Canário João, Poissant Laurier, O'Driscoll Nelson, Vale Carlos, Pilote Martin, Lean David
IPIMAR/National Institute of Biological Resources, Lisboa, Portugal.
Environ Pollut. 2009 Apr;157(4):1294-300. doi: 10.1016/j.envpol.2008.11.042. Epub 2008 Dec 30.
An open-bottom and a closed-bottom mesocosm were developed to investigate the release of mercury from sediments to the water column in a frozen freshwater lake. The mesoscosms were deployed in a hole in the ice and particulate mercury (Hg(P)) and total dissolved mercury (TDHg) were measured in sediments and in water column vertical profiles. In addition, dissolved gaseous mercury (DGM) in water and mercury water/airflux were quantified. Concentrations of TDHg, DGM, and mercury flux were all higher in the open-bottom mesocosm than in the closed-bottom mesocosm. In this paper we focus on the molecular diffusion of mercury from the sediment in comparison with the TDHg accumulation in the water column. We conclude that the molecular diffusion and sediment resuspension play a minor role in mercury release from sediments suggesting that solute release during ebullition is an important transport process for mercury in the lake.
开发了一个底部开放和一个底部封闭的中宇宙装置，以研究冰冻淡水湖中汞从沉积物向水柱的释放情况。这些中宇宙装置被放置在冰面上的一个洞中，并对沉积物和水柱垂直剖面中的颗粒汞（Hg(P)）和总溶解汞（TDHg）进行了测量。此外，还对水中的溶解气态汞（DGM）和汞的水/气通量进行了量化。底部开放的中宇宙装置中TDHg、DGM和汞通量的浓度均高于底部封闭的中宇宙装置。在本文中，我们将汞从沉积物中的分子扩散与水柱中TDHg的积累进行了比较。我们得出结论，分子扩散和沉积物再悬浮在汞从沉积物中的释放过程中起次要作用，这表明沸腾过程中的溶质释放是湖泊中汞的一个重要传输过程。
