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

The exposure of the Aires resonator to electromagnetic radiation with a frequency of 6 GHz is considered. The resonator is a silicon plate with a diameter of 7.4 mm with circular grooves applied by etching. The resulting resonator with a thickness of 0.5 mm contains 4084101 circles of various diameters, which in orthogonal cross sections represent rectangular slits 0.2 μm wide and 0.6 μm deep. It is assumed that the radiation source falls on the resonator evenly from all sides. Thus, we have a radiation source in the form of a hemisphere, the radius of which is substantially larger than the diameter of the resonator (10 m). The intensity of the incident radiation and the frequency of the radiation are assumed to be known. It is necessary to find: the intensity of the radiation at some point in space above the resonator. (Receiver). If the radiation falls on the resonator not in the slot, then a reflection occurs (the angle of incidence equals the angle of reflection). If the radiation falls into the gap, then the reflection does not occur, and absorption occurs. It is assumed that radiation is diffracted on the slits. If you change the time with a certain step, you can calculate the intensity at any point of the receiver at any time. As a result of irradiation of the resonator over its central part, periodic radiation with frequencies of 6.85 GHz and 5.38 GHz is generated. At other frequencies, radiation is generated that is not periodic and is similar to chaotic radiation. The resonator can be considered as a converter of the incident periodic irradiation into other periodic radiations. These periodic emissions have frequencies that can be resonant for some molecules and parts of living organisms that make up the cells. By varying the depth and width of the slits on the resonator, the size of the resonator and other parameters, it is possible to obtain specific frequencies to which particular components of living cells are sensitive. This will allow targeted action on the cells of a living organism.

Keywords: mathematical modeling, structured silicon surface, high-frequency electromagnetic radiation, resonant frequencies, living organisms