Sorption of 226Ra from oil effluents onto synthetic cation exchangers

► 226Ra was removed by ion exchange on birnessite and by surface sorption on SbSi. ► Investigating the effect of macro components showed that K+ was the greatest competitor. ► There was a relationship between TDS and chloride content in oil production waters. ► 226Ra in oil production waters based on age and geological formation of reservoir. ► Selectivity of materials was shown to be dependent on the pH of treated wastewater.