Reduction of nitrate from groundwater: powder catalysts and catalytic membrane.
The reduction of nitrate contaminant in groundwater has gained renewed and intensive attention due to the environmental problems and health risks. Catalytic denetrification presents one of the most promising approaches for the removal of nitrate from water. Catalytic nitrate reduction from water by powder catalysts and catalytic membrane in a batch reactor was studied. And the effects of the initial concentration, the amounts of catalyst, and the flux H2 on the nitrate reduction were also discussed. The results demonstrated that nitrate reduction activity and the selectivity to nitrogen gas were mainly controlled by diffusion limitations and the mass transfer of the reactants. The selectivity can improved while retaining a high catalytic activity under controlled diffusion condition or the intensification of the mass transfer, and a good reaction condition. The total nitrogen removal efficiency reached above 80%. Moreover, catalytic membrane can create a high effective gas/liquid/solid interface, and show a good selectivity to nitrogen in comparative with the powder catalyst, the selectivity to nitrogen was improved from 73.4% to 89.4%.
Chen
Ying-Xu
YX
Department of Environmental Engineering, Zhejiang University, Hangzhou 310029, China. yxchen@zju.edu.cn
Zhang
Yan
Y
Liu
Hong-Yuan
HY
D002384:Catalysis; D003300:Copper / Q000737:chemistry; D008567:Membranes, Artificial; D009566:Nitrates / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
D008567:Membranes, Artificial; D009566:Nitrates; D010165:Palladium; D003300:Copper