Exclusive Interview with OxyMem

H2O Global News’ Natasha Posnett, caught up with Andreas Gorenflo, Managing Director at OxyMem, part of DuPont brand to learn about what they offer, how OxyMem helps their customers worldwide and the role it plays in the sustainability of the water sector. Read our exclusive interview below:

What is OxyMem and how does it work?

OxyMem develops and manufactures membrane aerated biofilm reactor (MABR) modules. OxyMem MABR is a unique attached growth biofilm system where the dense silicone fibres act as both a support for biomass and an energy efficient oxygen delivery system. Our biological wastewater treatment technology helps wastewater treatment plants reach their goals such as handling increased loads, increased flow, achieving a better effluent quality (lower COD, ammonia, total nitrogen and phosphate concentration) while keeping energy consumption low. In retrofit applications, OxyMem MABR modules can be installed in existing plants, without the need for additional infrastructure and without taking the existing tanks offline. In greenfield plants the operational carbon footprint of OxyMem MABR plants is lower than conventional technologies such as activated sludge and MBBR (moving bed biofilm reactors) due to lower energy use. The MABR may also allow existing plants to reduce their nitrous oxide emissions which will also result in a lower carbon footprint.

At the heart of our OxyMem MABR modules are dense silicone hollow fiber membranes. Air is supplied to the lumen of the fibers and oxygen diffuses into the biofilm, which is in contact with the wastewater. Our bubble-less counter diffusional transfer of oxygen, designed to emulate a natural respiratory system, enables simultaneous nitrification and denitrification (SND) for total nitrogen removal in a single tank and without the need for energy intensive nitrate recycle flows.

One of the key parameters for any biofilm system is controlling the biofilm thickness. In extreme cases uncontrolled biofilm growth can lead to complete clogging of the system.  OxyMem has developed a unique and patented system for measuring and controlling the biofilm thickness online. In this system the biofilm thickness is determined by measuring the pressure decay test of an inert gas, argon. This biofilm thickness is then sent to a scour decision process which determines the optimal scour frequency and duration

Why should customers choose OxyMem?

Owners and operators of wastewater treatment facilities often struggle to increase biological treatment capacity while using minimal energy and keeping the footprint small. OxyMem MABR technology addresses these fundamental problems while also offering a low total cost of ownership. While conventional systems require a significant amount of space and energy to achieve a certain effluent standard, MABR requires only a fraction of space for tanks and a fraction of energy for aeration. For example, MABR runs with up to 75% less energy for aeration than activated sludge or 90% less than typical fixed-film biological systems. A fundamental saving, especially with the ever-increasing electricity prices.

When operated in pure biofilm mode, OxyMem MABR doesn’t have suspended biomass. Waste sludge is settled and withdrawn from the bottom of the tank so that downstream settlers may not be needed anymore – a significant saving in space and civil works. Furthermore, OxyMem MABR modules can be added to existing wastewater treatment tanks. We refer to a “drop-in solution”. This allows operators to increase their treatment capacity almost instantly without significant construction work. Think about a city with a treatment plant at its capacity but no free space. Instead of building a new facility elsewhere with a completely new network, MABR can increase the capacity without major construction work or additional space. The modules could be arranged and supported via cross beams or legs and connected to an air supply. The installation of the modules can be done in a day or two, directly into a live plant. We would not have to stop the process or divert flows.

Robustness is another key feature of our OxyMem MABR. The biofilm is attached to the silicone fiber, so high flow events like floods won’t wash out the bacteria. This is a known issue for systems with suspended sludge, and conventional systems often need weeks for new bacteria to grow or for sludge to build back up.

The ability to deal with varying conditions has another advantage: Ammonia peaks which occur seasonally or due to single events may pass through conventional treatment systems. This may lead to concentrations in the effluent above the limit. MABR can specifically increase the capacity of a treatment plant to remove ammonia, thus flattening such peaks. In combination with activated sludge, new systems can be designed smaller, and existing systems can delay or even avoid an expensive and time-consuming expansion. There is a huge saving potential for treatment plant owners.

It is worthwhile mentioning that, depending on the wastewater, each module has a certain treatment capacity, and with that OxyMem MABR offers incremental capacity increase, module by module. Combined with our drop-in solutions for existing plants, this allows gradual capacity increase to cope with more stringent effluent standards or additional feed load.

In summary, OxyMem MABR intensifies wastewater treatment, helps reduce energy consumption, is reliable and robust, and easily installed and operated.

Can OxyMem help the water sector meet its sustainability needs and stringent effluent standards?

Short answer: Yes, of course!

Long answer: The whole idea of OxyMem MABR, back in 2013 when the company was spun out from the University College Dublin, was to develop a solution to intensify wastewater treatment. It was all about increasing sustainability by using less resources like energy, concrete and space. The aim and challenge were to achieve this without compromising performance but instead helping operators meet more stringent effluent standards.

Apart from the obvious feature of improving water quality, our MABR technology has been noted to reduce greenhouse gases, particularly nitrous oxide (N₂O). N₂O is a by-product of the nitrification of Ammonia. It is 300 times more harmful to our climate than CO₂. Apart from agriculture, wastewater treatment is the major emitter of this dangerous greenhouse gas. In 2021, OxyMem was invited to become part of a consortium led by Anglian Water which has been awarded by Nesta and the Water Services Regulation Authority in the UK, to deliver the project “Triple Carbon Reduction”. One of the purposes is to develop technologies and processes to reduce the emission of carbon and other greenhouse gases like N₂O.  One aspect of it is to quantify and optimize the reduced N₂O emission of MABR compared to conventional treatment. The project has just started and will deliver initial results in the next six to twelve months. Stay tuned!

OxyMem is an established piece of technology. Where is it already being used, and what are some of your greatest success stories?

We currently have about 20 full scale contracted installations worldwide, plus demo units up and running in more than 20 countries.

In the province of Gansu, our largest install in China has recently been started up. It has increased the capacity of the existing municipal wastewater treatment plant from 260,000 m³/d to 300,000 m³/d. The first few months of operation have provided us with incredibly encouraging results Provisional results indicate very low effluent TN concentrations in the lane with the OxyMem MABR modules –  roughly 2 times lower than in the lanes with MBBR carriers – running in parallel with the exact same wastewater and loadings.

Another key installation is the one at Severn Trent in Spernal, UK where, OxyMem’s MABR modules are running in parallel to a conventional treatment line. The system has been in operation for two years achieving high nitrification rates throughout all season, and it is the biggest MABR installation in the UK. We see the successful operation at Severn Trent as a game changer, there is now sufficient operational data at a large scale for utilities that have the confidence in the MABR system. The Severn Trent reference has certainly contributed to the fact that commercial MABR projects in the UK are being tendered or will be tendered soon. Some of them will be multiple times larger than anything else we have done.

Other regions like Canada, New Zealand, Australia and recently Singapore are going ahead with MABR. We have recently won a Canadian project, which is being built as we speak.

More and more end-users and OEMs are considering MABR. It has become an established technology.

The WEX Global water conference took place last month. Who from OxyMem made an appearance at this event?

WEX Global 2022 occupies a unique place in the water conference calendar and we couldn´t miss it. DuPont, our parent company, strongly supports the event and we had several colleagues taking part in the panel discussions in Valencia. I had the pleasure of joining the Leaders forum on June 28^th and discussing digital actions, climate change and how technology could help create a water optimized world. Also, my colleagues Harith Al-Omar, Desalination Large Project Marketing Manager, Blanca Salgado, Global Technical Leader at DuPont Water Solutions and Verónica García Molina, Global Marketing Leader at DuPont Water Solutions, participated in several conference sessions.

WEX Global 2022 had the theme ‘unlocking the power of the smart circular economy’. How does this theme align with your approach at OxyMem?

The very topical theme of a smart circular economy closely links to our approach and technology at OxyMem.

I consider biological wastewater treatment a key part of achieving a circular economy. OxyMem’s technology aids this process to happen efficiently and effectively. Biologically degradable components, including water, are digested or processed into a state to be reused by nature. They can be taken up by organisms and – if entering the “human circle” – will ultimately end up back as wastewater or another type of organic waste. It creates a perfect circle which can be repeated again and again.

Another aspect that we focus on at OxyMem is being selective and focused. We make sure that MABR unlocks its full power and adds maximum value in each specific case it is used. We work ‘smart’ and prevent wasting our customer’s time and energy. This is a no brainer; every company should work like this. It’s a prerequisite for sustainability.

You hosted a webinar, ‘OxyMem Solutions for Wastewater Treatment’ at the beginning of June. Can you give us a little teaser as to what you discussed and why people should listen on demand to it now?

Yes, we were very excited to present this webinar and share our technology with a wider audience. While MABR is an established technology, it is not present in all countries. Compared to the high number of conventional systems, MABR is still at its beginning compared to where we ultimately see it. The webinar helped in facilitating this change and educating people on the benefits this technology can provide. We covered aspects of design and operation, talked about how the technology adds value to the wastewater treatment sector, and provide options for installing modules in existing tanks. We encourage everyone to listen, from operators and engineers to managers and academia. It is available to everyone and you will hopefully learn something useful! Watch the webinar here.

The water industry is a fast-changing and ever-evolving sector. Where do you see OxyMem being in five years?

OxyMem has grown quickly in the last few years. It started as the pioneer for MABR and has become a market leader with a strong global presence. The acquisition by DuPont in 2020 helped a lot to accelerate our growth and strengthen our position. We are now part of a versatile solution provider with a broad portfolio. Recently, DuPont invested several million in OxyMem to expand our capacity. Investments such as this one enable us to meet the growing global demand. The prospects for the coming years could not be better. MABR’s economic and environmental benefits are more than obvious and are essential for the wastewater treatment industry moving forwards. OxyMem is at the forefront of this exciting development and is working to make our planet cleaner and greener again.