Uni-Tübingen

P5 Pollutant Transformations at the Groundwater - Rock Matrix Interface

Principal Investigators

Jun.-Prof. Dr. Sara Kleindienst University of Tübingen, Microbial Ecology
Prof. Dr. Andreas Kappler University of Tübingen, Geomicrobiology
Prof. Dr. Peter Grathwohl University of Tübingen, Hydrogeochemistry

Contact:

Dr. Karsten Osenbrück

University of Tübingen, Hölderlinstr. 12, 72074 Tübingen

+49 (7071) 29 73123, karsten.osenbrueckspam prevention@uni-tuebingen.de

Research Objectives

Groundwater in limestone-fractured aquifers is often polluted by nitrate and pesticides, including legacy compounds such as atrazine. Due to long groundwater residence-times in these aquifers, microbial activities associated with pollutant turnover may substantially influence the fate of pollutants. A particular example is denitrification, which depends on the availability of electron donors such as organic carbon or Fe(II) minerals within the rock matrix. Further, storage of pollutants (e.g. atrazine) in immobile water of the rock matrix may become relevant and impact contaminant loads in these systems. A multidisciplinary approach will be used to:

- Determine the locations of pollutant (nitrate, atrazine) turnover in fractured rock aquifers

- Identify microbial key players mediating these processes and study their physiology

- Quantify rates of microbial pollutant turnover

- Examine factors that limit microbial activities and associated pollutant transformations

Approach

A combination of field studies and laboratory experiments will be employed to address the above mentioned research objectives:

- To examine microbial key players of pollutant turnover and their metabolic capabilities in situ, molecular tools (e.g. 16S rRNA amplicon sequencing, metagenomics, -transcriptomics, and -proteomics) will be applied to fractured aquifer samples, including in situ microcosms that were deployed in the field.

- To quantify pollutant turnover, examine the factors limiting pollutant turnover, identify the involved microorganisms, and determine sorption as well as diffusion of pollutants, laboratory experiments (incl. stable-isotope probing experiments) using aquifer limestone material will be conducted.

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