HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Schulthess, C.P. Articles by Hu, Z. Search for Related Content PubMed Articles by Schulthess, C.P. Articles by Hu, Z. GeoRef GeoRef Citation Agricola Articles by Schulthess, C.P. Articles by Hu, Z. Related Collections Structure and Properties Soil Chemistry Soil Mineralogy

DIVISION S-2 - SOIL CHEMISTRY

Impact of Chloride Anions on Proton and Selenium Adsorption by an Aluminum Oxide

Dep. of Plant Science, U-67, Univ. of Connecticut, Storrs, CT 06269

Corresponding author (c.schulthess@.uconn.edu)

The quantity of protons adsorbed for each anion adsorbed by a solid surface is an essential component of surface complexation models. This reaction stoichiometry is often assumed, or it is "confirmed" based on the goodness-of-fit of the pH-dependent adsorption models. This ratio can be experimentally measured, but the resulting measurement may be in error if secondary (unaccounted for) reactions are present that are also consuming or releasing protons. Using selenate and selenite adsorption isotherms on an Al oxide, the proton/anion stoichiometries were determined to be 2:1 at high pH values (>6), but they decreased rapidly at low pH values. The stoichiometry is 2:1 across a broader pH range when corrections are made for the change in Cl adsorption intensity by Al oxide in the presence of Se anions. Generalizing, if a weakly adsorbing anion is affected by another strongly adsorbing anion, then its impact on the balance of protons adsorbed (or balance of surface charge) must also be monitored. Although the Cl anion is very weakly adsorbing, the matrix needs to be considered as a ternary system consisting of H, Cl, and Se ions. A binary approach, one that views only H and Se ions, will misrepresent the H/Se adsorption ratios, particularly at low pH values.

Abbreviations: DRIFT, diffuse reflectance infrared Fourier transformed • EXAFS, extended x-ray absorption fine structure • FTIR, Fourier transformed infrared • ZPSE, zero point of salt effect • ZPT, zero point of titration

This article has been cited by other articles:

				U. K. Saha, L. M. Kozak, and P. M. Huang KINETICS OF CITRATE-INDUCED SELENITE DESORPTION FROM MONTMORILLONITE AS AFFECTED BY COMPLEXATION WITH HYDROXYALUMINUM AND HYDROXYALUMINOSILICATE IONS Clays and Clay Minerals, February 1, 2007; 55(1): 71 - 88. [Abstract] [Full Text] [PDF]

				U. K. Saha, C. Liu, L. M. Kozak, and P. M. Huang Kinetics of Selenite Adsorption on Hydroxyaluminum- and Hydroxyaluminosilicate-Montmorillonite Complexes Soil Sci. Soc. Am. J., July 1, 2004; 68(4): 1197 - 1209. [Abstract] [Full Text] [PDF]