Low-level mercury removal from groundwater using a synthetic chelating ligand

Mercury is present in many industrial processes at low concentrations and is a cause for concern due to the propensity for mercury to bioaccumulate. As a cumulative toxin, introduction of mercury into the environment at any level has the potential to adversely affect ecologic systems. To date, no commercial precipitants are available that can irreversibly and permanently bind mercury. In the current work, selected commercial reagents were compared alongside the dianionic ligand 1,3-benzenediamidoethanethiolate (BDET^2-) to test the feasibility of low-level (parts-per-billion, ppb) mercury treatment for groundwater near a chloralkali plant. Of all the reagents examined, only K₂BDET was capable of reducing mercury concentrations to below instrumental detection limits of 0.05 ppb with the added benefit of producing a stable precipitate.