Nitrogen and phosphorus discharges from wastewater contribute to the eutrophication of aquatic ecosystems, highlighting the need for effective and sustainable treatment solutions. In this context, constructed wetlands using alternative substrates derived from agricultural residues represent an interesting approach, particularly in tropical climates where the availability of local biomass offers opportunities for resource recovery. This study evaluates the performance of a vertical-flow constructed wetland planted with Canna indica and using sugarcane bagasse as a substrate under varying hydraulic and organic loading conditions under tropical climate conditions.
The experimental setup consisted of four pilot units: three units containing bagasse with different particle sizes and one control unit composed of gravel and sand. Performance was assessed through the monitoring of nitrogen species, total phosphorus, and alkalinity over several operational phases.
The results showed that the bagasse-based units achieved effective ammonium nitrogen removal, with efficiencies ranging from 65,4% to 87,5%, while finer bagasse particle sizes generally yielded better performance. For phosphorus removal, the control unit achieved the highest efficiencies, ranging from 40,5% to 64,0%, whereas the bagasse-based units exhibited removal efficiencies between 20,2% and 51,3%. A hydraulic loading rate of 144 mm/day provided the best overall nitrogen removal performance. Overall, decreasing the organic loading rate improved ammonium nitrogen removal but reduced total nitrogen removal performance. For phosphorus, the results highlighted the existence of an optimal organic loading rate, indicating that system performance depends on a balance between biological activity and phosphorus retention mechanisms. Despite the applied hydraulic and organic loading disturbances, the systems demonstrated good operational resilience.
These findings confirm the potential of bagasse as an alternative substrate for nitrogen removal in constructed wetlands while highlighting the limitations of this material for phosphorus retention.
| Date | 18 Aug 2026 |
|---|
| Original language | French |
|---|
| Awarding Institution | - École de technologie supérieure
|
|---|
| Supervisor | Frédéric Monette (Supervisor) |
|---|
Eymard, J. (Author),
Monette (Supervisor),
18 Aug 2026Student thesis: Master's thesis › Master in Engineering: Environmental Engineering