速生桉树皮基活性炭的制备及吸附特性

Preparation and adsorption property of activated carbons from fast-growing eucalyptus bark

为研究不同剂料比、炭化温度、升温速率以及炭化停留时间对制备速生桉树皮基活性炭的影响,采用响应曲面法设计实验,借助比表面积和孔隙分析、傅里叶红外光谱(FTIR)、激光拉曼光谱、X射线衍射(XRD)、X射线光电子能谱(XPS)等分析方法对活性炭进行了物理化学性质的表征,并考察了最优条件下制备的活性炭对环丙沙星的吸附性能。结果显示,剂料比和升温速率对速生桉树皮基活性炭碘吸附值影响显著,通过二次多项模型得出最优工艺条件为:剂料比0.861,温度为713.791℃,升温速率为30℃/min,炭化停留时间为30 min,制备得到的最优活性炭样品(C-Y)的碘吸附值为1225 mg/g,比表面积为611.373 m^2/g,孔体积为0.5379 cm^3/g,平均孔径为3.52 nm。当环丙沙星初始浓度为200 mg/L,吸附平衡时间为24 h,C-Y对环丙沙星的吸附量达到122.5 mg/g,吸附等温线符合Langmuir模型,吸附过程遵循拟一级动力学模型。

In order to study the effects of different ratio of agents and materials,carbonization temperature,heating rate and carbonization residence time on the preparation of fast-growing eucalyptus bark based activated carbon,response surface methodology was used to design the experiment,and the physical and chemical properties of activated carbon were characterized by specific surface area and pore analyzer,Fourier transform infrared spectroscopy(FTIR),laser Raman spectroscopy,X-ray diffraction analysis(XRD)and X-ray photoelectron spectroscopy(XPS).The adsorption properties of activated carbon prepared by optimal conditions on ciprofloxacin hydrochloride were analyzed.The results showed that the adsorption capacity of iodine of fast-growing eucalyptus bark based activated carbon was significantly affected by dosage ratios and heating rate.The optimal process conditions were obtained by the quadratic polynomial model as following:the dosage ratios was 0.861,the temperature was 713.791℃,and the heating rate was 30℃/min,the carbonization residence time was 30 min.And the iodine adsorption capacity of the optimal sample(C-Y)was 1225 mg/g,the specific surface area was 611.373 m^2/g,the pore volume was 0.5379 cm^3/g,and the average pore diameter was 3.52 nm.When the initial concentration of ciprofloxacin hydrochloride was 200 mg/L,the adsorption capacity of C-Y reached 122.5 mg/g,the adsorption equilibrium time was 24 h,and the adsorption isotherm was accorded with Langmuir adsorption isotherm model and followed the pseudo first order kinetic model well.