Oxidation of S（IV） to S（VI） in the effluent of a flue gas desulfurization（FGD） sys- tem is very critical for industrial applications of seawater FGD. This paper reports a pulsed corona discharge oxidation proces...Oxidation of S（IV） to S（VI） in the effluent of a flue gas desulfurization（FGD） sys- tem is very critical for industrial applications of seawater FGD. This paper reports a pulsed corona discharge oxidation process combined with a TiO2 photocatalyst to convert S（IV） to S（VI） in artificial seawater. Experimental results show that the oxidation of S（IV） in artificial seawater is enhanced in the pulsed discharge plasma process through the application of TiO2 coating electrodes. The oxidation rate of S（IV） using Ti metal as a ground electrode is about 2.0x10-4 mol. L 1. min-1, the oxidation rate using TiO2/Ti electrode prepared by annealing at 500 ~C in air is 4.5x 10-4 tool. L-a ~ min-1, an increase with a factor 2.25. The annealing temper- ature for preparing TiO2/Ti electrode has a strong effect on the oxidation of S（IV） in artificial seawater. The results of in-situ emission spectroscopic analysis show that chemically active species （i.e. hydroxyl radicals and oxygen radicals） are produced in the pulsed discharge plasma process. Compared with the traditional air oxidation process and the sole plasma-induced oxidation process, the combined application of TiO2 photocatalysts and a pulsed high-voltage electrical discharge process is useful in enhancing the energy and conversion efficiency of S（IV） for the seawater FGD system.展开更多
基金supported by National Natural Science Foundation of China(Nos.20836008,21076188,20976158 and 21076189)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(No.2008BAC32B06)the Zhejiang Provincial Natural Science Foundation of China(No.LY12B07001)
文摘Oxidation of S（IV） to S（VI） in the effluent of a flue gas desulfurization（FGD） sys- tem is very critical for industrial applications of seawater FGD. This paper reports a pulsed corona discharge oxidation process combined with a TiO2 photocatalyst to convert S（IV） to S（VI） in artificial seawater. Experimental results show that the oxidation of S（IV） in artificial seawater is enhanced in the pulsed discharge plasma process through the application of TiO2 coating electrodes. The oxidation rate of S（IV） using Ti metal as a ground electrode is about 2.0x10-4 mol. L 1. min-1, the oxidation rate using TiO2/Ti electrode prepared by annealing at 500 ~C in air is 4.5x 10-4 tool. L-a ~ min-1, an increase with a factor 2.25. The annealing temper- ature for preparing TiO2/Ti electrode has a strong effect on the oxidation of S（IV） in artificial seawater. The results of in-situ emission spectroscopic analysis show that chemically active species （i.e. hydroxyl radicals and oxygen radicals） are produced in the pulsed discharge plasma process. Compared with the traditional air oxidation process and the sole plasma-induced oxidation process, the combined application of TiO2 photocatalysts and a pulsed high-voltage electrical discharge process is useful in enhancing the energy and conversion efficiency of S（IV） for the seawater FGD system.
