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Titolo:
SOLID-PHASE CONTROLS OF DISSOLVED ALUMINUM WITHIN UPLAND PRECAMBRIAN SHIELD CATCHMENTS
Autore:
ALLAN CJ; ROULET NT;
Indirizzi:
UNIV N CAROLINA,DEPT GEOG & EARTH SCI CHARLOTTE NC 28223 YORK UNIV,DEPT GEOG N YORK M3J 1P3 ON CANADA
Titolo Testata:
Biogeochemistry
fascicolo: 2, volume: 26, anno: 1994,
pagine: 85 - 114
SICI:
0168-2563(1994)26:2<85:SCODAW>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
ALUMINOSILICATE CLAY-MINERALS; ACIDIC HEADWATER STREAM; SPODOSOL BS HORIZONS; GIBBSITE DISSOLUTION; WATERS; CHEMISTRY; SOILS; PRECIPITATION; SOLUBILITY; PRISTINE;
Keywords:
SOIL ALUMINUM; PRECAMBRIAN SHIELD; ORGANICALLY BOUND ALUMINUM; SATURATION INDEXES; LICHEN-BEDROCK SURFACES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
45
Recensione:
Indirizzi per estratti:
Citazione:
C.J. Allan e N.T. Roulet, "SOLID-PHASE CONTROLS OF DISSOLVED ALUMINUM WITHIN UPLAND PRECAMBRIAN SHIELD CATCHMENTS", Biogeochemistry, 26(2), 1994, pp. 85-114

Abstract

Solid phase controls of dissolved aluminum chemistry of soil and surface waters were investigated in several pristine, low order Precambrian shield catchments. Soil extraction and leaching experiments were conducted to quantify the various pools of solid phase soil aluminum and their relative mobility. Reactive soil aluminum (exchangeable + organic + amorphous forms), comprised < 20% of the total soil aluminum. Leaching soils with pH 3.0 HCl solutions indicated that Na4P2O7 extractable aluminum (largely organic complexes) was the most mobile form of reactive soil aluminum. Aluminum hydroxide from vermiculate interlayers was also mobilized from all soil horizons and its contribution to dissolved aluminum increased with soil depth. Runoff and soil waters from organic LFH and Ah soil horizons were highly undersaturated with respect to Al(OH)(3) solid-phases. Several natural bedrock surfaces (metagranites) covered with moss or lichen were leached with HCl solutions. Significantly more aluminum was removed from bedrock surfaces colonized with the moss Racomitrium microcarpon compared to that of the lichen-covered surfaces. Aluminum removal increased dramatically as the acidity of the leaching solution increased to pH 3.0. Leachates solutions collected from bedrock surfaces became increasingly undersaturated with respect to Al(OH)(3) minerals at lower pH values. Aluminum solubility appears to be controlled by equilibrium with organic complexation, modified by kinetically constrained dissolution of interlayer aluminum.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/12/20 alle ore 04:47:33