Methods for treating selenocyanate in wastewater
AssigneeThe Texas A&M University System
InventorYongheng Huang
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Abstract
Methods and systems for reducing the concentration of selenocyanate in water. In the methods and systems, water containing selenocyanate is treated an oxidant to provide oxidant-treated water, which is then contacted with a zero-valent iron treatment system comprising (a) a reactive solid comprising zero-valent iron and one or more iron oxide minerals in contact therewith and (b) ferrous iron.
Claims18
A method for reducing the concentration of selenocyanate in water containing selenocyanate, comprising:
- in a first step, treating water containing selenocyanate with an oxidant for a time sufficient to oxidize the selenocyanate to provide selenium species treatable by a zero-valent iron system in oxidant-treated water, wherein the oxidant is selected from the group consisting of hydrogen peroxide, permanganate, and persulfate;
- and
- in a second step, contacting the oxidant-treated water with a zero-valent iron treatment system that comprises (a) a reactive solid comprising zero-valent iron and one or more iron oxide minerals in contact therewith and (b) ferrous iron, wherein the selenium species in the oxidant-treated water treatable by the zero-valent iron system are reduced.
In a method for reducing the concentration of selenocyanate in water containing selenocyanate, comprising contacting water containing selenocyanate with a zero-valent iron treatment system comprising (a) a reactive solid comprising zero-valent iron and one or more iron oxide minerals in contact therewith and (b) ferrous iron, the improvement comprising treating the water containing selenocyanate with an oxidant selected from the group consisting of hydrogen peroxide, permanganate, and persulfate, for oxidizing selenocyanate for a time sufficient to oxidize the selenocyanate to provide selenium species treatable by a zero-valent iron system prior to contacting the water with the zero-valent iron treatment system.
A system for reducing the concentration of selenocyanate in water, comprising:
- a first vessel for receiving water containing selenocyanate, wherein the first vessel comprises an oxidant selected from the group consisting of hydrogen peroxide, permanganate, and persulfate, to oxidize selenocyanate to selenium species treatable by a zero valent iron system and does not comprise zero valent iron;
- and
- a first reactor in fluid communication with the first vessel for receiving oxidant-treated water from the first vessel, wherein the first reactor comprises a zero-valent iron treatment system comprising (a) a reactive solid comprising zero-valent iron and one or more iron oxide minerals in contact therewith and (b) ferrous iron.
Dependencies are inferred from the claim text.