江苏港口海域沉积物重金属污染状况

HEAVY METALS CONTAMINATION LEVELS AT THE PORTS ZONES OF JIANGSU

江苏海港建设方兴未艾,赣榆港和大丰港发展速度尤为突出。分别选取赣榆港和大丰港海域的6个和8个沉积物调查站位,通过地统计分析探讨主要污染来源空间分布和来源组成特征,并对重金属污染现状进行评价。结果显示,赣榆港表层沉积物中Cd、As、Cu、Pb、Cr、Zn含量范围分别为0.049 3~0.098 7、7.3~17.8、19.9~41.2、13.2~19.2、27.5~54.2、43.8~81.2mg/kg,空间分布上总体表现为近岸海域较离岸海域略高,沉积物重金属含量受到陆源影响,其中重金属Zn与Cu存在相同或相似的来源,而As的来源与其他重金属差异均较大;大丰港表层沉积物中Cd、As、Cu、Pb、Cr、Zn含量范围分别为0.037 8~0.229 0、5.7~19.0、3.2~27.5、10.0~23.1、62.0~87.0、32.0~85.9mg/kg,重金属空间上区域变异显著,除Cr外的重金属之间存在相同或相似来源。污染评价显示,赣榆港和大丰港整体污染程度总体较轻。港口建设初期的海洋沉积物调查与评价,不仅反映该海域初始的沉积环境状况,为沉积环境影响评价提供参考,还能为港口规模和产业选择提出限制条件。

Ganyu port and Dafeng port were the emerging ports zone in Jiangsu coastal area.In order to study the characteristics and status of heavy metals in surface sediments of the two ports,field survey was carried out in March 2013(Ganyu port)and March 2008(Dafeng port).Based on the investigation data of heavy metals,we carried out geostatistics analysis and pollution states evaluation.The geostatistics analysis results of Ganyu port showed that the contents of Cd,As,Cu,Pb,Cr,Zn were 0.049 3-0.098 7,7.3-17.8,19.9-41.2,13.2-19.2,27.5-54.2,43.8-81.2 mg/kg,respectively.The spatial distribution showed a seaward increasing trend,and land-based sources of pollution might be the main cause.Correlation analysis and cluster analysis of factors indicated that Zn and Cu had the same or similar source,and the source of As had significant difference against other heavy metals.The geostatistics analysis results of Dafeng port showed that the contents of Cd,As,Cu,Pb,Cr,Zn were 0.037 8-0.229 0,5.7-19.0,3.2-27.5,10.0-23.1,62.0-87.0,32.0-85.9 mg/kg,respectively.The spatial distribution showed significant variations among regions,probably because of the strong marine hydrodynamic conditions of Xiyang tidal channels.Correlation analysis and cluster analysis of factors indicated that most of the heavy metals(except Cr)had the same or similar source.The index of pollution evaluation indicated a lower pollution degree in the two ports.The three evaluation methods had different pollution assessment results,with the use of different reference values.The early survey and evaluation of marine sediment in ports could not only reflect the initial deposition of marine environmental conditions,but also providing a reference for environmental impact assessment and the port industry selecting.