Process for removal of selenium from water by dithionite ions
AssigneeEcolab USA Inc.
InventorsTarun Kumar BERA, Jitendra T. SHAH, Vaideeswaran SIVASWAMY
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Abstract
A method for efficiently removal of oxidised selenium from liquid, such as FGD wastewater. The method involves adding a non-iron-based reducing agent (e.g. sodium dithionite) and preferably Fe(II) ions to the liquid at a pH of above 7.5 or 8 and precipitating elemental selenium from the liquid.
Claims15
A method of reducing the selenium content of wastewater, the method comprising contacting the wastewater with Fe(II) ions and a non-iron-based reducing agent (M), preferably a dithionite ion, preferably at a pH of from 7.5 to 10.5 and/or preferably in the presence of lime.
A method of removing selenium from water, the method comprising contacting the water with a non-iron based reducing agent (M) at a pH of greater than 7.5, for example falling in the range of from 7.5 to 10.5, preferably greater than 8, for example falling in the range of 8 to 10.
A composition for the reduction of selenium in FGD wastewater, the composition comprising Fe(II) ions and dithionite ions, wherein the ratio of Fe(II) ions to dithionite ions is preferably in the range of 0.5 to 1.5.
Dependencies are inferred from the claim text.