Pilot Study On The Treatment Of Printing And Dyeing Wastewater By Dielectric Barrier Discharge Plasma

Dye wastewater is a kind of industrial organic wastewater that is difficult to degrade.It has the characteristics of complex composition,high COD value,large chroma,huge discharge,and poor biodegradability.Traditional methods are difficult to process them efficiently,and it is necessary to explore new technologies and processes to meet new requirements.Low-temperature plasma technology generates plasma containing a large number of high-energy electrons and active particles（·OH,·O,O₃,H₂O₂,etc.）by discharging at normal temperature and pressure,and with certain physical effects,it has a variety of advanced oxidation technologies The advantages.Among them,dielectric barrier discharge has attracted much attention in the field of low-temperature plasma technology research due to its advantages of simple operation,stable discharge,safety and efficiency.At present,dielectric barrier discharge wastewater treatment still has problems such as high energy consumption,unclear mechanism,poor treatment effect,low utilization of physical effects,and small amount of treated water,which make this technology unable to be promoted and applied in industry.In order to effectively improve the energy utilization efficiency of the dielectric barrier discharge,reduce the energy consumption of wastewater treatment,and explore the practical problems that may exist in industrial applications,this paper uses the methyl orange solution as the target pollutant to design a multi-electrode dielectric barrier discharge pilot reaction The reactor is mainly composed of three groups of electrodes,a microporous aeration head,and a 15L reaction box.At the same time,based on the designed plasma pilot reactor,several small reactors were made.Starting from changing the reactor structure,the effect of plasma technology on the treatment effect of dye wastewater was investigated;and by adding photocatalysis,the discharge generation was enhanced.The degradability of pollutants due to its physical effects provides meaningful reference value for realizing the wider application of dielectric barrier discharge technology in the field of wastewater treatment.The main research content and conclusions of this article are as follows:（1）Using methyl orange solution as a model wastewater,the degradation performance of dye wastewater by a multi-electrode dielectric barrier discharge low-temperature plasma pilot reactor was discussed.The chromaticity and COD degradation rate of methyl orange solution under different plasma power parameters,air flow rate and initial concentration of the target were mainly investigated.The results show that the degradation effect first increases and then decreases with the increase of the input power and voltage,and the degradation effect is best at 100V.With the increase of the reaction time,the effect of almost complete decolorization can finally be achieved.The reactor has a slightly lower degradation rate of the COD value of the methyl orange solution.For a 50mg/L methyl orange solution,the degradation rate of COD in 20 minutes is 29%,and the degradation rate of COD in 60 minutes of continuous degradation is 57%.The reactor shows higher energy efficiency when treating high-concentration dye wastewater.The initial mass concentration of dye is 50mg/L,and the energy efficiency of the reactor G50 is 28.13 g·k W^-1·h^-1at a power voltage of 100V;the initial concentration is At 200 mg/L,the maximum energy efficiency of G50 is 64.29g·k W^-1·h^-1.（2）A regression model for the degradation rate of methyl orange in the pilot reactor was established.Through response surface optimization,the optimal parameters were obtained as the discharge voltage 95.22v,the initial concentration was 50 mg/L,the discharge time was 20minutes,and the methyl orange was degraded.The maximum rate is 91.99%.（3）Using methyl orange solution as a model wastewater,through a self-made simple single-electrode dielectric barrier discharge device,the effects of adding fillers and changing electrodes on the degradation of methyl orange solution were investigated.Tests have found that the degradation effect decreases with the increase of the discharge gap.Adding suitable fillers can increase the residence time of the active gas in the water,thereby improving the degradation effect.In industrial applications,the extension length is likely to cause a waste of energy and the extension length of the general sewage treatment tank is easier than increasing the height.This can be achieved by adding discharge modules and placing them in the treatment tank in parallel.（4）In order to further improve the degradation rate and mineralization rate of wastewater,P25 titanium dioxide photocatalyst is used to strengthen the photolysis ability of the ultraviolet light generated by the discharge on the pollutants.The results show that the synergistic reaction can accelerate the degradation rate of the color of methyl orange solution and increase the degradation rate of COD.