Triple Carbon Reduction, Anglian Water, UK

Supported by UK Water Services Regulation Authority, Ofwat 

We are proud to join Anglian Water Services and an extensive team of partnering companies and academia on the current Triple Carbon Reduction initiative, part of Ofwat's Water Breakthrough Challenge.

OxyMem™The Triple Carbon Reduction project is an initiative that will demonstrate how MABR can help the sector minimise process emissions and energy consumption typically associated with municipal biological wastewater treatment.

The Triple Carbon Reduction project aims to showcase an integrated solution addressing three potential carbon benefits, aligned with the objectives of the whole water industry to achieve Net Zero by 2030:

1. Demonstrate a viable alternative wastewater treatment process (MABR - Membrane Aerated Biofilm Reactor) targeting elimination of nitrous oxide (N₂O) emissions from secondary treatment;
2. Achieve up to 85% reduction in energy consumption compared to conventional treatment processes currently in use (i.e. “activated sludge”);
3. Generate oxygen via electrolysis, to be utilised in the MABR process, and green hydrogen for use in applications that are currently challenging to decarbonise (i.e. diesel generators).

Why OxyMem™ MABR?

OxyMem is not like other solutions. OxyMem MABR is a fixed-film technology that doesn't use conventional aeration to move, treat and discharge water.

OxyMem™ MABR can help us meet Net Zero emission targets in wastewater treatment thanks to exceptional oxygen transfer efficiency. The process works on the same principle as human lungs, with oxygen being transferred via a concentration gradient. In humans oxygen flows easily into our airways and reaches a point where the magic happens; oxygen diffuses on a molecular level, from high concentration held within the lungs, to our bloodstream and metabolising cells throughout the body where oxygen levels are lower.  In the OxyMem™MABR process, oxygen flows easily to the internal surface of  tiny hollow fibre membranes. From here oxygen readily diffuses across the membrane wall to an active biofilm layer on the outside surface, which is constantly depleting oxygen as it breaks down wastewater pollutants. Oxygen moves from high concentration to low concentration 24/7.

As diffusion occurs at the membrane wall, direct to an attached growth biofilm layer (bacteria),  bubbles are not required within an MABR system. This means the excessive energy typically consumed to generate bubbles within conventional aeration systems, to force air under water (~ 5-10m) and then through thousands of perforations (<1.5mm), can be saved.

The results are considerable OPEX saving over other upgrade solutions for the life of the plant.

Packaged OxyMem™ MABR

This Packaged OxyMem™ MABR solution comprises two parallel steel tanks, each equipped with three OxyFilm MABR modules. The dedicated process blower supplies air to both tanks. The design incorporates a unique feature: one tank utilises air to the MABR, while the other boasts the capability to augment the oxygen concentration in conjunction with electrolyser.

Vent gas from the MABR undergoes rigorous testing for oxygen and nitrous oxide concentrations. To facilitate seamless control and monitoring, a control kiosk houses the local control panel and all quality analysers. The installed Packaged OxyMem™ MABR plant is showcasing the impact of MABR technology on energy consumption and greenhouse gas reduction. This installation marks a significant milestone as the first commercially available packaged MABR with the purpose of triple carbon reduction in the United Kingdom.

Once the system is running, OxyMem™ MABR will be assessed as to low energy requirements, reducing nitrous oxide emissions, pollutant reduction, usage with oxygen enriched air (working alongside hydrogen plant where oxygen is by-product). One bank of modules will be run with ambient, atmospheric air while the another is run with oxygen enriched air (as shown below in the process flow diagram).

The project will focus on a few potential key benefits for the water sector. Hydrogen generation through electrolysis will provide a source of energy, where the oxygen produced from generating hydrogen may be utilised in an MABR system to target increased efficiency and reduction in nitrous oxide process emissions.