Document Type


Date of Award


Degree Name

Master of Science in Chemical Engineering - (M.S.)


Chemical Engineering, Chemistry and Environmental Science

First Advisor

Basil Baltzis

Second Advisor

Gordon Lewandowski

Third Advisor

Piero M. Armenante


Mathematical models have been derived for describing biodegradation of ni¬trate and nitrite in an anaerobic environment. Monod model for nitrate and Andrews model for nitrite were used as kinetic models. Experimental data from literature suggest that nitrate is not an inhibitory substance, while nitrite is not only inhibitory but it may also have a toxic effect on the biomass. The models were brought in dimensionless form in order to reduce the number of parame¬ters. Biodegradation was mathematically described for a batch, and a sequencing batch mode of operation. Computer programs were developed for numerically simulating the process. Some of the numerical results (from the batch mode of operation) were compared with experimental data obtained from a pilot plant unit at the Sunflower Army Ammunition Plant in Kansas. It was found that the model could very nicely predict qualitatively the experimental results. Computer simulations were performed for a wide range of parameter values in order to study the effects of these (model and system) parameters on the behavior of the reactors. One of the main objective was to find operating parameter regions which do not lead to high nitrite concentrations, since nitrite is inhibitory and toxic for the biomass. Experiments under controlled conditions are needed in order to find the key kinetic constants, which will then help in optimizing the overall process of biodenitrification, both, from design and operation view point.