STUDY ON ION EXCHANGE BEHAVIOR OF AUCHLITEARA9366 AND AUCHLITEA378 RESINS CHEMICALLY DEGRADED IN PERCHLORIC ACID MEDIUM

The resins AuchliteARA-9366 and AuchliteA-378 in chloride form were degraded by treating with 0.005 M and 0.01M HClO4 for 24 h under continuous magnetic stirring. The degraded resins in chloride form were equilibrated separately with bromide and iodide ion solutions of different concentrations in the temperature range of 30.0 - 45.0 oC for 3 h. the equilibrium constants (K) values forCl-/I- and Cl-/Br- ion exchange reactions were calculated. The results indicate that during Cl-/I- reaction with rise in temperature the K values decreases from 4.59x 10-2 to 3.44x 10-2 for resin AuchliteARA-9366 degraded using 0.005 M HClO4medium which was lower than the decrease in K values from 4.61 x 10-2 to 3.74 x 10-2 observed for the resin AuchliteARA-9366 degraded using 0.01M HClO4 medium. Similar results were obtained for Cl-/Br-ion exchange reaction. Forresin AuchliteA-378 during Cl-/I- reaction the K values decreases from 5.83 x 10-2 to 4.14 x 10-2 for AuchliteA-378 degraded in 0.005 M HClO4 medium which was lower than the decrease in K values from 6.04 x 10-2 to 4.09 x 10-2 observed for the resin AuchliteA-378 degraded using 0.01M HClO4 medium. Similar results were obtained for Cl-/Br- ion exchange reaction. The decrease in K values with rise in temperature indicate exothermic ion exchange reactions which was supported by negative standard enthalpy (∆H0) and standard entropy(∆S0) values obtained during the two ion exchange reactions carried out by using both the resins AuchliteARA-9366 and AuchliteA-378. The thermodynamic data obtained here was used to predict the performance suitability of the chemically degraded nuclear grade strong base and industrial grade weak base resins in perchloric acid medium