Ibrahim Ahmed H, Lyu Xianjun, ElDeeb Amr B
College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
Mining and Petroleum Department, Faculty of Engineering, Al-Azhar University, Cairo 11884, Egypt.
Nanomaterials (Basel). 2023 Mar 17;13(6):1091. doi: 10.3390/nano13061091.
The increase of global environmental restrictions concerning solid and liquid industrial waste, in addition to the problem of climate change, which leads to a shortage of clean water resources, has raised interest in developing alternative and eco-friendly technologies for recycling and reducing the amount of these wastes. This study aims to utilize Sulfuric acid solid residue (SASR), which is produced as a useless waste in the multi-processing of Egyptian boiler ash. A modified mixture of SASR and kaolin was used as the basic component for synthesizing cost-effective zeolite using the alkaline fusion-hydrothermal method for the removal of heavy metal ions from industrial wastewater. The factors affecting the synthesis of zeolite, including the fusion temperature and SASR: kaolin mixing ratios, were investigated. The synthesized zeolite was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), particle size analysis (PSD) and N adsorption-desorption. The SASR: kaolin weight ratio of 1:1.5 yields faujasite and sodalite zeolite with 85.21% crystallinity, which then shows the best composition and characteristics of the synthesized zeolite. The factors affecting the adsorption of Zn, Pb, Cu, and Cd ions from wastewater on synthesized zeolite surfaces, including the effect of pH, adsorbent dosage, contact time, initial concentration, and temperature, have been investigated. The obtained results indicate that a pseudo-second-order kinetic model and Langmuir isotherm model describe the adsorption process. The maximum adsorption capacities of Zn, Pb, Cu, and Cd ions onto zeolite at 20 °C were 12.025, 15.96, 12.247, and 16.17 mg·g, respectively. The main mechanisms controlling the removal of these metal ions from aqueous solution by synthesized zeolite were proposed to be either surface adsorption, precipitation, or ion exchange. The quality of the wastewater sample obtained from the Egyptian General Petroleum Corporation (Eastern Desert, Egypt) was highly improved using the synthesized zeolite and the content of heavy metal ions was significantly reduced, which enhances the utilization of the treated water in agriculture.
除了气候变化导致清洁水资源短缺这一问题外，全球对固体和液体工业废物的环境限制日益增加，这引发了人们对开发替代性环保技术以回收和减少这些废物数量的兴趣。本研究旨在利用硫酸固体残渣（SASR），它是埃及锅炉灰多道加工过程中产生的无用废物。采用碱熔 - 水热法，以SASR和高岭土的改性混合物作为合成具有成本效益的沸石的基本成分，用于去除工业废水中的重金属离子。研究了影响沸石合成的因素，包括熔融温度和SASR与高岭土的混合比例。通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）扫描电子显微镜（SEM）、粒度分析（PSD）和N吸附 - 解吸对合成的沸石进行了表征。SASR与高岭土的重量比为1:1.5时可生成结晶度为85.21%的八面沸石和方钠石沸石，这显示了合成沸石的最佳组成和特性。研究了影响合成沸石表面对废水中Zn、Pb、Cu和Cd离子吸附的因素，包括pH值、吸附剂用量、接触时间、初始浓度和温度的影响。所得结果表明，拟二级动力学模型和朗缪尔等温线模型描述了吸附过程。在20℃下，Zn、Pb、Cu和Cd离子在沸石上的最大吸附容量分别为12.025、15.96、12.247和16.17mg·g。合成沸石从水溶液中去除这些金属离子的主要控制机制被认为是表面吸附、沉淀或离子交换。使用合成沸石后，从埃及通用石油公司（埃及东部沙漠）获得的废水样品质量得到显著改善，重金属离子含量大幅降低，这提高了处理后水在农业中的利用率。
