Pedosphere 4(3): 235--244, 1994
ISSN 1002-0160/CN 32-1315/P
©1994 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Effects of electrolyte anions and ph on adsorption of sulfate by variable charge soils |
| ZHANG Gang-Ya1, G. M. BRÜMMER2 and ZHANG Xiao-Nian1 |
1 Instttute of Soil Science, Chinese Academy of Sctences, Nanjing 210008 (China)
2 Department of Soil Sctence, University of Bonn, Nussaliee 13, 53115 Bonn (Germany) |
| ABSTRACT |
| The effects of three electrolyte anions, ionic strength and pH on the adsorption of sulfate by two variable charge soils, with different surface charge properties were studied. Under the conditions of the same pH and ionic strength the effect of electrolyte anions on the adsorption of sulfate was in the order of Cl- > NO3- > ClO4-, indicating the difference of the nature among these three anions. For Ferralsol in the same concentration of chloride and perchloride solutions, the two sulfate adsorption-pH curves could intersect at certain pH value. When pH was higher than the intersecting point, more sulfate was adsorbed in the perchloride solution, while when it was lower than the intersecting point, more sulfate was adsorbed in the chloride solution. In different concentrations of electrolyte solution, the curves of the amount of oxy-acid anion adsorbed, which changed with pH, could intersect at a certain pH, which is termed point of zero salt effect (PZSE) on adsorption. The nature of electrolyte anions influenced obviously the appearance of PZSE for sulfate adsorption. For ferralsol the curves of adsorption converged to about pH 7 in NaCl solution seemed to intersect in NaNO3 solution and to have a typical PZSE for sulfate adsorption in NaClO4 solution. For Acrisol the three curves of adsorption were nearly parallel in NaCl and NaNO3 solutions and converged to pH 6.5 in NaClO4 solution. |
| Key Words: effect of electrolyte anion, sulfate adorption, mariable charge soil |
| Citation: Zhang, G. Y., BrÜmmer, G. M. and Zhang, X. N. 1994. Effects of electrolyte anions and ph on adsorption of sulfate by variable charge soils. Pedosphere. 4(3): 235-244. |
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