Study On The Preparation And Adsorption Of Bamboo Root Activated Carbon

On the one hand,human society is facing increasingly serious environmental problems.On the other hand,the shortage of resources is also perplexing social development.Bamboo wood is widely used as a rich natural biomass resource in China.However,after the cutting of bamboo forest,the woodland has a large number of bamboo residues,and it is supplemented by carbonization,activation,modification and other processes,which will be prepared as porous adsorption materials,which will play an active role in improving the atmospHere and pollution control.In this study,3 kinds of activators?NaOH,HNO₃,ZnCl₂?were used as raw materials,and the effects of different preparation temperature,time and activator agent ratio on the carbon yield of bamboo activated carbon were investigated by orthogonal experiment.Using the following main modern analytical instruments,the specific surface area of activated carbon was measured,the number and category of main functional groups were analyzed by Fourier transform infrared spectroscopy,the micromorpHology was analyzed by scanning electron microscopy?SEM?,and the characteristic peaks were characterized by X ray diffraction and X ray pHotoelectron spectroscopy.The effects of the pH value and the amount of activated carbon added on the adsorption experiment of bamboo activated carbon in 4 kinds of adsorbate solution were analyzed and discussed.The adsorption model of different adsorbate was established by adsorption experiment,and the microcosmic characterization of bamboo activated carbon was integrated with the adsorption model.The adsorption mechanism of bamboo activated carbon and 4 kinds of adsorbents is the resource utilization of bamboo and how to effectively enhance the adsorption properties of metal ions and organic pollutants in the waste liquid.At the same time,based on the modified bamboo based activated carbon supported on amino group,the properties of modified bamboo based activated carbon for CO₂ adsorption were studied.The main conclusions of this paper are as follows:?1?Compared with other parts of bamboo and commonly used biomass raw materials,the value of iodine value of bamboo charcoal activated carbon is the optimum target value.It is determined that the activated carbon is activated by sodium hydroxide,with a higher adsorption value when the activation temperature is set to 700?,the activation time is 120min and the agent is 1.5.The activation temperature is set at700?,the activation time is 90min,the dosage of the agent is 2,and the zinc chloride is used as activator.When the activation temperature is set at 700?,the activation time is 90min,and the ratio of material to material is 1.5,it has higher adsorption value.The influence of the three activation conditions on adsorption is:activation temperature>ratio of material to material>activation time.?2?The performance of the activated charcoal prepared with NaOH as activator was higher than that of activated carbon prepared by other activation methods.After NaOH activation,the number and type of oxygen functional groups on the surface of bamboo activated carbon were changed,especially the increase of the content of-OH was the most significant.When the pH value of the activated carbon is 4 in the adsorbed waste liquid,the adsorption performance of the metal ions is the best when the adsorption temperature is 25.The adsorption value for Cu²⁺is 8.408mg/g,and the adsorption value of Zn²⁺is 10.14mg/g.Through the adsorption kinetics experiment and the adsorption equilibrium experiment,the adsorption model of metal ions Cu²⁺and Zn²⁺is consistent with the Lagergren quasi two class adsorption kinetic model.It is proved that the adsorption process of metal ions in the solution is a kind of comprehensive multi action process.Learning adsorption process.?3?The bamboo activated charcoal prepared with HNO₃ as an activator is the best adsorbent for adsorbate organic matter?pHenol,Methylene blue?,and the activated carbon prepared by the pyrolysis of HNO₃ at the temperature of 400?at the temperature of 400?at the temperature of 1.5 is high specific surface area and developed pore structure.Among them,the adsorption value of pHenol in waste liquid is 227.36mg/g and methylene blue adsorption value is 202mg/g.Through the adsorption kinetics experiment and the theoretical analysis of adsorption equilibrium experiment,the model of pHenol and methylene blue in the adsorbed waste liquid of bamboo based activated carbon is in accordance with the model of the quasi first order kinetic adsorption of Langmuir model.The adsorption experiments show that the degree of the pore structure and the size of the specific surface area are determined by the adsorption experiments.Adsorption of organic molecules in waste liquid by bamboo based activated carbon proved that the adsorption of organic molecules in bamboo based activated carbon was mainly pHysical adsorption.?4?Under 25?and 1atm,the adsorption capacity of carbon dioxide,which was prepared by two activators?NaOH,HNO₃?,was 0.1929mmol/g and 0.1575 mmol/g,respectively.The adsorption properties of amino modified bamboo activated carbon prepared under the modified process were greatly improved,and the amino modified bamboo activated carbon was used as the activated carbon.After 5 cycles of adsorption desorption cycles,CO₂ adsorption capacity did not decrease significantly.The adsorption isotherm curve of activated carbon with aminated bamboo sticks is still type IV,mainly in mesopores,but the specific surface area and pore volume decrease,and the average pore size increases.