20This study evaluates the removal of mercury from wastewater using chemical reduction and air stripping 21 using a full-scale treatment system at the Savannah River Site. The existing water treatment system 22 utilizes air stripping as the unit operation to remove organic compounds from groundwater that also 23 contains mercury (C ~ 250 ng/L). The baseline air stripping process was ineffective in removing 24 mercury and the water exceeded a proposed limit of 51 ng/L. To test an enhancement to the existing 25 treatment modality a continuous dose of reducing agent was injected for 6-hours at the inlet of the air 26stripper. This action resulted in the chemical reduction of mercury to Hg(0), a species that is removable 27 with the existing unit operation. During the injection period a 94% decrease in concentration was 28 observed and the effluent satisfied proposed limits. The process was optimized over a 2-day period by 29 sequentially evaluating dose rates ranging from 0.64X to 297X stoichiometry. A minimum dose of 16X 30 stoichiometry was necessary to initiate the reduction reaction that facilitated the mercury removal.