Kinetics with optimization studies of nitrogen and organic elimination from wastewater via heterotrophic biomass conversion process

Abstract

Heterotrophic biomass conversion (HBC) research was carried out for the removal of N-NH₃ and organic carbon from synthetic wastewater. Ammonium nitrate and glucose were used as the nitrogen and organic carbon source, respectively. In this study, N-NH₃ and organic nutrient concentrations were varied, keeping the biomass concentration invariable. The kinetics followed dual rates, i.e. faster initial rate followed by a slower one. The consumption of N-NH₃ and COD followed first-order kinetics. Kinetic model such as Monod was studied. The pH during the HBC process showed an increasing trend which may be due to heterotrophic nitrification (HN). Parameters like N-, N₂O, N-, time, and dissolved oxygen were studied. A part of N-NH₃ utilized for the emission of N₂O may be due to HN. Analyses of variance were carried out for better interpretation of results. Optimization studies were carried out to minimize N₂O emission and maximize N-NH₃ along with COD removal.

Keywords:

• HBC
• Kinetics
• Monod
• Diffusion
• Optimization
• Statistics

Acknowledgments

The authors are thankful to the Director, CSIR-IMMT, for his kind permission to publish this paper. One of the authors (SR) thanks DST, New Delhi, for the award of INSPIRE Fellowship. The authors are thankful to MoEF, New Delhi, for the financial support without which the work could not have been done.