These magnetic nanoparticles have the capacity to remove ultra-fine particulate pollution by forming aggregates with pollutant particles. In Florida, phosphorus from human activity is a long-term threat to the sensitive ecosystems found in the Everglades. Constructed wetlands are engineered upstream of the Everglades to reduce the nutrient discharge entering them. While this approach has significantly reduced the phosphorus entering the waterways, the South Florida Water District continues to struggle to achieve desired phosphorus levels in the waters leaving the engineered wetlands. The phosphorus remaining in the outflow of some of these engineered wetlands largely consists of ultrafine particulates. Further reducing phosphorus levels in these waters, potentially via removing ultrafine particulate, is a significant technical challenge. Approaches such as filtration are not feasible for these large volumes of water. The industry needs to address the technical challenges of removing contaminants from waterways.
Researchers at the University of Florida have developed magnetic nanoparticles as a potential option to reduce the amount of ultra-fine particulate phosphorus entering the Everglades. These nanoparticles have significant societal impacts, such as improving water management practices for surface water treatment.
Attracts and removes ultra-fine particulates and environmental contaminants from large volumes of water and reduces resuspension and export of ultra-fine particulates from soil sediment
These magnetic nanoparticles remove ultra-fine contaminants from aqueous suspension. The nanoparticles possess negatively or positively charged surfaces as a result of varying coating molecules, allowing for a degree of customization to address different contaminants with varying surface chemistry. The charged nanoparticles are then mixed with the contaminated body of water, forming aggregates of the magnetic nanoparticles and ultra-fine particulate pollutants. This approach applies a magnetic field to the aggregates for a time frame ranging from seconds to minutes to longer, dependent on the amount of fluid and contaminants. The nanoparticles are removed from the body of water to neutralize their charge and clear the contaminants, preparing the nanoparticles for reuse in future water treatments. Alternatively, the magnetic nanoparticles may also be used to treat sediment or solids from which particulate pollutants may be re-suspended, as a result of disturbance resulting from biological activity, weather, etc., to reduce ultrafine particulate export.