摘要
以浙江省五金工业之都——永康市主城区为研究区域,系统采集181个表层土壤样品,对样品中钛、铬、锰、钴、镍、铜、锌、砷和铅共9种重金属元素质量分数进行测定及分析,计算单因子污染指数及潜在生态风险指数,评价永康市土壤重金属的污染状况和潜在生态风险,并利用多元统计和地统计方法分析各重金属元素的空间分布特征。结果表明:(1)研究区9种土壤重金属元素中,钛、铬、锰、镍、铜、锌、钴和铅等8种元素的均值超过了金衢盆地土壤背景值,砷元素均值略低于金衢盆地背景值,各重金属元素均存在一定程度上的富集。(2)单因子污染指数显示,表层土壤中重金属污染程度依次为铬>镍>钴>钛>锰>铜>锌>铅>砷,铬元素存在轻度污染,其余各元素均为潜在污染。(3)铬、镍、铜、钴、砷元素的积累主要受到工业生产影响,锌和铅元素的积累主要受到交通运输活动的影响,钛、锰来源于工业冶金及制造活动,同时钛元素也在一定程度上来源于成土母质。(4)永康市综合潜在生态风险指数(IR)均值为49.05,处于轻度潜在生态风险,局部地区处于中度潜在生态风险,其中铜、砷和钴元素分别存在局部地区高度、中度潜在生态风险。
To assess pollution characteristics and the degree of heavy metal pollution and to discuss the spatial distribution characteristics, the study area was divided into 500 m × 500 m, according to land use types, a total of 181 samples were collected from surface soils in the main urban area of Yongkang City（the Hardware City of China）, and the contents of nine heavy metals： Ti, Cr, Mn, Co, Ni, Cu, Zn, As, and Pb, were determined. Pollution was assessed by a single-factor pollution index and potential ecological risks were assessed by the Hakanson Risk Index（IR）. A multivariate analysis and geostatistics were applied to examine the spatial distributions of heavy metals in the soils, each point we take 5 samples, then mixed, after pretreatment we assay the samples with 3 replications. Results showed that the mean values of Ti, Cr, Mn, Co, Ni, Cu, Zn, and Pb were higher than the natural soil background values in the Jinhua Quzhou Basin of Zhejiang（P〈0.05）, but the mean value of As was below（P 〈0.05）. The single-factor pollution index revealed the following order：Cr〉Ni〉Co〉Ti〉Mn〉Cu〉Zn〉Pb〉As. The correlation analysis showed highly significant, positive correlations for Ni—Cu（r = 0.743, P〈0.01）, Cu—Zn（r = 0.893, P〈0.01）, Ni—Zn（r = 0.652, P〈0.01）. The mean value of Hakanson IRwas 49.05, which indicated that the contamination level of heavy metals in Yongkang was slight in total. However, there was moderate contamination in local areas where Cu, As, and Co were at high or moderate ecological risk levels. Overall, accumulation of Cr, Ni, Cu, Co, and As were influenced by industrial production; Zn and Pb were influenced by traffic; and Ti and Mn originated from smelting and manufacturing with Ti also being controlled by parent materials. Industrial land has the highest potential ecological risk, which needs immediate attention.
出处
《浙江农林大学学报》
CAS
CSCD
北大核心
2017年第6期972-982,共11页
Journal of Zhejiang A&F University
基金
浙江省重点科技创新团队项目(2011R50027)
关键词
城市土壤
重金属
生态风险评价
普通克里格
永康市
urban soils
heavy metal
ecological risk assessment
ordinary Kriging
Yongkang City
