Clean Technology 2007
K. Mackenzie, H. Hildebrand and F.-D. Kopinke
Helmholtz Centre for Environmental Research - UFZ, DE
Pd nano catalysts, dechlorination, nanoscale zero-valent iron, water treatment
The presentation contains two innovative applications of nano-sized materials for environmental application: 1) Pd catalysts for wastewater treatment. The new ferromagnetic nano-sized Pd catalysts have proved effective for selective dechlorination of industrial wastewater. Extraction by magneto-separation assures catalyst recovery from treated waters. Several reactor configurations can be presented. One objective of the work is the evaluation of environmental risks of such catalytic systems. 2) The modification of activated carbon (AC) particles with zero-valent iron (ZVI) generated a novel tool for in situ water treatment where the sorptive property of the AC carrier is supplemented by the reactivity of ZVI. This carbo-iron (20 wt-% ZVI) proved its dechlorination activity for chlorinated methanes and ethenes in aqueous solution. Furthermore, the hydrophobic nature of carbo-iron permits its distribution in NAPL phases where dechlorination can be performed without the application of additives. This is a great advantage over nano-sized ZVI, which requires additives for source treatment.