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Mineralization of Hydrocarbons in Soils under Decreasing Oxygen Availability
Author(s) -
Freijer Jan I.
Publication year - 1996
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/jeq1996.00472425002500020013x
Subject(s) - mineralization (soil science) , soil water , chemistry , environmental chemistry , environmental remediation , decomposition , biomass (ecology) , soil science , contamination , environmental science , mineralogy , geology , ecology , oceanography , organic chemistry , biology
Techniques for remediation of soils contaminated with hydrocarbons (HCs) can be improved when the factors that control the decomposition rate are identified. In this study, the effect of O 2 availability on the decomposition rate of hydrocarbons in soils is examined. A kinetic second‐order model with the O 2 concentration and biomass concentration as rate‐controlling variables is used to quantify HC decomposition, O 2 consumption, and CO 2 production. Concentrations of O 2 and CO 2 are calculated analytically as a function of time in a three‐phase closed system. These calculations are compared with measurements of repetitive O 2 ‐depletion experiments in closed jars containing a layer of soil contaminated with HCs. About 80% of the HC decrease could be attributed to mineralization, while the other 20% was assumed to be converted into biomass and metabolites. After calibration, model calculations agree with the experimental results, which makes the concept of O 2 concentration and biomass concentration as rate‐controlling variables plausible. The parameter values that are obtained by calibration have a clear biochemical significance. It is concluded that attention has to be paid to the O 2 supply in closed‐jar experiments to avoid erroneous interpretation of the results.