School of Resources and Environment, University of Jinan, Jinan, China.
J Colloid Interface Sci. 2011 Jul 15;359(2):499-504. doi: 10.1016/j.jcis.2011.04.044. Epub 2011 Apr 18.
Benzoic acid removal is important for the water treatment, and adsorption is an efficient treatment process. Three kinds of modified bentonites, hydroxy-aluminum pillared bentonite (Al(OH)-Bent), octadecyl trimethyl ammonium chloride modified bentonite (OTMAC-Bent), and both octadecyl trimethyl ammonium chloride and hydroxy-aluminum modified bentonite (Al(OH)-OTMAC-Bent) were prepared and characterized by XRD, FTIR, and BET analysis. Experiments were conducted on the adsorption of benzoic acid by the prepared modified bentonites at different temperatures in batch experiments. The results show benzoic acid adsorption capabilities of Na-Bent and Al(OH)-Bent are even low, but high for OTMAC-Bent and Al(OH)-OTMAC-Bent. Optimal conditions for the adsorption of benzoic acid on OTMAC-Bent and Al(OH)-OTMAC-Bent were as follows: pH of 3.5, 0.04 g/mL adsorbent, and contact time of 90 min. Increased adsorption with temperature indicates that the adsorptions of benzoic acid onto Al(OH)-OTMAC-Bent and OTMAC-Bent are spontaneous and endothermic. The adsorption data could be well interpreted by the Langmuir model and Temkin Equation. The adsorption efficiency was higher than 85%, suggesting that OTMAC-Bent and Al(OH)-OTMAC-Bent are excellent adsorbents for effective benzoic acid removal from water.
苯甲酸的去除对水处理很重要，而吸附是一种有效的处理工艺。本研究制备了三种改性膨润土，分别为羟基铝柱撑膨润土（Al(OH)-Bent）、十八烷基三甲基氯化铵改性膨润土（OTMAC-Bent）和同时进行了十八烷基三甲基氯化铵和羟基铝柱撑改性的膨润土（Al(OH)-OTMAC-Bent），并通过 XRD、FTIR 和 BET 分析对其进行了表征。在批实验中，考察了不同温度下制备的改性膨润土对苯甲酸的吸附性能。结果表明，Na-Bent 和 Al(OH)-Bent 的苯甲酸吸附能力较低，但 OTMAC-Bent 和 Al(OH)-OTMAC-Bent 的吸附能力较高。OTMAC-Bent 和 Al(OH)-OTMAC-Bent 吸附苯甲酸的最佳条件为：pH 值为 3.5，吸附剂用量为 0.04 g/mL，接触时间为 90 min。吸附随温度升高而增加，表明苯甲酸在 Al(OH)-OTMAC-Bent 和 OTMAC-Bent 上的吸附是自发和吸热的。吸附数据可以很好地用 Langmuir 模型和 Temkin 方程来解释。吸附效率高于 85%，表明 OTMAC-Bent 和 Al(OH)-OTMAC-Bent 是从水中有效去除苯甲酸的优良吸附剂。
