【作者】 陈卫群；

【导师】 黄彪； 陈燕丹；

【作者基本信息】 福建农林大学 ， 林产化学加工工程， 2012， 硕士

【摘要】 本课题研究以红麻杆芯为原料，首次采用高锰酸钾、草酸钾两种化学活化剂制备活性炭，考察了单因素条件（活化温度、活化时间、浸渍比、活化剂浓度、浸渍时间）对制备的活性炭产品性能的影响。根据响应面分析法原理，使用Design-Expert统计软件的Box-behnken中心组合建立试验模型，对制备活性炭的三个重要影响因素进行了试验优化设计。实验结果表明，高锰酸钾、草酸钾两种化学活化剂用量少，浓度低，能制备出吸附性能优良的红麻芯活性炭，均可作为活性炭制备的优良化学活化剂。根据Design-Expert统计软件拟合试验数据，得出拟合度良好的符合碘及亚甲基蓝吸附实测值的回归方程模型。运用响应面分析法对影响活性炭性能的主要活化工艺参数进行显著性分析和交互作用分析，可以为活性炭最佳制备工艺条件的确立提供方便有效的理论指导。采用比表面及孔隙分析仪、场发射扫描电镜（FE-SEM）、傅里叶变换红外光谱（FT-IR）、零电荷点（pH_pzc）、能量散射X射线光谱仪(EDX)等方法对高锰酸钾法活性炭和草酸钾法活性炭进行表征。结果表明：高锰酸钾法活性炭的N2吸附-脱附等温线类型为典型的Ⅰ型吸附等温线；活性炭的孔隙结构以微孔分布为主，且含有较一定的中孔；活性炭表面织构较为致密且孔结构发达；活性炭表面含有丰富的含氧官能团，活性炭的零电荷点（pH_pzc）为3.25，显示出较强的酸性；高锰酸钾法活性炭能负载一定量MnOx。草酸钾法活性炭N2吸附-脱附等温线类型为典型的Ⅰ型吸附等温线，孔结构特征以微孔分布为主，且含有较丰富的中孔；活性炭表面光滑平整无沉淀物，呈现较规则的圆形，具有发达的孔隙结构；活性炭的零电荷点（pH_pzc）为2.94，表现出较强的酸性，说明含有丰富的酸性官能团。对两种活性炭产品的应用性能进行了初步研究。将高锰酸钾法活性炭应用于制备活性炭电极材料，结果显示适量负载氧化锰的活性炭电极具有良好的循环伏安性能和交流阻抗性能。草酸钾法活性炭应用于除Cr(Ⅵ)的研究结果表明，吸附质溶液的pH值、吸附时间、活性炭用量及Cr(Ⅵ)的初始浓度对Cr(Ⅵ)的去除率及吸附量具有显著的影响。室温条件下，当吸附实验的条件为pH=3，活性炭用量0.1g，吸附质初始浓度100mg/L，吸附时间1h，Cr(Ⅵ)的去除率为94.13%，单位吸附量为18.83mg/g。综上，本论文较系统地开展了高锰酸钾和草酸钾活化法制备红麻杆芯活性炭的工艺优化、表面织构及其性能的研究，为红麻杆芯资源的高值化利用、新型活化剂的探索以及功能活性炭的简易制备提供借鉴。更多还原

【Abstract】 In this thesis, activated carbons were prepared from kenaf core for the first time,using potassium permanganate and potassium oxalate as chemical activators. Thepreparation of activated carbons from kenaf core was optimized through single factorexperiments (activation temperature, activation time, mass ratio, activatorconcentration, impregnation time). According to the principle of response surfacemethodology, experimental model was established to optimize the preparation processon the basis of the most three significant single factors by the Box-behnken centercombination method derived from Design-Expert statistical software. The resultsshow that activated carbons from kenaf core with excellent adsorption capacity can bereadily prepared, using potassium permanganate or potassium oxalate as a benignchemical activator, respectively. Regression equations of the iodine and methyleneblue adsorption value of the as-prepared activated carbons were deduced fromDesign-Expert statistical software. Results of validate experiment prove that there aregood fitness between the predicted and actual value. The optimal processing conditioncan be theoreticly proposed according to the results of significant test and interactionanalysis of the key single factors by response surface methodology.Textural characteristics of the activated carbons activated by potassiumpermanganate (PPAC) or potassium oxalate (POAC) were characterized by specificsurface area auto-analyzer, field emission scanning electron microscope (FE-SEM),fourier transform infrared spectroscopy (FT-IR), the point of zero charge (pH_pzc),energy dispersive X-ray spectrometer (EDX). The N2adsorption-desorption isothermsof PPAC show a typical type I adsorption isotherm, which is featured of microporositycharacter of its pore architecture. The morphology of the produced PPAC observed byFE-SEM indicates a relatively dense texture and a well-developed pore structure. Adominant micropores along with some mesopores can be seen in PPAC as well. Thepoint of zero charge (pH_pzc) of PPAC was determined as3.25, indicating an obviouslyacidic surface property. Meanwhile, a certain amount of MnO_x loaded onto theas-prepared PPAC was proved by EDX. Moreover, electrochemical performance of PPAC loading with MnO_x using as working electrode is improved in terms of cyclicvoltammetry and impedance characteristics by comparison with the neat PPAC.The N2adsorption-desorption isotherms of POAC are type I according to IUPACclassification. A majority of micropores in combination with significant mesopores inPOAC can be concluded according to the characteristics of the adsorption-desorptionisotherms. The surface mophorlogy of the selected POAC shows smooth texture witha well-developed homogeneous pore structure. The point of zero charge (pH_pzc) ofPOAC was2.94, implying strong acidity probably due to rich acidic functional groupsproduced on its surface when activated by potassium oxalate. Finally, the adsorptionbehavior of the optimal POAC was detected. The results show that the pH ofadsorbate solution, adsorption time, dosage of activated carbon and initialconcentration of Cr(VI) had a significant impact on the removal efficiency of Cr(VI)and adsorption capacity. The removal efficiency and adsorption capacity of Cr(VI)from aqueous solution were measured as94.13%and18.83mg/g, respectively, whenthe adsorption experiment was carried out at room temperature for1h with theadsorbate solution pH of3, the activated carbon dosage of0.1g and the initialconcentration of adsorbate solution of100mg/L.In summary, the preparation technology, surface texture and performance ofactivated carbon from kenaf core by potassium permanganate and potassium oxalatewere systemically studied in this work, which can provide a theoretical guide for thethe use of kenaf core resource with higher value as well as a favorable reference forsimply preparation of functional activated carbon using potassium permanganate andpotassium oxalate as potentially desirable activators.更多还原