Study On Catalytic Degradation Of Dye Wastewater By DBD Plasma/CNTs-G-Ni_f

The dielectric barrier discharge?DBD?plasma alone and the combined technologies are used to treat dye wastewater.The technologies including DBD plasma alone,DBD plasma/NaClO₂ and DBD plasma/Ni foam-Graphene based materials are studied.In this paper,the CH₄ as carbon source is used to prepare and synthesize Ni foam-Graphene based materials which including Graphene-Ni foam?G-Ni_f?and carbon nanotubes-G-Ni_f?CNTs-G-Ni_f?.Meanwhile,hydrothermal method is used to synthesize ZnO.The XRD and SEM are used to characterize the materials.The growth mechanism of Ni foam-Graphene based materials is proposed.When the carbon source is CH₄,C will infiltrate Ni foam due to high temperature function.Then the supersaturated C will separate out to form G on the surface of Ni foam after cooling.After dipping,the Ni nanocrystals,which can be used as the catalysts for the growth of CNTs,will be formed on the surface of G under high temperature.Lastly,CNTs are formed because the C pile on the bottom of nanocrystals.The degradation process of alizarin green?AG?including the effects of pH value,the concentration of AG,conductivity and input power to degradation is investigated under DBD plasma alone.The investigated details include the establishment of apparent kinetics model,the implementation of the response surface model?RSM?and the study of degradation mechanism.The degradation process of AG fit pseudo-first-order kinetic process.By optimizing of RSM,the decolorization rate reaches to 100%under the best conditions of AG 51.01 mg.L^-1,p H 2.06,conductivity 171.51?S.cm^-1 and input power 108.50 W.The degradation of different dyes wastewaters are compared under DBD plasma alone and the combined technologies.The coupling factor comparison model that is the actual ratio of efficiency/time is put forward to evaluate the coupling effect of reaction systems.In terms of AG,compared with DBD plasma alone,DBD plasma/CNTs-G-Ni_f has 16.71%overall decolorization effect for promotion,while DBD plasma/NaClO₂ has 23.65%overall decolorization effect for promotion.According to the systems of DBD plasma/NaClO₂ and DBD plasma/Ni foam-Graphene based materials,the detailed coupling mechanisms are proposed in this paper.Furthermore,the relationship among the main treatment system-the adding reaction agent-the target of pollutants is also explored.Finally,the general degradation pathway and the detailed substep degradation paths of AG are illustrated.The results demonstrate that the produced ultraviolet?UV?,shockwave and strong electric field assists the actively strong oxidizing substances including O₃,.OH,H₂O₂ and etc to degrade the AG into small molecule acids,CO₂ and H₂O during the treatment process under DBD plasma system.