Master of Science
Noël, James J.
The single best water decontamination technique continues to be researched for by scientists globally. The purpose and subject of the decontamination determine the preferred technique to be used. For example, nanometre-sized contaminants require a different technique than those used for micrometer-scale contaminants. Recently, electrochemical membrane filtration techniques, such as electrodialysis, have gained great interest due to their capability to capture ionic contaminants. However, a lack of selective membranes continues to be a setback and so, novel polymers are under development. For this research, the sequestration behaviours of a commercial membrane and a novel phosphorus-based membrane are characterized for the application as potential metal decontaminants. A series of surface analytical and electrochemical techniques are applied to analyze the membranes and to explore their electrodialysis performance, respectively.
This work provides insight into the polymers’ ion exchange capabilities, chemical and electrochemical, contributing to the advancements required when developing ion exchange membranes for water decontamination.
Summary for Lay Audience
Contaminants, organic and inorganic, pave their way into masses of water either naturally or through human interventions, a result of the agricultural or electronics industries, for example. Various techniques have been employed over the years to decontaminate water and although advancements are on the rise, a universal solution has yet to be established. Specifically, a universal solution has yet to be established for heavy metals contaminants, which are comprised of elements with high atomic weights such as nickel, arsenic, or mercury. Heavy metals are commonly used in various industries, including the automotive industry, electronics, and mining operations. The demand for heavy metals is on the rise and this increases living beings’ exposure. Heavy metal ion contaminants are especially concerning due to their toxicity to life, in all forms, as they can cause countless serious health and environmental problems. Consequently, scientists continue to investigate the best water treatment method, in terms of performance, environmental impact, and economical value. Electrochemical water purification techniques have gained large interest recently because of their ease of operation, low maintenance cost, and their ability to target contaminants on the picometer scale, along with other advantages. Electrodialysis, which uses electrochemistry and ion-permeable polymers, is one such technique. Interestingly, electrodialysis uses a membrane that cannot be crossed by water and other chemicals, but with assistance from an electric field, ionic contaminants can be made to cross the membrane, leaving clean water behind.
In this thesis, the concept of electrodialysis was applied to investigate its capabilities in removing nickel and strontium ions from water. A commercial ion-exchange polymer was compared to a novel phosphorus-based polymer prepared at Western University. Chemical and electrochemical tests as well as surface characterization techniques were applied to evaluate the metal ion uptake behaviour of the polymers. The results presented in this thesis provide considerations required for commercialising a novel class of polymers as ion-exchangers, expanding the field of electrodialysis, and facilitating the advancement of water decontamination techniques.
Almusned, Baian, "Water Decontamination via Electrodialysis" (2023). Electronic Thesis and Dissertation Repository. 9606.
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Available for download on Tuesday, October 31, 2023