Iorhemen, Dr. Oliver

Dr. Oliver Iorhemen
PhD (University of Calgary), MSc (University of Leeds), BEng (Ahmadu Bello University), P. Eng Assistant Professor, Environmental Engineering
Email: Phone:
Website: Office:
  • Prince George



  • Ph.D in Civil Engineering (Environmental Engineering specialisation); University of Calgary, 2019
  • MSc(Eng) in Environmental Engineering and Project Management; University of Leeds, UK., 2011
  • B.Eng Water Resources and Environmental Engineering; Ahmadu Bello University, Nigeria, 2008

Honours and awards

  • NSERC Postdoctoral Fellowship - 2019 competition
  • Teaching Achievement Award, Schulich School of Engineering, UCalgary: May, 2020
  • UCalgary Silver Anniversary Graduate Fellowship - 2018/2019 and 2019/2020 sessions
  • Eyes High International Doctoral Scholarship - 2016/2017 and 2017/2018 sessions
  • Alberta Graduate Citizenship Award - 2018
  • UCalgary Faculty of Graduate Studies Doctoral Scholarship – 2016/2017 session
  • Schulich School of Engineering Late-Career Student Research Award - 2019
  • AOSTRA/Devenny Graduate Scholarship – 2015 and 2017
  • UCalgary Graduate College Scholarship – 2017/2018 and 2018/2019 sessions

Dr. Oliver Terna Iorhemen joined the University of Northern British Columbia (UNBC) as an Assistant Professor in Environmental Engineering on August 1, 2021. Prior to joining UNBC, Dr. Iorhemen was an NSERC Postdoctoral Fellow in the Department of Civil and Environmental Engineering, University of Alberta, Edmonton.

Dr. Iorhemen’s research interests include biological wastewater treatment, wastewater reclamation and reuse, nutrients removal, removal of contaminants of emerging concern from wastewater, rural water supply and sanitation, and resource recovery. His current research focuses on the recovery of various resource streams from wastewater, biosolids, and organic waste. He has participated in both university – municipality and university – industry collaborative research as well as multi-university research projects.

Academic service

  • Subject Editor, Energy, Ecology and Environment
  • Associate Editor, Frontiers in Water (Environmental Water Quality specialty section)
  • Reviewer, Top-tier journals in Environmental Engineering

Research and Expertise

Application of aerobic granular sludge biotechnology for the treatment of different industrial wastewater streams and resource recovery from biosolids.

Research Fields:
  • Energy
  • Environment
  • Natural Resources
Areas of Expertise:

Aerobic granular sludge (AGS), Biofilm processes, Biological wastewater treatment, Contaminants of emerging concern (CEC) , Nutrients removal, Resource recovery, Wastewater reclamation and reuse, Water quality

Languages Spoken:
  • English
Not accepting graduate students
Supervises in:
  • PhD NRES
  • MSc NRES
  • MASc
Available to be contacted by the media as a subject matter expert

Selected Publications

Hamza, R.A., Rabii, A., Ezzahraoui, F., Morgan, G., Iorhemen, O.T. (2022) A review of the state of development of aerobic granular sludge technology over the last 20 years: Full-scale applications and resource recovery. Case Studies in Chemical and Environmental Engineering. 5: 100173.

Iorhemen, O.T., Liu, Y. (2021) Effect of feeding strategy and organic loading rate on the formation and stability of aerobic granular sludge. Journal of Water Process Engineering. 39: 1017099.

Zaghloul, M.S., Iorhemen, O.T., Hamza, R.A., Tay, J.H., Achari, G. (2021) Development of an ensemble of machine learning algorithms to model aerobic granular sludge reactors. Water Research. 189: 116657.

Iorhemen, O.T., Zaghloul, M.S., Hamza, R.A., Tay, J.H. (2020) Long-term aerobic granular sludge stability through anaerobic slow feeding, fixed feast-famine period ratio, and fixed SRT. Journal of Environmental Chemical Engineering. 8(2): 103681.

Iorhemen, O.T., Hamza, R.A., Zaghloul, M.S., and Tay, J.H. (2019) Aerobic granular sludge membrane bioreactor (AGMBR): Extracellular polymeric substances (EPS) analysis. Water Research. 156: 305-314.

Vashi, H., Iorhemen, O.T., Tay, J.H. (2019) Extensive studies on the treatment of pulp mill wastewater using aerobic granular sludge (AGS) technology. Chemical Engineering Journal. 359: 1175-1194.

Hamza, R.A., Zaghloul, M.S., Iorhemen, O.T., Sheng, Z., and Tay, J.H. (2019) Optimization of organics to nutrients (COD:N:P) ratio for aerobic granular sludge treating high-strength organic wastewater. Science of the Total Environment. 650 (part 2): 3168-3179.

Tiwari, S.S., Iorhemen, O.T., Tay, J.H. (2019) Aerobic granular sludge and naphthenic acids treatment by varying initial concentrations and supplemental carbon concentrations. Journal of Hazardous Materials. 362: 348-357.

Hamza, R.A., Sheng, Z., Iorhemen, O.T., Zaghloul, M.S., and Tay, J.H. (2018) Impact of food-to-microorganisms ratio on the stability of ‎aerobic granular sludge treating high-strength organic ‎wastewater. Water Research. 147: 287-298.

Zaghloul, M.S., Hamza, R.A., Iorhemen, O.T., Tay, J.H. (2018) Performance prediction of an aerobic granular SBR using modular multilayer artificial neural networks. Science of the Total Environment. 645: 449 - 459.

Iorhemen, O.T., Hamza, R.A., Tay, J.H. (2017). Membrane fouling control in membrane bioreactors (MBRs) using granular materials. Bioresource Technology. 240(2): 9 - 24.