Remediation of aquaculture wastewater using wetland plants
| dc.contributor.author | Blandford, Nicholas | |
| dc.contributor.examiningcommittee | Grosshans, Richard (Biosystems Engineering) | |
| dc.contributor.examiningcommittee | Palace, Vince (Biological Sciences) | |
| dc.contributor.supervisor | Cicek, Nazim | |
| dc.date.accessioned | 2024-12-06T17:29:20Z | |
| dc.date.available | 2024-12-06T17:29:20Z | |
| dc.date.issued | 2024-12-04 | |
| dc.date.submitted | 2024-12-04T22:38:11Z | en_US |
| dc.degree.discipline | Biosystems Engineering | |
| dc.degree.level | Master of Science (M.Sc.) | |
| dc.description.abstract | The aquaculture industry is among the fastest growing food production sectors globally. Land-based aquaculture operations discharge aquaculture wastewater (AWW) high in nitrogen and phosphorus, which require effective management to mitigate environmental impacts. Constructed wetlands (CWs) are treatment technologies used for the remediation of nutrient-rich wastewaters, while nitrogenous wastes like ammonia and urea in AWW are viable fertilizers for biomass production in flooded soils. This research involved a series of four studies evaluating the performance of CW systems treating AWW. Model CW systems were constructed in mesocosms (~1500 L of water) and had a gradient of nutrient loading treatments applied through repeated AWW additions. In the first study, cattail (<i>Typha</i> spp.) CWs achieved >95% total phosphorus (TP) removal from water within 33 days of treatment, although elevations of TP (>0.2 mg L<sup>-1</sup>) occurred for 3–4 weeks under TP loadings of 1.02–1.64 mg m<sup>-2</sup> d<sup>-1</sup>. The second, third, and fourth studies utilized CWs planted with northern wild rice (<i>Zizania palustris</i> L.) and emulated established wetlands, managed natural stands, and flooded paddies, respectively. In the second study, TP concentrations increased to >0.25 mg L<sup>-1</sup> under TP loadings of 4.66–9.25 mg m<sup>-2</sup> d<sup>-1</sup>, whereas biofilm growth dominated at 14.46 mg m<sup>-2</sup> d<sup>-1</sup> and resulted in the removal of TP from the water column. In the third study, low wild rice biomass resulted in fewer plant nutrient sinks, facilitating algal growth. The fourth study achieved a 70% TP reduction in CW water within the first 27 days. However, among higher TP loadings (>54.63 mg m<sup>-2</sup> d<sup>-1</sup>), water quality degradations occurred throughout the subsequent 42 days. Wild rice biomass in flooded paddies contributed to ~3.8 g m<sup>-2</sup> of phosphorus uptake over 90 days. These findings provide insights into the operational timelines of cattail and wild rice CW systems treating AWW. The discharge of CW effluents should be coordinated with periods of low TP concentrations. Further assessments could evaluate the effectiveness of various fertilizer regimes, explore strategies for optimizing different biomass production systems, and investigate the practical integration of agronomy systems into a circular economy model. | |
| dc.description.note | February 2025 | |
| dc.identifier.uri | http://hdl.handle.net/1993/38695 | |
| dc.language.iso | eng | |
| dc.rights | open access | en_US |
| dc.subject | Bioremediation | |
| dc.subject | Phytoremediation | |
| dc.subject | Eutrophication | |
| dc.subject | Freshwater | |
| dc.subject | Sustainable agriculture | |
| dc.title | Remediation of aquaculture wastewater using wetland plants | |
| dc.type | master thesis | en_US |
| local.subject.manitoba | yes | |
| oaire.awardNumber | 566069-2021 | |
| oaire.awardTitle | Alexander Graham Bell Canada Graduate Scholarships - Master's | |
| oaire.awardURI | https://www.nserc-crsng.gc.ca/students-etudiants/pg-cs/cgsm-bescm_eng.asp | |
| project.funder.identifier | https://doi.org/10.13039/501100000038 | |
| project.funder.name | Natural Sciences and Engineering Research Council of Canada |