According to new research from scientists at Tarleton State University in Texas, okra — you know, the green, finger-shaped pod that is often added to delicious dishes like gumbo and soup — is a valuable weapon in the fight to get microplastics out of our drinking water.

What are microplastics?

Microplastics are fragments of plastic pollution that are constantly breaking down into tinier and tinier pieces that get into seemingly every corner of our planet. Since microplastics become so minuscule, it is incredibly difficult to prevent them from infiltrating any environment (including our own bodies), monitor them, or remove them.

Why okra?

While some may not be partial to okra because of its slimy, gooey texture, it is this quality that allows a compound from the plant (which is scientifically a fruit, by the way, even though it’s thought of as a vegetable) to be utilized as a safer method of filtering out microplastics from water.

Currently, water treatment plants typically remove microplastics from municipal water supplies by adding flocculants to the water. Flocculants are chemicals that plastic particles stick to. When flocculants are added to plastic-polluted water, they form clumps of microplastics that get big enough to be removed, taking the particles with them.

The problem with flocculants is that they can become toxic too. This is why Dr. Rajani Srinivasan and his colleagues at Tarleton State University decided to look for safer alternatives by investigating compounds extracted from several food-grade plants.

Through their investigation, Dr. Srinivasan and the team found that when polysaccharides from okra were combined with those from fenugreek, the resulting compound was very effective at removing microplastics from seawater. The researchers discovered that when the okra polysaccharides were paired with those from tamarind, the same positive effects were seen in freshwater.

The team found that, depending on factors such as the ratio of the polysaccharides and the water source, the okra-based flocculants did just as well or even better than the chemicals that are currently in use. As an added bonus, the okra compounds can be used in existing water treatment plants, without any expensive modifications to the facilities or processes. 

The next step for the scientists is to figure out if other combinations of plant-derived polysaccharides will work on specific types of microplastics.

This story was part of our Best of 2022 series highlighting our top solutions from the year. Today we’re featuring environment and climate-focused solutions.