Hg、As在海州湾不同功能区沉积物中的污染特征及污染历史演变评估

Pollution Characteristics and Assessment on the Pollution Historical Evolution of Hg,As in Sediments of Functional Zones in Coastal Waters of Northern,Jiangsu

2014年对江苏北部海州湾排污区(临洪河口)、滨海旅游区(连岛)、临海工业区(灌河口)3个不同功能区海域近岸柱状沉积物样品进行了Hg、As的测定,研究了Hg、As在不同功能区海域的垂直分布特征。结果表明,不同功能区沉积物中Hg、As的垂直分布不同,Hg和As在柱层的分布特征也不同。Hg在柱状沉积物中的浓度高值出现在1987年至2005年间,而As主要出现在近年,这和连云港经济发展结构有关。Hg主要来自工业污染,从上个世纪80年代中后期开始连云港工业大发展,导致近海环境中以Hg为代表的重金属污染加剧,2005年产业结构调整后,这种情况有所好转。As主要来自农业、渔业污染,属于非点源污染,没有有效的控制办法,因此污染量有逐年加大的趋势。通过计算金属的富集系数(EF),可知Hg、As在不同功能区沉积物中的富集状态和污染程度也不同。近40年来,Hg在排污区近岸沉积物中都呈现无富集或弱富集状态,未出现污染;在滨海旅游区近岸沉积物中基本呈现无富集状态,未出现污染;在临海工业区柱状样中出现强富集,严重污染。As在临洪河口近岸沉积物中近年来富集逐年增强,呈现严重污染现象;在连岛近岸沉积物中为弱富集,未出现污染;在灌河口柱状样中呈现弱富集,但总体趋势是从底层到表层富集系数呈上升势头,有严重污染现象。

In 2014,three sediment core samples were collected from different functional zones（drainage area：Linhong river mouth,coastal recreational area：Liandao,coastal industrial zone：Guanhe）in Haizhou Bay of northern Jiangsu.Concentrations and vertical distribution characteristics of Hg,As in sediment cores were examined.Results showed that vertical distributions of Hg,As were different in sediment cores from functional zones and in different layers in sediments.Hg had highest content from1987 to 2005,and As was found in recently years,which are related to economic development of Lianyungang.From 1980 sto 2005,the modern industry of Lianyungang had a rapid development,and then an adjustment was made to industrial structure in order to protect environment.As is mainly from agriculture and fishery,which belongs to nonpoint source.The trend of As pollution was increasing year by year,which may be correlated to no way to effective governance.According to enrichment factors（EF）of Hg,As,the accumulation states and contamination were different in sediment cores from different functional zones.Nearly 40,Hg was not enriched or minor enriched in sediment core in drainage area,and no enrichment in coastal recreational area,which showed no contamination of Hg in sediments.Severe enrichment and heavy contamination of Hg were found in sediments from coastal industrial zone.As was heavy enriched with an increasing tendency in sediment core in drainage area and showed heavy contamination.Minor enrichment of As was found in sediments from coastal recreational area and coastal industrial zone.The total tendency of As＇ EF was increasing from bottom to top layer in sediment core in coastal industrial zone and showed heavy polluted in some years.