Effects of C/N ratio and dissolved oxygen on aerobic denitrification process: A mathematical modeling study

Bo Hu; Jianing Quan; Kun Huang; Jianqiang Zhao; Guohua Xing; Pei Wu; Ying Chen; Xiaoqian Ding; Yuansheng Hu

doi:10.1016/j.chemosphere.2020.129521

Effects of C/N ratio and dissolved oxygen on aerobic denitrification process: A mathematical modeling study

Chemosphere. 2021 Jun:272:129521. doi: 10.1016/j.chemosphere.2020.129521. Epub 2021 Jan 12.

Authors

Bo Hu¹, Jianing Quan², Kun Huang², Jianqiang Zhao³, Guohua Xing², Pei Wu², Ying Chen³, Xiaoqian Ding⁴, Yuansheng Hu⁵

Affiliations

¹ School of Civil Engineering, Chang' an University, The middle section of the south 2nd ring road, 710064, Xi'an, Shaanxi Province, China; Key Laboratory of Water Supply & Sewage Engineering, Ministry of Housing and Urban-rural Development, Chang'an University, The middle section of the south 2nd ring road, 710064, Xi'an, Shaanxi Province, China. Electronic address: hubo1983@chd.edu.cn.
² School of Civil Engineering, Chang' an University, The middle section of the south 2nd ring road, 710064, Xi'an, Shaanxi Province, China; Key Laboratory of Water Supply & Sewage Engineering, Ministry of Housing and Urban-rural Development, Chang'an University, The middle section of the south 2nd ring road, 710064, Xi'an, Shaanxi Province, China.
³ Key Laboratory of Water Supply & Sewage Engineering, Ministry of Housing and Urban-rural Development, Chang'an University, The middle section of the south 2nd ring road, 710064, Xi'an, Shaanxi Province, China; School of Water and Environment, Chang' an University, The middle section of the south 2nd ring road, 710064, Xi'an, Shaanxi Province, China.
⁴ School of Architecture and Civil Engineering, Xi'an University of Science and Technology, Yanta Road No. 58, 710054, Xi'an, Shaanxi Province, China.
⁵ Civil Engineering, College of Engineering and Informatics, National University of Ireland, University Road, H91 TK33, Galway, Ireland.

PMID: 33485044
DOI: 10.1016/j.chemosphere.2020.129521

Abstract

COD to ammonium nitrogen (C/N) ratio and dissolved oxygen (DO) concentration are the most important factors affecting aerobic denitrification process, however, the effects of those on the mix-cultured aerobic denitrification process are still ambiguous. A mathematical model based on the framework of activated sludge model No. 3 (ASM3) was proposed for simulating nitrogen removal in an aerobic denitrification SBR process via anoxic/aerobic denitrification. AQUASIM 2.1G was employed for parameter estimation, sensitivity analysis and model calibration, as well as model validation. Ultimately, the impacts of the C/N ratio and the DO concentration on the aerobic denitrification process were revealed by the validated model. The model proposed well described nitrogen removal in an aerobic denitrification SBR process. The total nitrogen (TN) removal efficiency of the process increased with the increasing of C/N ratio and the decreasing of DO concentration. C/N ratio impacted the synthesis of cell internal storage products (X_STO), and the effects of DO concentration on the process resulted from the competition with substrate between heterotrophs and aerobic denitrifiers. High C/N ratio was preferred, however, the DO concentration should be maintained at a relatively lower level under the premise of ensuring the aerobic condition.

Keywords: Activated sludge model 3; Aerobic denitrification process; C/N ratio; Dissolved oxygen; Mathematical modeling.

MeSH terms

Bioreactors
Denitrification*
Models, Theoretical
Nitrification
Nitrogen
Oxygen*
Sewage

Substances

Sewage
Nitrogen
Oxygen