Study On The Preparation Of Two Activated Carbon Modified Materials And The Treatment Of Printing And Dyeing Wastewater

In this paper,grapefruit peel and waste beer yeast were used as the carrier to prepare activated carbon,which was loaded with titanium dioxide and doped with copper ion modified titanium dioxide.The modified materials prepared were used to treat printing and dyeing wastewater,and good results were obtained.At the same time,X-ray diffraction(XRD),Fourier infrared transform(FTIR),energy spectrum analysis(EDS)and scanning electron microscopy(SEM)were used to characterize the modified materials,and the effects of calcination temperature,titanium load,copper doping amount and other factors were analyzed.Methylene blue(MB)was used to simulate printing and dyeing wastewater,and the dosage of modified materials,initial concentration of solution,reaction time and illumination conditions were optimized in the process of adsorption and degradation.The results show that:(1)The activated carbon prepared from grapefruit peel and waste brewer's yeast has a good adsorption effect on methylene blue.The former has a layered structure with large specific surface area,while the latter has a honeycomb skeleton structure with abundant pores.(2)SEM characterization showed that crystal material,namely titanium dioxide,was uniformly attached to the surface of the TiO₂treated material prepared by hydrothermal method with two kinds of activated carbon as the carrier.When the load of titanium dioxide was too high,the agglomeration phenomenon would occur on the surface of activated carbon and some pore channels of activated carbon would be blocked.EDS results show that the actual doping ratio of the two activated carbon supported copper ion doped TiO₂is slightly lower than the target doping ratio due to the loss of copper ion in the preparation process.FTIR spectra showed that the titanium dioxide load can increase the processing of material surface types and volume of oxygen containing functional groups,copper ions doped redshift in the Ti-O keys,doped with copper ions into the lattice of titanium dioxide,change the level titanium dioxide,TiO₂light absorption range widen to visible light region,slows down the hole-electron pair of composite.The XRD spectra show that most of the titanium dioxide loaded are anatase type,and the doping of copper ion can reduce the crystal size of titanium dioxide and improve its crystallinity.(3)Calcination temperature has a significant effect on the activity of the modified materials.Calcination not only enlarges the pore channels of activated carbon,but also inhibs the transformation of anatase phase TiO₂to rutile phase.Copper ion doping can reduce the transition temperature,thus improving the photocatalytic activity of the modified materials.However,the calcination temperature should not exceed 600?,otherwise it will cause the ash of the carrier activated carbon.(4)Both the titanium dioxide load and the copper ion doping amount should be appropriate.Too little TiO₂will lead to less photocatalytic active sites on activated carbon and low photocatalytic efficiency.Excessive loading will cause the agglomeration of TiO₂and block the active pore channels,thus reducing the adsorption capacity of activated carbon.When the doping amount of copper ion is too low,the photocatalytic activity cannot be maximally improved due to the lack of traps in the semiconductor.When the photocatalytic reaction is too high,copper ions will occupy the active site of TiO₂and the photocatalytic reaction efficiency will decrease.(5)The optimal initial concentration of methylene blue was 10 mg/L,and the removal rate of methylene blue reached more than 95%under the optimal dosage of the four modified materials.Innovation point of this paper is based on biomass materials pomelo peel and waste beer yeast as raw material to the preparation of activated carbon,and use it as the carrier,the preparation of titanium dioxide and load of copper ion doping modification of titanium dioxide with four kinds of modified material,is realized with difficult treatment of organic pollutants in printing and dyeing wastewater treatment,and achieved the purpose of waste resource utilization,reflect the environmental and social benefits.