Decomposition of Spent Ion Exchange Resin Using Acid digestion, Fenton and Fenton-like Process

This research used the Fenton-like oxidation method to decompose the cationic and anionic resins. Acid digestion and the fenton method were also studied to compare the results. Acid digestion and Fenton methods did not show desirable results, so the research was focused on Fenton like process. For this purpose, Cu2+ was used as a catalyst and H2O2 as an oxidant. Five parameters including temperature, pH, Cu2+ concentration, H2O2 addition flow rate, and time were studied to obtain the optimum value for the decomposition of fresh resin. It was found that the optimum values were as follows: temperature: 75 C, Cu2+ concentration:0.3 M, H2O2 addition flow rate: 0.5 ml/min for cationic and 0.25 ml/min for anionic resin, and time: 2 hours. By optimization of the parameters decomposition weight percent of 88% was obtained for cationic resin and 83% for anionic resin. The optimum condition was applied for the actual sample, a mix of cationic and anionic resin from the Tehran research reactor. The decomposition percent of 81% was achieved. The resins were characterized before and after decomposition by FTIR and SEM, which showed the decomposition. COD analysis showed that only 2% of decomposed resin was maintained in the solution, and 98% was converted to CO2 and H2O.