阴离子粘土对水中瓜儿胶的吸附研究

Adsorption of guar gum from aqueous solution by anionic clay

利用实验室制备的镁铝阴离子粘土材料,研究了其吸附水中瓜儿胶的动力学和热力学。结果表明,在瓜儿胶初始质量浓度为20～60mg/L及温度为298～323K时,阴离子粘土对水中瓜儿胶的吸附动力学符合准二级速率方程。阴离子粘土对瓜儿胶的吸附符合Langmuir和Freundlich等温吸附方程,吸附是吸热反应,吸附量随温度升高而略有增加,但吸附表观活化能只有18.13kJ/mol,说明温度对吸附的影响不显著。实验还表明,阴离子粘土对水中瓜儿胶的吸附性能优于活性炭。

The Mg-Al anionic clay adsorbent LDH was prepared in the Western Research Institute （Laramie, Wyoming, USA）, and the adsorption of guar gum （GU） from aqueous solution by LDH was investigated. The adsorption rate data were consistent with predictions of the pseudo-second order rate equation within the initial GU concentration of 20-60 mg/L and experimental temperature of 298-323 K. The adsorption capacity data were well correlated by both Langmuir and Freundlieh isotherm models, The GU adsorption on LDH was an endothermic process; however, the effect of temperature on the adsorption process was small given the low apparent activation energy of 18.13 kJ/mol calculated from the thermodynamic data. The adsorption breakthrough data show that LDH was more effective than activated carbon in removing GU from the feed solution （30 mg/L GU）