Catalytic nitrate reduction using formic acid as a reductant

Samyoung Ahn
Environmental education, Sunchon National University

Eun Kyoung Choi
same as primary author

     Full text: Not available
     Last modified: February 15, 2006

Abstract
Nitrate is one of the most ubiquitous pollutants. Catalytic nitrate reduction using Pd/Cu bimetallic catalyst is a promising technology to control the nitrate concentration below the permitted level. Especially, using formic acid as a reductant instead of hydrogen offers several practical advantages; it is easy to handle compared to hydrogen gas, the loading of reductant can be exactly tuned to maximize the reduction efficiency, formic acid is more economical than hydrogen gas.
In this study, the nitrate reduction reactivity using formic acid as reductant was investigated in terms of catalysts loading, the ratio of Pd to Cu, the initial concentration of nitrate, the amount of formic acid, the dissolved oxygen and alkalinity. 0.75g of catalyst with Pd/Cu of 5%/1.25% reduced the 100ppm nitrate to nitrogen within three hours. The formation of undesired product ammonia was negligible. Two-fold excess of formic acid was required for best performance, dissolved oxygen and alkalinity had a negative impact on the nitrate reduction. The catalyst can be repeatedly used without significant loss of the catalyst efficiency.