Greenhouse gas emissions from waste stabilisation ponds in Western Australia and Quebec (Canada). (15th September 2016)

• Record Type: Journal Article
• Authors: Glaz, Patricia; Bartosiewicz, Maciej; Laurion, Isabelle; Reichwaldt, Elke S.; Maranger, Roxane; Ghadouani, Anas
• Is Part Of: Water research. Volume 101(2016)
• Page Start: 64
• Page End: 74
• Publication Date: 2016-09-15
• Subjects: Greenhouse gases -- CO2 -- CH4 -- N2O -- Waste stabilisation ponds -- Diffusive flux -- Wastewater treatment -- Global warming potential -- Spatiotemporal variability; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2016.05.060
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Waste stabilisation ponds (WSPs) are highly enriched environments that may emit large quantities of greenhouse gases (GHG), including CO2, CH4 and N2 O. However, few studies provide detailed reports on these emissions. In the present study, we investigated GHG emissions from WSPs in Western Australia and Quebec, Canada, and compared emissions to WSPs from other climatic regions and to other types of aquatic ecosystems. Surface water GHG concentrations were related to phytoplankton biomass and nutrients. The CO2 was either emitted or absorbed by WSPs, largely as a function of phytoplankton dynamics and strong stratification in these shallow systems, whereas efflux of CH4 and N2 O to the atmosphere was always observed albeit with highly variable emission rates, dependent on treatment phase and time of the day. The total global warming potential index (GWP index, calculated as CO2 equivalent) of emitted GHG from WSPs in Western Australia averaged 12.8 mmol m −2 d −1 (median), with CO2, CH4 and N2 O respectively contributing 0%, 96.7% and 3.3% of the total emissions, while in Quebec WSPs this index was 194 mmol m −2 d −1, with a relative contribution of 93.8, 3.0 and 3.2% respectively. The CO2 fluxes from WSPs were of the same order of magnitude as those reported in hydroelectric reservoirs and constructed wetlands in tropical climates, whereas CH4 fluxes were considerably higher compared to other aquatic ecosystems. N2 O fluxes were in the same range of values reported for WSPs in subtropical climate. Graphical abstract: Highlights: CO2 was either emitted or absorbed by WSPs. CH4 and N2 O emissions by WSPs were highly variable but always positive. The CO2 uptake was apparently linked to phytoplankton activity and daytime stratification. CO2 fluxes from WSPs were of the same order of magnitude as those reported in tropical climates. CH4 fluxes were considerably higher when compared to fluxes from other aquatic ecosystems.