College of Resource and Environmental Science, South-Central University for Nationalities, Wuhan 430074, Hubei Province, China.
College of Resource and Environmental Science, South-Central University for Nationalities, Wuhan 430074, Hubei Province, China.
Int J Biol Macromol. 2019 Sep 1;136:35-47. doi: 10.1016/j.ijbiomac.2019.05.125. Epub 2019 May 30.
A novel adsorbent, chitosan capsule with filler of CYPH@IL101 (CYPH@IL101/chitosan capsule), was prepared using a summary process for the adsorption of Cr(VI) from aqueous solution. The effects of CYPH@IL101 content, pH, contact time, rotational speed and Cr(VI) concentration on the adsorption were studied. The results showed that the adsorption capacity of the chitosan capsule was benefit from the increase of CYPH@IL101 content. Besides, solution pH also played an important role in the adsorption process and the maximum adsorption capacity was achieved at pH 3. Kinetic studies suggested that the adsorption rate was controlled by the diffusion step at low rotational speed (50 r/min), but was controlled by chemical reaction at high rotational speed (150 and 250 r/min). Furthermore, the adsorption isotherms were studied by using Langmuir, Freundlich, BET, and Temkin models. The results demonstrated that the adsorption process fit Langmuir and TemKin models better, which indicated that the adsorption of Cr(VI) onto CYPH@IL101/chitosan capsule mainly depended on chemisorption and the active sites were uniformly distributed on the adsorbent surface. While, the maximum adsorption capacity obtained from Langmuir model was 104.38 mg/g. Finally, XPS and FTIR analyses revealed that Cr(VI) was adsorbed and then reduced to Cr(III) by CYPH@IL101/chitosan capsule.
一种新型吸附剂，载有填料 CYPH@IL101 的壳聚糖胶囊（CYPH@IL101/壳聚糖胶囊），是通过使用一种从水溶液中吸附 Cr(VI) 的综合过程制备的。研究了 CYPH@IL101 含量、pH 值、接触时间、转速和 Cr(VI)浓度对吸附的影响。结果表明，壳聚糖胶囊的吸附容量受益于 CYPH@IL101 含量的增加。此外，溶液 pH 值也在吸附过程中起着重要作用，最大吸附容量在 pH 值为 3 时达到。动力学研究表明，在低转速（50 r/min）下，吸附速率受扩散步骤控制，而在高转速（150 和 250 r/min）下，吸附速率受化学反应控制。此外，通过 Langmuir、Freundlich、BET 和 Temkin 模型研究了吸附等温线。结果表明，吸附过程更符合 Langmuir 和 Temkin 模型，这表明 Cr(VI) 吸附到 CYPH@IL101/壳聚糖胶囊上主要取决于化学吸附，并且吸附剂表面上均匀分布有活性位点。而，从 Langmuir 模型获得的最大吸附容量为 104.38 mg/g。最后，XPS 和 FTIR 分析表明，Cr(VI)被 CYPH@IL101/壳聚糖胶囊吸附并随后被还原为 Cr(III)。
