The reduction of hexavalent chromium by sulphite in wastewater

摘要: The reduction of hexavalent chromium, Cr(VI), in unbuffered aqueous solution by sulphite was investigated as a function pH, possible dosage and contact time required to reach equilibrium. Dissolved Na 2 Cr O 7 .2H served the source Cr(VI). rate reaction between Cr(VI) exhibited very strong dependence on pH mixture, with decrease an increase from 2.0 5.0. For 5.0 x 10 -4 mol.dm -3 (∼26 mg/) concentration at least 5 times initial needed for complete this range. Above 6 large concentrations were reduce effectively. To check industrial relevance results, baghouse dust ferrochromium plant leached serve model wastewater containing conducting various comparative experiments. results clearly indicated that would be suitable reductant under specific conditions (2.0 ≤ [sulphite] = [Cr(VI)] ).