Water Treatment and Environmental Catalysis
The treatment of contaminated ground- and wastewater is a central demand of Environmental Technology. Site conditions, contamination profiles and treatment goals determine the method applied, which can reach from near-natural, cost-effective low-tech up to complex high-tech technologies.
Catalysts are not only for industrial use - they were as well developed to essential tools in environmental chemistry with the goal to realize fast and selective chemical reactions. In contrast to typical industrial processes, the reaction conditions in the environment are of course predetermined by nature and are rather disadvantageous for the chemical treatment of contaminated waters because:
- Heating of large water volumes is not economically feasible. Therefore, temperature cannot be used as a parameter to influence the reaction rate.
- Even if a natural water body is considered as 'highly contaminated', the pollutants to be removed are rather diluted (µg/L to mg/L) when compared with industrial processes.
- The contaminant spectrum of polluted water is usually very complex. The treatment method should therefore be applicable for various classes of substances simultaneously.
- The water matrix can contain catalyst poisons such as sulfides or heavy metal ions which can negatively affect the catalyst performance (catalyst poison).
- Toxicity might be increased instead of diminished in case of incomplete chemical transformation of pollutants.
The adaptation of known catalytic principles to environmental conditions and the described problems is the real challenge for the development of suitable catalytic water treatment technologies and main focus of the subject area "Environmental Catalysis" in our department. We carry out research on
- the combination of
sorption and reaction
for enrichment of pollutants in the proximity of a reagent or catalyst which is supported on a sorbent. For contaminant destruction we utilize
- reductive methods as well as
- oxidative removal (AOPs) of organic water pollutants.
-
nanoparticles
are often applied in our treatment approachen to ensure high reaction rates.