Sorption-desorption behaviour of barium on clays

Abstract

Batch experiments were performed to study the sorption behaviour of Ba2+ ion on three different clay minerals determined to be predominantly kaolinite, montmorillonite and mixed chlorite-illite. Synthetic groundwater was used and the concentration of Ba2+ ion was in the range of 10-8 to 10-4 N. Grain sizes of the solid particles were all <38 μm. Cation exchange capacities were obtained using the silver-thiourea (AgTU) method. The variation of RD values was studied as a function of contact time, shaking rate, Ba2+ ion concentration, v/m ratio and pH. The saturation time varied with each type of clay; about 6, 8 and 12 days of shaking time were necessary for chlorite-illite mixed clay, kaolinite and montmorillonite respectively. Shaking rate affected only the rate of sorption and not the saturaton RD values. Sorption was found to be reversible on kaolinite and partly reversible on montmorillonite and chlorite-illite clays. The variation of RD as a function of Ba2+ ion concentration exhibited characteristic inverse S-shaped curves suggesting the presence of at least two different types of exchange sites. Sorption of Ba2+ ion was observed to depend on pH and v/m ratio. The sorption isotherms were found to fit Freundlich and Dubinin-Radushkevich type isotherms well. © 1990

Temperature effects in barium sorption on natural kaolinite and chlorite-illite clays

“…If ln [C] s is plotted against 2 , and ln C m will be obtained from the slope and the intercept, respectively. The value of (mol/kJ) 2 is related to the adsorption mean free energy, E (kJ/mol), defined as the free energy change required to transfer one mole of ions from infinity in solution to the solid surface.…”

“…[2][3][4][5][6][7][8][9][10] In this work, the sorption behavior of Ba 2+ on kaolinite and chlorite-illite mixed clay as a function of temperature, contact time and initial Ba 2+ ion concentration was studied. Incorporating temperature effects in the studies led to the determination of enthalpy, entropy and free energy of sorption.…”

Sorption studies of Cs+ and Ba2+ cations on magnesite

“…Detailed work examining the sorption/desorption behavior of Cs + and Ba 2+ ions on dierent clays and soil fractions from various regions of Turkey was carried out (Erten et al, 1988;Eylem et al, 1990) In those studies, sorption of Cs + and Ba 2+ cations on magnesite was examined as a function of time, cation concentration and temperature. The interaction of Cs + with various soil fractions is of considerable interest in radioactive waste considerations.…”

Investigação de anomalias hidrogeoquímicas de Bário em aquíferos do Estado de São Paulo

“…Em relação à adsorção em argilas, Eylem et al (1990) estudando o comportamento de sorção-desorção de bário em argilas, constataram que o íon Ba 2+ ocorre adsorvido de forma reversível em caulinita e parcialmente reversível em montmorilonita e clorita-ilita. Na caulinita, o íon Ba 2+ ocorre adsorvido em superfície, e no caso da montmorilonita e clorita-ilita, ocorre adsorvido entre camadas.…”