Electrochemical chelation and reduction of nitrate ion on EDTA modified carbon paste electrode

The aim of this work is to combine two methods for removing nitrate ions from concentrated aqueous solutions. This involves chelating and then reducing NO3− by EDTE modified carbon paste electrode (EDTA-CPE). We find that in the absence of EDTA on the carbon paste electrode surface, the nitrate reduction is almost impossible. The reduction of nitrate ions was invested on the surface of the EDTA-CPE, the cyclic voltammograms recorded in electrolytic medium 0.1 M KCl, shows two reduction peaks, the first at −0.2 V, attributed to the reduction of nitrite ions (NO2−) and the second one at 0.8 V which corresponds to the reduction of nitrate to nitrite ions.