Barakat M A, Kumar Rajeev, Balkhyour M, Taleb Md Abu
Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University Jeddah-21589 Saudi Arabia
Central Metallurgical R & D Institute Helwan 11421 Cairo Egypt.
RSC Adv. 2019 May 7;9(24):13916-13926. doi: 10.1039/c9ra02246e. eCollection 2019 Apr 30.
In this study, an AlO/graphene oxide/halloysite nanotube (AlO/GO/HNT) nanocomposite has been synthesized and used as an adsorbent for the sequestration of cationic methylene blue (MB) and anionic congo red (CR) dyes from wastewater. The properties of the synthesized AlO/GO/HNT were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Various factors such as pH, contact time, initial concentration and temperature have been investigated for evaluation of the optimum adsorption in the batch sorption experiment and experimental results showed the highest adsorption capacity was found to be 329.8 mg g for CR and 258.4 mg g for MB at an initial concentration of 500 mg l which was three times higher than the individual AlO GO and HNT concentrations. Freundlich and Langmuir adsorption isotherm models were fitted to the experimental data and the results implied that the adsorption of MB well described with Langmuir and CR is related to the Freundlich isotherm model. The kinetics data of CR and MB adsorption was well fitted to pseudo-first-order. The calculated values for thermodynamic parameters indicated that the MB and CR adsorption process were spontaneous and exothermic in nature. The effectiveness of the AlO/GO/HNT composite was also tested for adsorption of Cu(ii), oxytetracycline (OTC) antibiotic, and 2-chlorophenol (2CP) and the results revealed that the AlO/GO/HNT composite is a promising adsorbent for the dyes as well as heavy metals and other organic pollutants.
在本研究中，合成了一种AlO/氧化石墨烯/埃洛石纳米管（AlO/GO/HNT）纳米复合材料，并将其用作吸附剂，用于从废水中螯合阳离子亚甲基蓝（MB）和阴离子刚果红（CR）染料。通过X射线衍射（XRD）、X射线光电子能谱（XPS）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对合成的AlO/GO/HNT的性能进行了表征。在间歇吸附实验中，研究了pH值、接触时间、初始浓度和温度等各种因素，以评估最佳吸附效果。实验结果表明，在初始浓度为500 mg/L时，CR的最高吸附容量为329.8 mg/g，MB的最高吸附容量为258.4 mg/g，这比单独的AlO、GO和HNT的吸附容量高出三倍。将Freundlich和Langmuir吸附等温线模型拟合到实验数据，结果表明MB的吸附符合Langmuir模型，CR的吸附与Freundlich等温线模型相关。CR和MB吸附的动力学数据很好地拟合了拟一级动力学模型。计算得到的热力学参数值表明，MB和CR的吸附过程本质上是自发的且放热的。还测试了AlO/GO/HNT复合材料对Cu（II）、土霉素（OTC）抗生素和2-氯苯酚（2CP）的吸附效果，结果表明AlO/GO/HNT复合材料是一种有前景的吸附剂，可用于吸附染料以及重金属和其他有机污染物。
