Open AccessEffect of Divalent Cations on RED Performance and Cation Exchange Membrane Selection to Enhance Power Densities
Author(s) -
Timon Rijnaarts,
Elisa Huerta,
Willem van Baak,
Kitty Nijmeijer
Publication year - 2017
Publication title -
environmental science and technology
Language(s) - English
Resource type - Journals
eISSN - 1520-5851
pISSN - 0013-936X
DOI - 10.1021/acs.est.7b03858
Subject(s) - divalent , reversed electrodialysis , chemistry , electrodialysis , membrane , inorganic chemistry , ion exchange , seawater , ion , organic chemistry , ecology , biochemistry , biology
Reverse electrodialysis (RED) is a membrane-based renewable energy technology that can harvest energy from salinity gradients. The anticipated feed streams are natural river and seawater, both of which contain not only monovalent ions but also divalent ions. However, RED using feed streams containing divalent ions experiences lower power densities because of both uphill transport and increased membrane resistance. In this study, we investigate the effects of divalent cations (Mg2+ and Ca2+) on RED and demonstrate the mitigation of those effects using both novel and existing commercial cation exchange membranes (CEMs). Monovalent-selective Neosepta CMS is known to block divalent cations transport and can therefore mitigate reductions in stack voltage. The new multivalent-permeable Fuji T1 is able to transport divalent cations without a major increase in resistance. Both strategies significantly improve power densities compared to standard-grade CEMs when performing RED using streams containing divalent cations