Protex!: Eliminating Legionella Through Electrolysis

30 June 2015

After several years of research, ESG has developed a new water disinfection device, which kills harmful bacteria in large-scale water systems without the use of chemicals.

Protex!, created by the UK’s leading provider of testing, inspection and compliance services, disinfects water by electrolysis - using a direct electric current to kill any pathogens that are present. After a three-year study conducted in collaboration with Brunel University London, overseen by Professor Tassos Karayiannis, Dr. Edwin Routledge, and Martin Ratcliffe, Protex! has become the first device of its kind to be proven effective in a real world environment.

In the UK, controlling Legionella and Pseudomonas bacteria in buildings, such as hospitals, universities, schools, leisure centres and hotels, can be an expensive challenge, thought to cost building owners and facilities managers around £140 million every year.

The device also increases the carbon efficiency of domestic hot water systems in buildings as it potentially allows water temperatures to be reduced from 60°C to 45°C. It is estimated that UK non-domestic buildings could generate energy savings of up to £62 million through the use of Protex!. 

Requiring minimal maintenance and no chemicals, the product is more economical than traditional methods of water treatment, and is safer in use as there is no requirement to handle or store chemical disinfectants.

The effectiveness of Protex! was observed at a medical centre, and monitored by Brunel University London over a two year period. The study proved the effectiveness of the device, and led to Knowledge Transfer Partnership funding being awarded by the UK Government’s Innovate UK scheme.

Giovanna Cossali, a PhD student at Brunel University working on the project, said: “Through our joint research we’ve been able to witness this device control the levels of Pseudomonas and Legionella bacteria in the building’s hot water system.

“By regularly dosing the water with a low voltage of electricity, bacteria levels at the centre have been reduced by up to 99 per cent and these levels have been maintained throughout the study. As we’ve also been able to prove the effectiveness of Protex! at lower temperatures, we have demonstrated it’s important role in helping buildings achieve low carbon emission standards.

“We are now looking for more building owners or facilities managers of non-domestic buildings to help with the trialling of the device.”

The project at the medical centre is the first reported long-term monitoring of an electrolytic device in a building’s hot water recirculation system.

ESG’s Mick Pratt, commercial director, Built Environment Services, added: “Investing in research and development is vital to understanding how Legionella bacteria can be effectively controlled.

“Ensuring safety in our hospitals and schools is of the upmost importance and this research has proven that Protex! is a big step forward in the field of water treatment.”