Challenge: Uncertainty of pathogen growth in cooling water systemsChange: Targeted monitoring identifies key risk factors for growthImpact: Better decisions for safer cooling towersJob descriptionOperational and treatment measures can help limit the growth of opportunistic pathogens, such as Legionella pneumophila, in cooling tower water. However, extreme heat and water events can disrupt system conditions in ways that promote pathogen growth and potentially increase the release of contaminated aerosols, thereby raising risks to human health. Although pathogen monitoring in cooling water can help assess whether microbiological control is maintained, current approaches do not capture the short-term growth dynamics associated with weather events, leaving risk estimates highly uncertain. Validated methods to determine when and where pathogen concentrations increase in cooling water systems, and to translate these dynamics into weather-informed risk predictions, are still lacking.
In this PhD project, you will investigate the occurrence and concentrations of opportunistic pathogens in water from full-scale cooling towers in the Netherlands and Brazil, with possible extension to irrigation systems. You will develop practical methods to monitor and predict pathogen growth events under weather-driven stress conditions, supporting more transparent, efficient, and risk-based decisions for the design and operation of climate-resilient cooling water systems.
You will:
- Develop and implement pathogen monitoring strategies for cooling water systems.
- Assess how pathogen concentrations vary across time, space, and weather conditions.
- Create an early warning system to support climate-resilient water safety management.
- Work with academic, governmental, and industrial partners in the Netherlands and Brazil.
- Present research at international conferences and publish in peer-reviewed journals.
You will join the Sanitary Engineering Section of TU Delft’s Department of Water Management and work with Hydroscope, KWR Water Research Institute, and The Green Village on the development of monitoring and risk assessment strategies. You will collaborate with researchers from Radboud University for microbiological analyses and from the University of São Paulo to compare findings across climatic and operational contexts. As part of our diverse and supportive team of PhDs, postdocs, researchers, and professors, you will receive all the support needed to develop your skills and build your career. Your daily supervisor will be Dr. Émile Sylvestre, Prof. Doris van Halem will serve as the promoter, and a co-promoter from Radboud University will join the supervision team.
Job requirementsWe are looking for a curious and motivated candidate with:
- An MSc degree (or equivalent) in civil, environmental, or chemical engineering, or in microbiology with strong interest in quantitative modelling.
- Hands-on laboratory experience in microbiology or water treatment, and a willingness to learn microbial quantification techniques.
- Demonstrated ability to analyse quantitative data using tools such as R and Python.
- Excellent English communication skills.
- Motivation to work in an interdisciplinary research environment and collaborate with industry and governmental partners.
TU DelftDelft University of Technology is built on strong foundations. As creators of the world-famous Dutch waterworks and pioneers in biotech, TU Delft is a top international university combining science, engineering and design. It delivers world class results in education, research and innovation to address challenges in the areas of energy, climate, mobility, health and digital society. For generations, our engineers have proven to be entrepreneurial problem-solvers, both in business and in a social context.
At TU Delft we embrace diversity as one of our core
values and we actively
engage to be a university where you feel at home and can flourish. We value different perspectives and qualities. We believe this makes our work more innovative, the TU Delft community more vibrant and the world more just. Together, we imagine, invent and create solutions using technology to have a positive impact on a global scale. That is why we invite you to apply. Your application will receive fair consideration.
Challenge. Change. Impact!
The Faculty of Civil Engineering & GeosciencesThe Faculty of Civil Engineering & Geosciences (CEG) is committed to outstanding international research and education in the field of civil engineering, applied earth sciences, traffic and transport, water technology, and delta technology. Our research feeds into our educational programmes and covers societal challenges such as climate change, energy transition, resource availability, urbanisation and clean water. Our research projects are conducted in close cooperation with a wide range of research institutions. CEG is convinced of the importance of open science and supports its scientists in integrating open science in their research practice. The Faculty of CEG comprises 28 research groups in the following seven departments: Materials Mechanics Management & Design, Engineering Structures, Geoscience and Engineering, Geoscience and Remote Sensing, Transport & Planning, Hydraulic Engineering and Water Management.
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here to go to the website of the Faculty of Civil Engineering & Geosciences.
Conditions of employment Doctoral candidates will be offered a 4-year period of employment in principle, but in the form of 2 employment contracts. An initial 1,5 year contract with an official go/no go progress assessment within 15 months. Followed by an additional contract for the remaining 2,5 years assuming everything goes well and performance requirements are met.
Salary and benefits are in accordance with the Collective Labour Agreement for Dutch Universities, increasing from €3059 - €3881 gross per month, from the first year to the fourth year based on a fulltime contract (38 hours), plus 8% holiday allowance and an end-of-year bonus of 8.3%.
As a PhD candidate you will be enrolled in the TU Delft Graduate School. The TU Delft Graduate School provides an inspiring research environment with an excellent team of supervisors, academic staff and a mentor. The Doctoral Education Programme is aimed at developing your transferable, discipline-related and research skills.
The TU Delft offers a customisable compensation package, discounts on health insurance, and a monthly work costs contribution. Flexible work schedules can be arranged.
Will you need to relocate to the Netherlands for this job? TU Delft is committed to make your move as smooth as possible! The HR unit,
Coming to Delft Service, offers information on their website to help you prepare your relocation. In addition, Coming to Delft Service organises events to help you settle in the Netherlands, and expand your (social) network in Delft. A
Dual Career Programme is available, to support your accompanying partner with their job search in the Netherlands.
Additional informationIf you would like more information about this vacancy or the selection procedure, please contact Émile Sylvestre (
e.sylvestre@tudelft.nl).
Application procedureAre you interested in this vacancy? Please apply before
12 April 2026 via the application button and upload:
You can address your application to Émile Sylvestre.
The interviews will take place during the week of April 20.
Doing a PhD at TU Delft requires English proficiency at a certain level to ensure that the candidate is able to communicate and interact well, participate in English-taught Doctoral Education courses, and write scientific articles and a final thesis. For more details please check the
Graduate Schools Admission Requirements.
Please note: - You can apply online. We will not process applications sent by email and/or post.
- As part of knowledge security, TU Delft conducts a risk assessment during the recruitment of personnel. We do this, among other things, to prevent the unwanted transfer of sensitive knowledge and technology. The assessment is based on information provided by the candidates themselves, such as their motivation letter and CV, and takes place at the final stages of the selection process. When the outcome of the assessment is negative, the candidate will be informed. The processing of personal data in the context of the risk assessment is carried out on the legal basis of the GDPR: performing a public task in the public interest. You can find more information about this assessment on our website about knowledge security.
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