Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya, 60114, Indonesia.
Graduate Institute of Applied Science, National Taiwan University of Science and Technology, 43 Keelung Road, Sec 4, Taipei, 10607, Taiwan.
Environ Sci Pollut Res Int. 2019 Feb;26(5):5020-5037. doi: 10.1007/s11356-018-4035-2. Epub 2019 Jan 2.
Robust and simple composite films for the removal of methyl orange (MO) and Cr(VI) have been prepared by combining chitosan, saponin, and bentonite at a specific ratio. There are several composite films (chitosan-saponin-bentonite (CSB)) prepared; among them, the composite films CSB and CSB have the highest removal efficiency toward MO and Cr(VI) where the maximum removal is 70.4% (pH 4.80) and 92.3% (pH 5.30), respectively. It was found that different types of adsorbate have different thermodynamic properties of the adsorption process; the adsorption of MO onto CSB, chitosan, and acid-activated bentonite (AAB) proceeded endothermically, while the adsorption of Cr(VI) onto CSB, chitosan, and AAB proceeded exothermically. The parameters of the adsorption were modeled by using isotherm and kinetic equations. The models of Langmuir, Freundlich, Redlich-Peterson, Sips, and Toth were used for fitting the adsorption isotherm data at a temperature of 30, 45, and 60 °C; all of the isotherm models could represent the data well. The result indicates that CSB has the highest adsorption capacity toward MO with q of 360.90 mg g at 60 °C; meanwhile, CSB has the highest adsorption capacity toward Cr(VI) with q 641.99 mg g at 30 °C. The pseudo-second-order model could represent the adsorption kinetics data better than the pseudo-first-order equation. The adsorption mechanism was proposed, and the thermodynamic properties of the adsorption were also studied.
已经通过特定比例的壳聚糖、皂苷和膨润土组合制备了用于去除甲基橙（MO）和 Cr(VI) 的坚固且简单的复合膜。已经制备了几种复合膜（壳聚糖-皂苷-膨润土（CSB））；其中，CSB 和 CSB 复合膜对 MO 和 Cr(VI) 的去除效率最高，最大去除率分别为 70.4%（pH4.80）和 92.3%（pH5.30）。结果表明，不同类型的吸附质具有不同的吸附过程热力学性质；MO 吸附到 CSB、壳聚糖和酸化膨润土（AAB）上是吸热的，而 Cr(VI) 吸附到 CSB、壳聚糖和 AAB 上是放热的。通过使用等温线和动力学方程对吸附参数进行了建模。在 30、45 和 60°C 的温度下，使用 Langmuir、Freundlich、Redlich-Peterson、Sips 和 Toth 模型来拟合吸附等温线数据；所有的等温线模型都可以很好地代表数据。结果表明，CSB 对 MO 的吸附容量最高，在 60°C 时 q 为 360.90mg/g；同时，CSB 对 Cr(VI) 的吸附容量最高，在 30°C 时 q 为 641.99mg/g。准二级模型比准一级方程更能代表吸附动力学数据。提出了吸附机理，并研究了吸附的热力学性质。
