Nutrient removal and bio-energy production from Netley-Libau Marsh at Lake Winnipeg through annual biomass harvesting

The primary goal of this research study was to evaluate the concept of combining bio-power production and nutrient removal by yearly biomass harvesting during ice-covered periods at Netley-Libau Marsh on Lake Winnipeg. Depending on the extent of vegetation within the marsh on any given year, removal rates range from 1.026 to 1.368 kt (3.1–4.2% of total Red River loading to Lake Winnipeg) of total nitrogen and 188–227 t (3.8–4.7% of total loading) of total phosphorus by harvesting 60% of the marsh area and 75% of the emergent parts of the vegetation. The effective management of water levels within the marsh was critical for vegetation growth and diversity. Suggestions on biomass harvesting and utilization methods were provided and a number of technologies were examined for the conversion of the harvested biomass to energy. The power produced in these systems ranged from 1.75 to 4.71 MW and, for some of the technologies, usable cogeneration heat was produced as a potential added value. CO2 emission credits of 55.07 kt y−1 can be expected with possible additional GHG credits for methane and NOx displacement.