Advanced Membrane Technology Research Lab, Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Shariati Ave., Babol, 47148-71167, Iran; Department of Green Chemistry, LUT University, Sammonkatu 12, FI-50130, Mikkeli, Finland.
Advanced Membrane Technology Research Lab, Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Shariati Ave., Babol, 47148-71167, Iran.
J Environ Manage. 2021 Apr 15;284:111996. doi: 10.1016/j.jenvman.2021.111996. Epub 2021 Jan 31.
The development of efficient strategies for the removal of heavy metal ions from aqueous solutions is rapidly demanded as these contaminants are very toxic and carcinogenic and show detrimental effects on the living creatures. The main focus of the current study is on the preparation and assessment of electrospun adsorptive nanofiber membranes for the removal of toxic Ni(II) and Cu(II) from wastewater in the ultrafiltration process. Hydrothermally synthesized titanate nanotubes (TNT) was modified with thiol functional groups and then directly incorporated to the polyvinyl chloride nanofiber matrices via electrospinning process to fabricate an adsorptive membrane. The as-prepared electrospun nanofiber membranes and the nanoadsorbents were characterized with respect to the physiochemical properties, surface structure and morphology, applying XPS, FTIR, FESEM, EDX and TEM analysis and then, the membranes were evaluated in terms of the removal of the heavy metal ions in a continuous ultrafiltration mode. In adsorptive filtration of the metal ions, the effective factors including nanoadsorbents loading (0.5-1.5 wt%), initial metal ion concentration (60-150 mg/L), feed temperature (~25 °C-45 °C), presence of competing ion and reusability were investigated in the UF system where the membranes containing 1.5 wt% thiol-modified TNT and virgin TNT adsorbents demonstrated excellent removal efficiency compared to the other membranes. The Cu(II) and Ni(II) removal efficiency of the membrane containing 1.5 wt% functionalized TNT was 90% and 86.7%, respectively which was the highest ones. As was expected and due to the uniform dispersion and less aggregation of the modified TNT adsorbents on the large surface area of the electrospun nanofibers, more adsorption capacity of the nanoparticles can be exploited. Moreover, the strong affinity of the thiol functional groups toward the metal cations, these membranes removed metal contaminants more efficiently. Besides, the Cu(II) removal efficiency of the fabricated membranes didn't show any drastic changes in the presence of the competing ions. Furthermore, acceptable performance was achieved for the prepared membranes even after four adsorption/regeneration cycles in the continuous UF experiments, demonstrating the feasibility and effectiveness of the prepared adsorptive nanofiber membranes for the removal of heavy metal ions.
从水溶液中去除重金属离子的有效策略的发展需求迅速增加，因为这些污染物具有很强的毒性和致癌性，并对生物产生有害影响。目前研究的主要重点是制备和评估用于超滤过程中从废水中去除有毒 Ni(II) 和 Cu(II) 的静电纺丝吸附纳米纤维膜。采用水热合成法合成的钛酸盐纳米管（TNT）被巯基官能团改性，然后通过静电纺丝工艺直接掺入聚氯乙烯纳米纤维基质中，制备吸附膜。对制备的静电纺纳米纤维膜和纳米吸附剂进行了物理化学性质、表面结构和形态的表征，采用 XPS、FTIR、FESEM、EDX 和 TEM 分析，然后以连续超滤模式下去除重金属离子的角度对膜进行了评估。在金属离子的吸附过滤中，考察了纳米吸附剂负载量（0.5-1.5 wt%）、初始金属离子浓度（60-150 mg/L）、进料温度（~25°C-45°C）、共存离子和可重复使用性等有效因素在 UF 系统中，与其他膜相比，含有 1.5 wt%巯基改性 TNT 和原始 TNT 吸附剂的膜表现出优异的去除效率。含有 1.5 wt%功能化 TNT 的膜对 Cu(II) 和 Ni(II) 的去除效率分别为 90%和 86.7%，这是最高的。正如预期的那样，由于改性 TNT 吸附剂在静电纺纳米纤维的大表面积上均匀分散且聚集较少，因此可以利用更多的纳米颗粒的吸附能力。此外，巯基官能团对金属阳离子的强亲和力，使这些膜更有效地去除金属污染物。此外，在存在竞争离子的情况下，制备的膜对 Cu(II) 的去除效率没有发生任何剧烈变化。此外，即使在连续 UF 实验中的四个吸附/再生循环后，制备的膜仍能达到可接受的性能，这表明制备的吸附纳米纤维膜去除重金属离子的可行性和有效性。
