[Chemical denitrification of nitrate from groundwater]

Batch experiments for catalytic reduction of nitrate from groundwater with Pd and/Cu catalysts were conducted. It was found that Pd-Cu combined catalysts at a ratio of 4 can maximize the nitrate reduction into nitrogen; above 80% total nitrogen removal efficiency was realized in this study. It was also found that the catalytic activity was affected by the amounts of catalysts, hydrogen flow rate and pressure, the initial concentration of nitrate. With an increasing in the amount of the catalysts, both nitrite and ammonia intermediates can be kept at a low level. A high flow rate and pressure of hydrogen was in favor of the catalytic reduction of nitrate, but not benefit for the selectivity. The catalytic reduction followed a first order kinetics in term of the initial nitrate concentration.