Abstract
This thesis explores the application of cavitation and photocatalysis as advanced oxidation processes (AOPs) for the removal of persistent organic pollutants (POPs) in wastewater streams. These utilize physical mechanisms to generate highly reactive radicals without the addition of external chemicals. Cavitation and photocatalysis, when applied simultaneously, produce a synergistic effect that surpasses the efficiency of either process applied independently, attracting significant interest for water treatment applications.The thesis begins by developing a method to reliably quantify radical species produced during cavitation and photocatalysis. This quantification is essential for monitoring and optimising radical generation, which is critical in enhancing AOP performance. A robust method for consistently measuring radical concentrations was proposed, which can be applied generally to AOPs.Utilizing this method, the thesis then evaluates cavitation devices and operating parameters to assess their impact on radical generation and treatment efficiency. Radical generation could be unambiguously linked to multiple operating parameters, and key differences were identified between device types. Synergistic effects between cavitation and photocatalysis were then investigated. The impact of various operating parameters was quantified on both individual and combined systems to speculate on how synergy occurs. It was found that synergy is likely a result of more efficient radical generation and utilisation.
Overall, this thesis provides a systematic investigation in coupling cavitation and photocatalysis to address POPs in water treatment. It lays the groundwork for future research to further refine these techniques and scale up their application, contributing to the development of more sustainable and efficient water treatment technologies.
| Date of Award | Jul 2024 |
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| Original language | English |
| Awarding Institution |
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| Sponsors | Northern Ireland Department for the Economy |
| Supervisor | Panagiotis Manesiotis (Supervisor) & Peter Robertson (Supervisor) |