Potential Applications of Graphene-Based Membrane in Solution Purification Processes

Climate change with industrial and environmental pollution are among the reasons for water quality deterioration. Unfortunately, conventional polymeric membranes have inherent limitations, such as low separation or rejection rate, fouling, limited water flux, and high energy consumption. Two-dimensional (2D) based layered materials with tunable chemical functionalities and surface charge properties have emerged for on-demand applications, including membrane technology. However, the instability of graphene oxide (GO) membranes during operation is one of the biggest challenges for its practical applications. Therefore, it is important to improve the stability of GO membranes without losing their physiochemical properties. This thesis aims to develop advanced performance GO membranes for water purification. Initially, research was conducted to investigate the pressure-assisted method for fabricating a GO membrane using polyvinyl alcohol (PVA) as adhesive materials for swelling control and molybdenum disulfide as nanospacer. The next study evaluated synergistic ionic complexation between 1D-CNT (carbon nanotubes), 2D-GO, and PVA to overcome the permeability-selectivity trade-off. Thermal treatment of GO membranes was also investigated in this study. Later, part of this thesis is focused on developing a proof of concept of preparing an antifouling GO membrane using a non-solvent induced phase separation method for a highly selective membrane. The potential of vanillin and GO for various model foulants and landfill leachate wastewater was investigated in this study. Finally, a surface modification technique was used to modify the commercially available loose nanofiltration (NF) membrane. In this study, kappa-carrageenan (κ-CGN)/GO composite has been used to modify a commercial NF membrane to improve salt rejection antifouling properties when landfill leachate wastewater is the feed solution. The techniques presented in this thesis demonstrates are not only simple and effective but can also be applied to a wide range of membrane substrates and even large-scale membrane development. GO membranes' mechanical integrity and structural stability are evaluated for 72 hours of operation; however, low water permeability is still challenging. Therefore, studies should prepare an efficient GO membrane of high permeability without compromising its rejection rate and stability. At the same time, the mechanical properties and stability of the GO membrane should be explored to understand its potential applications better.

Author dc:creator

• Yadav, Sudesh

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• The author owns the copyright in this thesis including all reproduction and reuse rights for the work. The work may not be altered without the permission of the copyright owner. Attribution is essential when quoting or paraphrasing from this thesis.
• au.edu.uts.lib/ppc
• info:eu-repo/semantics/openAccess

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en_US

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http://hdl.handle.net/10453/163137

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oai:opus.lib.uts.edu.au:10453/163137