Katharina Buczek
Christian Adlhart, a chemist at Zurich University of Applied Sciences in Switzerland who has also dabbled in developing sponge filters for microplastics, proposed another application: using these sponges in washing machines. Synthetic fabrics often release microplastics into water during washing cycles. Adlhart suggests that a sponge could be placed inside the washing machine drum to capture a significant portion of these released fibers.
These types of sponges operate through a couple of different mechanisms. When water is actively pushed through a sponge– say, by squeezing and releasing it– microplastic particles become ensnared in its pores, much like marbles collected in a bucket. Additionally, even when the sponge is just floating in stagnant water, some plastic particles will attach to it due to electrostatic forces.
Still, there are some bumps on the road to wide-scale adoption of these sponges. Adlhart pointed out how starch and gelatin, the main components, are also valuable to the food industry. So, there might be future competition for these raw materials.
That being said, alternative materials can be used to make similar sponges. For instance, the version that Adlhart and his team created uses chitosan, a sugar obtained from crustacean shells, as the structural base. Chitosan isn’t in high commercial demand, either, so it’s less likely to face the same supply challenges.
Adlhart explained that the inspiration for his sponge design, crafted from a web of chitosan nanofibers, came from oysters. These shellfish capture particles in their gills while circulating seawater through them.
While chitosan, starch, and gelatin are all biodegradable, there’s a hiccup in the eco-friendliness of the sponge developed by Wang and his team. They used formaldehyde, a highly toxic substance, in their manufacturing process, and traces of it remain in the finished sponges. Wang noted that they’re actively looking for an alternative method to create a fully green sponge.
Nonetheless, according to Alice Horton of the United Kingdom’s National Oceanography Center, what’s missing is evidence that these emerging sponge technologies are both cost-effective and capable of eliminating microplastics from water on a large scale. However, she’s fairly certain that attempts to remove microplastics once they’ve already entered the ocean are likely to be ineffective.
“I don’t think there is anything we can do on a large enough scale that will have any impact,” Horton said.
“We have to stop it getting there in the first place.”
To read the study’s complete findings, which have since been published in ScienceDirect, visit the link here.
If true crime defines your free time, this is for you: join Chip Chick’s True Crime Tribe
