Katharina Buczek
Sponges are like the Swiss Army knife of household items. For thousands of years, we have been using dried natural sponges for everything from cleaning and painting to even drinking liquids like honey and water.
Made from either natural or synthetic materials, sponges excel at trapping small debris in their multitude of pores. Not to mention, recent research suggests that these porous wonders might just have the potential to tackle one of today’s major environmental issues– microplastic pollution.
Back in August, a team of Chinese scientists released a study about their newly engineered synthetic sponge, designed to efficiently capture microscopic plastic particles.
Their experiments demonstrated that when a liquid containing carefully measured amounts of plastics is run through the sponge, it can effectively filter out not just microplastics but even tinier nanoplastics.
The performance of the sponge did vary, depending on factors like the amount of plastic in the liquid and its pH and salinity levels. However, under the right conditions, up to 90% of the microplastics were removed. The team also tested this in a range of liquids, from seawater and tapwater to even soup from a takeout restaurant.
These sponges are primarily composed of starch and gelatin. Resembling oversized marshmallows, they’re also so lightweight that you can place one on a flower without causing its petals to droop. This implies they would be cost-effective and simple to ship.
As for the sponges’ internal structure, their makeup doesn’t feature the typical bubble-like cavities you might expect. Instead, they have a more jagged surface structure.
Guoqing Wang, a materials chemist at Ocean University of China and one of the paper’s co-authors, detailed how the sponge’s composition is flexible. By adjusting the temperature during the mixing process of the two main compounds, the sponge’s porosity can be altered. In turn, this impacts the size of the particles the sponge can capture– with highly porous sponges being excellent for trapping extremely fine particles.
Should these spongers ever be manufactured on a large scale, Wang suggests they could serve practical purposes like filtering microplastics in wastewater treatment facilities or purifying water in food production plants.
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