ADSORPTION OF BARIUM AND HYDROXYL IONS BY SOILS AND MINERALS IN RELATION TO pH

Publisher Website
Google Scholar
Abstract
Natural soils, H-saturated silt and day fractions, peat, humic acid, and several minerals were treated with increasing amts. of triethanolamine and NaOH in the presence of a constant conc. of BaCl2. After shaking, leaching, and washing, the amounts of Ba++ and OH- ions adsorbed were measured volumetrically and the following results obtained Adsorption of Ba by soils and several minerals reaches a max. coincident with the neutralization of exchangeable H. The reaction at which this occurs varies with the soil or mineral, i.e., about pH 6 for humic acid, pH 6.8 for peat, pH 7.9 for Eutaw, pH 8.2 for Norfolk, pH 8.1 for bentonite, pH 8.3 for chabazite, pH 8.7 for pyrophyllite, and pH 9.6 for kaolin. Above these pH values both Ba and OH ions are adsorbed in increasing and essentially equivalent amts. Max. adsorption of barium by permutit, halloysite var. indianaite, silica, and lignite was not measurable. Equivalent adsorption of Ba and OH ions by these materials occurred above pH 52 for lignite, pH 7.6 for indianaite, pH 7.9 for silica, and pH 8.7 for permutit.[long dash]The BaCl2 method buffered at pH 8.2 with triethanolamine should yield maximum values for base-exchange capacity and exchangeable H for most agricultural soils.

This publication has 1 reference indexed in Scilit: