a method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent , such as ethylenediaminetetraacetic acid or other similar compounds like hedta , dtpa and / or nta , to the flue gas being scrubbed in a wet scrubber used in the industrial process . the chelating agent prevents the reduction of oxidized mercury to elemental mercury , thereby increasing the mercury removal efficiency of the wet scrubber . exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with edta addition . without edta , mercury removal totaled 42 %. with edta , mercury removal increased to 71 %. the invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying s 2 − ions to convert hg 2 + ions into mercuric sulfide and by supplying a chelating agent to sequester other ions , including but not limited to fe 2 + ions , which could otherwise induce the unwanted reduction of hg 2 + to the form , hg 0 .