A single stage anaerobic/anoxic/aerobic hybrid airlift bio-electrochemical reactor (HALBER) for enhancing nitrogen removal from wastewater
Author Identifier (ORCID)
Ali Akbar Zinatizadeh: https://orcid.org/0000-0002-0442-0841
Abstract
In the present research, the performance of a single stage anaerobic/anoxic/aerobic hybrid airlift bio-electrochemical reactor (HALBER) for enhancing nitrogen removal from wastewater with continuous feeding regime was investigated. The goal was to enhance nitrogen removal in wastewater by applying an external electrical voltage. Utilizing electrotrophic bacteria at the cathode represents an innovative autotrophic denitrification strategy that leverages electrical current as the electron donor instead of traditional chemical sources. For experimental design and data analysis, a standard response surface methodology (RSM) design, Face Center Cube (FCC), was used. The effect of three independent variables, i.e. hydraulic retention time (HRT) (12–24 h), total chemical oxygen demand (TCOD) (1500–2500 mg/L), and mixed liquor suspended solids (MLSS) (4000–7000 mg/L) on the bio-electrochemical reactor performance were investigated. The HALBER achieved a maximum total nitrogen (TN) removal of 84.8 % at an influent TN concentration of 300 mg/L, with a TCOD of 2000 mg/L, HRT of 24 h, and MLSS of 4000 mg/L using external voltage. Additionally, this study explored how feed characteristics influenced the removal rates of total nitrogen and chemical oxygen demand in wastewaters derived from soft drink production and dairy processing. Findings revealed that when treating dairy processing wastewater, HALBER showed a better performance in TN removal, whereas it was more effective at TCOD removal in soft drink wastewater. Consequently, the performance of HALBER is notably affected by the biochemical oxygen demand (BOD5)/COD ratio present in the wastewater. The outcomes demonstrated that this bio-electrochemical reactor is capable to treat wastewaters with high content of TN and COD in smaller volume compared to combined systems and existing conventional.
Keywords
air-lift bio-electrochemical reactor, biocathode, external voltage, simultaneous nitrification/denitrification
Document Type
Journal Article
Date of Publication
7-25-2026
Volume
159
Publication Title
Journal of Industrial and Engineering Chemistry
Publisher
Elsevier
School
School of Engineering
Funding Information
The authors would like to acknowledge Iran National Science Foundation (INSF), Razi University and Danab Knowledge-based Company for the full financial support and lab facilities provided for this research work.
Copyright
subscription content
First Page
391
Last Page
402
Comments
Nouri, A., Zinatizadeh, A. A., Zinadini, S., & Van Loosdrecht, M. (2026). A single stage anaerobic/anoxic/aerobic hybrid airlift bio-electrochemical reactor (HALBER) for enhancing nitrogen removal from wastewater. Journal of Industrial and Engineering Chemistry, 159, 391–402. https://doi.org/10.1016/j.jiec.2025.12.031