Boron Removal from Water Using Takovite: Adsorption vs. Anion Exchange

Abstract

Takovite, a kind of hydrotalcite-like compounds (HTlcs), was used for boron removal from water. It was prepared by coprecipitation method and characterized by X-ray diffraction technique (XRD). The equilibrium time of boron sorption by takovite as well as its boron uptake capacities was determined by the reaction kinetic experiments and isotherm sorption experiments. The effects of experimental conditions on boron removal efficiency were also evaluated. Generally, the boron uptake by takovites increases with increasing initial boron concentration in solution. The isotherm sorption data match well with the Freundlich model, indicating that the anion exchange contributes a lot to solution deboronation. Moreover, at higher temperature, greater boron removal by takovite was observed. As compared to calcined takovite, uncalcined takovite has better performance in terms of boron uptake, since the structural restoration of calcined takovite didnt happen during its contact with boron-containing solution, which is quite different from the behavior of other HTlcs as reported.