USask PhD student Deysi Venegas poses for a photo outside of a USask building.
USask PhD student Deysi Venegas is investigating an effective treatment process to remove potential crude oil contaminants from the South Saskatchewan River. (Photo: Submitted)

USask grad student working to protect Saskatchewan's water sources

If an oil spill occurred in the South Saskatchewan River, what would happen to this important water source that is critical to Saskatchewan communities, both human and wildlife? How would we control it or remove it from our water supply? University of Saskatchewan (USask) graduate student Deysi Venegas is on a mission to find out.

By Brooke Kleiboer

“Crude oil spill disasters are a serious environmental hazard that cause widespread negative environmental and economic impact,” said Venegas, who is working towards a doctorate degree in chemistry through USask’s College of Arts and Science. “Petroleum is a complex mixture containing hundreds of organic compounds. Due to their persistence, toxicity, and solubility in water, serious physical and mental health effects can be caused by the various components in crude oil.”

A signature area of research at USask, water security refers to protecting the world’s water supply, safeguarding drinking water, and preserving water quality. Through community partnerships and innovative technologies, USask researchers like Venegas are pursuing solutions to the pressing water security issues that are currently challenging our world.

Under the supervision of professor Dr. Lee Wilson (PhD), Venegas is helping to develop an effective water treatment process for removing oil, using a conventional treatment process currently used by the City of Saskatoon water treatment plant.

The experiment involved using a substance that mimics the chemical makeup of crude oil to investigate a process that would successfully remove these harmful molecules from water sources like the South Saskatchewan River, should an oil spill ever occur.

“Crude oil is a complex mixture; selecting a model compound that represented an oil component was one of the most important parts of the work,” said Venegas.

A current water treatment process uses ferric salt combined with lime (calcium oxide) to remove petrochemical contaminants from water. This process was analyzed by Venegas’ team to determine ideal environmental factors that would make the process even more effective at removing chemical compounds.

Venegas said factors such as temperature and the movement of molecules were assessed to determine how they played into compound removal, and to lend insight into how the process could be optimized. Experiments were conducted using both laboratory and river water samples, in partnership and with technical support from the City of Saskatoon.

“The list of contaminants and possible sources of release [into the water supply] are endless, and this is my motivation to make a contribution to science,” said Venegas. “Not just to present a method to remove these contaminants but also to understand the underlying chemical basis of how these treatment processes take place.”

Venegas said the optimized version of the treatment process can be easily adopted by other water treatment plants using basic laboratory equipment, and may result in cost savings due to its increased efficiency.

“The optimized removal process for [petrochemical contaminants] revealed greater removal, increasing from approximately 89 per cent relative to previous values outlined in an external consultants’ 2018 report, which ranged from 10 to 20 per cent,” said Venegas.

Results of the studies have appeared in academic open access journals, including Surfaces and Materials.

“Based on the process that was developed and optimized, the knowledge developed from our research can be readily transferred and adopted by other water treatment plants globally,” said Venegas.

She added that the study was inspired by a general need expressed in scientific literature for the use of new materials and methods in water treatment processes designed to remove petrochemical contaminants from water. The next step of the research is to make the oil remediation process more environmentally-friendly by incorporating the use of biomaterials.

“This strategy will allow us to enhance the original ferric-lime process, and further reduce the chemical consumption footprint,” said Venegas, who hopes to complete her PhD at USask in 2025.

The project is funded by the Research Junction Development Grant program, a partnership between the City of Saskatoon and USask designed to support the development of joint research projects that address contemporary urban issues for the benefit of Saskatoon residents.

This article first ran as part of the 2023 Young Innovators series, an initiative of the USask Research Profile and Impact office in partnership with the Saskatoon StarPhoenix.

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