The fate of arsenic in sediments of the Laurentian Trough

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(88)90131-7· OSTI ID:5180408

Belzile, N ^[1]

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1. Universite du Quebec, Rimouski (Canada)

Vertical profiles of total dissolved As, Fe, Mn, phosphate, nitrate, and sulfate, Eh, pH, and total solid As, hydroxylamine/acetic acid-extractable As and Fe, and extractable pyrite were determined in seven cores from the estuary and the Gulf of the Laurentian Trough. The surface enrichment of solid As and the increase of dissolved As with depth at many stations suggests that a mobile portion of As is associated with Fe-oxyhydroxides and follows a redox-pattern of dissolution in the suboxic zone, upwards diffusion, and precipitation near the sediment-water interface under non-steady state conditions. Conditions existing in the Gulf, promote the formation of pyrite in the reducing zone, the presence of which strongly affects the distribution of arsenic. Pore water arsenic concentrations are increasing along with the concentrations of solid As associated with pyrite, and As is captured by pyrite according to a constant Fe/As ratio of 1,000. The behavior of As is presented in a qualitative model.

• OSTI ID: 5180408
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 52:9; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ARSENIC
ATLANTIC OCEAN
CANADA
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHEMISTRY
DISSOLUTION
DRILL CORES
ELEMENTS
GEOCHEMISTRY
GROUND WATER
HYDROGEN COMPOUNDS
INTERFACES
INTERSTITIAL WATER
IRON
IRON COMPOUNDS
IRON SULFIDES
ISLANDS
MANGANESE
METALS
MINERALS
NEWFOUNDLAND
NORTH AMERICA
OXYGEN COMPOUNDS
PH VALUE
PYRITE
REDOX REACTIONS
REDUCTION
SEAS
SEDIMENT-WATER INTERFACES
SEDIMENTS
SEMIMETALS
SOLUTES
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
SURFACE WATERS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
WATER
WATER CHEMISTRY