活化温度对桉树皮基活性炭的特性影响及吸附性能研究

Effect of Activation Temperature on the Properties and Adsorption Performance of Eucalyptus robusta Based Activated Carbon

以速生桉树(Eucalyptus robusta)皮为原料,焦磷酸钾为活化剂,采用响应曲面法研究了不同剂料比、活化温度、升温速率及活化时间对制备活性炭的影响。借助X射线衍射(XRD)、比表面积和孔隙分析仪、傅里叶红外光谱(FT-IR)、激光拉曼光谱(laser-Raman spectrum)等分析方法对不同炭化温度下制备的活性炭进行物理化学性质的表征,并考察其对碘和盐酸四环素的吸附性能。结果显示,通过二次多项模型得到的最佳制备条件为:剂料比0.9,活化温度710℃,升温速率30℃·min-1,活化时间30 min,制备的活性炭比表面积为611.373 m2·g-1,总孔容积为0.537 9 cm3·g-1,平均孔径为3.52 nm,对碘的吸附值为1 225 mg·g-1。该活性炭对盐酸四环素的吸附受孔径分布和表面化学性质的共同控制,吸附行为符合Langmuir等温吸附模型。

Activated carbons were prepared from fast-growing Eucalyptus robusta bark by potassium pyrophosphate activation. The effects of different dosage ratio(activating agent/raw material), activation temperature, heating rate and activation time were investigated by response surface method. The physicochemical properties of activated carbon in various carbonization temperature preparation were characterized by X-ray diffraction(XRD), surface area and pore size analyzer. Fourier transform infrared spectroscopy(FT-IR), laser-Raman spectrum(LRS) and the adsorption performance of fast-growing Eucalyptus robusta bark activated carbon on iodine and tetracycline hydrochloride were analyzed. It was found that the optimal process conditions were obtained by the quadratic polynomial model as the followings: The dosage ratios was 0.9. The temperature was 710 ℃. The heating rate was 30 ℃·min-1. The activation time was 30 min. The specific surface area of the obtained activated carbon was 611.373 m2·g-1. The pore volume was 0.537 9 cm3·g-1. The average pore diameter was 3.52 nm. The adsorption value of activated carbon for iodine was 1 225 mg·g-1. The adsorption of tetracycline hydrochloride by fast-growing Eucalyptus robusta bark activated carbon was controlled by pore size distribution and surface chemistry and the adsorption behavior was consistent with the Langmuir model.