Transferring And Transforming Of Mercury During Resuspension Under Dynamic Disturbing At Tidalflat Of Yangtze Estuary

The intertidal flat of coastal areas of the Yangtze estuary is a complex-open ecosystem influenced both by natural factors and strong human activities.The runoff and tide meet here,making acuity disturbing to transport and transfer of sand and suspensions.Parameters here,both Physical and Chemical change quite often.So its biochemistry process is very complexible,and biata is very sensitive and frailty. However,the environment of Yangtze estuary is suffering serious pollution of mercury because of its special geography position and gathering of climate, hydrography and human activities.So here,we choose Henhang wellspring as typical case of sampling profile,in order to study Transfer and Transform of Mercury during Resuspension under Dynamic Disturbing,concerning affection of pH,salinity,and dynamics.We conclude under firsthand datas as follow:1) The tideflat of Yangtze estuary has suffered serious mercury pollution especially at Chenhang wellspring.The mercury in water reaches 0.159μg/L,50% overtoil to National Standard ofⅢsurface water;and 0.133μg/g in sediment,4.93 times more than Standard of sediment of Yangtze river.The environment condition makes much risk to drinking water.2) The resuspension in surface sediment deal to tide disturbing drives periodical fluctuation of water characteristics.On the one hand,the rising of Eh and salinity intensify the release and disadsorption of mercury;on the other hand,the pH and TSS climb up,making it benefits the adsorption and deposition of mercury.So it's the compositive result of release and deposition of mercury,by coupling action of all environmental factors.3) Tide disturbing and adsorbtion-disadsorbtion on TSS are two factors controlling transfer and transport of mercury.Under strong disturbing,the mercury would release from surface sediment for resuspension,and particle mercury would also dissolve into water.That will make high concentration of dissolved mercury. However,TSS would adsorb mercury while dynamics change weaker,and mercury would back to sediment through deposition of suspending particles.4) Dyamics,pH and salinity can affect adsorbtion-disadsorbtion balance upon suspending particles.Strong dynamics,high pH(＞8.5) and salinity(＞1.5) would advance deposition of particle,benefit for wipping off dissolved mercury.5) There are boundaries for resuspension,which arranging 100cm depth in water,and 4-5cm in sediment from sediment-water counterface.