Proposed experiment for SnCl2 treatment of Outfall 200 for the purpose of mercury removal from East Fork Poplar Creek, Y-12 Plant, Oak Ridge, Tennessee

摘要

Identification and treatment/elimination of point sources of mercury (Hg) to East Fork Poplar Creek (EFPC) within the Y-12 Plant have reduced base flow mercury concentrations considerably; but, after all such actions are completed, nonpoint sources will continue to add mercury to the creek. Studies conducted in 1996 on the use of air stripping to remove elemental mercury from Outfall 51, a mercury-contaminated natural spring, demonstrated that the addition of trace concentrations of stannous chloride (SnCl2) converted a large fraction of the dissolved mercury in the outfall to elemental mercury, which could subsequently be removed by air stripping. Preliminary calculations estimate that 75% or more of the elemental mercury could be removed via evasion between the North/South (N/S) pipes and the Y- l2 Plant boundary (Station 17). Alternatively, elemental mercury might be removed from EFPC in a short reach of stream below the N/S pipes by an in-situ air stripping system which bubbles air through the water column. The purpose of these proposed experiments is to test whether natural volatilization or in-situ air stripping may be used to further reduce baseflow concentrations of mercury in EFPC. Results of this experiment will be useful for understanding the transport and fate of other volatile chemicals in the upper reaches of EFPC.