Sustainable disinfection of cooling water


Radboud University Medical Center is a leading academic center for patient care, education and research, with the mission ‘to have a significant impact on healthcare’. It’s activities seek to improve healthcare, the health of individuals and society by providing excellent quality, participatory and personalized healthcare, operational excellence by working together in sustainable networks.


In order to prevent bacteria growth and legionella outbreaks in the cooling towers, chemicals can be added. However, disinfection with hazardous chemicals is not sustainable. The client has now opted for cooling water management with ozone: “It’s energy efficient, no chemicals are used, safer, and the blowdown water quantity is reduced” says maintenance manager Perry Janssen from Radboudumc.

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  • Radboud Installation-Facts

Installation Facts

Customer: Radboudumc Nijmegen Industry: Utilities (hospital) Location: Nijmegen, the Netherlands


Contract type: Design and build, total water management including i-MONITORING Added value services: Design, project management and engineering, manufacturing, delivery, installation, commissioning, training on site and monitoring. Solution: 8 ozone installations (including softener, oxygengenerator and sand filter) Intelligent services: i-MAINTENANCE and i-MONITORING Official start date: 2004 (first supplied installation) Latest supplied installation: 2016


The management of cooling water is in line with the sustainability policy of Radboudumc for waste, energy, procurement and construction. The medical center follows the principles of the circular economy as a starting point for sustainable business. Water management using ozone saves intake water when compared to traditional disinfection using chemicals, maximizing the profit of this disinfection method. Additionally, blowdown water quantity will be reduced with the advantage that no hazardous chemicals need d to be stored and transported by employees. since no chemicals will be added into the discharged water, there is also a significant saving on costs for regional water authorities.

Eight Nijhuis ozone installations

The cooling water is used in air handling systems for MRIs and CT scanners. Eight Nijhuis ozone installations are installed in approximately one square kilometre of land. In winter with, reducing ambient temperature, it is possible to turn off some of the cooling water systems and during warmer days, the hospital has additional capacity to use all the cooling towers.

Total water management

Nijhuis i-CONSULT provide total water management by investigating client requirements and then presenting an integrated approach and control plan. The cooling water system is continuously monitored by the Nijhuis i-MONITORING department with samples taken each month by an approved body. There is an advanced remote system which reads the installation with the systems being inspected weekly.

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  • Radboud Benefits

Customer Benefits

1. Sustainable disinfection of cooling water without chemicals

2. Customized ozone solution for utility cooling water

3. Total water management including i-MONITORING

4. Ozone dosing based on real-time pollution (redox/pH)

5. Water savings and reduced blowdown costs

6. Prevention of bacteria growth and legionella outbreaks