[Electrocatalytic reduction of nitrate from drinking water by porous titanium loaded Pd-Cu cathode].

We investigated performances as well as influencing factors of electrocatalytic denitrification of a porous titanium loaded Pd-Cu (4:1) cathode, from drinking water. Up to 96.9% of NO3(-)-N may be reduced to N2 with electrocatalytic activity as 16.69 mg/ (g x h). The Nitrate reduction presented an apparent first order reaction at lower nitrate concentration, while a zero order reaction at higher nitrate concentration. Little nitrate reduction was observed when cell voltage (or current) was lower than 1.5 V (or 5 mA); the side reaction of ammonium production became noticeable if the cell voltage (or current) was higher than 4.2 V (or 30 mA). Both the activity and the selectivity were good at a neutral pH; at acidic pH, the activity increased while the selectivity decreased. Mass transfer in solution was found little effect on the reactions in the tests. Other anions such as ClO4-, HCO3-, Cl- did somewhat harms to NO3(-)-N removal with sequence of ClO4- < HCO3- < Cl-.