Common Plant Shows Promise for Removing Microplastics From Drinking Water

Researchers at São Paulo State University's Institute of Science and Technology have discovered that seed extract from Moringa oleifera trees can effectively remove microplastics from water through coagulation, matching the performance of conventional aluminum sulfate treatments. Published in ACS Omega, the study used Jar Tests and Scanning Electron Microscopy to demonstrate that saline extracts from Moringa seeds neutralize negative charges on polyvinyl chloride microplastics, causing them to cluster into filterable aggregates. The plant-based solution performs especially well in alkaline water and avoids the toxic residues and increased dissolved organic matter associated with aluminum-based chemicals. Because Moringa seeds can be processed locally without industrial facilities, the technology offers particular promise for rural and resource-limited communities in tropical regions where the plant thrives, though researchers note that further studies are needed to verify large-scale feasibility and consistent quality.

Moringa seed extract as a natural coagulant for microplastic removal

• ▪Saline extracts from Moringa oleifera seeds induce a coagulation effect in water that is comparable to aluminum sulfate.
• ▪The research on Moringa oleifera seed extract for microplastic removal was published in ACS Omega journal by the American Chemical Society.
• ▪Moringa oleifera is native to India but now thrives in many tropical regions worldwide.
• ▪Coagulation neutralizes negative surface charges on microplastic particles, causing them to cluster into larger aggregates that can be filtered out.
• ▪A study at the Institute of Science and Technology of São Paulo State University revealed that Moringa oleifera tree seeds can remove microplastics from water.

Research methodology and experimental validation

• ▪The Moringa oleifera research team tested the seed extract on natural water samples from the Paraíba do Sul River.
• ▪Gabrielle Batista is the lead author of the Moringa oleifera microplastic removal study and a postgraduate student in Civil and Environmental Engineering at FEB-UNESP.
• ▪Moringa oleifera seed extract and aluminum sulfate produced flocs of similar size and microplastic removal efficiencies in laboratory tests.
• ▪The Moringa oleifera microplastic removal study used Jar Tests to replicate water treatment plant conditions on a small scale.
• ▪The Paraíba do Sul River provides drinking water to São José dos Campos, Brazil.
• ▪Scanning Electron Microscopy was used to count microplastic particles before and after treatment with Moringa oleifera seed extract.
• ▪High-speed cameras and laser beam measurements were employed to analyze the dynamic behavior and size distribution of flocs formed during Moringa oleifera treatment.
• ▪The Moringa oleifera study tested coagulation on water contaminated with polyvinyl chloride microplastics.
• ▪The FAPESP-funded project titled "Direct and In-Line Filtration for the Removal of Microplastics from Drinking Water" explores scalable filtration processes integrating coagulation before filtration.
• ▪Professor Adriano Gonçalves dos Reis leads the research team conducting the Moringa oleifera water treatment study.

Environmental and practical advantages over chemical coagulants

• ▪Aluminum and iron-based coagulants are non-biodegradable and leave toxic residues.
• ▪Moringa oleifera is a biodegradable and natural product that offers a safer alternative for water coagulation.
• ▪Aluminum sulfate increases dissolved organic matter in treated water, which complicates further treatment and raises costs.

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