Nanocatalysts for Wastewater Treatment
Nano-sized catalysts are highly active and are therefore also attractive for utilization in environmental applications, such as water treatment. Two metal systems are under study for dehalogenation of water contaminants showing a different but complementary target spectrum. Besides enhancement of the catalyst life-time, we are working on the optimization of selectivity, particle extraction from treated water, recycling and ecotoxicological properties of the catalyst particles.
Pd catalysts (with or without carrier) are able to support hydrodehalogenation in water at ambient temperature with hydrogen as reducing agent. The spectrum of treatable halogenated hydrocarbons is very broad. Our studies focus on
- coating of Pd particles by polymer membranes (= protect Pd from water constituents and avoid Pd leaching into the water)
- generate long-term stable catalysts
- optimize catalyst production
- develop application for AOX-reduction of industrial waste water containing halogenated contaminants (such as halogenated pharmaceuticals or herbicides)
Copper is able to catalyse the dehalogenation using hydride as reducing agent. Copper is markedly less sensitive to poisoning compared to Pd catalysts, which makes it to a welcome alternative to Pd. However, copper offers another spectrum of treatable halogenated hydrocarbons than Pd, where both metals are complementary in their abilities. While Pd is especially suitable for reduction of olefinic and aromatically bound hydrogen, copper is well-suited to reduce saturated halogenated compounds.
We work on
- completion of a matrix of treatable halogenated compounds and their relative reaction rates
- optimization of reaction selectivities and
- comparison of various dehalogenation approaches with the aim to provide recommendations for making the right choice of treatment means