Article ID Journal Published Year Pages File Type
189641 Electrochimica Acta 2011 6 Pages PDF
Abstract

We report on the possibility of removing boron (in the form of boric acid) from water by electrochemical means. We explore capacitive de-ionization (CDI) processes in which local changes in pH near the surface of high-surface-area activated carbon fiber (ACF) electrodes during charging are utilized, in order to dissociate boric acid into borate ions which can be electro-adsorbed onto the positive electrode in the CDI cells. For this purpose, a special flow-through CDI cell was constructed in which the feed solution flows through the electrodes. Local pH changes near the carbon electrode surface were investigated using a MgCl2 solution probe in three- (with reference) and two-electrode cells, and described qualitatively. We show that, to a certain extent, boron can indeed be removed from water by CDI.

► Boron removal by electrochemical means. ► Temporary local pH changes developed within the pores were indicated by using MgCl2 in the solution as a probe. ► The process of Boron extraction from water takes place in two stages: 1. dissociation of boric acid on the negatively polarized electrode. 2. Electro-adsorption of borate ion onto the positively polarized electrode.

Related Topics
Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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