Sorption of mono-carboxylic acids by an anion-exchange membrane

✍ Scribed by Hiroshi Takahashi; Kazuya Ohba; Ken-ichi Kikuchi

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 93 KB
• Volume: 16
• Category: Article
• ISSN: 1369-703X
• DOI: 10.1016/s1369-703x(03)00077-9

✦ Synopsis

Sorption characteristics of eight mono-carboxylic acids by an anion-exchange membrane were studied. The experiments were carried out as batch determinations of the equilibrated concentrations of chloride and carboxylic acid in the membrane and the solution. The sorption of a carboxylic acid by the ion-exchange membrane rapidly increased with increase in the solution concentration of the carboxylic acid, and was considerably different at different pH. However, these pH-dependent sorption equilibria were successfully represented as one curve in terms of the concentration of the dissociated carboxylic acid ion in the solution. This means that the sorption behavior of carboxylic acids can be explained by the ion exchange between a dissociated carboxylic acid ion and a counter ion on the fixed charge in the membrane. On the basis of the experimental results, the selectivity coefficients of mono-carboxylic acids were determined by a model which considered with dissociation equilibrium of carboxylic acids, material balance in the solution, and electrical neutrality in the membrane. The model successfully explained the observed sorption characteristics for carboxylic acids.