via UNEP
In many cuisines, okra serves as a master thickener of stews and soups. The goo from that fruit and other plants, such as aloe, cactus and psyllium, can also clean water and wastewater of some types of solid pollutants, as well as some that are dissolved. Now, researchers have demonstrated that combinations of these food-grade plant extracts can remove microplastics from wastewater.
The researchers will present their results today at the spring meeting of the American Chemical Society (ACS). ACS Spring 2022 is a hybrid meeting being held virtually and in-person March 20-24, with on-demand access available March 21-April 8. The meeting features more than 12,000 presentations on a wide range of science topics.
The health effects of ingesting microplastics — tiny pieces of plastic 5 mm or smaller — are currently unclear, but studies suggest that people unintentionally consume tens of thousands of these particles every year. “We think that microplastics by themselves may not be much of a health hazard, but anything that they get into or any type of toxic substance that gets attached to these plastics could go inside our bodies and cause problems,” says Rajani Srinivasan, Ph.D., the principal investigator for the project.
In the typical wastewater treatment process, microplastics are removed from water in two steps. First, those that float are simply skimmed off the top of the water. However, this step only removes a fraction of the total microplastics that are present. The rest must be removed by adding flocculants, or sticky chemicals that attract microplastics and form large clumps. The clumps then sink to the bottom of the water and can be separated from it.
Srinivasan, who is at Tarleton State University, points out that some of the substances currently used to remove contaminants are potentially harmful, so she and her team have been investigating nontoxic alternatives. For example, one common flocculant, polyacrylamide, can break down into toxic chemicals under certain conditions. “It doesn’t help if we try to clean up water but add potentially toxic substances to remove the pollutants,” she says.
Previously, Srinivasan had studied the use of food-grade plant extracts as nontoxic flocculants to remove textile-based pollutants from wastewater. Her team specifically focused on polysaccharides in the extracts because these biopolymers possess the appropriate chemical and biological properties to attract and capture pollutants like dyes or even bacteria. “I was working with the removal of microorganisms and things like that, and I thought, ‘Why not try microplastics?’” she says.
So, the team of undergraduate and master’s students tested polysaccharide extracts from fenugreek, cactus, aloe vera, okra, tamarind and psyllium — all of which are food-grade materials — as flocculants to capture microplastics. They tested compounds from the individual plants, as well as in different combinations. To do this, they added these extracts to various microplastic-containing water sources. Then, they examined microscope images of the flocculant clumps before and after treatment and counted the microplastics to determine how many particles had been removed.
In their experiments, the researchers found that polysaccharides from okra paired with those from fenugreek could best remove microplastics from ocean water, whereas polysaccharides from okra paired with those from tamarind worked best for freshwater samples. Overall, the plant-based polysaccharides worked better than, or as well as, the traditional flocculant polyacrylamide, depending on the combination of extracts and water source.
Importantly, the plant-based flocculants can be implemented in existing water treatment processes. “The whole treatment method with the nontoxic materials uses the same infrastructure,” says Srinivasan. “We don’t have to build something new to incorporate these materials for water treatment purposes.”
Looking forward, she and her team will continue tailoring the ratios and combinations of plant-based flocculants to optimize removal of different microplastic types from a variety of water sources, such as ocean water, estuary water, freshwater and groundwater. They also plan to scale up their nontoxic microplastics removal process in field studies outside of the lab. Ultimately, they hope to commercialize this new, plant-based method so that microplastics can be removed from water on an industrial scale — enabling cleaner and safer water for everyone to drink.
Original Article: Cooking up a way to remove microplastics from wastewater — with okra, aloe
More from: American Chemical Society | Tarleton State University
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Removing microplastics from wastewater
- Removing Fukushima's melted nuclear fuel harder than release of plant's wastewater: Officials
A graph on a computer monitor nearby shows a steady decrease of water levels as treated radioactive wastewater is diluted ... the contaminated water is to remove the melted fuel debris,” said ...
- Junior Wins Udall Scholarship, Rutgers’ First Recipient Since 2004
The 21-year-old is the first Rutgers student to be named a Udall Scholar since 2004, said Anne Wallen, director of the Office of Distinguished Fellowships at Rutgers-New Brunswick.
- MIT Technology Review
Electrical engineer Nili Persits, PhD ’24, has developed low-cost Raman spectroscopy systems that allow instant chemical analysis.
- Recycling and Waste News
A Virus Could Help Save Billions of Gallons of Wastewater Produced by Fracking ... plant-based plastic material releases nine times less microplastics than conventional plastic when exposed ...
- It's time to act on microplastics in Lake Tahoe: Ban certain plastics
it’s all the more alarming that Lake Tahoe’s levels of microplastics have plastic particle concentrations larger than the ocean gyres. So, why does the Tahoe Basin, with all its wastewater ...
Go deeper with Google Headlines on:
Removing microplastics from wastewater
[google_news title=”” keyword=”removing microplastics from wastewater” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
Microplastics
- Microrobotic Swarms Tackle Microplastics and Bacteria Pollution
In recent research published in the journal ACS Nano, researchers reported how swarms of microscale robots, or microrobots, collected microorganisms and plastic fragments from water.
- Is Your Teabag Exposing You to Microplastics? Yes, According to New Research
I remember the first cup of hot tea I ever had. I was 17 and recovering from a misdiagnosis that left me unable to walk or feed myself. My mom had to go to work and so left me with my grandmother to ...
- Swarms of Miniature Robots Clean Up Microplastics and Microbes, Simultaneously
Microscale robots that mimic natural swarms, like schools of fish, have been designed to capture microplastics and bacteria from water.
- Tiny tenacious robots snatch bacteria and microplastics out of the water
Scientists have developed tiny "robots" which appear to be very effective at removing microplastics pollution from water. What's more, the little bots also target the harmful bacteria that often hitch ...
- America has a $250 billion problem: Microplastics have invaded our bloodstreams and may increase the risk of heart attack and stroke
For all the damage that microplastics are doing to the planet, it may be that only an impending threat to the human body will direct the kind of attention to the issue that it has long deserved. That ...
Go deeper with Google Headlines on:
Microplastics
[google_news title=”” keyword=”microplastics” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]