News

A new paper reconstructs the agricultural phosphorus (P) inputs across the province of Ontario since the 1960s. The first author of the paper, entitled Agricultural phosphorus surplus trajectories for Ontario, Canada (1961-2916), and erosional export risk, is former ERG MSc student Tamara Van Staden. Co-authors include the ERG members Chris Parsons, Zahra Akbarzadeh, and Philippe Van Cappellen, as well as their colleagues Kim Van Meter and Nandita Basu.

The oxidation of Fe(II) plays an important role in the biogeochemical cycling of redox-sensitive elements and the fate and transport of pollutants in subsurface environments. In a joint study by researchers from ERG and China University of Geosciences, the kinetics of aqueous Fe(II) oxidation by O₂ were measured at variable pH in the presence of riboflavin and desferrioxamine B as representative flavins and siderophores, respectively. The study closes important gaps in our understanding of the reaction mechanisms involved.

A Letter article by Ecohydrology members Arash Rafat, Eunji Byun, Fereidoun Rezanezhad and Philippe Van Cappellen was published in Environmental Research Communications journal! In this study, the impact of alternative definitions of the non-growing season (NGS) for a peatland site with multiple years of CO2 flux records was analysed with defining three NGS climatic parameters: air temperature, soil temperature, and snow cover.

Phosphorus (P) retention in Fanshawe Reservoir was evaluated based on a two-year intensive sampling of water chemistry. The Fanshawe Dam is located on the Thames River, the largest Canadian tributary source of P to the western basin of Lake Erie.  The results indicate that Fanshawe Reservoir reduces the total river P load by as much as 47%. The reservoir, however, is not only an important P sink on the Thames River, but also modulates the seasonal variability and chemical speciation of the river’s P load.

A study led by Prof. Nandita Basu published in Nature Geoscience provides a roadmap for scientists, policymakers, and the public to overcome the challenges associated with agricultural nitrogen legacies that delay improvements to water quality. While we now have a much better theoretical understanding of the accumulation and fate of nitrogen legacies in agricultural landscapes, there is an urgent need for more systematic measurements and monitoring to effectively support water quality policies.

The Ecohydrology Research Group hosted a successful 10th Annual World Wetlands Day Research Symposium at the University of Waterloo on Wednesday February 2, thanks to the efforts not only of our group but also that of wetland researchers across the University.This is the second year in a row that ERG has been partnering with the Waterloo Public Library to organize the symposium virtually.

A new paper by Tariq Aziz and Philippe Van Cappellen uses economic valuation to highlight the importance of Southern Ontario’s wetlands for sediment and phosphorus filtration. A total annual value of $4.2 billion in sediment and phosphorus filtration services was found based on the average rate of sediment accretion plus the associated total phosphorus concentration in each type of wetland in Southern Ontario and estimating how much the removal and disposal of the same amounts of sediment and phosphorus in stormwater management facilities in Ontario would cost.

Phosphorus (P), in the form of aqueous phosphate, is an essential nutrient for the growth of plants and algae. Because it often limits or colimits primary production in freshwater and nearshore marine systems, phosphate enrichment can result in eutrophication and algal blooms. A major process driving phosphate enrichment is the desorption of phosphate from mineral surfaces, in particular those of ferric iron oxyhydroxides.

Check out the new publication by former ERG researchers Bijen Bajracharya, Christina Smeaton, Igor Markelov, and Ekatarina Markelova, together with Philippe Van Cappellen. The paper presents a novel a bioenergetics-informed kinetic model for the anaerobic degradation of macromolecular organic matter that accounts for extracellular hydrolysis, fermentation, and respiration. The model dynamically calculates the catabolic energy generated by fermentation and respiration.

Philippe presented recent collaborative research on riverine nutrient fluxes and their impacts as part of the 2021-2022 OCGC-Logan Club Seminar Series. The seminar series is jointly offered by the University of Ottawa, Carleton University, and the Geological Survey of Canada's Logan Club in Ottawa. Due to the pandemic, the seminar was delivered virtually