再悬浮作用对长江口潮滩Hg释放影响的实验室模拟研究  

Laboratory Simulation Study on the Influence of Resuspension on the Release of Mercury from Yangtze Estuarine Tidal Flat

作　　者：李猛[1] 毕春娟[1] 张晶晶[1] 吕金刚[1] 陈振楼[1] 

机构地区：[1]华东师范大学地理信息科学教育部重点实验室,上海200062

出　　处：《环境科学》2011年第11期3318-3326,共9页Environmental Science

基　　金：国家自然科学基金项目(40701164;40971259);国家水体污染控制与治理科技重大专项(2009ZX07317-006)

摘　　要：利用再悬浮装置研究不同扰动强度、不同盐度下,再悬浮作用对长江口中、低潮滩沉积物中Hg释放的影响.结果表明,在扰动期间,上覆水环境(pH、Eh、DO、TSS等)剧变.在再悬浮实验中,上覆水中HgD(溶解态汞)和HgP(颗粒态汞)含量分别主要集中在0.152～2.657μg.L-1、0.080～2.722μg.L-1范围内.再悬浮作用使得盐度为4.1‰、8.0‰、10.0‰、13.0‰条件下的中潮滩及盐度为13.0‰条件下的低潮滩都发生了汞释放,释放的汞含量为0.053～0.673μg.g-1,但对盐度为4.1‰、8.0‰、10.0‰条件下的低潮滩汞释放影响并不明显,这反映了上覆水盐度对再悬浮中汞释放具有重要影响.同时,也表明再悬浮作用对长江口中、低潮滩的Hg释放影响也有差异,中潮滩表现出了比低潮滩要明显的汞释放.扰动动力为(210±5)r.min-1时能明显增加汞的解吸,从而对汞释放产生影响.Using a Particle Environment Simulator,laboratory simulation experiment on the influence of resuspension on the release of mercury from sediments collected from medium tidal flat and low tidal flat in Chongming Dongtan was conducted.Results indicated that the conditions of overlying water changed significantly during resuspension.The concentrations of HgD and HgP were mainly in the rang of 0.152-2.657 μg·L-1,0.080-2.722 μg·L-1 separately.In the resuspension processes,mercury was released from the medium intertidal sediments under the salinity condition of 4.1‰,8.0‰,10.0‰,13.0‰,and from the low intertidal sediments under the salinity condition of 13.0‰.However,the release of mercury from the medium intertidal sediments is not significant under the salinity condition of 4.1‰,8.0‰,10.0‰.The salinity of overlying water had an important effect on resuspension.In different salinity condition,the release of mercury was different.And the release of mercury from medium tidal flat and low tidal flat was different during the resuspension periods,the release of mercury from the medium intertidal sediment was significantly higher than the release from the low intertidal sediment.When the rotate speed was（210±5） r·min-1,the desorption of mercury significantly increased,thereby the rotate speed had an effect on the release of mercury.

关 键 词：长江口潮滩 再悬浮 汞释放 盐度 沉积物底质 

分 类 号：X522[环境科学与工程—环境工程]