Singh Swatantra Pratap, Rathinam Karthik, Kasher Roni, Arnusch Christopher J
Department of Desalination and Water Treatment, Zuckerberg Institute for Water Research, The Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990 Israel
RSC Adv. 2018 Jul 30;8(48):27027-27036. doi: 10.1039/c8ra03907k.
Sericin, a protein waste product of the silk industry, was crosslinked with chitosan, and a chitosan-sericin conjugate (CS) was prepared, characterized and used to remove hexavalent chromium (Cr(vi)) ions and methyl orange (MO) dye from aqueous solutions. The CS was shown to effectively remove Cr(vi) ions and MO dye at maximum adsorption capacities (Langmuir) of 139 mg g for Cr(vi) ions and 385 mg g for MO dye. Moreover, the adsorption of both Cr(vi) ions and MO dye was highly pH dependent and varied under different experimental conditions. Cr(vi) ion and MO dye uptake by the CS was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometry analysis. Additionally, XPS analysis of the Cr(vi)-loaded CS revealed that Cr(vi) was reduced to the less toxic Cr(iii). The CS was shown not only to be highly amenable to regeneration, but also to be able to effectively remove MO dye and Cr(vi) ions from a binary mixture.
丝胶蛋白是丝绸工业的一种蛋白质废弃物，它与壳聚糖发生交联反应，制备、表征了壳聚糖 - 丝胶蛋白共轭物（CS），并用于从水溶液中去除六价铬（Cr(Ⅵ)）离子和甲基橙（MO）染料。结果表明，CS对Cr(Ⅵ)离子和MO染料具有高效去除能力，其最大吸附容量（朗缪尔吸附等温线）分别为：Cr(Ⅵ)离子139 mg/g，MO染料385 mg/g。此外，Cr(Ⅵ)离子和MO染料的吸附都高度依赖于pH值，且在不同实验条件下有所变化。通过衰减全反射傅里叶变换红外光谱、X射线光电子能谱（XPS）和能谱分析证实了CS对Cr(Ⅵ)离子和MO染料的吸附。此外，对负载Cr(Ⅵ)的CS进行XPS分析表明，Cr(Ⅵ)被还原为毒性较小的Cr(Ⅲ)。结果表明，CS不仅易于再生，而且能够有效去除二元混合物中的MO染料和Cr(Ⅵ)离子。
