Study On The Influence Of Sea Ice On The Temporal And Spatial Distribution Of Heavy Metals In Coastal Of Liaodong Bay

The temporal and spatial distribution,migration and transformation of heavy metals in the sea have always been the research focus by scholars home and abroad.However,most researches on heavy metals are concentrated in seawater and sediment,there are few studies on the research of migration and distribution of heavy metals under the condition of seawater freezing.In this study,we choose sea ice in coastal of Liaodong Bay as the research object.Combining with outdoor sampling and indoor simulation test,the temporal and spatial distribution of heavy metals in the ice-water system of Liaodong Bay is studied during non-glacial period and glacial period.This study shows that:(1)The distribution of heavy metals in sea ice coastal of Liaodong Bay is as followed: In the whole,the concentration of heavy metals in the sea ice on the west is higher than east.The spatial distribution presents a high concentration from the Erhekou area in the west of Liaodong Bay,which decreases in the middle,and gradually increases at Jinzhou Bay,and then from the top of the bay to the upper half of the east side is lower generally,and finally the concentration becomes higher again in the lower half of the east side of Liaodong Bay.The concentration of heavy metal showed Zn> Cu> Cd> Pb.The high value of ice heavy metal concentration is mostly in industrial and urban areas,tourism and leisure area.The concentration of heavy metals in the ice at all points corresponds to the requirements of the corresponding sea water quality standards in the functional area.(2)The temporal and spatial distribution of heavy metals in non-icing and glacial waters is as followed: heavy metals are discharged and concentrated from non-icing waters to subglacial waters,and the concentration of heavy metals in sub-glacial waters is greater than that of non-icing waters.The Nemerow index method evaluation results using heavy metals as the environmental pollution influencing factors are roughly reflected that subglacial water>nonglacial>ice in coastal waters of Liaodong Bay.(3)The partition coefficient of heavy metals in the ice-water system: the partition coefficient of Cu in the ice-water system at each point is ＜ 1.The distribution coefficient of Pb and Zn is ＜ 1 mostly.The distribution coefficient of Cd is roughly evenly distributed around 1.(4)The laboratory-simulation experiment about the influence of sea-ice on the distribution of heavy metals in ice-water system shows that: the simulation results is the same as the outdoor measured value basically.In the distribution experiment different concentrition conditions is setted.The result shows that concentration of heavy metals in the bottom water is the highest.And the distribution coefficient is 0.25 for Pb,0.39 for Cu,0.55 for Cd and 0.7for Zn.The order of concentration of heavy metals in ice under different p H conditions is:p H=7 > p H=8 > p H=9,and the concentration of heavy metals in the bottom water is: p H=9 >p H=8 > p H=7.In melting ice experiment,different concentrition conditions is also setted.The result shows the higher concentration of heavy metals in the water before freezing is,the higher concentration of melt-1 will be found,while the difference between melt-2 and melt-5is not obvious.The order of concentration of melt-1 in heavy metal under different p H conditions is: p H=9 > p H=8 > p H=7,except melt-2 to melt-5.The discharge ability of Pb is the weakest among the four heavy metals,and Cu is stronger.