MICRO PLASTICS -
ENVIRONMENT
News: IISc researchers design novel
hydrogel to remove microplastics from water
What's in the news?
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Researchers at the Indian Institute of Science
(IISc) have designed a sustainable hydrogel to remove microplastics from water.
Key takeaways:
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According to IISc, microplastics pose a great
threat to human health as these tiny plastic debris can enter our bodies
through the water we drink and increase the risk of illnesses.
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They are an environmental hazard and found even in
remote areas such as polar ice caps and deep ocean trenches, endangering
aquatic and terrestrial lifeforms.
Three-layer Polymer:
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The sustainable
hydrogel designed by the researchers has a unique intertwined polymer
network that can bind the contaminants and degrade them using UV light
irradiation.
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Scientists have previously tried using filtering
membranes to remove microplastics.
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The IISc said the novel hydrogel developed by the
team consists of three different polymer
layers – chitosan, polyvinyl alcohol and polyaniline – intertwined
together, making an interpenetrating polymer network (IPN) architecture.
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The team infused this matrix with nanoclusters of a
material called copper substitute
polyoxometalate (Cu-POM).
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These nanoclusters are catalysts that can use UV
light to degrade the microplastics.
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The combination of the polymers and nanoclusters
resulted in a strong hydrogel with the ability to adsorb and degrade large
amounts of microplastics.
Microplastics:
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They are defined as plastics less than five millimeters (0.2 inches) in diameter.
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They are tiny plastic particles that result from
both commercial product development
and the breakdown of larger plastics.
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The name is used to differentiate them from
“macroplastics”, such as bottles and bags made of plastic.
Found in:
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They are present in a variety of products, from cosmetics to synthetic clothing to plastic
bags and bottles.
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Many of these products readily enter the
environment as waste.
Features:
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They consist
of carbon and hydrogen atoms bound together in polymer chains.
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Other chemicals, such as phthalates, polybrominated
diphenyl ethers (PBDEs), and tetrabromobisphenol A (TBBPA), are typically also
present in microplastics.
Types of Microplastics:
1. Primary
Microplastics:
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They are tiny particles designed for commercial use, such as cosmetics, as
well as microfibers shed from clothing and other textiles, such as fishing
nets.
2. Secondary
Microplastics:
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They are particles that result from the breakdown of larger plastic items, such as
water bottles.
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This breakdown is caused by exposure to
environmental factors, mainly the sun’s radiation and ocean waves.
Environmental Impacts:
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The problem with microplastics is that, like
plastic items of any size, they do not readily break down into harmless
molecules. They can accumulate and
persist longer in the environment.
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Microplastics in the ocean can bind with other harmful chemicals before being ingested by marine
organisms. Standard water treatment facilities cannot remove all traces of
microplastics.
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Microplastics are also a source of air pollution, occurring in dust and
airborne fibrous particles.
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They can also carry toxic chemicals and pollutants, posing additional risks to
organisms and ecosystems.
Go back to basics:
Polymers:
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They are materials made of long, repeating chains of molecules.
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The materials have unique properties, depending on
the type of molecules being bonded and how they are bonded.
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Some polymers bend
and stretch, like rubber and polyester. Others are hard and tough, like
epoxies and glass.
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The term polymer is often used to describe
plastics, which are synthetic polymers.
However, natural polymers also
exist; rubber and wood, for example, are natural polymers that consist of a
simple hydrocarbon, isoprene.
Phthalates:
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Phthalates are a group of chemicals used to make plastics more durable.
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They are often called plasticizers. Some phthalates are used to help dissolve other
materials.
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Phthalates are in hundreds of products, such as vinyl flooring, lubricating oils, and
personal-care products (soaps, shampoos, hair sprays).