Microplastics are defined as having a diameter of 5nm or less and are too small for filtering or screening during wastewater treatment. Microplastics are often included in soaps, shower gels, and facial scrubs for their ability to exfoliate the skin. Microplastics can also come off clothing during normal washing.
These microplastics then make their way into waterways and are virtually impossible to remove through filtration. Small fish are known to eat microplastics and as larger fish eat smaller fish these microplastics are concentrated into larger fish species that humans consume.
Ferreira used a combination of oil and magnetite powder to create a ferrofluid in the water containing microplastics. The microplastics combined with the ferrofluid which was then extracted.
After the microplastics bound to the ferrofluid, Ferreira used a magnet to remove the solution and leave only water.
After 1,000 tests, the method was 87% effective in removing microplastics of all sorts from water. The most effective microplastic removed was that from a washing machine with the hardest to remove being polypropylene plastics.