Dynamic chamber system for determining equilibrium phosphorus concentration (EPC0) in sediments

Eutrophication of lakes is a major driver promoting algal blooms which have presented significant social, economic and ecological challenges to humanity. Phosphorus (P) is a common limiting nutrient in North American freshwater lakes including the Laurentian Great Lakes that is transported to receiving waters by rivers and streams, especially those adjacent to agricultural lands. The bed sediment of such tributaries can act as both a sink and source of inorganic reactive phosphorus and thus modify the amount of P received by downstream lakes. The sorptive capacity of sediments for P is commonly determined by measuring the Equilibrium phosphorus concentration (EPC0) of a sediment. EPC0 is typically measured by batch reactors where small quantities of sediment and water are continuously shaken following addition of varying amounts of initial P to determined adsorbed fraction after a fixed period of time. These systems cannot maintain bed sediment structure or redox gradients critical to regulating sediment-P associations and therefore can generate artifacts in sediment sorptive capacity estimation. This thesis describes the development, calibration and application of a dynamic chamber system to measure EPC0 using intact sediment cores. Calibration trials demonstrated time to steady state ranging from 7 – 30+ days in a temperature dependent manner. When compared against batch reactor systems, the dynamic chamber cores demonstrated EPC0 values over double that of the batch EPC0 values in two of the three sites. This system was created and optimized successfully to minimize errors in system set-up and operation. Comparisons between intact core and batch systems revealed the significance of the chamber system to measure EPC0 and has opened opportunities to directly examine intact sediment properties ex-situ such as redox, pore-water, and biofilms to further elucidate the underlying mechanisms controlling sediment-water interface dynamics related to phosphorus.

Discipline thesis:degree_discipline

Great Lakes Institute for Environmental Research

Grantor

University of Windsor

Year dc:date.issued

2025

Author dc:creator

• Patel, Tilak

Advisors dc:contributor.advisor

• Drouillard, Kenneth G.
• Weisener, Christopher G.

Contributors dc:contributor

• scholarship@uwindsor.ca

Statement dc:rights

• info:eu-repo/semantics/openAccess

Handle dc:identifier.uri

https://hdl.handle.net/20.500.14776/12275

OAI identifier oai:identifier

oai:uwindsor.scholaris.ca:20.500.14776/12275