Researchers at the University of Missouri are developing a new method to remove microscopic plastic pollutants from water using specially engineered algae.
Mizzou researcher Susie Dai recently created an engineered algae strain designed to capture harmful microplastics from contaminated water. In addition to cleaning waterways, her long-term goal is to recycle the plastic she collects into safer bioplastic materials, such as composite plastic films.
“Microplastics are pollutants found almost everywhere in the environment, including ponds, lakes, rivers, sewage, and the fish we consume,” said Dai, a professor of engineering and principal investigator at the Bond Life Science Center. “Currently, most wastewater treatment plants can only remove large plastic particles, but microplastics are so small that they can slip through and enter drinking water, contaminating the environment and harming ecosystems.”
Artificial algae targets microplastics
In recent research, Dai used genetic engineering to develop algae that produce limonene, the natural oil responsible for orange’s familiar aroma.
Limonene changes the surface properties of the algae, making it repellent to water. Microplastics are also water-repellent, so when the particles come into contact with algae in water, they naturally stick to them. This process creates a mass that sinks to the bottom, forming a dense layer of biomass that can be more easily collected and removed.
The modified algae also grow in wastewater, absorbing excess nutrients while purifying the water during the process.
“We can tackle three problems in one approach by removing microplastics, purifying wastewater, and ultimately using the removed microplastics to permanently manufacture bioplastic products,” Dai said. “Although our research is still in its early stages, our ultimate goal is to integrate this new process into existing wastewater treatment plants to allow cities to more effectively purify water and reduce pollution while producing a useful product.”
Plan to scale up your technology
Dai’s lab is already growing algae in large tank bioreactors. One of the systems, a 100-litre bioreactor nicknamed ‘Shrek’, is currently being used to treat industrial exhaust gases as part of efforts to reduce air pollution.
Looking to the future, Dai hopes to eventually create a larger version of the Schreck system that could be adapted to treat wastewater and remove other pollutants.
This research, “Remediation and upcycling of microplastics by algae” nature communications.
