Segment Preparation Activated Carbon Of Southern Xinjiang And Its Adsorption Capability Of Cu²⁺

This study uses the waste agricultural and forestry resources of cotton stalks in South Xinjiang as raw materials.The physical and chemical properties of activated carbon,elemental composition,surface microstructure,and activated carbon surface functional groups of cotton crown,cotton stalks,and roots were studied by longitudinally sectioned cotton stalks.The optimal preparation process of cotton stalk-based activated carbon in different parts was discussed.At the same time,the adsorption characteristics of the same metal adsorbent on the three-segment cotton stalk-based activated carbon modified by unmodified segmented pyrolysis and activated by NaOH as an activator were studied,and the adsorption mechanism was studied.Firstly,the anisotropy of transverse and The internal structure of cotton stalks in the longitudinal segment under pyrolysis conditions was discussed.longitudinal structures of cotton stalks is taken as the basic theoretical reference for this study.The research significance and optimal parameters of the cotton stalk segment preparation were clarified,and the preparation process of cotton stalk-based activated carbon was optimized.Next,the three-segment cotton-based activated carbon under pyrolysis and Na OH oxidation modification conditions was comparatively studied.The adsorption properties of metal Cu²⁺were analyzed.The elemental composition,surface morphology structure,and specific surface area?BET?of the longitudinal structures of cotton stalk activated carbon were measured by elemental analyzer,scanning electron microscopy,specific surface area analyzer,and Fourier transform infrared spectroscopy?FT-IR?.The physicochemical properties of the three-segment cotton-based stalk-based activated carbon and the effects of unmodified and NaOH modification processes on the physical and chemical properties of the three-segment stalk-based activated carbon were studied both macroscopically and microscopically from the perspectives of the pore volume,the type and content of surface functional groups on the activated carbon,and the internal crystal structure.The effect of the Cu²⁺adsorption effect.In this dissertation,the main physicochemical properties of the internal structures of cotton stalk activated carbon were studied by longitudinally sectioning cotton stalks,Find the best preparation site of cotton stalk.At the same time,through the modification of the metal Cu²⁺adsorption process,the adsorption mechanism and interaction between the cotton stalk-based activated carbon and the adsorbate were clarified.To provide a certain amount of data and theoretical support for longitudinally segmented research on cotton stalk-based activated carbon technology,At the same time,it provides basic theoretical guidance for improving the adsorption capacity of heavy metal Cu²⁺on cotton stalk-based activated carbon.The main conclusions of this paper are as follows:?1?The cotton canopy,cotton stalks,and roots that are segmented by the longitudinal structure of cotton stalks are used as raw materials.Preparation of cotton stalk-based activated carbon using NaOH as an activator,The effects of activation temperature,activation time and impregnation ratio on the basic physical parameters of cotton stalk-based cotton,cotton stems and root activated carbon were explored through a single-factor test,and the best longitudinal position and optimal carbon activation conditions for preparation of cotton stalk-based activated carbon were selected.The physical and chemical properties of the vertical segmented activated carbon prepared by comparing the pyrolysis with Na OH as the activator were compared and characterized from the surface physical and chemical properties.The results show:The three sections of cotton stalk-based activated carbon obtained under the two conditions have great differences in the specific surface area,the type and content of surface functional groups.The surface pore structure of the three-stage cotton stalk activated carbon prepared with strong oxidizing NaOH as an activator was subjected to certain structural deformation due to the strong oxidation reaction.However,the number of hydroxyl functional groups greatly increased;The char yield of three-segment cotton-based activated carbon is directly related to the temperature,When pyrolyzed at 375?,the higher carbon content of the cotton crown is 38.14%.Under this condition,the adsorption effect of the three-segment cotton-based activated carbon is not ideal.?2?Based on the analysis of the surface physicochemical properties of the three-segment cotton-based activated carbon,The adsorption performance of heavy metal Cu²⁺on modified stem cotton segment activated charcoal was investigated in detail,and some iodine adsorption and zinc ion adsorption experiments were performed to compare the activated carbon performance under this condition.The experimental results show that when the activator is NaOH,the adsorption performance of cotton stalk-based activated carbon is effectively improved when the pyrolysis temperature is 400?,the pyrolysis time is 150 min,and the impregnation ratio is 1.Under this condition,the maximum adsorption balance of Cu²⁺on heavy metals was 8.084 mg/g,which had a higher adsorption value for iodine and the adsorption value reached 370mg/g.At the same time,the maximum adsorption balance of activated carbon for heavy metal Zn²⁺was 7.65 mg/g,adsorption is not ideal.The activated carbon under this condition was calculated by the BET multipoint method to have a total specific surface area of 127.11 m²/g,a total pore volume of0.1581 mL/g,and an average pore diameter of 4.22 nm.By Fourier spectral analysis,the NaOH activator can effectively increase the number of hydroxyl functional groups.