Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
578914 | Journal of Hazardous Materials | 2011 | 8 Pages |
Abstract
Kinetics of heterotrophic denitrification was investigated using an oil reservoir culture with the ability to function under both autotrophic and heterotrophic conditions. In the batch system nitrate at concentrations up to 30Â mM did not influence the kinetics but with 50Â mM slower growth and removal rates were observed. A kinetic model, representing the denitrification as reduction of nitrate to nitrite, and subsequent reduction of nitrite to nitrous oxides and nitrogen gas was developed. The value of various kinetic coefficients, including maximum specific growth rate, saturation constant, yield and activation energy for nitrate and nitrite reductions were determined by fitting the experimental data into the developed model. In continuous bioreactors operated with 10 or 30Â mM nitrate, complete removal of nitrate (no residual nitrite) and linear dependency between nitrate loading and removal rates were observed for loading rates up to 0.21 and 0.58Â mMÂ hâ1, respectively. The highest removal rates of 0.31 and 0.94Â mMÂ hâ1 observed at loading rates of 0.42Â mMÂ hâ1 and 1.26Â mMÂ hâ1, with corresponding removal percentages of nitrate and total nitrogen being 75.4, 54.4%, and 74.4 and 17.9%, respectively. Developed kinetic model predicted the performance of the continuous bioreactors with accuracy.
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Authors
Shijie An, Heather Stone, Mehdi Nemati,