Building advanced water filters for the oil sands and rural communities

Albertans depend on water in many forms — from the drinking water that flows into homes, to the steam used to release bitumen from the earth. Water is critical for both communities and industry, but keeping that water clean can be a tricky technological challenge.

For Mohtada Sadrzadeh, professor in the Department of Mechanical Engineering at the University of Alberta and principal investigator of the Advanced Water Research Lab, this challenge is an endless source of fascination. For the last fifteen years, he has focused on advancing water filtration methods for use in the oil sands industry and to improve drinking water quality for rural communities. His work is helping to conserve Canada's freshwater and improve the energy efficiency of the water treatment process in industrial settings.

“The water filtering process affects everything. My work is at the interface of water, energy and greenhouse gas emissions,” says Sadrzadeh.

Sadrzadeh acquired his PhD in Engineering in Iran before coming to the University of Alberta as a postdoctoral fellow. In 2015, he began collaborating with Alberta Innovates to improve membrane filtration techniques in oil sands operations.

The Alberta oil sands industry depends on water for steam-assisted gravity drainage operations (SAGD). SAGD involves the injection of steam deep underground to heat up thick bitumen until it can flow and be easily extracted. The process requires about 8.4-12.5 gallons of fresh water for every gallon of bitumen extracted, and Alberta’s SAGD operations produce over seventy million gallons of bitumen per day. This requires an enormous amount of water, which is why oil sands companies recycle about 90% of the water used in operations. However, incomplete filtration leaves behind impurities which can damage equipment.

Ultrafiltration and microfiltration membrane fabrication machine.

“Conventional water treatment methods often fall short of removing all the organic and inorganic particles in the water,” says Sadrzadeh. “This causes fouling and scaling in steam generators and other critical process equipment in bitumen extraction facilities, so they must shut down and repair these facilities more frequently, costing them time and money. My research team is finding ways to treat the water with advanced methods — with membrane-based technologies playing a key role — to enhance water quality, reduce operational disruptions, and improve overall process efficiency.”

Reverse osmosis, nanofiltration, and ultrafiltration membranes remove more particles from the water than conventional methods, helping protect steam generators from damage and reducing the risk of frequent facility shutdowns. To enhance the process’s energy efficiency, Sadrzadeh’s team has developed the world’s first membranes which can withstand the extreme heat of thermal bitumen extraction processes capable of withstanding the extreme temperatures typical of thermal extraction operations. With these membranes, pre-treated water fresh out of the SAGD extraction process does not need to be cooled prior to filtration, saving significant energy costs. These thermally resilient membranes enable the direct treatment of hot, pre-treated SAGD produced water, eliminating the need for energy-intensive cooling prior to filtration. In addition, these advanced, thermally stable membranes allow facility operators to transition from traditional steam generators to more energy-efficient drum boilers, further reducing greenhouse gas emissions.

In 2022, Sadrzadeh expanded the scope of his research to address one of Canada's persistent public health challenges: providing reliable access to clean drinking water in remote, rural, and Indigenous communities. Although microfilters are available on the market, they come with several drawbacks. They often rely on electrically powered pumps, which is not always available in remote areas. Further, they are susceptible to fouling and need to be maintained and replaced frequently which limits their viability in resource-constrained settings.

Dr. Sadrzadeh's team working on ultrafiltration and microfiltration development.

In partnership with Alberta Innovates and Associated Engineering (AE), Sadrzadeh’s team is developing a gravity-assisted membrane, which passively removes hazardous pathogens and other contaminants from the water without the need for external power. To operate the filter, pre-treated water goes into a container 3 metres above the filtering membrane. Gravity alone pulls the water through the membrane, making the water safe to drink.

“Currently, there is no gravity-driven membrane in the market that functions at this scale, so this will be the first one that provides this patent to companies to manufacture and get into the hands of consumers,” says Sadrzadeh. His team is now focused on making the membrane resistant to fouling, reducing the need for frequent replacements.

For Sadrzadeh, creating environmentally friendly technology does not end with water conservation and energy efficiency. In 2022, he launched his startup Greenvi, which aims to build membranes with biodegradable biopolymers.

“Membranes should be used for an average 5 years in a water treatment plant, but once that time is up, they just get thrown away,” says Sadrzadeh. “We don’t want secondary waste, so we’re working on a biodegradable filter.”

Sadrzadeh’s team is currently testing a variety of filters in both lab and applied settings, and next steps will involve working with manufacturers to commercialize the technology.

“We are now making membrane filters at the scale that can be tested and validated in a real water treatment plant,” says Sadrzadeh. “That’s what drives me, knowing that the technologies we create are not confined to the lab. They’re tangible, scalable, and ready to be tested by end users in practical settings.”

This article is part of Making Waves, an annual Alberta Innovates publication highlighting water solutions we support. You can read more stories from this issue below.