Song DH  Kang JH  Park HS  Song HJ  Chung YG

Vol. 27,  No. 4, pp. 341-349, Dec.  2021
10.7464/ksct.2021.27.4.341

nitrogen oxide Sulfur oxide Simultaneous removal Microbubble Reducing agent

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In combustion facilities, the nitrogen and sulfur in fossil fuels react with oxygen to generate air pollutants such as nitrogen oxides (NOX) and sulfur oxides (SOX), which are harmful to the human body and cause environmental pollution. There are regulations worldwide to reduce NOX and SOX, and various technologies are being applied to meet these regulations. There are commercialized methods to reduce NOX and SOX emissions such as selective catalytic reduction (SCR), selective non-catalytic reduction (SNCR) and wet flue gas desulfurization (WFGD), but due to the disadvantages of these methods, many studies have been conducted to simultaneously remove NOX and SOX. However, even in the NOX and SOX simultaneous removal methods, there are problems with wastewater generation due to oxidants and absorbents, costs incurred due to the use of catalysts and electrolysis to activate specific oxidants, and the harmfulness of gas oxidants themselves. Therefore, in this research, microbubbles generated in a high-pressure disperser and reducing agents were used to reduce costs and facilitate wastewater treatment in order to compensate for the shortcomings of the NOX, SOX simultaneous treatment method. It was confirmed through image processing and ESR (electron spin resonance) analysis that the disperser generates real microbubbles. NOX and SOX removal tests according to temperature were also conducted using only microbubbles. In addition, the removal efficiencies of NOX and SOX are about 75% and 99% using a reducing agent and microbubbles to reduce wastewater. When a small amount of oxidizing agent was added to this microbubble system, both NOX and SOX removal rates achieved 99% or more. Based on these findings, it is expected that this suggested method will contribute to solving the cost and environmental problems associated with the wet oxidation removal method.