An apparatus and method for removing mercury, and in particular elemental mercury, from a fluid stream by exposing the fluid stream to a polyethersulfone or filter-coated with anion exchange resin, or anion exchange resin-coated surface onto which has been loaded elemental iodine. Elemental iodine is loaded onto the PES or anion exchange resin-coated surface by immersing the PES or anion exchange resin-coated substrate in an iodine/pentane solution, then removing the substrate from the iodine/pentane solution and rinsing in pentane.