Department of Mechanical and Process Engineering, The Sirindhorn International Thai-German Graduate School of Engineering (TGGS), King Mongkut's University of Technology North Bangkok, 1518 Wongsawang Road, Bangsue, Bangkok, 10800, Thailand.
Government Women's Polytechnic College, Calicut, Kerala, India.
Sci Rep. 2020 Sep 22;10(1):15452. doi: 10.1038/s41598-020-72398-5.
In this study, a novel PVA/SA/ZSM-5 zeolite membrane with good regeneration capacity was successfully prepared by solvent casting technique. The properties of the membranes were assessed by employing different characterization techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), optical microscopy (OP), thermogravimetric analysis (TGA), contact angle and universal testing machine (UTM). XRD, TGA and UTM results revealed that the crystallinity and thermo-mechanical performance of the membrane could be tuned with zeolite content. The successful incorporation of zeolite into the polymer matrix was confirmed by FT-IR, SEM and OP analysis. The adsorption ability of the as-prepared membrane was evaluated with a model anionic dye, Congo red. Adsorption studies show that the removal efficiency of the membrane could be tuned by varying zeolite content, initial concentration of dye, contact time, pH and temperature. Maximum dye adsorption (5.33 mg/g) was observed for 2.5 wt% zeolite loaded membrane, at an initial dye concentration of 10 ppm, pH 3 and temperature 30 °C. The antibacterial efficiency of the membrane against gram-positive (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli) was also reported. The results show that membrane inhibits the growth of both gram-positive and gram-negative bacteria. The adsorption isotherm was studied using two models: Langmuir and Freundlich isotherm. The results show that the experimental data fitted well with Freundlich isotherm with a high correlation coefficient (R = 0.998). Meanwhile, the kinetic studies demonstrate that pseudo-second-order (R = 0.999) model describe the adsorption of Congo red onto PVA/SA/ZSM-5 zeolite membrane better than pseudo-first-order (R = 0.972) and intra particle diffusion model (R = 0.91). The experimental studies thus suggest that PVA/SA/ZSM-5 zeolite could be a promising candidate for the removal of Congo red from aqueous solution.
在这项研究中，通过溶剂浇铸技术成功制备了一种具有良好再生能力的新型 PVA/SA/ZSM-5 沸石膜。通过使用不同的特征化技术，如 X 射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、光学显微镜（OP）、热重分析（TGA）、接触角和万能试验机（UTM）来评估膜的性能。XRD、TGA 和 UTM 结果表明，通过沸石含量可以调节膜的结晶度和热机械性能。FT-IR、SEM 和 OP 分析证实了沸石成功地掺入聚合物基质中。通过使用模型阴离子染料刚果红评估了所制备的膜的吸附能力。吸附研究表明，通过改变沸石含量、染料初始浓度、接触时间、pH 值和温度，可以调节膜的去除效率。在初始染料浓度为 10ppm、pH 值为 3 和温度为 30°C 的情况下，负载 2.5wt%沸石的膜观察到最大染料吸附（5.33mg/g）。还报道了膜对革兰氏阳性（金黄色葡萄球菌）和革兰氏阴性菌（大肠杆菌）的抗菌效率。结果表明，该膜抑制了革兰氏阳性菌和革兰氏阴性菌的生长。使用两种模型：朗缪尔和弗伦德利希等温线研究了吸附等温线。结果表明，实验数据与弗伦德利希等温线拟合良好，相关系数高（R=0.998）。同时，动力学研究表明，准二级（R=0.999）模型比准一级（R=0.972）和内颗粒扩散模型（R=0.91）更好地描述了刚果红在 PVA/SA/ZSM-5 沸石膜上的吸附。因此，实验研究表明 PVA/SA/ZSM-5 沸石可能是从水溶液中去除刚果红的有前途的候选物。
