FAQs: Protex!

Protex! is an innovative electrolytic disinfection (ED) device which kills harmful bacteria in large-scale water systems, eliminating the use of chemicals.

The Protex! system disinfects water by electrolysis, using a direct electric current to kill any pathogens by generating disinfectants from chloride ions naturally present in the water. This also provides the residual disinfection needed to inhibit bacterial growth.

Water flows through the unit, as shown, with temperature and flow rates being continuously monitored by the flow sensor.

An electric charge is passed through the water via purposely designed electrodes, causing the decomposition of water and the chlorides contained within it. As shown in schematic A, positively charged ions (NA+ and H+) migrate to the negative electrode whilst negative charges ions (OH- O- and Cl-) to the positive electrode. Some of the elements expected during electrolysis are shown in schematic B, including ozone, chlorine gas and hypochlorous acid, which are the disinfectants needed to inactivate pathogens.

Protex! can either be installed in the hot water recirculation systems or on a recirculation loop of cold water storage tanks for large buildings such as hotels, offices, hospitals, schools, universities, residential building and leisure centres.

Installed in the hot water recirculation system in conjunction with a softener, Protex! continuously provides disinfectants, keeping bacteria levels within acceptable levels whilst enabling  temperatures to be lowered. Reducing hot water temperatures reduces heat losses in periods of low water demand, generating energy savings.

Installed in a recirculatory loop in a cold water storage tank, it reduces biofilm formation and it provides disinfection of the cold water services as shown in the schematic.

Requiring minimal maintenance, Protex! is more economical than traditional methods of water treatment. As disinfectants are generated on site, eliminating the handling, storage and transport of hazardous chemicals, it is also safer.

Protex! also increases the carbon efficiency of domestic hot water systems in buildings as it allows water temperatures to be reduced from 60°C to 45°C. As an example, we estimate that lowering the temperatures in commercial buildings in the UK could generate savings of £62 million.

Protex! was developed during a three-year study conducted in collaboration with Brunel University London, carried out by Dr. Giovanna Cossali and overseen by Professor Tassos Karayiannis, Dr. Edwin Routledge, and Martin Ratcliffe. To the best of our knowledge, this study was the first to report on long-term monitoring of an electrolytic prototype device in the hot water system.

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

With minimal chemicals required, Protex!, in conjuction with a softener, is ideal for use at healthcare facilities where the wellbeing of patients is paramount. The water disinfection system is playing a key part in supporting Chilterns MS Centre in meeting regulatory requirements and preventing the growth of legionella bacteria.

Protex! officially received WRAS approval on 21 October 2015, demonstrating the acceptance of Protex! by UK water supplier representatives.

To our knowledge, Protex! is the only electrolytic disinfection unit of its type to receive WRAS approval in the UK.