skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The role of basic aluminum sulfate minerals in controlling sulfate retention in the mineral horizons of two spodosols

Abstract

The authors collected soil solutions during the spring snowmelt at two depths using tension-free lysimeters in two Humic Cryorthods located in forested catchments. They also extracted soil solutions by centrifugation from the B and the C horizons of these soils. Although most data points cluster around the solubility line of natural gibbsite, the relationship between Al{sup 3+} activity and solution pH showed a marked departure from Al(OH){sub 3} solubility with a slope of {minus}1.91. Moreover, at pH values below 4.6, solutions were slightly undersaturated with respect to natural gibbsite. Results from thermodynamic calculations suggested that the Hermine B, and probably the Coniferous B, horizons have attained chemical conditions sufficient to enter the stability field of a basic aluminum sulfate mineral formed in the presence of Al(OH){sub 3}. Mineral stability relationships indicated that the solid phase of concern could be alunite (pK{sub s} = 85.4) and that the apparent saturation status of the soil solutions with respect to alunite increased with increasing reaction time. However, physical evidence for the presence of alunite in these horizons is still lacking. Solutions from the C horizons were all clearly undersaturated with respect to any Al{sub x}(OH){sub y}(SO{sub 4}){sub z} mineral. While the possible formationmore » of alunite could be affecting sulfate retention in these acid soils, the results do not exclude the pH-dependent sulfate adsorption mechanism proposed by a number of investigators.« less

Authors:
 [1];  [2]
  1. Univ. of Montreal, Quebec (Canada)
  2. McGill Univ., Ste-Anne de Bellevue, Quebec (Canada)
Publication Date:
OSTI Identifier:
5395993
Resource Type:
Journal Article
Journal Name:
Soil Science; (United States)
Additional Journal Information:
Journal Volume: 150:3; Journal ID: ISSN 0038-075X
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ALUMINIUM SULFATES; SOIL CHEMISTRY; SOILS; ACIDIFICATION; SULFATES; RETENTION; PH VALUE; SOLUBILITY; THERMODYNAMICS; ALUMINIUM COMPOUNDS; CHEMISTRY; OXYGEN COMPOUNDS; SULFUR COMPOUNDS; 540220* - Environment, Terrestrial- Chemicals Monitoring & Transport- (1990-)

Citation Formats

Courchesne, F, and Hendershot, W H. The role of basic aluminum sulfate minerals in controlling sulfate retention in the mineral horizons of two spodosols. United States: N. p., 1990. Web. doi:10.1097/00010694-199009000-00002.
Courchesne, F, & Hendershot, W H. The role of basic aluminum sulfate minerals in controlling sulfate retention in the mineral horizons of two spodosols. United States. doi:10.1097/00010694-199009000-00002.
Courchesne, F, and Hendershot, W H. Sat . "The role of basic aluminum sulfate minerals in controlling sulfate retention in the mineral horizons of two spodosols". United States. doi:10.1097/00010694-199009000-00002.
@article{osti_5395993,
title = {The role of basic aluminum sulfate minerals in controlling sulfate retention in the mineral horizons of two spodosols},
author = {Courchesne, F and Hendershot, W H},
abstractNote = {The authors collected soil solutions during the spring snowmelt at two depths using tension-free lysimeters in two Humic Cryorthods located in forested catchments. They also extracted soil solutions by centrifugation from the B and the C horizons of these soils. Although most data points cluster around the solubility line of natural gibbsite, the relationship between Al{sup 3+} activity and solution pH showed a marked departure from Al(OH){sub 3} solubility with a slope of {minus}1.91. Moreover, at pH values below 4.6, solutions were slightly undersaturated with respect to natural gibbsite. Results from thermodynamic calculations suggested that the Hermine B, and probably the Coniferous B, horizons have attained chemical conditions sufficient to enter the stability field of a basic aluminum sulfate mineral formed in the presence of Al(OH){sub 3}. Mineral stability relationships indicated that the solid phase of concern could be alunite (pK{sub s} = 85.4) and that the apparent saturation status of the soil solutions with respect to alunite increased with increasing reaction time. However, physical evidence for the presence of alunite in these horizons is still lacking. Solutions from the C horizons were all clearly undersaturated with respect to any Al{sub x}(OH){sub y}(SO{sub 4}){sub z} mineral. While the possible formation of alunite could be affecting sulfate retention in these acid soils, the results do not exclude the pH-dependent sulfate adsorption mechanism proposed by a number of investigators.},
doi = {10.1097/00010694-199009000-00002},
journal = {Soil Science; (United States)},
issn = {0038-075X},
number = ,
volume = 150:3,
place = {United States},
year = {1990},
month = {9}
}