Experimental and Numerical Analysis of Biological Regeneration of Perchlorate Laden Ion-Exchange Resins in Batch Reactors

Abstract

Removal of perchlorate ions from ion-exchange resins is essential for the economical treatment of perchlorate contaminated water. The objectives of this study were to prove that single-use ion-exchange resins could be regenerated in biological batch systems and to develop a numerical model that could be used to predict the time for regeneration of perchlorate from exhausted ion-exchange resins under varying conditions. This research uniquely addresses both the biological and physical/chemical aspects of the regeneration of single-use resins. Experimental studies demonstrated that perchlorate exhausted resin was effectively regenerated by a salt-tolerant, perchlorate-reducing culture. A numerical model was developed that incorporates physical desorption and biodegradation parameters. Results suggest that the model generates an acceptable correlation to experimental data and can predict the time to regeneration when no perchlorate is detectable in the aqueous phase in equilibrium with the ion exchange resin. A sensitivity study showed that biological activities have the most significant effects on the biological regeneration process. Results of this research can be directly applied to process design for biological regeneration of perchlorate exhausted single-use ion-exchange resins.