| Dye wastewater has the characteristics of high organic content,poor biodegradability and high chromaticity.Due to the application of new processes and technologies in the dye industry,the difficulty of dye wastewater degradation is increased again.The treatment results of traditional water treatment technology have been difficult to meet the national water treatment standards.Advanced oxidation technology has become the focus of scholars because of its strong oxidation,good treatment effect and no secondary pollution.In advanced oxidation technology,dielectric barrier discharge combines ozone oxidation,ultraviolet degradation and high-energy electron bombardment,but the effect of ultraviolet light is often ignored;Ti O2 photocatalyst has great application prospects because of its stability,non toxicity and low price.However,Ti O2 has low efficiency,small particles and easy agglomeration,which will cause the problem of difficult recovery and separation in the experimental process.Based on this,this paper simulates wastewater with Rhodamine B（RhB）solution,combines dielectric barrier discharge technology with supported Ti O2 photocatalytic technology to remove RhB wastewater,and fully solves the problems of low UV utilization and Ti O2 efficiency.Ti O2/diatomite composites were prepared by sol-gel method.The composites were characterized by scanning electron microscopy（SEM）,Fu Liye transform infrared spectroscopy（FTIR）and X ray diffraction（XRD）.The effects of different experimental factors on the degradation of RhB wastewater in a single dielectric barrier discharge system were investigated,the kinetics of each factor was analyzed,and the response surface method was used to determine the best reaction conditions;Combining dielectric barrier discharge with composite photocatalyst to build a synergistic system,explore the influence of composite addition under the best reaction conditions,and preliminarily explore the degradation mechanism.The experimental results are as follows:（1）The degradation rate of RhB wastewater was used as an index to investigate the effects of experimental conditions such as input frequency,initial concentration of solution,solution conductivity,Fe2+and initial pH value of solution on the degradation rate of RhB solution.The experimental results show that in a certain range,the input power of the system increases,and the degradation rate of RHB also increases gradually;However,the increase of initial pH value,conductivity and initial concentration of solution reduced the degradation rate of RhB;Fe2+can promote the degradation of RhB in a certain range.（2）The treatment of RhB wastewater by dielectric barrier discharge system is a complex and changeable reaction system.Therefore,the degradation of RHB solution by dielectric barrier discharge is analyzed from a macro point of view.The kinetic analysis shows that the degradation process of RhB wastewater by dielectric barrier discharge conforms to the quasi first-order reaction kinetics.Through the performance rate constants in the reaction process under various factors,it is concluded that the three factors that have the greatest impact on the degradation performance of RhB are input power,initial concentration and conductivity.（3）The experimental conditions were optimized by design expert software.The optimal reaction conditions were as follows:input power:100W;The initial conductivity is 8.2us/cm;The initial concentration is 50mg/L.Under the optimum reaction conditions,the degradation rate of RHB reached 89.27%.（4）Diatomite was pretreated at 200℃,500℃and 900℃.Through the adsorption experiment of diatomite,it was concluded that the adsorption effect of diatomite was the best under the pretreatment of 500℃.Ti O2 and Ti O2/diatomite composites were prepared by sol-gel method.The appearance,composition and structure of diatomite and Ti O2/diatomite composites were analyzed by means of a series of characterization methods such as SEM,FTIR and XRD.（5）Composite materials were added into the dielectric barrier discharge system to construct the synergistic photocatalytic system of dielectric barrier discharge technology.By adding different amounts of composite materials to the system,the experimental results show that when the dosage is 1.5g/L,the system has the best degradation effect of RhB,and the decolorization rate of RhB reaches 95.22%.After the optimal dosage is obtained,the degradation effect of the synergistic system under different pH conditions is studied.The experiment shows that the synergistic system can achieve the best effect at pH=2,and the treatment effect is the worst at pH=10.（6）By observing the changes of COD and pH in the process of degradation of RHB wastewater by dielectric barrier discharge combined with Ti O2/diatomite composite,it is concluded that the pH finally decreases to 3.4,while the degradation rate of COD is70.62%.It is proved that the system can effectively degrade RHB wastewater. |
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