| Air pollution caused by SO2, NO and other harmful gases has been a significant problem in environmental protection. It can not only destroy the balance of nature but also threaten the health and life of human. Many efforts have been devoted to find a more efficient way to decrease or remove the released SO2 and NO. By using the water and electricity associated effect, a new method to remove SO2 and NO in flue gas, developed from the popularly studied methods at present, is mainly discussed in this paper and described in detail as following: A simplized model is built to describe the desulfuration and denitration process in gas phase by corona discharge plasma. Runge-Kutta method is used to simulate the chemical reaction process of SO2 and NO with some active species caused by discharge, such as HO·, HO2·, O·, and O3, the results of which show that SO2 and NO are removed by the oxidation process of radicals, meanwhile the desulfuration and denitration efficiency are influenced by the initial concentrations of the components of flue gas, especially the contents of water and oxygen. Desulfuration and denitration experiments of the simulated flue gas under DC supply are implemented in the plasma reactor designed by ourselves using the water combined with electricity based on gas-water interface corona discharge, the results of the effect of discharge parameters and the content of gas component on the desulfuration and denitration efficiency shows good consistent with the theoretically calculated results. The methods to detect hydroxyl radicals are reviewed and Fenton reaction, which is capable of producing stable hydroxyl radicals, is investigated in this dissertation. The experimental system adopting bromophenol blue as an indicator to detecting the hydroxyl radicals during discharge process is determined on the basis of colorimetry. It is confirmed that the hydroxyl radicals produced in water during corona discharge process enhance the desulfuration and denitration effects. The theory about electromotion effect on the interface between gas and water, formation of ion wind during corona discharge and double film absorption is used to explain the effect of simultaneously desulfuration and denitration in the gas and water phases. Furthermore, the theory about denitrifying by oxidation in gas phase and absorption in liquid phase and desulfurizing by absorption and oxidation in liquid phase is deduced. It can be theoretically concluded that the removal of SO2 should be mainly attributed to absorption action of water although discharge plasma can also exert some influence while the removal of NO should be mainly attributed to the oxidation reaction in the gas phase and oxidation products absorption in the water. According to inorganic chemistry theories, ferrous sulfate, a waste in titanium dioxide production, can react with HNO3 and H2SO4 to synthesize polymerized ferric sulphate, which is of practical value. Thus, the acid solution containing a great deal of NO3-and SO42-released from the plasma reactor by using the water combined with electricity can be utilized efficiently. The feasibility of the method is proved by both theoretical analysis and experimental results. The technique by using the affect of water combined with electricity to remove SO2 and NO present superior effect on desulfuration and denitration to the dry-type electrical technique. Thus, the new technique studied in this paper possesses a prospective application future. Moreover, theoretical investigation of plasma chemistry reaction and desulfuration and denitration mechanism is of reference value to the cross-knowledge study, such as plasma chemistry, thermodynamics and hydromechanics.
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