Montag, 11. November 2013, 16:30 - 18:00 iCal

Aktuelle Themen in den Umweltgeowissenschaften III

PD Dr. Tobias Licha, Universität Göttingen

"New perspectives arising from the application of organic molecules as indicators in the aquatic environment: How to teach an old dog a new trick"

Eberhard Clar-Saal (2B 204), Center for Earth Sciences
Althanstrasse 14, UZA II, 1090 Wien

Seminar, Workshop, Kurs

According to the latest WHO water safety plan (2005) it is important that risk management for water bodies is inclusive and, therefore, covers the whole system from catchment to consumer. Within this context it is highly desired that selective and predictive indicators allowing risk evaluation in the catchment and in raw water are made available. The presentation gives insights into closing these gaps by offering and describing new indicators which allow system studies on a time scale between minutes and up to several tenths of years. Although this is the classical field of tracers, applications of organic compounds as indicators are promising. This includes compound classes like pharmaceuticals, pesticides, personal care products and industrial chemicals which have been detected at ever increasing concentrations in the environment over the last decade.

In a classical hydro(geo)logical sense a tracer has a known and defined input function. Quantitative information is gained from tracers by relating their input functions to their respective breakthrough curves. For an indicator, however, its input function into the system is largely unknown. Nonetheless, the occurrence or absence of a compound or a compound class may be used as a qualitative indication for a connection between or processes within systems. Semi-quantitative information from indicators can be derived by studying compound concentration ratios and their evolvement with time and/or space. Quantitative information can only be derived from indicators in case of constant input functions as long as these functions can somehow be estimated, e.g., from land use and compound-specific application schedules. Finally, in case of a transient input function it may be possible to obtain quantitative information from indicators only if additionally their system-specific reactive transport behaviour is fully understood. Further explanations and examples on how this can be achieved are presented.

The reactive behaviour of an indicator is defined as indicator functionality to characterise e.g. aquifer properties (heterogeneity, organic carbon distribution, and catchment boundaries), groundwater chemistry (redox zones, pH changes) and groundwater hydraulics (transit and residence times, mixing processes). Further, the specific use or local application of selected compounds adds another indicator functionality which can be used for source apportionment or pathways tracking.

The indicator concept for using organic molecules together with their advantages and drawbacks are presented using real world examples.




Andreas Gondikas
Universität Wien
0043 1 4277 53371