Supported liquid membrane process for chromium removal and recovery
AssigneeCommodore Separation Technologies, Inc.
InventorW. S. Winston Ho
Life of this patent
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Abstract
The present invention is directed toward a two-step process for the removal and recovery of chromium from a feed solution, such as waste water, using supported liquid membranes (SLMs). In the first step of the process, the feed solution, which contains hexavalent chromium, is treated with a first strip solution to produce a moderately concentrated Cr(VI) solution. In the second step, the moderately concentrated Cr(VI) solution is treated with a second strip solution. The process advantageously produces a treated feed solution having a decreased concentration of chromium which is acceptable for discharge or recycle and a product solution which contains a highly concentrated Cr(VI) solution having little or no sulfate contaminants.
Claims31
A process for removal and recovery of chromium from a feed solution containing hexavalent chromium Cr(VI) comprising
- (1) in a first supported liquid membrane comprising an amine embedded in a microporous support material, treating a feed solution containing hexavalent chromium with a first strip solution to produce a moderately concentrated Cr(VI) solution comprising from 1,000 ppm to 20,000 ppm Cr(VI) and a treated feed solution comprising a chromium concentration of less than about 0.5 ppm;
- and
- (2) in a second supported liquid membrane comprising an amine embedded in a microporous support material, treating the moderately concentrated Cr(VI) solution with a second strip solution to produce a product solution comprising from 50,000 ppm to 300,000 ppm Cr(VI) and less than 100,000 ppm sulfate and to produce a treated solution, resulting from the moderately concentrated Cr(VI) solution, comprising an amount of chromium similar to the feed solution for recycling to this feed solution.
Dependencies are inferred from the claim text.