identified by using spatial analysis and multivariate statistics, the results as follows： 1） Soil As, Cu, Hg, Pb and Zn in Wuxi are all over the corresponding background value caused by anthropogenic ac- tivities, even if Hg is over the threshold value of grade II of The Chinese Environmental Quality Standard for Soils, and is the most major pollution factor of soil; 2） Soil heavy metals tend to reduce with the increasing of distance apart from the built-up lands, present a remarkable gradient effect; 3） Two distinct gradient effect zones （zone 1 （0-10 km） and zone 2（10-16 km））are divided based on different gradient characters. Anthropogen- ic activities are the mainly responsible for zone 1, and soil heavy metals concentration in zone 2 are caused by both natural factors and human factors; 4） Soil Co, Cu, Fe and Zn have a positive relationship with natural soil properties （CEC, pH and P）; 5） The influence scope of anthropogenic activities on soil heavy metals concentra- tion in Wuxi is about 10km. The positive meaning of this study is helpful for classified management of soil heavy metals pollution that is the strong human-effecting lands can be restored by means of engineering mea- sures （including promoting land-use efficiency, reducing the volumes of wastes as well as the fill and cubage of excavation, etc）, as in zone 1 （0-10 km）; However, ecological measures （i.e. heavy metal hyperaccumulator plants, etc） may be adopted in zone 2（10-16 km）.

关 键 词：重金属富集 梯度效应 来源 无锡市 

分 类 号：X53[环境科学与工程—环境工程]