Evaluation of the Impacts of De-Icing Salts on the Performance of Bioretention Media in Retaining Phosphorus From Urban Stormwater

Bioretention systems are a low impact development system that can remove pollutants such as phosphorus (P) from urban stormwater. P retention in bioretention systems is complicated in cold climate regions due to factors such as inputs of road de-icing salts. This study evaluates the impact of prolonged and periodic salt inputs on P retention by conducting column experiments using three different bioretention media with and without an amendment added. Non-amended columns showed net P release, whereas amended columns showed net P retention. While some non-amended columns showed prolonged salt exposure increases P release, the largest P release for all columns occurred during the freshening period following the switch from high to low salt influent. High porewater pH (> 9) observed during the freshening period may be causing the high P release. This study provides new insights needed to improve year-round P retention in bioretention systems installed in cold climates.

Name thesis:degree_name

M Eng Sci

Discipline thesis:degree_discipline

Civil and Environmental Engineering

Grantor dc:publisher

The University of Western Ontario

Year dc:date.issued

2022

Author dc:creator

• Donado Visbal, Brennan S.

Advisor dc:contributor.advisor

• Robinson, Clare

• Bioretention
• Phosphorus
• Road Salt
• Low Impact Development
• Water Treatment Residuals
• Biogeochemical Processes

Language dc:language.iso

en_ca

Handle dc:identifier.uri

https://hdl.handle.net/20.500.14721/31890

OAI identifier oai:identifier

oai:uwo.scholaris.ca:20.500.14721/31890