Nitrate Reduction Using As-Synthesized Nanoparticles Zero Valent Iron (NZVI) at Ambient Environment

Nitrate removal or denitrification, involves reduction of nitrate into nitrogen and oxygen. The use of nanoparticles zero valent metals for denitrification receives great attention as they have been proven to be effective and environmentally safe. In this work, the nanoparticles were prepared by reducing the metals salts, dissolved in a mixed solution of water and ethanol, using sodium borohydrate. The nitrate reduction reaction took place in an ambient environment – room temperature, neutral pH and aerobic condition. Results from the experiments carried out showed that nitrate has been successfully reduced up to a maximum of 40% in all the samples without an increase in the pH of the solution, a strong indication that ammonia was not produced. As for the study on the reactivity of the recycled NZVI, the samples synthesized with 4:1 (v/v) ethanol/water and using 9: 1 (v/v) ethanol/water, the reactivity of the iron is similar to the fresh NZVI for the first two hours of the study.