Abstract

The environmental pollution, particularly water pollution, has gradually caused severe human health issues. Organic dyes are one of the most emerging pollutants in the environment. In the present study, graphene oxide (GO) was functionalized with chitosan (CS) and magnetic nanoparticles (Fe-NPs) and tested to remove Sudan I, II, III, and IV dyes from water. The synthesized GO-CS-Fe was characterized using UV–vis, SEM, TEM, EDX, and FTIR spectroscopy, and confirmed the structural composition of nanocomposite, with the Fe-NPs dimension over the GO-CS surface to be 31–44 nm. The effects of various experimental factors; time,pH, adsorbent amount, dyes concentrations, and temperature were executed using the batch experiment. The experimental data were fitted to pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich kinetic models. The isotherm models parameters of the Langmuir, Freundlich, Redlich–Peterson, Temkin, and Hill isotherms, along with the thermodynamics parameters were also calculated. The data was explained by the Langmuir isotherm model with maximum adsorption capacities for Sudan I, II, III, and IV as 360.6, 353.7, 351.0, and 347.6 mg/g, respectively. The rapid uptake of the dyes fitted the pseudo-second-order kinetic, asserting that the adsorption was diffusion controlled. The process was spontaneous and endothermic in nature. The reusability study of GO-CS-Fe was performed up to five cycles. The nanocomposite can retain its efficacy even after the considered cycles. In conclusion, the GO-CS-Fe nanocomposite has exhibited a high potential for removing Sudan dyes from the aqueous solution due to its high adsorption and regeneration capability.

摘要

环境污染，特别是水污染，已逐渐引起严重的人类健康问题。有机染料是环境中最新兴的污染物之一。在本研究中，氧化石墨烯 (GO) 用壳聚糖 (CS) 和磁性纳米粒子 (Fe-NPs) 进行功能化，并测试从水中去除苏丹红 I、II、III 和 IV 染料。使用 UV-vis、SEM、TEM、EDX 和 FTIR 光谱对合成的 GO-CS-Fe 进行了表征，并确认了纳米复合材料的结构组成，GO-CS 表面上的 Fe-NPs 尺寸为 31-44 nm . 各种实验因素的影响；时间、pH、吸附剂用量、染料浓度和温度使用分批实验进行。实验数据符合伪一级、伪二级、粒子内扩散和 Elovich 动力学模型。还计算了 Langmuir、Freundlich、Redlich–Peterson、Temkin 和 Hill 等温线的等温线模型参数以及热力学参数。数据由 Langmuir 等温线模型解释，苏丹红 I、II、III 和 IV 的最大吸附容量分别为 360.6、353.7、351.0 和 347.6 mg/g。染料的快速吸收符合伪二级动力学，表明吸附是扩散控制的。该过程本质上是自发的和吸热的。GO-CS-Fe 的可重复使用性研究进行了多达五个循环。即使在考虑的循环之后，纳米复合材料仍能保持其功效。总之，GO-CS-Fe 纳米复合材料由于其高吸附和再生能力，显示出从水溶液中去除苏丹红染料的巨大潜力。