This paper describes experiments on the application of sodium bicarbonate desulphurisation in the coal-fuel boiler. The boiler has been in operation for several years now and it has refiably fulfilled the original assignment to reduce SO2 emissions from the value of 1200 - 1500 mg/Nm3 to 400 mg/Nm3. Higher desulphurisation efficiency is determined only by the ratio of Na/S sorbent dosage. The resulting product of desulphurisation is stored together with fly ash in underground mines, and has no influence on the groundwater. Positive experience of the tests and boiler operation lies in higher reactivity of sodium and sulphur as compared with conventional methods based on limestone. Within the scope of the secondary measures of elimination of sulphur oxides in combustion products, an experimental dry-method desulphurisation of combustion products was performed by blasting an agent containing sodium bicarbonate NaHCO3 (99.6 %) into the flue ways before the electrostatic precipitator in a coal-fuel furnace with the steam output of 220 t/h.

This article presents the effects of the application of the passive method of flue gas purification from mercury compounds emitted during combustion. The research was carried out on a fluidized bed installation using coal. The dry method of acid gas pollutants reduction was applied during the combustion with the use of 9 modified sodium sorbents. They were fed into a gas jet of 573 K in two molar ratios (sodium contained in the sorbent to the sulphur contained in the fuel). The mercury emission level into the atmosphere was determined based on the mercury content in the solid substrates of the combustion process (in the fuel and the sorbent) and the solid products (fly ash and bottom waste). The combustion process was accompanied by mercury emission 14.7 μgHg/m3. During the removal of acid pollutants from fumes, a decrease in mercury concentration was achieved. The degree of the mercury reduction depended on the type the sorbent used, the manner of modification and the molar ratio in which they were fed into the installation (2 Na/S = 0.5; 2.1). Each time, the more the sorbent was fed into the installation, the bigger the reduction of the mercury emission level. Among the unmodified sorbents, the lowest emission level was achieved for the raw bicarbonate – 3.7 μgHg/m3. For baking soda it was 9.7 μgHg/m3. The application of mechanically modified compounds based on baking soda resulted in the reduction of the Hg emission in fumes up to 2.5–2.6 μgHg/m3. The determined mercury concentration levels in the gases during the purification of the fumes were compared with the accepted Hg emissions contained in the BAT conclusions for large combustion plants. As for all of the existing and newly built plants with a heat capacity below 300 MW, satisfactory effects would be achieved by the use of mechanically modified sorbents in the molar concentration of 2 Na/S = 2.1.

The aim of the research was to study the temporal and spatial dynamics of a set of agronomic criteria for irrigation water in the process of transporting it from the Southern Buh River intake site to the lands of the Southern Buh and Kamianska irrigation systems situated in southern Ukraine. Six stationary research sites for monitoring the quality of irrigation water were established along the route of irrigation water transportation. Determination of agronomic criteria for irrigation water quality was carried out in two terms: at the beginning of the irrigation season, in May, and at the end, in September. The content of cations of sodium, magnesium, calcium, and anions of chlorine, sulphates, carbonates, and bicarbonates was determined. In the field, the pH and electrical conductivity of water, the total salt content, and the total amount of dissolved solids were determined. It is determined that waters have an average level of danger from the point of view of salinisation of soils. This fact leads to a decrease in yield of sensitive to salinity crops (corn, alfalfa and most vegetables). The high content of sodium cations along with the low content of calcium and magnesium cations indicates the danger of degradation of the physical properties of the southern chernozems and the need to use the meliorants containing calcium. There is a high probability of toxic effects on crops caused by sodium cations. At the same time, it is stated that there is no negative effect of chlorine anions on plants.