goodwater

WP 5 aims to understand how groundwater systems initially react to pollutant contamination, what controls biodegradation and how aquifers recover after contaminant removal (resistance and resilience). We have only a vague idea about the resistance and resilience of an intact pristine (energy limited) aquifer towards organic impact. The project will thus investigate the succession of geochemical conditions and natural groundwater microbial communities starting from initial pristine conditions to a well defined organic point source contamination (e.g. toluene or naphthalene). Towards the end of the project, the regeneration of the system back to natural conditions will be studied. The project will be conducted in a large indoor heterogeneous sandy aquifer mesocosm. Work will focus on the identification of microbes which (i) react fast and are sensitive to contamination, (ii) organisms with a high bioindicative potential for contaminant impact, and (iii) microbes which are persistent members of the community independent of disturbance. We will further evaluate the effects of sediment heterogeneity on mixing in porous media and biodegradation. A major task will be the identification of degradation-limiting factors others than mixing (biokinetic factors). The project of fellow 5 (SV: C. Griebler, HMGU) is intended to be closely linked to work of fellow 2 (GEUS) and fellow 15 (DTU) who also focus on the effect of spatial heterogeneity as a controlling/limiting factor and the role of transition zones for biodegradation. Work package 5 will further interact interdisciplinary with the fellows working at the indoor heterogeneous sandy aquifer mesocosm at the HMGU. Here, interactions are planned with fellows 1, 7, 8, and 11 (all HMGU) and support will be provided to those fellows via our expertise in high-resolution sampling. Fellow 5 will spend altogether 4 weeks at the LfU (M. Gierig) being introduced into daily groundwater authority work.