Cloth catalysts in water denitrification. II. Removal of nitrates using Pd-Cu supported on glass fibers

The use of glass fibers in the form of woven cloth (GFC), as a new type of catalytic support, was studied for the reduction of aqueous nitrate solutions using a Pd/Cu–GFC catalyst. The activity (per gram Pd) and selectivity to nitrogen were found to be comparable with those found for Pd–Cu catalysts supported on the other carriers. The maximal initial removal activity was found for a catalyst with a Pd/(Pd+Cu) ratio of 0.81. The corresponding activity was 0.7 mmol min-1 (gPd)-1, and the selectivity was 97 mol% at 25°C and pH 6.5 for initial nitrate concentration of 100 mg l-1. The selectivity to nitrogen declined at high conversions of nitrate and high pH.