Breath of fresh air: USask researcher combats odours and emissions from sewage plants

Sometimes the compounds emitted by municipal wastewater treatment plants can be potential climate hazards, as some are associated with greenhouse gases (GHGs). 

For his doctoral research in civil and environmental engineering, University of Saskatchewan (USask) researcher Dr. Mohsen Asadi (PhD) focused on developing a way to calculate the amount of GHGs and smelly compounds released from wastewater treatment plants in order to address potential downwind impacts on neighbourhoods and the environment.  

Asadi used the Saskatoon Wastewater Treatment Plant (SWTP) as a case study because it contains state-of-the-art equipment and is exposed to multiple variations in weather and seasonal temperatures. He worked closely with SWTP personnel, led by plant manager Mike Sadowski, who earned his civil engineering degree from USask.  

“Typical wastewater treatment plants include a wide variety of physical, chemical, and biological treatment processes,” said Asadi. “These processes can result in the release of the odours as they are often performed in parts of the facilities that are open to the air.” 

Accurately determining gas production and emissions from wastewater plants through routine sampling is difficult because of the variety of treatment processes in these facilities, he said. 

By analyzing both types of emissions, Asadi’s research team developed a mathematical modelling system that can be used to accurately estimate the amount of GHGs, and odorous compounds emitted from wastewater treatment plants.  

The information can be used to design more efficient plant operations to better manage both smelly compounds and gas emissions, leading to cleaner air and increased environmental protection. 

 The work is unique, Asadi explained, because it incorporates a type of machine learning model called a Generative Adversarial Network, which can provide accurate simulated emission data to fill in areas where actual data may be limited or difficult to obtain. 

“This technique can be valuable as it will lead to reducing time and effort, as well as related cost savings,” said Asadi. “Greenhouse gases have gained more attention in Canada given the recent carbon pricing initiatives that make capturing greenhouse gases economically beneficial to treatment plants.” 

Asadi completed his PhD in 2022 under the supervision of USask College of Engineering associate professor Dr. Kerry McPhedran (PhD). The research was published in four top scholarly journals, including Science of the Total Environment. 

“There is no Planet B, and this simply keeps driving me forward to seek easy-to-implement, cost-effective, and accessible solutions to help protect the Earth,” said Asadi. 

Research funding was provided by a USask College of Graduate and Postdoctoral Studies Dean’s Scholarship and by the Natural Sciences and Engineering Research Council of Canada Discovery Grant program. 

This article first ran as part of the 2022 Young Innovators series, an initiative of the USask Research Profile and Impact office in partnership with the Saskatoon StarPhoenix.