The life of the ion-exchange resin catalysts used by the chemical industry is limited, because they are deactivated after a few cycles. Disposal of the used catalyst is also a prime concern for the industry. In this work we attempted to regenerate the catalysts, Indion-130 and Amberlyst-15, used in the alkylation reaction of phenol and to make it in reusable form. The physically adsorbed impurities are removed by solvent extraction and acid-alkali treatments, and properties were found to improve. The residual unsaturation content of the conventional catalyst is found to be 6-7%. The possibility of grafting of the phenolic compounds to this residual double bonds was suspected. Oxidation of the grafted phenolic compounds was performed by treatment with ozone and chlorine dioxide solutions. Most of the characteristic properties of the catalyst were restored after regeneration. The total exchange capacity was about 20% lower. The chances of macroporous resin to become gellular cannot be ruled out. Therefore the suitability of the regenerated resin, in the field of gellular resin was tried. It was found to work satisfactorily in the esterification reaction of n-butanol with acetic acid. Reusability of the regenerated resin in water-softening process was also studied.