A new study has indicated that okra and fenugreek may have microplastic-removal qualities, providing a biodegradable and nontoxic alternative to conventional water treatment. 

Published in ACS Omega by researchers from Tarleton State University in Texas, US, the study concludes that okra and fenugreek extracts can attract and remove up to 90% of microplastics from ocean water, freshwater, and groundwater.

“Conventional wastewater treatment using inorganic and organic polymeric solutions are non-biodegradable and toxic to ecosystems. Plant-derived polysaccharides can provide a highly efficient, nontoxic, and eco-friendly substitute to synthetic solutions,” say the researchers.

Plant power

To create the plant-based solutions, the researchers extracted gel from fenugreek seeds and polymers from sliced okra and placed them into separate containers of water overnight. They then removed the plant extracts and dried them into powders. 

The researcher mixed the plant extracts with microplastic contaminated water, determining that one gram of either powder in one liter of water trapped microplastics the most effectively. 

Specifically, dried okra removed 67% of microplastics in one hour, while the fenugreek extract removed 93%. 

Polyacrylamide — a chemical compound that separates and suspends solids in water — is commonly used to remove contaminants during wastewater treatment. However, the researchers say that okra and fenugreek extracts could be a biodegradable and nontoxic alternative. 

Beyond the lab

The researchers also tested the plant-based extracts on polluted water bodies around Texas. 

They found that the microplastic removal efficiency changed depending on the original water source. Okra performed best in ocean water, removing 80% of microplastics, while fenugreek worked best in groundwater, removing around 80–90%.

A one-to-one ratio of okra and fenugreek powder performed best in freshwater. The study indicates that the different removal efficiencies are a result of each water sample having various types, sizes, and shapes of microplastics. 

According to the researchers, microplastics from plastic pollution in the ocean threaten human and environmental health. 

“These new emerging pollutants cause physical harm and serve as a substrate for other contaminants that adhere to and/or are adsorbed in microplastics. Consumption of these fine particles by organisms may lead to bioaccumulation and bioamplification.”

Recently, another study revealed that a mixed blend of microplastics may be more harmful than a single polymer to marine copepods, a key food web species. Moreover, Chomps, a US-based snack brand, announced a collaboration with 4ocean, a global clean-up organization, to help reduce plastic pollution in the ocean.