Siberian Federal University (SibFU) researchers, joined by their colleagues from China and Sweden, have developed a technology for recovering ammonia from wastewater. The peculiarity of the method is in the use of electrochemical catalysis to convert nitrates from sewage to a precious gas. SibFU informs that its solution helps neutralise harmful nitrogen oxides contained in water whilst producing ammonia, which is widely used in, for instance, fertiliser manufacturing.
"To reduce nitrate to ammonia – a compound of nitrogen and hydrogen – we needed new electrochemical catalysts (electrocatalysts). By converting organometallic compounds, we have established such that would ensure a substantial ammonia yield yet have sufficient selectivity. These are copper- and nickel-based catalysts, so the solution is also cheap. The metals are embedded in a matrix formed by boron, carbon and nitrogen," says Artem Kuklin, a senior researcher at SibFU's International Research Center of Spectroscopy and Quantum Chemistry
Nowadays, the most common way of producing ammonia is the Haber-Bosch process, a reaction between nitrogen and hydrogen at a moderately-elevated temperature and high pressure in the presence of a catalyst. This process is very energy-intensive and results in considerable greenhouse gas emissions, SibFU's Press Office reports. Electrocatalysis is, however, an environmentally friendly method. Moreover, the reaction between nitrates contained in water and a hydrogen cation can start if supplied with energy from solar panels or wind farms.
Let us recall that Gubkin researchers have obtained patents registered in Canada and China for their invention – a biocomposite for treating wastewater from nitrite, nitrate and phosphate ions. The research team's solution will help remove pollutants from water, making it thus safe for swimming and drinking.