Environmental Geosciences Group
Prof. Thilo Hofmann (Chair)
What is the impact of human activities on soil and groundwater quality? How can we effectively protect and use our water resources in a sustainable manner? Do nanoparticles have a major impact on contaminant relocation and toxicity? What is the behaviour and fate of organic pollutants in water and soils? Can we identify and predict geological hazards like landslides? These are some of the questions Prof. Hofmann´s group try to answer in the Department for Environmental Geosciences. We work in the fields of hydrogeology, environmental pollutants and nanogeosciences and want to understand processes from the nanometer up to the regional scale. Field experiments and controlled laboratory studies with the aid of modern high performance analytics and numeric modelling are our approach to solve these challenges.
Live depends on water. Save drinking water will be one of the major challenges in this century. Beside quantitative problems, groundwater contamination is a major environmental concern. Contamination can be due to inorganic, organic or biological sources. Hydrogeology involves all processes from groundwater recharge to discharge in springs and rivers or oceans. It includes the fade and behaviour of contaminants and trace elements in subsurface aquatic environments. Within the Department of Environmental Geosciences at Vienna University we cover projects from groundwater recharge models, hydrogeological models, isotop hydrogeology, artificial recharge of groundwater, groundwater salinisation and modelling of groundwater flow by numerical codes (e.g. Modflow, Feflow). Regional groundwater studies are currently carried out in Vienna and Lower Austria. We also study the behaviour of oraganic and inorganic substances linked to the leaching of contaminated materials, recycling material, mining activities or colloidal transport of trace substances.
Understanding the fate of organic contaminants after their release in the environment is fundamental to the accurate assessment of their environmental behavior and to the prediction of the associated risks. It is essential to ensure the safe use of existing/developing products and is also needed in order to design efficient and economically viable remediation strategies for contaminated soil and water.
Sorption and degradation are key processes affecting the fate of organic contaminants. Interactions with colloids are known to significantly affect those processes. Colloidal systems are technically challenging to study and there is still a poor understanding of the underlying mechanisms of interactions.
Our group develops and combines a range of approaches suitable to study those complex systems (e.g. passive sampling, column experiments). Tight links with the Nanogeoscience group allows extensive characterization of the systems studied to produce reliable and meaningful data.
Our research aims:
- to elucidate the mechanisms of interactions between organic contaminants and natural/engineered colloids,
- to develop prediction methods for situations where experimental data are not available, and
- to analyze consequences in terms of environmental fate and remediation strategies.
Organic contaminants include a range of surfactant metabolites, PAHs, chlorinated compounds, and pesticides. Both natural and engineered colloidal systems are considered, including carbonaceous nanoparticles (e.g., fullerenes, carbon nanotubes), metallic nanoparticles (e.g., nanoscale zero-valent iron), and natural colloids (humic acids, clays, and oxides).
Particles in the nanoscale (colloids) are abundant in all environmental compartments. These nanophases are composed of natural organic matter (e.g. humic substances), are biota itself (viruses, bacteria incl. pathogens), inorganic particles (clays, oxides or carbonates) or are man-made originating either from engineering (nanotechnology) or from wear/combustion/corrosion. They span a broad size range from some fractions of a nanometer to several micrometers. Hence a natural colloidal system typically consists of a wide variety of macromolecules and particles. This heterogeneity poses high demands on the analytical equipment and analysis strategy. On the other side engineered nanoparticles are typically well defined but occur in extremely low concentrations what makes them difficult to distinguish from natural ones. Nanoparticles are involved in natural processes as soil development and nutrient cycling but can also act as vehicles of contaminant transport, alter the bioavailability of substances and hence their toxicity. Especially in nanotechnology the proposed future market of several hundred billion US dollars will result in a widespread emission of specially designed nanoparticles into the environment. Today virtually nothing is known about the behaviour of those materials. Nevertheless it is clear already that those materials have characteristics different to those of the bulk materials due to their large surface areas and that some may penetrate the skin, cell membranes and the blood-brain barrier. The future research of the Nanogeosciences at the Vienna University aims at three main topics: Characterization - Environmental Processes - Behavior of Engineered Nanoparticles.
Geohazards (a.o. Prof. Häusler)
High mountain regions worldwide are highly sensitive to climate change, and therefore mountain hazards increase in number and magnitude. In the Himalayas as well as the Tienshan - Pamir - Hindukush Range mountain hazards affect the Asian- and Central Asian countries and their population more severely as they are exposed to a number of hazardous processes such as floods, avalanches, rockslides, and earthquakes. In the worst case a chain of reactions increases the magnitude of a damage e.g. if an earthquake simultaneously triggers both landslides and glacier lake outburst floods. As some rivers flow from one neighboring country to another, transboundary effects of floods should be taken into account. Glacier lake outburst floods (GLOFs) are catastrophic outburst from ice-dammed or moraine-dammed glacial lakes. Assessment of georisks is an important further step in the risk management process. For the high mountain environment we can only attempt to reduce the risk – not the geohazard, either controlling the exposure of human settlements, energy supply and infrastructure to hazards or reducing their vulnerability. Within the working group on “Applied Geology, Remote Sensing & GIS” we investigate the high mountain environmental system in order to reduce the georisks by providing integrated hazard zonation plans or the installation of Early Warning Systems (EWS). An EWS is a data based and/or knowledge based system to warn residents and officials of impending floodwaters on major rivers so they can take action and prepare themselves before serious flooding occurs. The use of such an integrated system is manyfold. It records the meteorologic and hydrologic conditions of the high mountain catchments, it monitors the outburst flood itself and it provides warning to those downstream that a GLOF has occurred.