Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade 118, P.O. Box 47, Serbia.
Faculty of Agriculture, Department of Chemistry, University of Belgrade, Nemanjina 6, 11080 Zemun, Serbia.
J Hazard Mater. 2010 Dec 15;184(1-3):477-484. doi: 10.1016/j.jhazmat.2010.08.059. Epub 2010 Aug 21.
This work reports results on phenol adsorption from aqueous solutions on synthetic BEA (β) and MFI (ZSM-5) zeolites, studied by heat-flow microcalorimetry. For the sake of comparison, the adsorption was performed on activated carbon, a solid customarily used for removal of phenol from water. The obtained values of heats evolved during phenol adsorption indicate the heterogeneity of active sites present on the investigated systems for the adsorption of phenol. In addition, the amounts of adsorbed pollutant were determined and presented in the form of adsorption isotherms, which were interpreted using Langmuir, Freundlich, Dubinin-Astakov and Sips' equations. The latter was found to express high level of agreement with experimental data. The results obtained in this work reveal that the adsorption of phenol on zeolites depends on both Si/Al ratio and on the pore size. Hydrophobic zeolites that possess higher contents of Si show higher affinities for phenol adsorption. Among investigated zeolites, zeolite β possesses the highest capacity for adsorption of phenol. The possibility of regeneration of used adsorbents was investigated by thermal desorption technique. It has been shown that in the case of β zeolite the majority of adsorbed phenol is easily released in the low temperature region.
本工作报道了在合成 BEA（β）和 MFI（ZSM-5）沸石上通过热流微量热法研究从水溶液中吸附苯酚的结果。为了进行比较，还在活性炭上进行了吸附实验，活性炭是一种常用于从水中去除苯酚的常用固体吸附剂。吸附苯酚过程中产生的热量值表明，在所研究的苯酚吸附体系中，存在着活性位的非均一性。此外，还测定了吸附污染物的量，并以吸附等温线的形式呈现，这些等温线使用 Langmuir、Freundlich、Dubinin-Astakov 和 Sips 方程进行了解释。结果表明，后一种方程与实验数据具有高度一致性。本工作的结果表明，苯酚在沸石上的吸附既取决于 Si/Al 比，也取决于孔径。具有较高 Si 含量的疏水性沸石对苯酚吸附具有更高的亲和力。在所研究的沸石中，β沸石对苯酚的吸附容量最高。通过热解吸技术研究了使用过的吸附剂的再生可能性。结果表明，对于β沸石，吸附的大部分苯酚在低温区很容易释放。
