Wednesday, October 11, 2017

Barley straw shows promise tackling farm pollutants

Lab testing is showing that treated barley straw can absorb antibiotics, raising hopes that it could be used to prevent water pollution.

 Pharmaceuticals, including antibiotics, are an increasingly common pollutant in water systems, says Catherine Hui Niu, associate professor in the Department of Chemical and Biological Engineering at the University of Saskatchewan.

 After pharmaceuticals are used in humans and animals, traces end up in manure and sewage and, from there, become pollution in the environment.

There are concerns that polluted water might risk human health and ecosystems. To date there has been no effective way to remove them from water sources.

 There are some materials that attract pharmaceutical pollutants to them in a process called adsorption, and could hypothetically be used to help remove them from water, says Niu. But their adsorption capacities need to be enhanced to make them useful for large scale clean-up efforts.

That’s where barley straw comes in.

Niu and Bei Yan, a member of her research team, used the Canadian Light Source at the University of Saskatchewan to study samples of pretreated barley straw exposed to norfloxacin.

It’s a type of quinolone antibiotic commonly used to treat bladder infections and a few other conditions, and has been detected as a pollutant in some water and sewage samples.
The scientists’ work revealed some of the mechanisms of how the pretreated barley straw works as an adsorbent.

They found that subjecting the straw to a chemical and microwave heating protocol actually improved its adsorption qualities, specifically for removing the antibiotic norfloxacin from water. These results have been published in Chemical Engineering Journal.

“The pretreated barley straw’s adsorption capacity is much higher than many other materials out there,” says Niu.

It’s about six times greater than that of untreated raw barley straw.