It may come as a surprise to learn that almost 3 per cent of all electricity generated in the world is consumed by wastewater treatment plants.
Some 60 per cent of this is used in adding oxygen to the wastewater and anywhere up to 70 per cent of this is being wasted as a result of inefficiencies in existing systems.
UCD spinout company OxyMem has developed a revolutionary new system which can dramatically improve the energy efficiency of those plants as well as bringing other improvements in terms of ease of deployment.
Wastewater treatment is a biological process which uses bacteria to break down the waste substances in the water.
To do this the bacteria requires oxygen which in traditional plants is supplied through an energy intensive forced aeration system which sends bubbles of compressed air through the bottom of the treatment tank; technology which has been in use since 1914.
Typically less than 30 per cent of the oxygen supplied is transferred to the wastewater resulting in enormous energy waste.
The OxyMem system has no such limitations and is capable of achieving up to 95 per cent transfer efficiency.
Instead of relying on bubbles to transfer oxygen the system uses gas permeable membranes, which allow oxygen to be transferred directly to the wastewater treating bacteria delivering oxygen transfer efficiency (OTE) of up to 95 per cent.
The easiest way to describe the OxyMem system is a sealed container containing a gas-permeable silicon tubing through which air is pumped.
The wastewater passes through the container on the outside of the tubing.
Oxygen passes through the tubing in one direction but the water cannot pass through it in the other.
The tubing itself provides an excellent oxygen rich habitat for a diverse bacterial culture which breaks down the wastewater contaminants.
This means that the bacteria are receiving an oxygen supply directly from the tube.
Cost reductions
The system has been shown to deliver operating cost reductions of 75 per cent and this will be very attractive to the main markets for the new technology which are in the developing world.
"With energy prices rising across the globe, obtaining effective treatment with the least energy expenditure is becoming the top priority in product selection," says OxyMem managing director Wayne Byrne.
“We estimate the potential for energy savings for wastewater aeration is in the order of €45 billion. We estimate the overall global market for wastewater treatment technology to be €4 billion at the moment and to grow to €6 billion by 2020.”
The original research into the process was carried out by Prof Eoin Casey in University College Dublin, one of the world leaders in membrane technology, with support from Enterprise Ireland since 2003.
Following successful trials of a pilot scale unit at Severn Trent Water's Minworth, Birmingham facility in 2013 OxyMem was spun out of the university as a standalone company.
“We have raised €250,000 in seed funding with the support of Enterprise Ireland and have opened a manufacturing facility employing six staff in Blyry in Athlone,” says Mr Byrne.
“We are hoping to grow to 25 to 30 staff by the end of this year. We are in the happy position of having more interest in the product than we have capacity to produce it at the moment.
“We hope to have three demonstration units in operation in different markets by the end of this year and to scale up production after that.”
