水热法制备γ-AlOOH对酸性大红GR的吸附性能

Adsorption performance of acid scarlet GR by γ-Al OOH prepared with hydrothermal method

以十八水合硫酸铝为铝源,尿素为沉淀剂,采用水热合成法制备γ-AlOOH吸附剂,通过X射线衍射仪(XRD)、扫描电镜(SEM)和N_(2)吸附−脱附法对γ-AlOOH的显微结构与形貌,以及对酸性大红GR的吸附性能进行分析与测试,研究吸附时间、酸性大红GR溶液的初始pH和初始质量浓度对γ-AlOOH吸附酸性大红GR的影响。结果表明,γ-AlOOH吸附剂为核−壳微米花分级结构,纯度较高,比表面积为205.07 m^(2)/g,平均孔径为3.07 nm。在酸性大红GR溶液的初始质量浓度为300 mg/L、体积为200 mL、pH值为2、温度为25℃条件下,1 gγ-AlOOH吸附剂对酸性大红GR的吸附量达470.65 mg,酸性大红GR脱除率为78.44%,吸附过程的吸附动力学符合准二级动力学模型,吸附热力学符合Langmuir热力学模型;经过8次循环吸附后,1 g再生吸附剂对质量浓度为300 mg/L的溶液中酸性大红GR的吸附量仍达到422.57 g,脱除率为70.43%。

Using aluminum sulfate octadecahydrate as the aluminum source and urea as the precipitant, the γ-AlOOH adsorbent was prepared by hydrothermal synthesis. The microstructure, morphology and adsorption performance ofγ-Al OOH were analyzed and tested by X-ray diffractometer (XRD), scanning electron microscope (SEM) and Nadsorption-desorption method. The effects of adsorption time, initial pH and initial mass concentration of acidic scarlet GR solution on the adsorption performance of acid scarlet GR by γ-Al OOH were studied as well. The results show that the γ-Al OOH adsorbent has a core-shell micron-flower hierarchical structure with high purity, a specific surface area of205.07 m~2/g, and an average pore size of 3.07 nm. When the initial mass concentration of the acid scarlet GR solution is300 mg/L, the volume is 200 mL, the pH value is 2, and the temperature is 25 ℃, the adsorption amount of acid scarlet GR by 1 g γ-AlOOH reaches 470.65 mg, the removal rate is 78.44%. The adsorption kinetics of the adsorption process conforms to the pseudo-second-order kinetic model, and the adsorption thermodynamics conforms to the Langmuir thermodynamic model. After 8 cycles of adsorption, the adsorption amount of acid scarlet GR by 1 g γ-Al OOH regenerated adsorbent in 300 mg/L acid scarlet GR solution can still reach 422.57 mg, and the removal rate is 70.43%.