The Regeneration of Saturated Ionites after Extraction of Hexavalent Chromium from Wastewater of Chromium Production Plant

The process of hexavalent chromium recovery by various eluents (alkaline solutions of sodium sulfate, alkaline solutions of sodium chloride and ammonium chloride solutions with the addition of ammonia) from saturated anion exchange resin Purolite A500/4994 was investigated. The desorption process was most efficiently carried out using ammonium chloride solutions (100 g L-1) with the addition of ammonia (1-5 %) and sodium chloride solutions (100 g L-1) with the addition of sodium hydroxide (10-50 g L-1). The degree of chromium recovery was more than 98 %. The chromium content in pregnant solution was 14-23 g/L. When using alkaline solutions of sodium sulfate for regeneration, chromium recovery degree was 78-96 %. In addition, the chromium content in pregnant solution did not exceed 6 g/L.