A new paper in Science of the Total Environment presents a reaction-transport model to simulate the multi-year fate and transport of phosphorus (P) in a bioretention cell facility in the greater Toronto metropolitan area. The paper is authored by Bowen Zhou, a PhD student in ERG. Co-authors from ERG include Mahyar Shafii, Chris T. Parsons, Elodie Passeport, Fereidoun Rezanezhad, Ariel Lisogorsky and Philippe Van Cappellen. The model results indicate that groundwater recharge is principally responsible for decreasing the surface water outflow from the bioretention cell while the outflow of P is mainly reduced through accumulation in the filter medium and plant uptake. Colloid filtration and sorption dominate P retention in filter media and immobilize P in the unreactive pool. The findings indicate that this bioretention facility has a high P reduction efficiency, and also that its P retention capacity is still far from approaching saturation after 7 years of operation. The reactive transport modeling approach developed here can in principle be transferred and adapted to fit other bioretention cell designs and hydrological regimes to estimate P surface loading reductions at a range of temporal scales. To download the paper, please follow this LINK.
Thursday, March 16, 2023