Thilanka K K T, Pathinayaka R H W, Udayanga W P V S, de Silva Rohini M, de Silva K M Nalin
Centre for Advanced Materials and Devices (CAMD), Department of Chemistry, Faculty of Science, University of Colombo Colombo Sri Lanka
Department of Life Sciences, Faculty of Science, NSBM Green University Pitipana, Homagama Sri Lanka.
RSC Adv. 2025 Jan 27;15(4):2632-2644. doi: 10.1039/d4ra07538b. eCollection 2025 Jan 23.
The global scarcity of irrigation-grade water poses severe concerns in the agricultural sector. Desalination techniques including reverse osmosis, electrodialysis, capacitive deionization, membrane filtration, and multi-stage flash are some dynamic solutions to mitigate this challenge. In this study, novel bio-filter materials were explored and developed for the application of membrane-based electrodialysis. Firstly, a series of composites were synthesized comprising different compositions of carboxymethyl cellulose (CMC), graphene oxide (GO), and to serve as cationic-selective membranes. Then desalination abilities of the composite series were assessed through permselectivity and ion exchange capacity (IEC) studies. Membrane matrix developed by integrating all the above three materials exhibited the highest permselectivity and IEC. The composites were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). It was determined that the designed composites can function effectively as cationic-selective membranes, while dried banana leaves can serve directly as an anionic-exchanger in an electrodialysis apparatus. Optimal performance was achieved when the pH of the system was maintained between 4.5 and 8.1. This system successfully desalinated a 3.5% (w/v) sodium chloride solution, achieving ∼75% desalination within 20 minutes. The potential to use banana leaves as a bio-filter material was explored in a parallel study. The results revealed that banana leaves dried for over 28 days at room temperature have high potential to function as anionic-selective membranes effectively in the electrodialysis desalination process. Altogether, this innovative approach offers a sustainable, eco-friendly and cost-effective solution for electrodialysis based water desalination.
灌溉级用水的全球稀缺给农业部门带来了严重问题。包括反渗透、电渗析、电容去离子、膜过滤和多级闪蒸在内的海水淡化技术是缓解这一挑战的一些动态解决方案。在本研究中，探索并开发了用于基于膜的电渗析应用的新型生物过滤材料。首先，合成了一系列由不同组成的羧甲基纤维素（CMC）、氧化石墨烯（GO）组成的复合材料，用作阳离子选择性膜。然后通过选择透过性和离子交换容量（IEC）研究评估了该系列复合材料的脱盐能力。将上述三种材料整合开发的膜基质表现出最高的选择透过性和IEC。使用傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）和X射线衍射（XRD）对复合材料进行了表征。确定所设计的复合材料可以有效地作为阳离子选择性膜发挥作用，而干燥的香蕉叶可以直接在电渗析装置中用作阴离子交换剂。当系统的pH值保持在4.5至8.1之间时，实现了最佳性能。该系统成功地对3.5%（w/v）的氯化钠溶液进行了脱盐，在20分钟内实现了约75%的脱盐率。在一项平行研究中探索了使用香蕉叶作为生物过滤材料的潜力。结果表明，在室温下干燥超过28天的香蕉叶具有在电渗析脱盐过程中有效用作阴离子选择性膜的高潜力。总之，这种创新方法为基于电渗析的水脱盐提供了一种可持续、环保且具有成本效益的解决方案。
