Enhancement of mercury(II) sorption from water by coal through chemical pretreatment

Enhancement of mercury(II) sorption from water by bituminous coal through chemical pretreatment was explored in the laboratory using batch sorption tests and downflow column studies. Both intensity of sorption and equilibrium sorptive capacity were enhanced significantly following nitric acid and hydrogen peroxide oxidation. Sulfurization and manganese oxide impregnation also showed promise. The chemically pretreated coal sorbents exhibited mercury sorption to a level higher than that accomplished using active carbon. Nitric acid or hydrogen peroxide oxidized or sulfurized coal may well replace active carbon in polishing mercury-laden waste following sulfide precipitation or removing mercury during municipal water treatment.