Date of Award

Fall 2015

Project Type


Program or Major

Civil Engineering

Degree Name

Master of Science

First Advisor

James P Malley

Second Advisor

Erik Koreman

Third Advisor

Michael R Collins


This research investigated 1) evaluation and optimization of the SIX® anion exchange regeneration efficiency and 2) compatibility of cation exchange for hardness removal and shared-regeneration with the current anion exchange regenerant. The first objective was addressed by comparing the effects of three variables on desorption efficiencies: regenerant volume, salt concentration, and contact time. Sorption studies were performed to quantify resin blinding, and removal kinetics were established and compared. The second part of this research tested a strong acid cation resin for softening performance and regenerability with sodium chloride regenerant.

Inefficient DOC and nitrate desorption were observed as larger regenerant volume and higher salt concentration were required than sulfate and bicarbonate desorption. This indicated organic and nitrate accumulation on the resin, so the follow-up adsorption kinetics study compared its effects on target removal performance. The study also investigated desorption equilibrium, equivalent balance, and sorption kinetics observed during regeneration. Finally, the tested cation exchange resin achieved the desired hardness removal but was incompatible for sodium chloride regeneration, highlighting the complexity of resin selection for shared-regeneration. This report includes a comprehensive overview of the background, techniques, results and conclusions related to this investigation of resin regeneration.