Efficacy of Various Sorbic Media in Attenuation of Selenium
1988
Fritz, Steven J. | Hall, Steven D.
A series of adsorption tests were performed on material used in the construction of a clay-lined fly-ash waste pile at a lignite-burning power plant in Texas to determine which soil component is the most effective in adsorbing selenium. Selenium, in the form of selenite, is adsorbed by hydrous iron oxides to a greater extent than selenite adsorbed by clays chemically treated to remove organics and free iron. In natural systems, clays will be coated by iron oxides and organic material, and these coatings may prevent anions like HSeO⁻₃ and SeO⁻²₃ from sorbing onto positive exchange sites of clay surfaces. However, anions can be effectively adsorbed by these highly reactive surface coatings. Thus, the efficacy of clay as an adsorption medium may be overestimated in construction of environmental barriers for retention of elements like selenium.
显示更多 [+] 显示较少 [-]