Exploring the potential for ammonia recovery from wastewater with bipolar membrane electrodialysis

October 10th, 2023

R&D Focus Areas:
Water use and treatment, Electrolysis

Lead Organisation:
CSIRO

Partners:
Water Corporation Western Australia; Electroseparations-Veolia Water Technologies & Solutions; Palermo University, Italy; McMaster university, Canada; University of Western Australia

Status:
Active

Start date:
August 2022

Completion date:
August 2025

Key contacts:
Lead Investigator Sebastien Allard – Sebastien.Allard@csiro.au

Funding:
AUD$800,000 – Hydrogen – Future Science Program
AUD$680,000 – Water Corporation Western Australia

Project total cost:
AUD$1,480,000 –cash contribution

Project summary description:
Ammonia (NH3) has recently been recognised as a suitable renewable energy carrier. This project will evaluate the technical feasibility of recovering NH3 from wastewater as a resource using bipolar membrane electrodialysis (BPMED) and determine the achievable NH3 recovery and energy efficiencies. Recovering NH3 from wastewater is potentially more energy efficient than producing NH3 by Haber-Bosch process. It is also more energy efficient to produce hydrogen from NH3 than by water electrolysis.

A proof-of-concept BPMED prototype allowing to efficiently recover NH3 from a wastewater treatment stream will be developed. The effects of different process parameters and BPMED configuration on the efficiency of NH3 recovery and a range of pre-treatment options (e.g., biogas sparging, struvite precipitation, membrane filtration unit) allowing to reduce fouling on the membranes based on the wastewater quality will be evaluated. Moreover, the energy efficiency of the process will be thoroughly assessed.

Initial results indicate that BPMED allows ammonium to be removed from water and to simultaneously produce concentrated dissolved NH3 (ammonium hydroxide), without using chemicals, only electricity. BPMED was found to be a reliable technology with 85 to 91% nitrogen recovery. However, wastewater typically has high levels of inorganic anions and cations (calcium, magnesium, bicarbonate and phosphate) and organics; as a result, there is potentially a serious risk of membrane fouling and decreased separation efficiency as well as reduced membrane life. Further research is currently being undertaken to investigate these issues.

The expected impacts of this projects are:

  • Recovering NH3 from wastewater will contribute to making wastewater treatment operations energy self-sufficient and thus potentially reduce wastewater treatment costs.
  • Establishment of a sustainable NH3/H2 energy industry that is based on circular economy principles.
  • Improved national fuel security from fuel recovered from local waste streams.
  • Recovering NH3 from wastewater is expected to reduce greenhouse gas emissions (N2O) as compared to removing NH3 through aerobic NH3 oxidation and anoxic denitrification.
  • The NH3 recovered may be used as a transport fuel for car or trucks used by water treatment operators and contributes to green-house gas reduction.
  • The NH3 recovered may be used as a feedstock to produce green chemicals and contributes to greenhouse gas reduction.
  • Improving the quality of treated wastewater effluent through effective NH3 recovery from centrate.

Related publications and key links:
Turning waste into resources: Ammonia recovery from wastewater with bipolar membrane electrodialysis. IWA World Water Congress & Exhibition-Circular economy and resource recovery. https://worldwatercongress.org

Ammonia recovery from wastewater with bipolar membrane electrodialysis, a circular economy initiative. AWA Connected by water. https://www.awa.asn.au/upcoming-events/cbw24

Exploring the potential for ammonia recovery from wastewater with bipolar membrane electrodialysis. IWA Specialised Conference on Water and Wastewater Management with Special interest to Developing Countries. https://iwa-network.org/events/specialised-conference-on-water-and-wastewater-management-with-special-interest-to-developing-countries/

Ammonia recovery from waste stream: a source of hydrogen and carbon-free renewable energy carrier. Australian Hydrogen Research Conference. https://ahrc2024.com.au

CSIRO ‘Future Science Platforms: Hydrogen Energy Systems’:  Exploring the potential for ammonia recovery from wastewater with bipolar membrane electrodialysis – Hydrogen Energy Systems (csiro.au)

Higher degree studies supported:
A research scientist supported by the Impossible Without You program.
Two PhD students at the University of Western Australia are supported by this project.
Two Masters students from France were supported by this project.

 

Reviewed: July 2024