The Department of Earth Sciences is now looking for a highly-motivated applicant to fill a postdoctoral research position on visualization of the impact of microbial treatment on stone weathering at the pore scale. Physical, chemical and biological weathering has a profound impact on the Earth’s landscape and on its building infrastructure. Rock and masonry are constantly damaged and disaggregated by chemical reactions, water infiltration and temperature changes. Strengthening efforts to protect and safeguard the world’s cultural and natural heritage is one of the United Nations’ Targets for Sustainable Cities and Communities in the 2030 Agenda for Sustainable Development. Fluids are a major driver of rock weathering: they trigger, among others, dissolution, precipitation, frost and salt weathering. The key to manipulating weathering lies in understanding and controlling fluid flow within the internal pore structure of rocks and thereby influencing the related pore-scale processes. While microbial organisms are generally known to alter rock surfaces, some actually display physiological capabilities that have beneficial effects on rock properties due to their production of bio-cement and biogas. Before we can harness these beneficial effects, we must first study how these organisms impact fluid flow at the pore scale.

The Dutch Research Council founded VICI project, led by Prof. Veerle Cnudde, 'Towards protecting and improving building stones through microbial manipulation of pore structure' (short: BugControl), will focus on the understanding of bio-manipulated pore-scale processes inside rocks. This 5-year project aims to steer fluid-rock interaction by applying microbial organisms on and inside stone. The current position aims to visualize the bacteria and their activity (e.g. production of MICP, biogas) inside stone.

Your tasks:

• The postdoctoral researcher will work on the non-destructive 3D-characterization and 4D-monitoring of microbial-induced pore-scale processes inside rocks. The effect of biocolonization will be examined both in 2D (using micromodels) and in 3D-4D (using advanced X-ray imaging). Special attention will be paid to their effect on pore clogging, calcite precipitation, gas production and dissolution, and how these effect fluid flow inside the rocks at the pore and on the centimeter scale in real time. A major leap in understanding microbial induced pore-scale processes will be gained through this direct pore scale observation using advanced 2D and 3D imaging techniques.
• Therefore, a workflow needs to be developed that correlates the data retrieved from the different characterization techniques. Also, a methodology to visualize and monitor biofilms inside rocks will be set.
• The postdoctoral  researcher will help to answer in what way the application of bacteria induces bioclogging, bio-cement and bio-gas production inside the different pore structures and how this activity is influenced by the original pore structure. Additionally, the researcher will visualize and quantify the influence of the bacterial application on the fluid flow.

Outcomes of this postdoctoral research will be incorporated into a team-effort to predict the impact of microbial organisms on rock properties and develop smart bio-conservation strategies. The research project is led by Project Leader Prof. Veerle Cnudde and will be mainly performed at Utrecht University, The Netherlands. Access to the X-ray CT scanners of the Centre for X-ray Tomography, at Ghent University, Belgium, is also foreseen within this project.

The candidate should be/have: 

• ambitious and have a PhD degree in Earth Sciences, Physics or Material Science at the start of the position.
• a background in advanced 2D/3D/4D imaging and fluid mechanics/bacteria and an interest in experimental work (would be an advantage).
• a broad interest in Geosciences, and the willingness and capacity to interact in a multidisciplinary team, are essential.
•  fluent in spoken and written English, since the host group is highly international in composition.

You will be offered a temporary full-time postdoctoral position for a period of 1.5 years in an international working environment. The minimum gross salary is €3,413 and the maximum gross salary is €3,974 (scale 10.3 - 10.7 of the Collective Labour Agreement of Dutch Universities) per month, at a full-time employment.

Besides that, you will receive a holiday allowance of 8 % and a year-end bonus of 8.3 %. Utrecht University also has an appealing package of terms of employment, including the choice for a good balance between work and private (a good arrangement for leave, among other things), possibilities for development and an excellent pension scheme. For more information, please visit working at Utrecht University.

A better future for everyone. This ambition motivates our scientists in executing their leading research and inspiring teaching. At Utrecht University, the various disciplines collaborate intensively towards major societal themes. Our focus is on Dynamics of Youth, Institutions for Open Societies, Life Sciences and Sustainability.
Utrecht University's Faculty of Geosciences studies the Earth: from the Earth's core to its surface, including man's spatial and material utilisation of the Earth - always with a focus on sustainability and innovation. With 3,400 students (BSc and MSc) and 720 staff, the Faculty is a strong and challenging organisation. The Faculty of Geosciences is organised in four Departments: Earth Sciences, Human Geography & Spatial Planning, Physical Geography, and Sustainable Development.

The Department of Earth Sciences conducts teaching and research across the full range of the solid Earth and environmental Earth sciences, with activities in almost all areas of geology, geochemistry, geophysics, biogeology and hydrogeology. The department hosts a highly international tenured staff of over 50 scientists and more than 110 PhD students and postdoctoral researchers. Our research programme spans four intertwined themes: Climate & Life, Earth interior, Earth materials, and Environmental Earth Sciences. We house or have access to a wide variety of world-class laboratories.

This project is based within the Environmental Hydrogeology group. We perform fundamental and applied research on the transport of fluids, colloids, and reactive chemical components in the shallow and deep subsurface. We apply a combination of theoretical, statistical, computational, and experimental methods to upscale processes from micro (pore) scale to column, and up to the field scale. Our work is related to environment and subsurface remediation, geo resources, and CO2 storage. The generated knowledge on upscaling in porous materials is highly cross disciplinary fostering collaborations with many scientific groups from (Earth) Science, applied research, as well as industrial partners.

About Utrecht
Utrecht is the fourth largest city in the Netherlands with a population of nearly 360,000 and forms a hub in the middle of the country. Its ancient city centre and its modern central station can easily be reached from the Utrecht Science Park by public transport or by a 15 minute bicycle ride. Utrecht boasts beautiful canals with extraordinary wharf cellars housing cafés and terraces by the water, as well as a broad variety of shops and boutiques.