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An investigation into plant (Juncus effusus) biofilter nitrification modelling
Munhemba, T. 2025. An investigation into plant (Juncus effusus) biofilter nitrification modelling. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/2d2e8b91-da74-4348-b322-9e343ff3d2f5
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613800055701504 |
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| access_status_str | Open Access |
| author | Munhemba, Tinashe |
| author2 | Bosman, Adele |
| author_browse | Bosman, Adele Munhemba, Tinashe |
| author_facet | Bosman, Adele Munhemba, Tinashe |
| author_sort | Munhemba, Tinashe |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Munhemba, T. 2025. An investigation into plant (Juncus effusus) biofilter nitrification modelling. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/2d2e8b91-da74-4348-b322-9e343ff3d2f5 |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132565 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:41:53.663Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132565 An investigation into plant (Juncus effusus) biofilter nitrification modelling Munhemba, Tinashe Bosman, Adele Cloete, Eugene Brink, Isobel Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Urban runoff -- Mathematical models Aquatic organisms -- Effect of water pollution on Nitrification Prototypes, Engineering UCTD Eutrophication -- Control Munhemba, T. 2025. An investigation into plant (Juncus effusus) biofilter nitrification modelling. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/2d2e8b91-da74-4348-b322-9e343ff3d2f5 Thesis (PhD)--Stellenbosch University, 2025. ENGLISH ABSTRACT: This research investigates the removal of ammonia from stormwater using biofilters planted with the native South African species, Juncus effusus. Ammonia, a significant nitrogen-based contaminant, poses a major challenge in stormwater management, and this research addresses that challenge by developing a conceptual model and applying it to a laboratoryscale biofilter prototype. This prototype integrates critical processes, including nitrogen fixation, plant uptake, bacterial nitrification, and soil sorption, all aligned with the conceptual framework. A key innovation in the prototype design is the incorporation of a plug compartment, implemented to emulate plug flow dynamics, an integral aspect of the conceptual model. The efficacy of the biofilters, both with and without inoculated bacteria, was compared. The results showed a substantial improvement in ammonia removal for the biofilter that was enriched with the inoculated bacteria, achieving a 61% concentration reduction in ammonia as N, compared to only 15% in non-inoculated setups. Building upon these findings, a nitrification model was developed using a mass balance approach, integrating microbial nitrification, plant uptake, and soil sorption processes. Various laboratory configurations, based on the initial prototype design, were tested to establish model parameters. The study explored the role of rhizosphere bacteria in improving nitrification efficiency. Two biofilm flux models: a fully penetrated model and a partially penetrated model, based on ammonia concentrations measured either in the influent or within the plug compartment of the biofilter were developed. The fully penetrated model and partially penetrated model with ammonia influent as a parameter showed a fit with the experimental results and were further tested in full-scale experiments. The model was validated through a series of experimental runs using different ammonia concentrations (2.5-15 mg/L). The model could predict an upper and lower limit for ammonia mass effluent as N, with most measured effluent values falling between the two predicted ranges. Statistical analysis confirmed the model's validity for stormwater applications. The study concludes with recommendations for refining the model and provides guidelines for practical implementation of these biofilters. This research contributes to the development of green infrastructure and sustainable stormwater management solutions. AFRIKAANSE OPSOMMING:Hierdie navorsing ondersoek die verwydering van ammoniak uit stormwater deur biofilters met die inheemse Suid-Afrikaanse plantsoort Juncus effusus. Ammoniak, 'n beduidende stikstofgebaseerde besoedelstof, stel 'n groot uitdaging in stormwaterbestuur, en hierdie navorsing spreek daardie uitdaging aan deur 'n konseptuele model te ontwikkel en dit toe te pas op 'n laboratoriumskaal-biofilterprototipe. Die prototipe integreer kritiese prosesse soos stikstofbinding, plantopname, bakteriële nitrifikasie, en grondsorpsie, wat alles volgens die konseptuele raamwerk geïntegreer is. 'n Sleutelinnovasie in die ontwerp van die prototipe is die insluiting van 'n propkompartement, wat ontwerp is om propvloeidinamika na te boots, 'n integrale aspek van die konseptuele model. Die doeltreffendheid van die biofilters, beide met en sonder geïnokuleerde bakterieë, is geëvalueer en vergelyk. Die resultate het getoon dat die biofilter met geïnokuleerde bakterieë 'n aansienlike verbetering in ammoniakverwydering behaal het, met 'n 61%-vermindering in vergelyking met slegs 15% in nie-geïnokuleerde opstellings. Benewens die vermindering van ammoniak, het die sisteem ook die vorming van nitriete en nitrate bevorder. Gebaseer op hierdie bevindings, is 'n nitrifikasiemodel ontwikkel met behulp van 'n massabalansbenadering, wat mikrobiële nitrifikasie, plantopname en grondsorpsieprosesse geïntegreer het. Verskeie laboratoriumopstellings, gebaseer op die aanvanklike prototipeontwerp, is getoets om modelparameters te bepaal. Die studie het ook die rol van risosfeer-bakterieë in die verbetering van nitrifikasie-doeltreffendheid ondersoek deur twee biofilmvloeimodelle toe te pas: 'n volledig gepenetreerde model en 'n gedeeltelik gepenetreerde model, gebaseer op ammoniakkonsentrasies wat óf in die invloei óf in die propkompartement van die biofilter gemeet is. Albei modelle het 'n sterk ooreenstemming met die eksperimentele resultate getoon en is verder getoets in grootskaalse eksperimente. Die model is gevalideer deur 'n reeks eksperimentele lopies met verskillende ammoniakkonsentrasies (2.5-15 mg/L). Die resultate het getoon dat die model betroubaar 'n boonste en onderste grens vir ammoniak-uitvloeisel kon voorspel, met die meeste gemete uitvloeiwaardes wat tussen die twee voorspelde reekse val. Statistiese ontledings het die model se geldigheid vir stormwater-toepassings bevestig. Die studie sluit af met aanbevelings vir die verfyning van die model en verskaf riglyne vir die praktiese implementering van hierdie biofilters. Hierdie navorsing dra beduidend by tot die ontwikkeling van groen infrastruktuur en volhoubare stormwaterbestuuroplossings. Doctoral 2025-06-11T08:35:37Z 2025-06-11T08:35:37Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132565 en Stellenbosch University xiii, 134 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Urban runoff -- Mathematical models Aquatic organisms -- Effect of water pollution on Nitrification Prototypes, Engineering UCTD Eutrophication -- Control Munhemba, Tinashe An investigation into plant (Juncus effusus) biofilter nitrification modelling |
| title | An investigation into plant (Juncus effusus) biofilter nitrification modelling |
| title_full | An investigation into plant (Juncus effusus) biofilter nitrification modelling |
| title_fullStr | An investigation into plant (Juncus effusus) biofilter nitrification modelling |
| title_full_unstemmed | An investigation into plant (Juncus effusus) biofilter nitrification modelling |
| title_short | An investigation into plant (Juncus effusus) biofilter nitrification modelling |
| title_sort | investigation into plant juncus effusus biofilter nitrification modelling |
| topic | Urban runoff -- Mathematical models Aquatic organisms -- Effect of water pollution on Nitrification Prototypes, Engineering UCTD Eutrophication -- Control |
| url | https://scholar.sun.ac.za/handle/10019.1/132565 |
| work_keys_str_mv | AT munhembatinashe aninvestigationintoplantjuncuseffususbiofilternitrificationmodelling AT munhembatinashe investigationintoplantjuncuseffususbiofilternitrificationmodelling |