(北京科技大學(xué) 冶金與生態(tài)工程學(xué)院，北京 100083)
摘 要: 采用一種活化赤泥吸附劑用于水溶液中亞甲基藍的吸附凈化。考察吸附劑用量、pH值、亞甲基藍濃度、吸附溫度和吸附時間對活化赤泥吸附性能的影響規(guī)律。結(jié)果表明：采用稀檸檬酸活化處理可顯著提高赤泥對染料分子的吸附效率；吸附率隨吸附劑用量增加而增加，隨初始亞甲基藍濃度和溫度升高而降低；測得活化赤泥對亞甲基藍的最大吸附容量為30 mg/g，吸附過程符合Langmuir等溫吸附模型；吸附動力學(xué)過程可用準(zhǔn)二級動力學(xué)方程描述，計算出吸附過程的表觀活化能為9.88 kJ/mol。對吸附過程焓和熵值的計算結(jié)果表明，活化赤泥對水溶液中亞甲基藍染料的吸附是一個自發(fā)的放熱過程。
關(guān)鍵字: 赤泥；檸檬酸；活化；吸附；亞甲基藍
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
