Newswise – New research led by Texas A&M AgriLife Research It has identified what could be a new biological approach to removing extremely small and potentially dangerous plastic particles from water.
A study called “Removal of microplastics in the aquatic environment by fungal pelletization,” led by Huaimin Wang, PhD, a postdoctoral fellow at Texas A&M. College of Agriculture and Life Sciences Department of Plant Pathology and Microbiology. Collaborators included Susie Dye, Ph.D., associate professor in the department, and a team of researchers.
US Department of Agriculture Forest Service Northern Research Station Also participated in the study, which can be found online in the September issue Bioresource Technology Reports.
“Although mushroom pellets have been studied for algae harvesting and wastewater treatment over the past decade, to our knowledge, it has not yet been used to remove microplastics from the aquatic environment,” Dai said. “This study will explore their use for this purpose.”
Microplastics in the environment
Microplastics, the tiny particles of plastic that result from commercial product development and the breakdown of larger plastics, have attracted increasing attention in recent years because of their potential damage to the ecosystem. With the continuous increase in global production of plastics, the contamination of this group of persistent waste pollutants derived from synthetic polymers represents a significant environmental challenge.
Although the health risks posed by submicron microplastics to humans are not yet fully understood, those who study them generally believe that the overall risk is associated with submicron microplastics – the specified measurement of less than a micron. – Higher than large plastic. They suggest that this is largely due to a greater potential for long-range transport and an ability to more easily penetrate the cells of living organisms.
“Previous research has shown that sub-micron microplastics can easily travel significant distances in the environment, penetrating plant root cell walls,” Wang said. “They have been shown to be transferred to plant fruiting bodies and the human placenta.”
In addition to microplastics produced by direct human activities, such as cosmetics and industrial production, nanoplastics – synthetic polymer particles between 1 nanometer and 1 micrometer in diameter – can also be produced by the fragmentation or degradation of larger plastics.
A significant part of the microplastics produced by human activity is disposed of in sewage and wastewater treatment facilities. Although these plants are able to remove the vast majority of them, many sub-micron particles are unfiltered.
“Microplastics and nanoplastics removed after activated sludge treatment can be further removed by additional conventional methods such as coagulation, disc filters and membrane filtration,” Dai said. “But enriched microplastics still pose a waste management challenge.”
Unfortunately, he said, some disposal methods, such as landfilling or incineration, are not environmentally friendly for returning them to the natural carbon cycle.
For the study, three candidate fungal strains were selected based on their growth rate, dye degradation, spore production, and pellet formation. Two were newly isolated strains of white rot fungi.
The research yielded promising findings on the removal of polystyrene and polymethyl methacrylate microplastics and nanoplastics – from 200 nanometers to 5 micrometers in the aquatic environment – using these isolated fungal strains.
“These types of microplastics and nanoplastics are the most common,” Dai said.
Three strains showed high rates of microplastic removal and demonstrated potential microplastic assimilation.
“The microplastics are attached to the surface of the fungal biomass, making it easy to remove them from the water as part of the pellets,” Dai explained.
Wang said that because of the unique capacity of the selected white rot fungus strains to form pellets, they should be suitable for remediating microplastics.
“They may also have potential for use in upgrading wastewater treatment plants and as a cost-effective way to further remove microplastics and minimize plastic pollution in natural water bodies,” he said.
More about Dai's research on natural bioremediation
Current research using mushrooms to remove microplastics is compatible with Dai Previous research Using fungi to remediate PFAS or “forever chemicals” in the environment.
“Fungi have unique environmental applications because of their diversity and resilience,” Dai said. “They have also been instrumental in the ability to develop new technology for bioremediation of these chemicals, which may threaten human health and ecosystem sustainability.”
PFAS are used in many applications, from food packaging and packaging, to dental floss, firefighting foam, non-stick cookware, textiles and electronics.
Dai's new technology uses plant-derived materials to absorb PFAS and dispose of them through microbial fungi that literally eat them.