Contamination and assessment of potential ecological risk of heavy metals in sea water and sediment from aquaculture areas of Dongtou islands,Zhejiang
In order to assess the aquaculture environmental quality of Dongtou sea area,24 sea water samples and 24 surface sediment samples were collected from aquaculture areas of Dongtou and the con-tents of heavy metals including Hg,As,Cu,Pb,Zn,Cd and Cr were determined.Then the levels of heavy metal pollution in sea water and surface sediment were evaluated by single factor method and comprehensive pollution index.The potential ecological risk of heavy metals in sediments were evalua-ted by Hankanson potential ecological risk index.The results showed that the contents of seven heavy metals in sea water of the aquaculture areas investigated were below the standard values by the national standard of mariculture sea water quality.The Hg,As,Pb,Cd and Cr quality in surface sediment con-formed to the first grade by the national standard of marine sediment quality which was suitable for aq-uaculture.However,the single pollution index of Cu and Zn in sediment were a bit more than 1,it means that the sediment quality was slightly polluted.When the geochemical background values of sed-iments in the Yangtze estuary offshore marine areas were used as reference values,the degree of heavy metals potential ecological risks was in the order:Hg＞Cd＞As＞Cu＞Pb＞Zn＞Cr and Hg contributed the most to the total potential ecological risk.The potential ecological risk indexes(RI)of 7 heavy metals at all aquaculture areas were in the range of 129.31 and 157.45,and posed medium level poten-tial ecological risks for the Dongtou sea area.
heavy metalssea watersurface sedimentpotential ecological risk evaluation
NETL
NSTL
万方数据
