Farm waste can filter microplastics in surface runoff, prevent pollution

Using treated plant waste as a filter reduced the presence of harmful microplastics in agricultural runoff by more than 92%, according to a new study authored by a University of Mississippi research team. Microplastics—tiny plastic particles that are fewer than 5 millimeters in diameter—have been found in every ocean on earth, in food, water, and recently, in farmlands.

An Ole Miss-led research group has recently published proof-of-concept data in Frontiers in Environmental Science that shows biochar to be a cost-friendly and effective method of filtering microplastics from overland water runoff. Biochar is a type of charcoal made from plant material that has been heated or burned in an oxygen-limited environment. Microplastics in agriculture come from two primary sources, said Boluwatife Olubusoye, an Ole Miss doctoral student in chemistry and an author of the study. Sewage sludge from wastewater treatment plants, which is used as a fertilizer, and plastic mulch and row covers, which insulate plants and promote growth, both bring measurable amounts of microplastics to agricultural areas.

Using biochar reduced the amount of microplastics in samples of runoff by between 86.6% and 92.6%. Because of the success of the initial tests, the researchers are scaling up their efforts and currently testing biochar in the field. “Our work could result in new agricultural and stormwater management practices to mitigate microplastic pollution stemming from farms and urban runoff in order to safeguard environmental and human health.”

Source: Phys.org