ADSORPTION AND DESORPTION OF Cd~(2+) IONS ON ION-EXCAHNGE RESIN USING SUB-CRITICAL WATER AND CARBON DIOXIDE

摘要

A study of regeneration of the ion exchange resins using a sub-critical mixture of CO_2-H_2O solution was reported. The experimental data were obtained by measuring the outlet concentration of ions Cd~(2+) eluated from a column packed with a commercial ion exchange resin Amberlite IRC-86 until the effluent reached the input concentration. The adsorption isotherm was also reported. The correlation of the experimental data indicated that the Langmuir model can be applied in this sorbent system. After adsorption process, the resin bed was desorbed in the same apparatus, but using the countercurrent process. The results indicated that the resin can be fully regenerated, with desorption efficiency above 99 %. However, The adsorption and respective desorption of metal ions was strongly dependent on the feed concentration. Lean feed is found to be better for both adsorption and desorption processes.