Ion exchange membrane-assisted electro-activation of aqueous solutions: Effect of the operating parameters on solutions properties and system electric resistance

• DOI: 10.1016/j.psep.2014.04.005
• Publication Date: 2014-04-29T02:15:30Z
• Authors: Viacheslav Liato; Steve Labrie; Marzouk Benali; Mohammed Aïder
• Keywords: Reduction potential

Abstract The properties of electro-activated (EA) aqueous solutions as well as the dynamics of their changes were considered in the current study using aqueous solutions of NaCl and NaHCO 3 . The concentrations of the salt solutions were 0.5, 0.25, 0.125 and 0.05 M. The tests were performed at the DC current densities of 25, 37.5, and 50 A/m 2 . The electro-activation reactor consisted of three individual cells assembled together and separated by anion-exchange (AEM) and cation-exchange (CEM) membranes. During the experiments, four configurations of the membrane placements and solutions concentrations were studied. The obtained results showed the dynamics of the electro-activation process that allows obtaining electro-activated solutions with targeted properties such as pH and oxydo-reduction potential (ORP). It was possible to obtain electro-activated solutions at the anodic side (acid anolyte) with pH of 3.0, 3.5, and 4.0 and ORP of +1100 ± 15 mV when NaCl solution was used as electrolyte. Furthermore, several types of electro-activated solutions with high redox potential (ORP = +921 ± 12 mV) and neutral pH (6.48 ± 0.05) were obtained on the anode side when sodium carbonate was used. At the same time, two types of solutions, one with acid pH (2.14 ± 0.14) and the other one with alkaline pH (10.46 ± 0.03) with ORP = +689 ± 10 and 110 ± 21 mV, respectively, were obtained in the central compartment which considered as electro-activated solutions obtained by means of noncontact electro-activation.