'We don't see agricultural residue as waste': U of S researchers tackling Sask.'s arsenic problem in water

SASKATOON -

A team of chemical engineering scholars at the University of Saskatchewan (U of S) are tinkering with agricultural waste, to create water filters that remove harmful chemicals such as arsenic from drinking water and wastewater.

Using the synchrotron at the Canadian Light Source (CLS), along with funding from the province’s Agricultural Development Fund, engineers were able to look at agricultural waste such as wheat and canola straw on a microscopic level, to study how this residue absorbs toxins in water.

Jafar Soltan, professor of chemical and biological engineering at U of S said the research into removing harmful chemicals from water could be used at the industry level, to help mining companies clean up tailings from mine sites, but it can also be used at the municipal level, helping communities such as First Nations reserves and clean drinking water supplies.

“Our initial thought was the industry that is dealing with tailings, so we could find these filters … something you pass the water through or you put the filter in the lake and it grabs the pollutants,” Soltan said. “Now we’re looking at a wider range of applications, maybe drinking water, surface water flowing through communities and we want to treat it. We can translate this science into technology.”

Khaled Zoroufchi Benis, a Ph.D. candidate in chemical engineering at U of S says arsenic is a harmful carcinogen found in many sources of water in Saskatchewan, and his research focuses on ways to develop environmentally-friendly filtration systems to get the harmful toxins out.

“We know we have an arsenic problem in our water in Saskatchewan, in drinking water in some rural areas and also in northern Saskatchewan and in the mining industry,” Zoroufchi Benis said.

He added U of S is collaborating with the mining industry to see how agricultural-based residue filtration systems can help remove arsenic from uranium wastewater. But, Zoroufchi Benis is also looking at how this natural filtration system could be used to comb out pharmaceutical chemicals from water systems.

If his research is adopted by technology and used as a new form of water filtration, the country’s agricultural sector could see a big opportunity to recycle its waste into something useful.

“We don’t see agricultural residue as waste, it’s more valuable and in the future we will hear a lot about using agricultural residue not just in water treatment but other applications like energy generation,” Zoroufchi Benis said.

According to an annual report from Saskatchewan’s Water Security Agency, who regularly test Saskatchewan water for chemicals including arsenic, of all the testing for arsenic resulting from regular required sampling, there were 32 instances of arsenic exceedances that occurred in samples from 15 human consumptive systems in 2020, according to its report.

Additional voluntary arsenic testing was conducted by 10 human consumptive municipal systems, resulting in 66 additional exceedances.