Vinh Dien Le
Research Mentor(s): Jovan Kamcev
Mentor Department: Chemical Engineering
Authors: Vinh-Dien Le, Mingyu Shin, Jovan Kamcev
Session: Session 2 (10:00- 10:50am)
Presentation Type: Oral
Abstract
In recent days, as the need for acid recovery in mining and industrial wastewater treatment has increased, there is a growing interest in the use of ion-exchange membranes (IEMs) for electrodialysis owing to their high efficiency in the recovery rate and energy usage. However, applying electrodialysis to acid recovery is subjected to acid leakage as protons bypass the membrane via water-mediated hopping. This phenomenon decreases both current efficiency and recovered acid concentration. It is important to have a better understanding of this phenomenon in current commercial anion exchange membranes (AEMs). In this study, the acid transport properties of 20 different commercial membranes with diverse membrane properties (varying water and charge contents) that govern the molecular transport behavior of AEMs contacted by 0.2 M HCl solution are investigated. AEM transport properties are comprehensively investigated based on the Solution-Diffusion and Nernst-Einstein frameworks. Results show that membranes with better counter-ion/co-ion selectivity generally exhibit better acid-blocking performance. There is also a clear trade-off between the membrane water content over charge content and counter-ion/co-ion selectivity. The results of this study highlight shortcomings in the performance of these membranes for acid recovery application and identify gaps in our fundamental understanding of acid transport in IEMs in acidic conditions.
