CHANGES IN SELENIUM SPECIATION IN WETLAND SEDIMENTS INDUCED BY LABORATORY TESTING

Analysis of wet and laboratory-dried samples of wetland sediment showe d that the concentrations of soluble and adsorbed selenium (Se) increa sed greatly if samples were dried. This effect was more pronounced at higher temperatures. The release of organic Se through rapid decomposi tion of sediment organic material and Se oxidation to selenate appear to be the major processes resulting in the increase of the concentrati ons of the soluble and adsorbed Se in dried sediment. This study shows that sediment drying, especially al higher temperatures, could affect the evaluation of Se speciation and availability in wetland sediment.