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A Laboratory Study on the Role of Stream Sediment in Nitrogen Loss from Water
Author(s) -
Sain Pritam,
Robinson J. B.,
Stammers W. N.,
Kaushik N. K.,
Whiteley H. R.
Publication year - 1977
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/jeq1977.00472425000600030009x
Subject(s) - nitrate , denitrification , sediment , nitrogen , environmental chemistry , chemistry , water column , aeration , environmental science , hydrology (agriculture) , geology , geomorphology , geotechnical engineering , oceanography , organic chemistry
Laboratory experiments were conducted on samples of sediment collected from a stream having an appreciable input of nitrate at its source. Earlier work had shown that the water lost much of the nitrate as it moved downstream, presumably by denitrification. Columns of sediment were reconstituted in plexiglass tubes, overlain with water containing nitrate, and incubated at 10, 15, or 22C. The water was aerated with a helium‐oxygen mixture. Nitrate concentration decreased rapidly but the rate varied with temperature and depth of sediment. At 22C, in water overlying 10‐cm columns of sediment, over 90% of the nitrate was removed in 3 weeks from a solution originally containing 10 mg/liter nitrate‐N. Nitrate disappeared less rapidly at lower temperatures and when sediment columns were < 5 cm deep. It was concluded that in columns < 5 cm deep and at low temperatures nitrate diffused to the bottom of the columns, while columns 5 cm deep or more were effectively of infinite depth. Because of the interdependence of diffusion from the liquid phase into the sediment and denitrification, it is not possible to infer kinetics of denitrification in these experiments. It appeared that denitrification in these columns proceeded at a rate compatible with observations made previously in the stream from which the sediment originated.