Microplastics have become a cause for concern as they can create significant harm to the environment. Natural polymers are looking promising compared to the synthetic polymers that have been used in the past by researchers in hopes to clean up ocean water, freshwater and groundwater. Okra and Fenugreek extracts are reported to have the ability to attract and remove up to 90% of microplastics in waters.
After examination, research showed that the extracts contained a natural polymer called polysaccharides. To extract the polymers, researchers-soaked sliced okra pods and blended Fenugreek seeds in water overnight in their own containers. Next the extracts were removed from the solution and turned into a powder.
Initial experiments conducted in water spiked with microplastics showed that one gram of either okra or fenugreek powder in a quart of water trapped microplastics the most effectively. Research also found that in one hour 67% and 93% of plastic were removed by dried okra and fenugreek extracts. Furthermore, within 30 minutes, an equal part mixture of both powders reaches maximum removal efficiency, which is 70%. Compared to synthetic polymers the natural polymers performed significantly more effectively promising strong potential for removing microplastics.
To evaluate the effectiveness of the polymers, researchers then decided to test the powders on water samples from bodies of water around Texas. The samples were polluted by real microplastics to gain real-world results. Researchers discovered the difference in microplastic removal efficiency depends on the water source. It was discovered that ocean water had the best results with okra being 80% effective, fenugreek works best with groundwater being 80-90% effective and one part okra and one part fenugreek combination works best on fresh water being 77% effective. The hypothesis among researchers is that each sample has different types of microplastics, making certain polymers more effective.
Researchers believe that the polymers from okra and fenugreek can be used as a biodegradable and safe treatment compared to Polyacrylamide which is currently used during wastewater treatments.
“Utilizing these plant-based extracts in water treatment will remove microplastics and other pollutants without introducing additional toxic substances to the treated water,” says Srinivasan, “thus reducing long-term health risks to the population.”
Tarleton State University was one of the contributors to funding along with the U.S. Department of Energy; High Plains Water District located in Lubbock, Texas; the Burnaby Munson Endowed Research Professorship; the National Science Foundation Research Experiences for Undergraduates program; and the Welch Foundation.