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The Oxygen Status of Lake Sediments
Author(s) -
Howeler R. H.
Publication year - 1972
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1972.00472425000100040006x
Subject(s) - sink (geography) , sediment , organic matter , environmental chemistry , soil water , diffusion , flux (metallurgy) , oxygen , phosphate , chemistry , surface layer , mineralogy , soil science , environmental science , geology , layer (electronics) , geomorphology , physics , cartography , organic chemistry , geography , thermodynamics
The presence of oxygen in the surface layer of sediments greatly affects the abundance and availability of Fe, Mn, nitrates, phosphates, and sulfates. The concentration of O 2 in the oxidized layer depends on the balance between the rate of O 2 diffusion into the sediment and the rate of consumption by the sediment. Several mathematical diffusion models were developed to describe this relationship between diffusion and consumption. With these models the flux of O 2 across the water‐mud interface and the thickness of the oxidized zone can be calculated. Experimental testing of the models showed that the steady state O 2 consumption rates were proportional to the square root of the O 2 concentration at the mud surface. The relative contribution of biological and chemical O 2 consumption depended mainly on the organic matter content of the sediment, the biological consumption being highest in high‐organic matter soils. Determination of the Fe distribution near the sediment surface showed that Fe diffused upward from the reduced soil and accumulated in the oxidized zone. This freshly precipitated Fe could function as a phosphate sink, absorbing phosphates from the water and storing it in the sediment.