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Laccase immobilized on metal-polymer composites for wastewater treatment and sensing applications
Thesis (PhD (Chemical Engineering))--University of Pretoria, 2024.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2025
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| _version_ | 1867613697254359040 |
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| access_status_str | Open Access |
| author2 | Brink, Hendrik Gideon |
| author_browse | Brink, Hendrik Gideon |
| author_facet | Brink, Hendrik Gideon |
| collection | Thesis |
| dc_rights_str_mv | © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Thesis (PhD (Chemical Engineering))--University of Pretoria, 2024. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/101041 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:40:15.875Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/101041 Laccase immobilized on metal-polymer composites for wastewater treatment and sensing applications Brink, Hendrik Gideon u21830658@tuks.co.za Feleni, Usisipho Kyomuhimbo, Hilda Dinah UCTD Sustainable Development Goals (SDGs) Enzyme immobilization Wastewater treatment Biosensors Detection of pollutants Nanoparticle-polymer composites Thesis (PhD (Chemical Engineering))--University of Pretoria, 2024. This study explores the multifunctional applications of laccase, a versatile multi-copper enzyme found in fungi, plants, and bacteria. Laccase facilitates the direct reduction of molecular oxygen to water while oxidizing various electron donors, making it appealing for biotechnological applications across sectors such as food, paper and pulp, wastewater treatment, pharmaceuticals, and biosensing. Despite its advantages, challenges related to high costs, instability under harsh conditions of pressure and temperature, and non-reusability in continuous processes necessitate the exploration of enzyme immobilization techniques. In this thesis, laccase enzyme was immobilized on metal-polymer composites comprising either zinc oxide nanoparticles (ZnONPs) or silver-doped ZnONPs (Ag@ZnONPs) embedded in chitosan, polyvinylpolypyrrolidone (PVPP) and polyaniline (PANI) polymers. Characterization studies, including UV-Vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD), demonstrate that Ag doping increased the surface area and reduced the bandgap energy without significantly altering nanoparticle size. The resulting polymer composites exhibit high stability and surface area, enabling effective dye adsorption and immobilization matrices for laccase enzyme. The composite beads were studied to remove four dyes: Bismarck brown, orange G, brilliant blue G, and indigo carmine from sewage wastewater and papermill industrial effluent. Applying these composite beads showcases their efficacy with an efficiency of over 90% and 70% chemical oxygen demand (COD) and over 60% and 80% dye removal from wastewater and papermill effluent respectively. Insights from liquid chromatography-mass spectrometry (LC-MS) indicate that laccase facilitated the cleavage of azo bonds and the formation of smaller compounds that were further mineralized by Aspergillus sp. that only thrive on the degradation by-products. Additionally, laccase-activated composites demonstrated significant antibiotic degradation capabilities, removing over 20% more tetracycline and ciprofloxacin when laccase was included, and exhibiting altered degradation pathways with reduced antibiotic activity over time. Finally, the development of a laccase-immobilized ZnO-polyaniline (PANI) nanocomposite biosensor for detecting CTAB highlights the potential for innovative analytical techniques in environmental monitoring. The biosensor exhibited a high sensitivity and wider dynamic linear detection ranges of 0.5 – 100 µM, 200 – 500 µM and 700 – 1900 µM. Overall, the findings underscore the potential of laccase and its immobilization strategies for sustainable biotechnological applications across various domains. National Research Foundation (NRF) of South Africa [MND210426597525 and CSRP2204204025] Margaret McNamara Education grants Schlumberger Foundation Faculty for the Future program Chemical Engineering PhD (Chemical Engineering) Unrestricted Faculty of Engineering, Built Environment and Information Technology SDG-06: Clean water and sanitation SDG-11: Sustainable cities and communities SDG-12: Responsible consumption and production SDG-14: Life below water 2025-02-19T10:00:59Z 2025-02-19T10:00:59Z 2025-04 2024-10 Thesis * A2025 http://hdl.handle.net/2263/101041 https://doi.org/10.25403/UPresearchdata.28443302.v1 https://doi.org/10.25403/UPresearchdata.28443302 en © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Sustainable Development Goals (SDGs) Enzyme immobilization Wastewater treatment Biosensors Detection of pollutants Nanoparticle-polymer composites Laccase immobilized on metal-polymer composites for wastewater treatment and sensing applications |
| title | Laccase immobilized on metal-polymer composites for wastewater treatment and sensing applications |
| title_full | Laccase immobilized on metal-polymer composites for wastewater treatment and sensing applications |
| title_fullStr | Laccase immobilized on metal-polymer composites for wastewater treatment and sensing applications |
| title_full_unstemmed | Laccase immobilized on metal-polymer composites for wastewater treatment and sensing applications |
| title_short | Laccase immobilized on metal-polymer composites for wastewater treatment and sensing applications |
| title_sort | laccase immobilized on metal polymer composites for wastewater treatment and sensing applications |
| topic | UCTD Sustainable Development Goals (SDGs) Enzyme immobilization Wastewater treatment Biosensors Detection of pollutants Nanoparticle-polymer composites |
| url | http://hdl.handle.net/2263/101041 https://doi.org/10.25403/UPresearchdata.28443302.v1 https://doi.org/10.25403/UPresearchdata.28443302 |