2013 Volume 29 Issue 1 Pages 139-141
Ion exchange properties of five different Japanese natural zeolites in seawater were examined. Sodium ions could be reduced by all zeolites, although anions, Cl− and SO42−, in seawater showed barely changes. Natural zeolite desalination treatment mainly depends on the ion exchange between Na+, K+ and Mg2+ in seawater and Ca2+ in natural zeolite. This study found that mordenite is superior to clinoptilolite for use in Na+ reduction. Mordenite with high cation exchange capacity containing Ca2+ resulted in the highest Na+ reduction from seawater.