CHARACTERISTICS OF BORON ADSORPTION ON STRONG-BASE ANION-EXCHANGE RESIN

The adsorption characteristics of boric acid on a strong-base anion-exchange resin, Amberlite IRN-78LC in OH- form, were investigated at 10, 30, 45 and 60-degrees-C in concentrations of boron up to 1500 ppm. The expression for the adsorption of boric acid is proposed as q = q(infinity)(K(L)C/(1 + K(L)C) + K(C)C+K0), where q and q(infinity) are the quantity of boron adsorbed on the resin and the ion exchange capacity of the resin, respectively, and C is the concentration of boron in solution. The K(L) introduced represents a Langmuir-type adsorption of boric acid in a low concentration of boron. K(C) can be interpreted as a so-called polymerization effect representing that borate ions with less boron atoms in the resin turn into polyborate ions with more boron atoms as the boron concentration in solution increases. In addition, K0 represents the initial adsorption that takes place abruptly in the extremely low concentration of boron.