Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Diamond based electrodes for water quality applications: disinfection, micropollutant removal and the suppression of biofilm proliferation.
Thesis (MSc)--Stellenbosch University, 2024.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | en_ZA en_ZA |
| Published: |
Stellenbosch : Stellenbosch University
2024
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613737678012416 |
|---|---|
| access_status_str | Open Access |
| author | Louw, Carli |
| author2 | Wolfaardt, Gideon M.
|
| author_browse | Louw, Carli Wolfaardt, Gideon M. |
| author_facet | Wolfaardt, Gideon M.
Louw, Carli |
| author_sort | Louw, Carli |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2024. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/130368 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA en_ZA |
| last_indexed | 2026-06-10T12:40:54.381Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/130368 Diamond based electrodes for water quality applications: disinfection, micropollutant removal and the suppression of biofilm proliferation. Louw, Carli Wolfaardt, Gideon M. Botes, Marelize Stellenbosch University. Faculty of Science. Dept. of Microbiology. Rivers -- Effect of pollution on Water -- Treatment -- Developing countries Water -- Purification -- Disinfection Micropollutants Biofilms -- Treatment Water quality -- Purification Diamond based electro-oxidation Electrolytic oxidation UCTD Thesis (MSc)--Stellenbosch University, 2024. ENGLISH ABSTRACT: Rivers in most low and middle income countries face a growing burden of pollution in the form of pathogens and persistent micropollutants caused by waste discharge from informal settlements and poorly maintained wastewater treatment plants, operating above capacity. Farming communities are often reliant on the these rivers for irrigation. This study investigated the potential application of diamond based electro-oxidation in decentralized water treatment systems for disinfection and micropollutant abatement. The diamond-electrode based electrochemical in-situ system (DiaDis) forms ozone and hydroxyl radicals via electro-generation. It was hypothesised that the system would possess strong disinfection properties, but that micropollutant abatement would be dependent on the compounds and organic matter present. The disinfection study included the treatment and prevention of biofilms by monitoring the effects on biofilm metabolic activity during DiaDis treatment. A pure culture of Pseudomonas fluorescens sp. was used for the single culture biofilm disinfection study, and for the mixed species biofilm study the culture was sampled from a polluted river. The disinfection capabilities of the DiaDis was found to be comparable or slightly superior to 1:10 dilution sodium hypochlorite in this study for the single culture biofilms, however, the mixed species biofilms were more effectively treated with sodium hypochlorite. Biofilm-forming species have varying resistance to disinfectants and the results suggest the presence of synergistic adaptation. For the single and mixed species biofilms the treatments studied proved more effective when used preventatively than to treat mature biofilms. Removal efficiency of micropollutants by the mixed species biofilms was comparable to published literature, although lower abatement rates were reported for caffeine and acetaminophen, which could be the result of higher organic matter acting as oxidation scavenger in the environmental water. Negative removal rates were obtained for sulfamethoxazole, benzotriazole and efavirenz, likely due to electro- oxidation facilitated reconstitution of breakdown products to the respective parent compounds. The DiaDis was evaluated as a final disinfection step in an aquaponics, as well as a constructed floating wetland system. It performed better in the floating wetland, possibly due to higher levels of organic matter coming from fish-feed in the aquaponics system. Overall the DiaDis showed promising disinfection capabilities, which will benefit from future work to better control pH reduction and to reduce interference of organic matter with micropollutant abatement. AFRIKAANSE OPSOMMING: Riviere in die meeste lae- en medium-inkomste lande het toenemende las van besoedeling in die vorm van patogene en mikro-besoedelstowwe. Hierdie word veroorsaak deur afvalwater vanaf informele nedersettings en swak onderhoud van rioolwaterbehandelingsaanlegte, wat bo hul kapasiteit opereer. Boeregemeenskappe is dikwels afhanklik van hierdie riviere vir besproeiing. Hierdie studie het die potensiële toepassing van diamant-gebaseerde elektro-oksidasie in gedesentraliseerde waterbehandelingsisteme vir disinfeksie en vermindering van mikro-besoedelstowwe ondersoek. Die diamant-elektrode-gebaseerde elektrochemiese in-situ-sisteem (DiaDis) vorm osoon en hidroksielradikale deur elektro-generasie. Die hipotese was dat die sisteem sterk disinfeksie eienskappe sou besit, maar dat die vermindering in mikro-besoedelstowwe afhanklik sou wees van die chemiese samestellings en organiese stowwe teenwoordig in die water. Die disinfeksie studie het die behandeling en voorkoming van biofilms ingesluit deur die effek op biofilm metaboliese aktiwiteit tydens DiaDis- behandeling te monitor. 'n Suiwer kultuur van Pseudomonas fluorescens sp. is gebruik vir die enkel- kultuur biofilm disinfeksie studie, en vir die gemengde spesies biofilmstudie is die kultuur verkry uit 'n besoedelde rivier. Die disinfeksie eienskappe van die DiaDis was bevind om vergelykbaar (of effens beter) te wees as 1:10 verdunning natriumhipochloriet, vir die enkele kultuur biofilms. Die gemengde spesies biofilms was meer effektief behandel met natriumhipochloriet. Biofilm-vormende spesies het uiteenlopende weerstand teen disinfeksie middels, en die resultate dui op die teenwoordigheid van sinergistiese aanpassing. Vir die enkele en gemengde spesies biofilms was die bestudeerde behandeling meer effektief wanneer dit voorkomend gebruik is as om volwasse biofilms te behandel. Verwyderingdoeltreffendheid van mikro-besoedelstowwe deur die DiaDis was vergelykbaar met gepubliseerde literatuur, alhoewel laer afname koerse vir kafeïen en asetaminofeen aangemeld is, wat die resultaat kon wees van hoër organiese materiaal as oksidasie-opvanger in die omgewingswater. Negatiewe verwyderingskoerse is verkry vir sulfametoksasool, benzotriasool en efavirenz, waarskynlik as gevolg van elektro-oksidasie gefasiliteerde rekonstitusie van afbreekproduk tot die betrokke ouer verbindings. Die DiaDis is geëvalueer as 'n finale disinfeksiestap in 'n akwaponiese, sowel as 'n gekonstrueerde drywende vleiland-sisteem. Dit het beter presteer in die drywende vleiland, moontlik as gevolg van hoër vlakke van organiese materiaal afkomstig van visvoer in die akwaponiese sisteem. Oor die algemeen het die DiaDis belowende disinfeksie eienskappe getoon, wat meer effektief mikro- besoedelstowwe sal verwyder indien pH beter beheer word en inmenging van organiese materiaal verminder word. Masters 2024-02-29T15:25:14Z 2024-04-26T15:04:02Z 2024-02-29T15:25:14Z 2024-04-26T15:04:02Z 2024-03 Thesis https://scholar.sun.ac.za/handle/10019.1/130368 en_ZA en_ZA Stellenbosch University ix, 80 pages : illustrations (some color) application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Rivers -- Effect of pollution on Water -- Treatment -- Developing countries Water -- Purification -- Disinfection Micropollutants Biofilms -- Treatment Water quality -- Purification Diamond based electro-oxidation Electrolytic oxidation UCTD Louw, Carli Diamond based electrodes for water quality applications: disinfection, micropollutant removal and the suppression of biofilm proliferation. |
| title | Diamond based electrodes for water quality applications: disinfection, micropollutant removal and the suppression of biofilm proliferation. |
| title_full | Diamond based electrodes for water quality applications: disinfection, micropollutant removal and the suppression of biofilm proliferation. |
| title_fullStr | Diamond based electrodes for water quality applications: disinfection, micropollutant removal and the suppression of biofilm proliferation. |
| title_full_unstemmed | Diamond based electrodes for water quality applications: disinfection, micropollutant removal and the suppression of biofilm proliferation. |
| title_short | Diamond based electrodes for water quality applications: disinfection, micropollutant removal and the suppression of biofilm proliferation. |
| title_sort | diamond based electrodes for water quality applications disinfection micropollutant removal and the suppression of biofilm proliferation |
| topic | Rivers -- Effect of pollution on Water -- Treatment -- Developing countries Water -- Purification -- Disinfection Micropollutants Biofilms -- Treatment Water quality -- Purification Diamond based electro-oxidation Electrolytic oxidation UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/130368 |
| work_keys_str_mv | AT louwcarli diamondbasedelectrodesforwaterqualityapplicationsdisinfectionmicropollutantremovalandthesuppressionofbiofilmproliferation |