| Nitrogen oxides(NOx)are the primary contributors to atmospheric pollutants and precursors of photochemical smog and acid rain that potentially threaten human health and living conditions.The traditional NOx treatment method has the problems of large investment and secondary pollution,while the low-temperature plasma treatment technology has the advantages of high treatment rate and low cost.Dielectric barrier discharge(DBD)is widely used in industry as a kind of low-temperature plasma that can be generated under normal temperature and pressure.Although DBD processing has many advantages,its energy utilization is low,the processing speed is slow,and many byproducts need to be further improved.In recent years,the development of photocatalytic technology has attracted more and more attention in the field of exhaust gas treatment.Combining photocatalytic technology with DBD processing technology not only can bring out the advantages of the two technologies,but also the two technologies can complement each other.The UV light generated by DBD can activate photocatalyst,and the use of DBDgenerated ultraviolet light to activate photocatalyst can not only improve.The energy utilization rate in the system can also increase the treatment rate and reduce the production of by-products.In this paper,the gas discharge morphology,discharge power and emission spectrum of a single gas-liquid two-phase DBD are measured first,and photocatalysts Ti O2 and Na OH solutions are introduced on a single gas-liquid two-phase DBD,respectively,under the same conditions under the comparison of the three conditions.Discharge morphology,discharge power,and emission spectra were studied to investigate the effects of photocatalysts Ti O2 and Na OH solutions on their optical and electrical properties.The experimental results show that compared with the gas-liquid two-phase DBD whose liquid phase is water,the addition of Ti O2 increases the discharge power by 9.1%-38.9%,and the hydroxyl content in the emission spectrum increases by 46.9%-53.1%.The gas-liquid two-phase DBD with Ti O2 supporting liquid-phase Na OH solution and the two-phase gas-liquid two-phase DBD with Ti O2 supporting liquid-phase water increased the discharge power by 32.6%-49.6%,and the hydroxyl content in the emission spectrum increased by 107.3.%~125.7%.Secondly,this paper analyzes the effects of parameters such as peak voltage,treatment time,Ti O2 loading layer,Na OH solution concentration,and NOx initial concentration on NOx treatment performance.The treatment rates of nitrogen oxides were compared between gas-liquid twophase dielectric barrier discharge(DBD),Ti O2-supported liquid-phase water-gas-liquid twophase DBD,and Ti O2-supported liquid-phase two-phase DBD with Na OH.The experimental results show that the co-processing efficiency in the experiment increases with the increase of peak voltage and gradually tends to be flat.When the peak voltage reaches 20 k V,the gas processing time is positively correlated with the co-processing efficiency.When the processing time reaches 35 s,the co-processing.The efficiency gradually slows down.The number of Ti O2 layers increases,and the co-processing efficiency increases until the number of load layers reaches 4 layers.In addition,the higher the concentration of Na OH is,the higher the synergistic treatment efficiency is.When the concentration of Na OH exceeds 1 mol/L,the co-processing efficiency gradually becomes stable,and the co-processing efficiency decreases as the initial concentration of NOx increases.Through the research results of this paper,photocatalytic synergistic gas-liquid two-phase DBD provides a certain theoretical basis and engineering application value for the removal of exhaust gas from thermal power plants. |
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