EFFECT OF SOLUTION CONDITIONS ON THE PRODUCT DISTRIBUTION OF CATALYTIC NITRATE REDUCTION USING Pd-ln CATALYSTS IN A CONTINUOUS-FLOW PACKED-BED REACTOR

摘要

Nitrate contamination of drinking water supplies is a widespread problem across the globe. Current methods used to remove nitrate (NO_3~-) from drinking water sources (i.e., electrodialysis, ion exchange and reverse osmosis) results in the production of a concentrated-waste brine that requires further treatment or disposal. Due to this drawback, a more sustainable treatment approach is desired. Bimetallic Pd-based catalysts (BPC) have emerged as a possible alternative treatment strategy for nitrate removal from drinking water . Several studies have shown that BPC reduce NO_3~- to end products of N2 and NH3 when an electron donor is added to solution (e.g., H2) Nitrous oxide (N2O) and nitrite (NO_2~-) are intermediates of the reaction, and both of these compounds are of environmental concern. The resulting product distribution from NO_3~- reduction has been linked to the catalyst structure, solution pH, solution composition and concentration of H2 added.