Sulfate adsorption and desorption reversibility in a variety of forest soils

Journal Article · · Journal of Environmental Quality; (United States)

DOI:https://doi.org/10.2134/jeq1989.00472425001800040004x· OSTI ID:5885124

Harrison, R B ^[1]; Johnson, D W ^[2]; Todd, D E ^[3]

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1. Univ. of Washington, Seattle (United States)
2. Desert Research Inst., Reno, NV (United States)
3. Oak Ridge National Lab., TN (United States)

Subsurface soil samples were collected from 20 forest sites of differing soil and cover type, atmospheric deposition history and physiographic location. Samples were analyzed for S pools, sulfate adsorption capacity, adsorption reversibility, and associated soil properties in order to compare the relative S chemistry and SO{sub 4} retention capacities of the sites. A total of 32 out of 36 soil horizons studied showed net SO{sub 4} adsorption, ranging from a desorption of 0.4 to an adsorption of 7.2 mmol SO{sub 4} kg{sup {minus}1}. Thus, most of these soils were not yet saturated with respect to a solution concentration of 0.25 mM SO{sub 4}. Most soil horizons showed irreversible SO{sub 4} adsorption (an average of 36% of adsorbed SO{sub 4} was retained irreversibly) as evidenced both by changes in phosphate extractable SO{sub 4} and by a comparison of desorption of SO{sub 4} before and after saturation by the 0.25 mM SO{sub 4} solution. When adsorption and adsorption reversibility observations were compared with measured soil properties, the presence of hydrous oxides of Al and native SO{sub 4} were the best indicators of SO{sub 4} adsorption potential. Most adsorption/desorption/extraction sequences showed mass conservation of SO{sub 4}, indicating inorganic SO{sub 4} adsorption appeared to be far more important in these procedures than organic S incorporation or mineralization. It is unclear how much air-drying, sample treatment, and the procedures followed might have changed the inorganic and organic S pools of these soils.

• OSTI ID: 5885124
• Journal Information: Journal of Environmental Quality; (United States), Journal Name: Journal of Environmental Quality; (United States) Vol. 18:4; ISSN JEVQA; ISSN 0047-2425
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
ADSORPTION
CHEMISTRY
CONTAMINATION
DESORPTION
ECOLOGICAL CONCENTRATION
FORESTS
MONITORING
OXYGEN COMPOUNDS
SOIL CHEMISTRY
SOILS
SORPTION
SULFATES
SULFUR COMPOUNDS