Scientists have identified an unlikely ally in the fight against microplastic pollution: a widely grown tropical plant already used as food across much of the world.
Researchers at Brazil’s São Paulo State University report that seeds from Moringa oleifera — commonly known as moringa — can remove microscopic plastic particles from drinking water using a natural process that avoids harsh industrial chemicals. The study was published in the peer-reviewed journal ACS Omega.
Microplastics, produced as larger plastics break down or shed from synthetic fabrics and packaging, have been found in water supplies across the globe. Their presence has raised alarm among scientists and health experts, as long-term exposure risks remain unclear. Conventional treatment plants typically depend on chemical coagulants such as aluminum sulfate to capture these particles, but those chemicals can generate environmental concerns and leave residual by-products.
The Brazilian research team discovered that a salt-based extract derived from moringa seeds works by neutralizing the electrical charges that keep microplastic particles floating in water. Once destabilized, the particles bind together into larger clumps that can be filtered out more easily.
Laboratory experiments showed the plant extract performed as effectively as aluminum sulfate and, in some alkaline conditions, even delivered stronger results. Because moringa grows widely in tropical regions and requires minimal processing, researchers believe the method could offer an affordable purification option for communities lacking advanced water treatment infrastructure.
To evaluate the technique, scientists introduced polyvinyl chloride (PVC) microplastics — considered among the more hazardous forms of plastic — into tap water samples. The particles were exposed to ultraviolet light to simulate environmental aging before treatment began.
Using filtration systems modeled on real water treatment operations, the team recorded significant reductions in microplastic concentrations after applying the moringa-based solution. High-resolution imaging confirmed that large numbers of plastic particles were successfully removed.
Unlike conventional chemical coagulants, moringa is biodegradable and already consumed as a nutritional plant in many countries, reducing concerns over toxicity or chemical residue. Researchers say this natural compatibility could make it an attractive sustainable alternative as regulators increasingly scrutinize chemical additives used in water purification.
The scientists are now testing the method using untreated river water to determine how well it performs outside controlled laboratory conditions. Early findings suggest the plant extract remains effective in more complex, real-world environments.
If further trials confirm these results, plant-based purification techniques such as moringa treatment could become a low-cost tool in tackling one of the fastest-growing environmental threats — ensuring safer drinking water in both developing and industrialized regions.
