All Posts

Energy-saving UCD technology breathes life into wastewater treatment

Energy-saving UCD technology breathes life into wastewater treatment

Chemical engineers at University College Dublin (UCD) have developed new technology to save energy in wastewater treatment.

Our approach targets a particularly wasteful step in wastewater treatment. Conventionally, this step involves forcing oxygen bubbles through the wastewater ‘sludge’ in order to support bacterial growth. The bacteria then absorbs contaminants and nutrients from the water, thereby helping to clean it so it can be released back into the environment or recycled for human use. 

My research group at UCD’s School of Chemical and Bioprocess Engineering has developed an alternative technology: membranes that diffuse or ‘breathe’ oxygen and thereby directly support biofilms of bacteria. Our studies show that this membrane-aerated biofilm reactor (MABR) technology can save up to 75 per cent of the energy conventionally needed to support bacteria in their wastewater treatment role.

In 2014, OxyMem (the UCD spin-out company) delivered the first commercial MABR technology to the market, and it is now reducing energy use for wastewater treatment in numerous countries.

 bubble pin cgae.png

 Clean drinking water costs energy

In many parts of the world, we take clean water for granted. We turn on the tap and clean, safe water flows out. But the process of treating or recycling water requires energy – as much as 2-3 per cent of a nation’s electricity demands. This is where the OxyMem technology is making a difference.

‘Forced aeration’ has been used in wastewater treatment for more than a century, but it is known to waste as much as 65-70 per cent of the energy it takes to push those oxygen bubbles into the water. Why? Many of the bubbles simply float away without transferring oxygen to the bacteria, so the job is left undone.

For more than a decade, UCD Biofilm Engineering Laboratory members have been working on an alternative approach: MABR technology. This grows communities or ‘biofilms’ of bacteria directly on membranes, and sustains them with diffused oxygen. By putting the membranes into wastewater tanks and ‘breathing’ oxygen into the biofilms, the bacteria become activated to remove nutrients and contaminants from the sludge.

With funding from Science Foundation Ireland and Enterprise Ireland, the UCD group was initially able to show in small-scale laboratory-based experiments that MABR used up to 75 per cent less energy compared to forced air bubbles to support bacteria for wastewater treatment.

Importantly, the process was then scaled up to operate in a large wastewater plant in the UK near Birmingham. Again, it was found that MABR could reduce energy usage by as much as 75 per cent from the bacterial-treatment stage.



MABR reduces energy for wastewater treatment

UCD's research on MABR is having academic, commercial, environmental and societal impact, and the innovation has been recognised through numerous awards. For more than a decade, we have been looking at how bacterial biofilms function in MABR. Bacterial biofilms can be problematic, such as when they contaminate medical devices, but biofilms can be helpful – in our case, we harness the biofilm configuration to function on membranes and clean water effectively.

Our research into this positive application of biofilms has contributed to scientific investigations of bacterial biofilms through the UCD group’s numerous journal papers, book chapters and academic conferences. The MABR research carried out in UCD also led directly to the formation of OxyMem, founded in 2013 with the support of NovaUCD. With support from Enterprise Ireland and UCD, OxyMem have developed the MABR technology for commercialisation, and the company has gone from strength to strength in recent years and now employs 22 people in Athlone.

One of the key steps to commercialising the MABR technology was to demonstrate its energy efficiency in a large wastewater treatment plant in the UK. Since the success of the UK demonstration, the MABR technology is now being deployed further afield in numerous countries: Canada, Africa, Brazil, China, Spain and Japan, to name a few.

What makes the MABR technology particularly suitable for the wastewater treatment market is that it can be directly dropped into existing wastewater plants as flexible, modular systems, which means it is easy to retrofit. This makes it more economically viable for plants to adopt and bring down their energy bills, thereby bringing cost savings to operators and potentially to consumers.


 Award-winning technology

OxyMem’s innovations have earned recognition in numerous articles in the media, through awards including the 2014 Irish Times Innovation Award, the US Imagine H2O 2015 Infrastructure Challenge and a Knowledge Transfer Ireland 2015 Impact Award. In 2016, 2017 and 2018, OxyMem was named in the prestigious Global Cleantech 100.

oxymem clentech 100.png

Ultimately, the commercial MABR technology developed through research at UCD addresses a major facet of energy conservation in water treatment plants. The MABR solution will mitigate a global environmental and societal challenge. The stress on water and energy supplies will increase with climate change, and MABR technology is reducing energy consumption in wastewater treatment, thus lowering its environmental impact and enabling clean water supplies for communities around the world.



Eoin Casey
Eoin Casey
Professor and head of UCD School of Chemical and Bioprocess Engineering, Principal investigator (PI), UCD Biofilm Engineering Laboratory

Subscribe to stay informed

*Environment  *Legislation  *Socio-economics  *Technology

Related Posts

Advantages of OxyMem MABR over standard attached growth systems

Advantages of OxyMem MABR over standard attached growth systems OxyMem solves OPEX intensive wastewater treatment with an innovative ‘Drop in’ solution for wastewater treatment. Easily deployed OxyMem modules provide wastewater treatment plants with the simplest means of increasing their plant treatment capacity and effluent quality. Our patented  bubble-less transfer of oxygen emulates a natural respiratory system, providing highly efficient oxygen transfer and provides simultaneous nitrification and denitrification for total nitrogen removal. Save up to 75% on energy, reduce waste sludge by up to 50% and decrease your upgraded plant's carbon footprint when compared to traditional biological systems, with no additional infrastructure and no plant downtime.

When is an MABR not an MABR?

When is an MABR not an MABR? For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." -Richard Feynman's referring to the laws of Nature"   The MABR is gaining a lot of attention recently for use in Water Resource Recovery Facilities and rightly so, as it can potentially expand the capacity of existing plants without the need for capital investment, while at the same time reducing the relative energy demand. This ground-breaking treatment technology which can achieve simultaneous nitrification and denitrification with reduced sludge generation now has installations in all corners of the globe.

MABR Technology creates new opportunities for growth.

MABR Technology creates new opportunities for growth MABR technology can be transformative for a business and can open the doors to new opportunities   Is your wastewater treatment capacity restricting your potential growth. All manufacturing activities produce wastewater, if your manufacturing facility is already producing high volumes of wastewater and you are close to breaching regulations, you may be faced with a barrier to expansion, limiting the potential growth of your company. Increased environmental awareness and a demand for greater environmental protection have meant that stricter regulations are being introduced, which business need to adhere to. Meeting compliance can have an impact on the growth potential of a company, as the volume of wastewater they produce is limited. Failure to comply with water discharge standards can result in severe legal and financial consequences.