As plastic pollution continues to grow and infiltrate living organisms, a Brazilian research team has developed a process capable of recovering PET micro- and nanoparticles from water using magnets.
Researchers from the University of São Paulo in Brazil have devised a novel method to extract micro- and nanoparticles of plastic from water. These tiny plastic fragments originate from the breakdown of plastic waste in nature, tire wear, clothing fibers, and industrial leaks. Microplastics are notoriously difficult to treat, and there are currently no large-scale solutions to remove them from water. Present in soil, air, and water, microplastics infiltrate all plant and animal species, including humans. However, their health effects remain poorly understood. Nanoplastics, which are a thousand times smaller than microplastics, can cross natural biological barriers and reach vital organs. Recent studies have even detected them in the human brain.
The process developed by Brazilian researchers uses magnetic nanoparticles modified with a polydopamine group. Polydopamine is a polymer derived from dopamine, a neurotransmitter naturally found in the human body. The nanoparticles created by the researchers are designed to bind to PET (polyethylene terephthalate) micro- and nanoplastics, the material used in bottles and polyester clothing. Once combined, the particles can be collected using an electric field. “Polydopamine mimics the adhesive properties of mussels, which attach very firmly to various surfaces. It adheres tightly to plastic fragments in water, allowing the magnetic nanoparticles to capture them. This unwanted material can then be removed from water with a magnet,” explained Henrique Eisi Toma, a professor at the Institute of Chemistry at the University of São Paulo, in a press release.
Breaking Down PET
In parallel, the researchers aim to degrade plastics using enzymes, similar to what the French company Carbios is already doing. Carbios, currently building its first factory in Meurthe-et-Moselle, enzymatically depolymerizes PET and polyester.
The Brazilian scientists hope to use lipase to break PET down into its basic components: terephthalic acid and ethylene glycol. “Lipase breaks PET into its initial monomeric forms, which can then be reused to synthesize new PET. Our study focused on PET, but other researchers can incorporate specific enzymes to process other plastics, such as polyamide or nylon,” concluded Henrique Eisi Toma.
Source: Techniques Ingenieur
