In this work,a novel gas phase silent-packed bed hybrid discharge plasma reactor has been proposed,and its ability to control a simulative gas stream containing 240 ppm benzene is experimentally investigated.In order to optimize the geometry of the reactor,the benzene conversion rate and energy yield(EY) were compared for various inner electrode diameters and quartz tube shapes and sizes.In addition,benzene removal efficiency in different discharge regions was qualitatively analyzed and the gas parameter(space velocity) was systematically studied.It has been found that silent-packed bed hybrid discharge plasma reactor can effectively decompose benzene.Benzene removal proved to achieve an optimum value of 60% with a characteristic energy density of 255 J/L in this paper with a 6 mm bolt high-voltage electrode and a 13 mm quartz tube.The optimal space velocity was 188.1 h-1,which resulted in moderate energy yield and removal efficiency.Reaction by-products such as hydroquinone,heptanoic acid,4-nitrocatechol,phenol and 4-phenoxy-phenol were identified by mean of GC-MS.In addition,based on these organic by-products,a benzene destruction pathway was proposed.
A hybrid gas/liquid pulsed discharge plasma reactor using a porous ceramic tube is proposed for dye wastewater treatment.High voltage pulsed discharge plasma was generated in the gas phase and simultaneously the plasma channel was permeated through the tiny holes of the ceramic tube into the water phase accompanied by gas bubbles.The porous ceramic tube not only separated the gas phase and liquid phase but also offered an effective plasma spreading channel.The effects of the peak pulse voltage,additive gas varieties,gas bubbling rate,solution conductivity and TiO 2 addition were investigated.The results showed that this reactor was effective for dye wastewater treatment.The decoloration efficiency of Acid Orange II was enhanced with an increase in the power supplied.Under the studied conditions,97% of Acid Orange Ⅱ in aqueous solution was effectively decolored with additive oxygen gas,which was 51% higher than that with argon gas,and the increasing O 2 bubbling rate also benefited the decoloration of dye wastewater.Water conductivity had a small effect on the level of decoloration.Catalysis of TiO 2 could be induced by the pulsed discharge plasma and addition of TiO 2 aided the decoloration of Acid Orange Ⅱ.
