Method for accelerating recovery of selenium from aqueous streams

Abstract

The invention provides a method for accelerating the removal and recovery of selenium from aqueous solutions, such as agricultural irrigation drainage streams or mine waste waters by the bioreduction of Se(VI) to Se(IV) species by using Clostridium soil bacteria together with a rapid exchange reaction which occurs between the aqueous selenium species selenous acid (H.sub.2 SeO.sub.3) and pyrite (FeS.sub.2) to remove all forms of selenium from the aqueous solution. The exchange reaction product FeS.Se may be treated with dilute mineral acid such as sulfurous acid to generate hydrogen selenide (H.sub.2 Se), which is burned in air to yield free selenium. The free selenium recovered is available for use in the electronics, photocopying equipment and other industries. A reusable bacteria-containing soil and pyrite filter apparatus for installation in drainage canals and other conduits is additionally provided to facilitate the removal of aqueous selenium pollutants.

Dependencies are inferred from the claim text.