Water security is a huge global issue, and so is the polluting effect of plastics on the environment. In an effort to tackle both problems, a team of researchers from the University of Saskatchewan (USask) in Canada has developed a unique bioplastic material that can absorb excess nutrients from water and then be used as a fertiliser on decomposition.
This plastic-like material was created by USask chemistry professor Dr Lee Wilson and his research team, with the paper recently published in RSC Sustainability. The research team includes PhD candidate Bernd G.K. Steiger, BSc student Nam Bui, and postdoctoral fellow trainee Bolanle M. Babalola.
According to Dr Wilson, who is also a member of the Global Institute for Water Security (GIWS), elevated levels of phosphate in surface water represent a huge global water security issue. The bioplastic material functions as an absorbent, taking phosphate out of water and the pellets can be harvested and used as an agricultural fertiliser.
The bio-composite pellets created by the research team resemble plastic but are made of biological materials that are designed to decompose, and include a marine polysaccharide (chitosan), eggshells, and wheat straw.
Phosphate is an essential nutrient commonly used in fertilisers for agriculture. However, excessive levels of this chemical can lead to a proliferation of aquatic plants such as blue green algae, which releases toxins harmful to humans and animals.
Phosphate is also a non-renewable resource and obtained through phosphate rock mining. The USask research team’s bioplastic offers an alternative solution to mining phosphate by using the nutrients already present in water sources. It also addresses the increasing menace of microplastics pollution in the environment.
"Within the last decade, as plastic breaks down into small particles, it can get into food, and penetrate into cells," Dr Wilson explained.
"If you placed a plastic margarine container into your backyard and bury it, it might be there for 50 years or more until it starts to crumble apart. But it's those small particles that are harmful to human health.
"With bioplastics, you can avoid all of that and you basically get something that breaks down into its original components or can be more readily composted or degraded through natural processes," he added.
Image: USask chemistry professor Dr Lee Wilson holds an example of bioplastic pellets designed to absorb phosphate from water. Photo credit: Kristen McEwen
Based on the article published by University of Saskatchewan.
