Development of a point-of-use water treatment system for organic contaminant degradation
department or school: Applied Science, Faculty of
department or school: Chemical and Biological Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Hejazi, Seyyed Arman
issued: 2023-01-31T08:00:00Z
issued: 2020
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: Organic pollution of water is one of the most persistent types of impurities. In municipal water treatment plants, the degradation of organic compounds is achieved by advanced oxidation processes (AOPs), where the exposure of hydrogen peroxide (H₂O₂) containing influent to ultraviolet (UV) lamps converts H₂O₂ to hydroxyl radicals (·OH), which oxidize organic pollutants. However, the need to introduce a chemical (H₂O₂) and the use of bulky UV lamps prevent this process from being scaled down. In this study, an electrochemical cell was developed for the in situ generation of H₂O₂ from water and atmospheric oxygen using a two-electron oxygen reduction reaction (2e-ORR), thus eliminating the need for the external addition of H₂O₂. Moreover, the electrochemical reactor was equipped with novel UV sources, ultraviolet light-emitting diodes (UV-LEDs) with a wavelength of 277 nm, and microplasma lamps with wavelengths of 172 nm, 222 nm, and a broad spectrum of 220–280 nm. The electrochemical cell exhibited a high current efficiency of nearly 90% toward H₂O₂ production. The degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and methylene blue (MB) was monitored based on various operational parameters. The performance of the system for electro-Fenton (EF) and photoelectro-Fenton (PEF) processes was studied using the three microplasma lamps. In all cases, the system exhibited high removal of the organic compounds (e.g., >70% of 2,4-D with UV-LEDs at the water flow rate of 50 mL min⁻¹). A gas diffusion electrode (GDE) was developed based on expanded polytetrafluoroethylene (ePTFE) substrate to produce H₂O₂. The GDE characterization indicated its tolerance to a pressure difference of >70 psi. The performance of the GDE for the cathodic generation of H₂O₂ was evaluated based on catalyst loading, electrolyte flow rate, and current density. The results indicated a direct relationship between the current and H₂O₂ production. Higher catalyst loading led to increased H₂O₂ production…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/76849
note: DEVELOPMENT OF A POINT-OF-USE WATER TREATMENT SYSTEM FOR ORGANIC CONTAMINANT DEGRADATION by Seyyed Arman Hejazi B.Sc., Sharif University of Technology, 2018 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Chemical and Biological Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) December 2020 © Seyyed Arman Hejazi, 2020 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, a thesis entitled: Development of a point-of-use water treatment system for organic contaminant degradation submitted by Seyyed Arman Hejazi in partial fulfillment of the requirements for the degree of Master of Applied Science in Chemical and Biological Engineering Examining Committee: Dr. Fariborz Taghipour, Professor, Chemical and Biological Engineering, UBC Supervisor Dr. Előd Gyenge, Professor, Chemical and Biological Engineering, UBC Supervisory Committee Member Dr. Yankai Cao, Assistant Professor, Chemical and Biological Engineering, UBC Supervisory Committee Member iii Abstract Organic pollution of water is one of the most persistent types of impurities. In municipal water treatment plants, the degradation of organic compounds is achieved by advanced oxidation processes (AOPs), where the exposure of hydrogen peroxide (H2O2) containing influent to ultraviolet (UV) lamps converts H2O2 to hydroxyl radicals (·OH), which oxidize organic pollutants. However, the need to introduce a chemical (H2O2) and the use of bulky UV lamps prevent this process from being scaled down. In this study, an electrochemical cell was developed for the in situ generation of H2O2 from water and atmospheric oxygen using a two-electron oxygen reduction reaction (2e-ORR), thus eliminating the need for the external addition of H2O2. Moreover, the electrochemical reactor was equipped with novel UV sources, ultraviolet li…
has type: Thesis/Dissertation
date issued: 2021-05
is shown at: 10.14288/1.0395349
language: eng
degree discipline: Chemical and Biological Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/76849