Effect Of The Heavy Metal's Pollution And Potential Toxicity In Sediments Of Huaihe River Mainstream

The Huaihe River,one of the seven largest rivers in China,the population density of drainage basin is the top of the seven major drainage basin.Its economic status is very important.Recent years,with the rapid development of Huaihe drainage basin,a large increasing of non-agricultural population make the urban's pollution worse more.Serious occurrence of malignant pollution accidents were occurred in the Huaihe River Basin,the poor water quality had already caused drinking water probleming in some areas,the Huaihe river had become one of the most polluted rivers in China.The river sediments can reflect the characteristics of pollutants in the river and the degree of pollution.Twelve surface sediments were collected from typical mainstream of the Huaihe River to assess the metals biological toxicity.The acid volatile sulfides(AVS),simultaneously extracted metals(SEM),organic carbon(TOC),heavy metals(As?Cd?Cr?Cu ? Pb ? Zn),BCR morphological analysis and other parameters were measured,the correlation between TOC,AVS,?SEM,grain size of sediment and the morphological distribution of heavy metals in each sample section were analyzed.Index of Geoaccumulation,the Potential Ecological Risk Index and the EqP model was applied to assess the potential metal toxicity.This study draws the following conclusions:(1)The results of Spearman correlation analysis showed that the TOC was positively correlated with clay and silt,and negatively correlated with sand,which was consistent with the higher organic carbon formed by fine particulate matter.?SEM was positively correlated with TOC,clay and silt content,and negatively correlated with sand content.It showed that ?SEM was similar to the total amount of metal,and it was easy to accumulate in sediments with high organic carbon.The smaller the particle,the bigger the specific surface area,particle surface will generate more negative charges,so it will adsorb more heavy metal ions.(2)The results of the analysis of heavy metals in the sediments showed that the average of the extracted acid content of Cd was 27.5%,which indicated that Cd in the sediments of the Huaihe River was unstable and active,its bioavailability was high and easily absorbed,and thus harm to the environment;As in Bengbuwujiadu non-residue state is higher,Cu in Bengbuzhashang and Bengbuwujiadu's reducible was 41.96% and 38.28%,Pb in Bengbu zhashang and Bengbuwujiadu's reducible was 41.96% and 38.28%.Therefore,there are some ecological risks of As,Cu and Pb in the mainstream of Huaihe River.(3)The EqP model shows that,TOC of Linhuaiguan section is less than 0.2%,and the equilibrium model can not be used.There is no potential biological toxicity of metals could be detected sampled from Linhuaiguan,Fengtaidaqiao,Funanwangjiaba,Lutaizi,Xiaoliuxiang and Xuyishuiwenzhan section,while the ESBAVS,OC of metals in the sediments of Huaibingudui,Laobatou,Huainandajiangou,Matoucheng,Bengbuzhashang and Bengbuwujiadu ranged from 130 to 3000?mol/g,suggesting potential toxicity.The value of ESBAVS,OC in Huainandajiangou was 1233.9?mol/g,and it was a high potential toxicity.(4)Index of Geo-accumulation and the Potential Ecological Risk Index evaluation show the results as follows:The heavy metals in the sediments of Funanwangjiaba,Huaibingudui,Laobatou,Lutaizi,Fengtaidaqiao,Huainandajiangou,Matoucheng,Bengbuzhashagn,Bengbuwujiadu and Xuyushuiwenzhan stations have caused some pollution to the environment.Cd is the most ecologically harmful element in several heavy metals and large harm to the environment,the rest of the metals is slightly ecological Hazard.Due to the large contribution of Cd,so that the total metal damage's degree is from moderate reach to strength of ecological hazards.In summary,the Huaihe River has a different degree of heavy metal pollution,relevant departments should pay cause the attention.