Ullah Rahman, Ahmad Waqas, Yaseen Muhammad, Khan Mansoor, Iqbal Khattak Mehmood, Mohamed Jan Badrul, Ikram Rabia, Kenanakis George
Institute of Chemical Sciences, University of Peshawar, Peshawar 25120, Khyber Pakhtunkhwa, Pakistan.
Department of Chemistry, Kohat University of Science and Technology, Kohat 26000, Khyber Pakhtunkhwa, Pakistan.
Materials (Basel). 2021 Nov 16;14(22):6923. doi: 10.3390/ma14226923.
Herein, we report the synthesis of magnetic nanoparticle (MNP)-reduced graphene oxide (rGO) and polymethylmethacrylate (PMMA) composite (MNPs/rGO/PMMA) as adsorbent via an in situ fabrication strategy and, in turn, the application for adsorptive removal and recovery of Cr(VI) from tannery wastewater. The composite material was characterized via XRD, FTIR and SEM analyses. Under batch mode experiments, the composite achieved maximum adsorption of the Cr(VI) ion (99.53 ± 1.4%, i.e., 1636.49 mg of Cr(VI)/150 mg of adsorbent) at pH 2, adsorbent dose of 150 mg/10 mL of solution and 30 min of contact time. The adsorption process was endothermic, feasible and spontaneous and followed a pseudo-2nd order kinetic model. The Cr ions were completely desorbed (99.32 ± 2%) from the composite using 30 mL of NaOH solution (2M); hence, the composite exhibited high efficiency for five consecutive cycles without prominent loss in activity. The adsorbent was washed with distilled water and diluted HCl (0.1M), then dried under vacuum at 60 °C for reuse. The XRD analysis confirmed the synthesis and incorporation of magnetic iron oxide at 2θ of 30.38°, 35.5°, 43.22° and 57.36°, respectively, and graphene oxide (GO) at 25.5°. The FTIR analysids revealed that the composite retained the configurations of the individual components, whereas the SEM analysis indicated that the magnetic FeO-NPs (MNPs) dispersed on the surface of the PMMA/rGO sheets. To anticipate the behavior of breakthrough, the Thomas and Yoon-Nelson models were applied to fixed-bed column data, which indicated good agreement with the experimental data. This study evaluates useful reference information for designing a cost-effective and easy-to-use adsorbent for the efficient removal of Cr(VI) from wastewater. Therefore, it can be envisioned as an alternative approach for a variety of unexplored industrial-level operations.
在此，我们报道了通过原位制备策略合成磁性纳米颗粒（MNP）-还原氧化石墨烯（rGO）和聚甲基丙烯酸甲酯（PMMA）复合材料（MNPs/rGO/PMMA）作为吸附剂，并将其应用于制革废水吸附去除和回收Cr(VI)。通过XRD、FTIR和SEM分析对复合材料进行了表征。在间歇模式实验中，该复合材料在pH为2、吸附剂剂量为150 mg/10 mL溶液和接触时间为30分钟的条件下，实现了对Cr(VI)离子的最大吸附（99.53±1.4%，即1636.49 mg Cr(VI)/150 mg吸附剂）。吸附过程是吸热、可行且自发的，遵循准二级动力学模型。使用30 mL NaOH溶液（2M）可使Cr离子从复合材料中完全解吸（99.32±2%）；因此，该复合材料在连续五个循环中表现出高效率，活性没有明显损失。吸附剂用蒸馏水和稀释的HCl（0.1M）洗涤，然后在60℃真空干燥以重复使用。XRD分析分别在2θ为30.38°、35.5°、43.22°和57.36°处证实了磁性氧化铁的合成与掺入，在25.5°处证实了氧化石墨烯（GO）的存在。FTIR分析表明该复合材料保留了各组分的结构，而SEM分析表明磁性FeO-NPs（MNPs）分散在PMMA/rGO片材表面。为预测穿透行为，将Thomas和Yoon-Nelson模型应用于固定床柱数据，并表明与实验数据吻合良好。本研究为设计一种经济高效且易于使用的吸附剂以有效去除废水中的Cr(VI)评估了有用的参考信息。因此，它可被设想为各种未探索的工业级操作的替代方法。
