Abstract

Membranes with selective filtering capabilities are being designed globally, to tackle freshwater scarcity. In this study, we report the formulation of a bovine serum albumin (BSA) fabricated graphene oxide (GO) membrane for adsorptive removal of cobalt(II) from water. Large surface area along with abundant oxygen moieties upon interaction with biomolecules such as proteins, enable enhanced water purification. Free standing GO-BSA membrane was formulated by using covalent conjugating approach using cross—linkers, followed by vacuum-assisted filtration process. The chemical composition and structural morphology of the membrane was analyzed by different spectroscopic techniques. Water contact angle (WCA) studies exhibited hydrophilic behavior (58°) of GO which enabled efficacious conjugation of the protein to the graphitic derivative. Brunauer-Emmert–Teller (BET) surface area analysis showed an increase in surface area from 3.60 to 10.2 m² g⁻¹ in GO and GO-BSA conjugate, respectively. Further, the adsorption efficiency of cobalt by the prepared membranes was studied at different physical parameters such as concentration, pH, temperature and contact time of the adsorbent with the membrane. The GO-BSA membrane exhibited maximum adsorptive capacity of 184 mg/g at pH 6 which further amplified with rise in temperature from 25 to 35 °C. The reported work demonstrates formulation of a facile, low cost approach to efficiently remove cobalt ions from simulated wastewaters. The composed GO-BSA membrane will open new avenues for construction of portable water purification systems in future.

Graphic abstract

Schematic depicting adsorptive removal of Cobalt from water by using covalently conjugated GO-BSA membrane by application of vacuum filtration

中文翻译：

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吸附去除水中钴（II）的氧化石墨烯-牛血清白蛋白共轭膜的合成与表征

摘要

具有选择性过滤功能的膜正在全球范围内设计，以解决淡水短缺问题。在这项研究中，我们报告了牛血清白蛋白（BSA）制成的氧化石墨烯（GO）膜的配方，该膜可从水中吸附去除钴（II）。与生物分子（如蛋白质）相互作用时，大的表面积以及丰富的氧部分使水净化效果增强。通过使用交联剂的共价结合方法，然后通过真空辅助过滤工艺，配制了独立式GO-BSA膜。通过不同的光谱技术分析了膜的化学组成和结构形态。水接触角（WCA）研究显示GO的亲水行为（58°），使蛋白质有效地缀合到石墨衍生物上。GO和GO-BSA共轭物中分别为²  g ^-1 。此外，在不同的物理参数如浓度，pH，温度和吸附剂与膜的接触时间下，研究了制备的膜对钴的吸附效率。GO-BSA膜在pH 6时显示最大吸附能力184 mg / g，随着温度从25升高到35°C而进一步放大。报道的工作证明了一种简便，低成本的方法，可以有效地从模拟废水中去除钴离子。组成的GO-BSA膜将在将来为便携式净水系统的建设开辟新的途径。

图形摘要

示意图描绘了通过应用真空过滤通过使用共价结合的GO-BSA膜吸附去除水中的钴