Department of Chemical Engineering, College of Engineering and Technology, Adigrat University, Tigray, Ethiopia.
Department of Chemical Engineering, Indian Institute of Technology Guwahati, 781039, Assam, India.
Chemosphere. 2018 Jan;191:673-684. doi: 10.1016/j.chemosphere.2017.10.107. Epub 2017 Oct 22.
In this work, TiO nanoparticles (NPs) were modified using tetraethylenepentamine (TEPA), ethylenediamine (EDA), and hexamethylenetetramine (HMTA) amines using impregnation process. The prepared amine modified TiO samples were explored as an additive to fabricate ultrafiltration membranes with enhanced capacity towards the removal of chromium ions from aqueous solution. Modified membranes were prepared from cellulose acetate (CA) polymer blended with polyethylene glycol (PEG) additive, and amine modified TiO by using phase inversion technique. Fourier transform infrared spectroscopy (FTIR), zeta potential (ζ), thermo gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), water contact angle (WCA), and atomic absorption spectrophotometer (AAS) studies were done to characterize the membranes in terms of chemical structure, electric charge, thermal stability, morphology, hydrophilicity, and removal performance. The pure water permeability and Cr (VI) ion removal efficiency of the unmodified (i.e. CA/U-Ti) and the amine modified (CA/Ti-HMTA, CA/Ti-EDA, and CA/Ti-TEPA) membranes were dependent on pH and metal ion concentration. Incorporation of amine modified TiO composite to the CA polymer was found to improve the fouling and removal characteristics of the membranes during the chromium ultrafiltration process. The maximum removal efficiency result of Cr (VI) ions at pH of 3.5 using CA/Ti-TEPA membrane was 99.8%. The washing/regeneration cycle results in this study described as an essential part for prospect industrial applications of the prepared membranes. The maximum Cr (VI) removal results by using CA/Ti-TEPA membrane for four washing/regeneration cycles are 99.6%, 99.5%, 98.6% and, 96.6%, respectively.
在这项工作中，使用浸渍法用四乙烯五胺（TEPA）、乙二胺（EDA）和六亚甲基四胺（HMTA）对 TiO 纳米粒子（NPs）进行了改性。研究了制备的胺改性 TiO 样品作为添加剂，以制备超滤膜，以增强从水溶液中去除铬离子的能力。通过相转化技术，用纤维素乙酸酯（CA）聚合物与聚乙二醇（PEG）添加剂和胺改性 TiO 制备了改性膜。通过傅里叶变换红外光谱（FTIR）、zeta 电位（ζ）、热重分析（TGA）、场发射扫描电子显微镜（FESEM）、水接触角（WCA）和原子吸收分光光度计（AAS）研究对膜进行了表征，以评估其化学结构、电荷、热稳定性、形态、亲水性和去除性能。在未改性（即 CA/U-Ti）和胺改性（CA/Ti-HMTA、CA/Ti-EDA 和 CA/Ti-TEPA）膜中，纯水透过率和 Cr（VI）离子去除效率取决于 pH 值和金属离子浓度。将胺改性 TiO 复合材料掺入 CA 聚合物中，发现可以改善膜在铬超滤过程中的污染和去除特性。在 pH 为 3.5 时，使用 CA/Ti-TEPA 膜对 Cr（VI）离子的最大去除效率为 99.8%。本研究中的洗涤/再生循环结果描述为制备膜在工业应用中的重要部分。在四个洗涤/再生循环中，使用 CA/Ti-TEPA 膜对 Cr（VI）的最大去除率分别为 99.6%、99.5%、98.6%和 96.6%。
