崇明东滩表层沉积物重金属空间分布特征及其污染评价  

Spatial Distribution and Contamination Evaluation of Heavy Metals in the Intertidal Surface Sediments of Eastern Chongming

作　　者：李雅娟[1] 杨世伦[1] 侯立军[1] 周菊珍[1] 刘英文[1] 

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200062

出　　处：《环境科学》2012年第7期2368-2375,共8页Environmental Science

基　　金：国家自然科学基金项目(41021064);科技部中荷合作项目(2008DFB90240);上海市科委项目(10dz1210505)

摘　　要：以崇明东滩潮间带表层沉积物为研究对象,在粒度分析、重金属以及有机碳含量测定的基础上,采用ArcGIS中的地统计分析模块研究了重金属Cu、Pb、Zn、Cr、Cd的空间分布格局,应用克里金法进行空间插值作图,估算了沉降通量,并运用地质累积指数法和潜在生态危害指数法对重金属污染现状进行了评价.结果表明:①目前崇明东滩重金属Cu、Pb、Zn、Cr、Cd含量平均值分别为42、27、69、71、0.23μg.g-1,均超过上海潮滩背景值,且受沉积物粒径分布和有机碳的影响,重金属含量呈现自岸向海和自北向南下降的趋势;②崇明东滩重金属Cu、Pb、Zn、Cr、Cd的年沉降量分别为187、121、395、312、1.04 t,总沉积通量为11 g.(m2.a)-1,反映崇明东滩仍具有较强的重金属污染物"过滤器"功能;③重金属污染状况总体为清洁,但Cd、Pb和Cu的污染程度相对较高.Using the ArcGIS geostatistical analysis module, this work investigated the spatial distribution pattern of heavy metals （Cu, Pb, Zn, Cr, Cd） and their deposition fluxes in the intertidal surface sediments of Eastern Chongming based on the analysis of grain size, heavy metal concentrations and organic carbon content. The spatial interpolation （Kriging） was performed to estimate the deposition fluxes, and the contamination status of heavy metals was evaluated using geoaccumulation index and potential ecological risk index. The results showed that the average contents of Cu, Pb, Zn, Cr and Cd were 42, 27, 69, 71 and 0.23μg.g-1, respectively, all of which exceeded the background value in the Shanghai tidal flat. The contents of heavy metals showed a landward as well as northward increasing trend due to the influences of sediment grain size and organic carbon content. The annual deposition of Cu, Pb, Zn, Cr and Cd in Eastern Chongming were 187, 121, 395, 312 and 1.04 t, respectively; the total deposition flux of these heavy metals was 11 g-（ m2. a）-1. Although the overall contamination level of heavy metals in Eastern Chongming was relatively low, Cd, Pb and Cu had a potential pollution threat to the sediment environment.

关 键 词：崇明东滩 沉积物 重金属元素 空间分布 沉积通量 污染评价 

分 类 号：X131.2[环境科学与工程—环境科学]