Bioprocess and Biosystems Engineering

, Volume 38, Issue 7, pp 1373–1380

N2O production in the FeII(EDTA)-NO reduction process: the effects of carbon source and pH

Original Paper

DOI: 10.1007/s00449-015-1378-7

Cite this article as:
Chen, J., Wang, L., Zheng, J. et al. Bioprocess Biosyst Eng (2015) 38: 1373. doi:10.1007/s00449-015-1378-7

Abstract

Chemical absorption–biological reduction (BioDeNOx), which uses FeII(EDTA) as a complexing agent for promoting the mass transfer efficiency of NO from gas to water, is a promising technology for removing nitric oxide (NO) from flue gases. The carbon source and pH are important parameters for FeII(EDTA)-NO (the production of absorption) reduction and N2O emissions from BioDeNOx systems. Batch tests were performed to evaluate the effects of four different carbon sources (i.e., methanol, ethanol, sodium acetate, and glucose) on FeII(EDTA)-NO reduction and N2O emissions at an initial pH of 7.2 ± 0.2. The removal efficiency of FeII(EDTA)-NO was 93.9 %, with a theoretical rate of 0.77 mmol L−1 h−1 after 24 h of operation. The highest N2O production was 0.025 mmol L−1 after 3 h when glucose was used as the carbon source. The capacities of the carbon sources to enhance the activity of the FeII(EDTA)-NO reductase enzyme decreased in the following order based on the C/N ratio: glucose > ethanol > sodium acetate > methanol. Over the investigated pH range of 5.5–8.5, the FeII(EDTA)-NO removal efficiency was highest at a pH of 7.5, with a theoretical rate of 0.88 mmol L−1 h−1. However, the N2O production was lowest at a pH of 8.5. The primary effect of pH on denitrification resulted from the inhibition of nosZ in acidic conditions.

Keywords

Nitrous oxide FeII(EDTA)-NO Carbon source pH Denitrification 

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Engineering Research Center of the Ministry of Education for Bioconversion and BiopurificationZhejiang University of TechnologyHangzhouPeople’s Republic of China
  2. 2.College of Biological and Environmental EngineeringZhejiang University of TechnologyHangzhouPeople’s Republic of China