Recovery process for wastes containing hexavalent chromium

A process for recovery of hexavalent chromium from a stream comprising:

• providing the stream containing hexavalent chromium;
• reacting a soluble non-toxic precipitating reagent with the hexavalent chromium to form an insoluble precipitating reagent-chromate precipitate;
• and
• recovering the insoluble precipitating reagent-chromate precipitate.

A process for recovery of hexavalent chromium from a stream comprising:

• providing the stream containing hexavalent chromium;
• reacting a soluble non-toxic precipitating reagent with the hexavalent chromium to form an insoluble precipitating reagent-chromate precipitate, the soluble non-toxic precipitating reagent selected from bismuth compounds;
• lanthanide compounds;
• aluminum compounds;
• titanium compounds, trivalent chromium compounds;
• organic compounds containing a group selected from nitronium, phosphonium, sulfonium, stibonium, iodonium, pyrylium, or combinations thereof;
• or combinations thereof;
• reacting the insoluble precipitating reagent-chromate precipitate with an acidic solution to form an insoluble precipitating reagent precipitate and a soluble hexavalent chromium compound;
• recovering the soluble hexavalent chromium compound;
• and
• reacting the insoluble precipitating reagent precipitate with a solubilizing reagent to form the soluble non-toxic precipitating reagent.