Nitrogen oxides are one of the most common and toxic gaseous air pollutants of large industrial centers. The main difficulty of cleaning gas emissions is related to the dependence of the efficiency of the applied cleaning technologies on the NOx concentration, the frequency of emissions, the need for processing and/or disposal of products of interaction of nitrogen oxides with absorbers and regeneration of catalysts. The article analyzes the features of currently used and promising methods of cleaning waste gases from NOx, systematizes data on the effectiveness of such technologies. Based on the analysis of the processes of formation of nitrogen oxides, rational approaches to reducing NOx emissions in metal etching technology and electroplating are proposed.
Keywords: nitrogen oxides, biogenic and technogenic sources, catalytic and non-catalytic purification, selective purification, absorption purification, comparative efficiency