Study On The Release Law And Pollution Features Of Heavy Metals In The Sediments Of Harbin Section Of Songhua River

River ecosystem plays an important role in human living environment. Along withthe water pollution situation is increasingly serious, more and more efforts is made byour country to complete the river treatment comprehensively, study on the migrationand transformation of sediments contamination and sediment pollution characteristicsshows great practical significance.In this study, the sediments of Songhua River in Harbin section were selected assample sites. From the heavy metal content of the sediment, multivariate statisticalanalysis, pollution levels and risk assessment three areas, heavy metal contaminationproperties of river sediments is analyzed exhaustively. Heavy metal contents of eachsampling point except the one near Hejiagou outfall, show an upward trend from theupstream to downstream. The result of comparison for the concentration all the heavymetals is Zn> Cr> Pb> Cu> Ni> Cd, and just Cd is seriously overweight compared tothe heavy metal background values.Multivariate analysis result that Cd and Pb hassignificant positive correlation and there are positive correlations between heavymetals Ni, Zn, Cu and Cr. Cd and Pb elements of the sediments are mainly fromindustrial wastewater and municipal sewage pollution emissions. Ni, Zn, Cu and Crelements are from natural rock, probably also affected by some human activities.Accumulation index and potential ecological risk index evaluation results show thatthe sampling points of Songhua River in Harbin section have strong to high risk as aresult of Cd, and the remaining of heavy metals show minor ecological risk. Thecomplex ecological risk are from mild to strong. There does not exist unacceptablecarcinogenic and non-carcinogenic health risks.The study used the endogenous release researching model to explore the differentrelease patterns of nutrients nitrogen, phosphorus and heavy metal elements Cr, Pb, Znin single factor changing conditions and orthogonal factors changing conditions. Theresults show that: the temperature has an impact on TN, TP and heavy metal emissions t,the release amounts at temperature16℃are higher than at temperature4℃; pHvalue changes has a significant effect on the release of TP and heavy metals, but almostno effect on TN. with the increasing of pH value, TP release amout also increases.While heavy metal emissions decrease with the increasing of pH value; Waterdisturbance can greatly facilitate the release of TN, TP, and various heavy metals intooverlying water, the release concentration can be twice or triple as much as it ofstanding water. It is an important factor for controlling pollutant transportation andtransformation from sediment to the overlying water; Salt concentration changes within a certain range, there is no significant effect on the release of heavy metals. When itrising up to a certain limit, there is a strong promotion on the release of the heavymetals Cr, Pb, Zn. Orthogonal test results consistent with the experimental results ofsingle factor, changes between the various environmental factors showed some mutuallyreinforcing effect.The research results provide reliable data for the comprehensive treatment ofSonghua River in Harbin. To reduce pollution in river sediments, we need to controlexogenous input of pollutants primarily, while strengthen the implementation of theaccountability and improve the supervision system.