Banat F A, Al-Bashir B, Al-Asheh S, Hayajneh O
Department of Chemical Engineering, Jordan University of Science and Technology, Irbid 22110, Jordan.
Environ Pollut. 2000 Mar;107(3):391-8. doi: 10.1016/s0269-7491(99)00173-6.
The potential of bentonite for phenol adsorption from aqueous solutions was studied. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, initial concentration, pH, presence of solvent, and the desorption characteristics of bentonite. The adsorption of phenol increases with increasing initial phenol concentration and decreases with increasing the solution pH value. The adsorption process was significantly influenced by the solvent type in which phenol was dissolved. The affinity of phenol to bentonite in the presence of cyclohexane was greater than that in water and was lowest in the presence of methanol. Methanol was used to extract phenol from bentonite. The degree of extraction was dependent on the amount of phenol adsorbed by bentonite. X-ray diffraction analysis showed that the crystalline structure of bentonite was destroyed when cyclohexane was used. The ability of bentonite to adsorb phenol from cyclohexane decreased as the water to cyclohexane ratio was increased. Furthermore, hysteresis was observed in phenol desorption from bentonite in aqueous solutions. The equilibrium data in aqueous solutions was well represented by the Langmuir and Freundlich isotherm models. The removal of phenol from aqueous solutions was observed without surface modification.
研究了膨润土从水溶液中吸附苯酚的潜力。进行了间歇动力学和等温线研究，以评估接触时间、初始浓度、pH值、溶剂的存在以及膨润土的解吸特性的影响。苯酚的吸附量随初始苯酚浓度的增加而增加，随溶液pH值的增加而降低。吸附过程受到溶解苯酚的溶剂类型的显著影响。在环己烷存在下，苯酚对膨润土的亲和力大于在水中的亲和力，在甲醇存在下最低。用甲醇从膨润土中萃取苯酚。萃取程度取决于膨润土吸附的苯酚量。X射线衍射分析表明，使用环己烷时膨润土的晶体结构被破坏。随着水与环己烷比例的增加，膨润土从环己烷中吸附苯酚的能力下降。此外，在水溶液中苯酚从膨润土的解吸过程中观察到滞后现象。水溶液中的平衡数据能用朗缪尔和弗伦德里希等温线模型很好地表示。在未进行表面改性的情况下观察到了从水溶液中去除苯酚的现象。
