(北京科技大学 冶金与生态工程学院，北京 100083)
摘 要: 采用一种活化赤泥吸附剂用于水溶液中亚甲基蓝的吸附净化。考察吸附剂用量、pH值、亚甲基蓝浓度、吸附温度和吸附时间对活化赤泥吸附性能的影响规律。结果表明：采用稀柠檬酸活化处理可显著提高赤泥对染料分子的吸附效率；吸附率随吸附剂用量增加而增加，随初始亚甲基蓝浓度和温度升高而降低；测得活化赤泥对亚甲基蓝的最大吸附容量为30 mg/g，吸附过程符合Langmuir等温吸附模型；吸附动力学过程可用准二级动力学方程描述，计算出吸附过程的表观活化能为9.88 kJ/mol。对吸附过程焓和熵值的计算结果表明，活化赤泥对水溶液中亚甲基蓝染料的吸附是一个自发的放热过程。
关键字: 赤泥；柠檬酸；活化；吸附；亚甲基蓝
aqueous solution using citric acid activated red mud
（School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing,
Beijing 100083, China）
Abstract:The activated red mud was prepared as the adsorbent for the removal of methylene blue (MB), from aqueous solution by the batch adsorption technique under different operational parameters including adsorbent dosage, pH, initial dye concentration, contact temperature and time. The results demonstrate that the adsorption percentage of the citric acid activated red mud is improved evidently, and increases with the increase of activated red mud dosage, white decreases with the increase of initial MB concentration and temperature. The red mud activated by using dilute citric acid is quite effective to improve its adsorption efficiency for the dye molecules from the aqueous solution. The uptake capacity for MB is evaluated as 30 mg/g and the equilibrium data fits well to the Langmuir model, and the adsorption kinetic follows the pseudo-second-order equation with its apparent activation energy equal to 9.88 kJ/mol. The thermodynamic parameters, such as the changes in enthalpy and entropy, were determined, revealing the adsorption to be an exothermic yet spontaneous process.
Key words: red mud; citric acid; activation; adsorption; methylene blue
