Study on sorption characteristics of citric acid modified rape-seed pellet considering the chemical pre-treatment processes

The ground rape-seed pellet was pre-treated then reacted with citric acid which resulted in a rape-seed citrate having ion exchange capacity. The effects of pre-treatment steps (including extraction of fatty substances by organic solvent, moreover acidic and alkali treatment of the rape-seed pellet) on the ion binding capacity of the materials were investigated. The capacity was determined for three cations (copper, zinc and nickel) separately, from aqueous solutions in batch mode of operation. Based on the experimental results it was found that the highest ion exchange capacity for all the cations was obtained by the process involved the pre-treatment combining of extraction and alkali treatment followed by the reaction with the citric acid.