The Department of Earth Sciences is now looking for a highly-motivated applicant to fill a postdoctoral research position on examining the positive effects of microbial treatment on stone weathering at the pore and building 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. You will work primarily in the lab, using traditional and advanced (non-) destructive characterization methods to examine the effect on microbial treatment on the stones conservation. The effect of biocolonisation within the pores can be examined both in 2D (using micromodels) and in 3D-4D (using advanced X-ray imaging). Special attention will be paid to the effect of biocolonisation on pore clogging, calcite precipitation, gas production and dissolution, and how these influence fluid flow inside the rocks at the pore and on the centimeter scale in real time. You 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, you will test different application methods for optimal used of microbial treatment.
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