以粉煤灰合成MCM-41及其对Cr(VI)的吸附特征研究

Preparation of Mesoporous Molecular Sieve MCM- 41 from Fly Ash and Its Adsorption Behavior for Chromium Ion in Waste Water

以淮南燃煤火电厂粉煤灰为初始原料,十六烷基三甲基溴化铵(CTAB)为模板剂,采用水热晶化法制备出介孔分子筛MCM-41样品。采用XRD、BET、N2吸附-脱附等手段对样品进行表征,将该介孔分子筛MCM-41应用于水中Cr(VI)离子的吸附,研究了吸附剂用量、吸附时间、吸附温度、pH值等对分子筛吸附性能的影响。结果表明:样品具有典型介孔分子筛MCM-41的特性,比表面积为596.7 m2/g,平均孔径为5.19 nm,孔壁厚为0.96 nm;在吸附温度为25℃、溶液pH值为6、离子浓度为10 mg/L、吸附时间为60 min的条件下,Cr(VI)离子最大去除率可达到87.86%,吸附性能符合Langmuir吸附等温线模型。

The mesoporous molecular sieve MCM-41 was synthesized by hydrothermal synthesis method with fly ash of Huainan as starting material, and n-hexadecyhrimethyl ammonium bromide （CTAB） as template agent. The samples were characterized by small-angle XRD, BET and nitrogen adsorption meas-urements. The effects of adsorption conditions such as the adsorbent time, adsorbent dose, adsorbent tem- perature ,and pH value ,on the adsorption efficiency for Cr（ Ⅵ ） by the MCM -41 absorbents were system-ically studied. The results showed that the products possess typical properties of mesoporous molecular sieve MCM -41, specific surface was 596.7 m^2/g, and the average pore size was 5.19 nm, hole wall thickness was 0. 96 nm, under the condition of adsorbent temperature 25 ℃, adsorbent time 60 min, pH value 6, ion concentration 10 mg/L, the best absorption rate was 87.86%. The adsorption model could fit the Langmuir model.