Reduction of chromium(VI) ions from aqueous solutions by using the solvent impregnated resin

The solvent impregnated resins enables effective recovery of microquantities of chromium(VI) ions from wastewaters. The solvent impregnated resin (SIR) Amberlite XAD 7 HP as polymer matrix has been prepared by the wet-impregnation technique. Aliquat 336 was employed as the extractant and acetone as the solvents for impregnation. Sorption of chromium(VI) was investigated in the batch process . Sorption of chromium(VI) was studied in the pH range from 1.5 to 7. It was stated that sorption of chromium(VI) ions depends on acidity of solution. The values of recovery factors of chromium(VI) are higher at low pH than in neutral solution. The speciation of chromium was investigated in the studied pH range. Reduction of chromium(VI) to chromium(III) under acidic conditions was observed. Chromium was determined by using the spectrophotometric and atomic absorption spectroscopy methods. Both methods permit to observe changing of valence of chromium(III) and (VI) oxidation states. The prepared SIR is a new sorbent used for recovery of chromium ions from wastewaters.