Researchers at Talton State University have discovered that extracts from okra and/or fenugreek can attract and eliminate as much as 90% of microplastics from sea, freshwater, and groundwater.
Srinivasan et al. We demonstrated that plant-based polysaccharides exhibited better microplastic removal efficiency than polyacrylamides commercially used in water treatment. Image credit: Srinivasan et al., doi: 10.1021/acsomega.4C07476.
Microplastics are emerging as significant pollutants that pose a threat to aquatic environments globally.
These solid polymers, measuring less than 5 mm, originate from larger plastic debris and the fragmentation of environmental emissions.
These contaminants not only inflict physical damage but also act as carriers for other harmful pollutants that cling to microplastics.
When consumed by organisms, these microparticles can lead to bioaccumulation and bioproliferation.
Conventional wastewater treatment methods using inorganic and organic polymer flocculants are not eco-friendly and can introduce toxicity.
Dr. Rajani Srinivasan and her team at Talton State University have been investigating a safe, plant-based strategy for attracting and eliminating contaminants from water sources.
In laboratory experiments, they found that okra, fenugreek, and tamarind polymers effectively adhered to microplastics, allowing them to aggregate and sink for easy separation from water.
To prepare the sticky plant polymer, sliced okra pods were soaked in separate containers of water overnight.
The resulting extracts were collected, dried, and ground into a powder.
Analysis revealed that the powdered extracts contained polysaccharides, which are natural polymers.
Initial tests on pure water contaminated with microplastics indicated: (i) One gram of any of the quart (1 liter) powders was highly effective in trapping microplastics. (ii) Dried okra and fenugreek extracts removed 67% and 93% of the plastic in one hour, respectively. (iii) A combination of equal parts okra and fenugreek powder reached a maximum removal efficiency of 70% within 30 minutes. (iv) Natural polymers proved significantly more effective than synthetic commercial polyacrylamide polymers typically used in wastewater treatment.
The researchers conducted tests using real water samples contaminated with microplastics.
They collected samples from various water sources around Texas and analyzed them in the lab.
The removal efficiency of plant extracts varied based on the original water source: okra was most effective in seawater (80%), fenugreek showed 80-90% efficiency in groundwater, and a 1:1 mixture of okra and fenugreek achieved 77% efficiency in freshwater.
The scientists suggest that natural polymers display different efficiencies due to the diversity of microplastic types, sizes, and shapes across water samples.
“While polyacrylamide is commonly used for contaminant removal in wastewater treatment, extracts from okra and fenugreek provide biodegradable and non-toxic alternatives,” they stated.
“Using these plant-based extracts for water treatment can eliminate microplastics and other pollutants without introducing additional toxins into the treated water, thereby reducing long-term health risks for the public,” Dr. Srinivasan added.
The team’s work has been published in the journal ACS Omega.
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Rajani Srinivasan et al. 2025. Fenugreek and okra polymers as therapeutic agents for removing microplastics from water sources. ACS Omega 10(15):14640-14656; doi:10.1021/acsomega.4C07476
Source: www.sci.news
