Keep those used coffee grounds!

Keep those used coffee grounds!

Just as we thought coffee couldn’t be any more awesome, new scientific research has found that coffee grinds can help eliminate toxins from water - read on to find out exactly how this process works.

In an article recently published in the American Chemical Society’s journal Sustainable Chemistry and Engineering, we learned that scientists have recently discovered a new way to reduce coffee waste generated everyday by home coffee brewers, coffee shops and restaurants, and simultaneously help remove toxic chemicals from water. Researches took used coffee grounds and molded them into a sort of sponge block that can absorb heavy metals from water. The chemicals found in coffee such as cellulose, fatty acids, and polyphenols stick to heavy metals in a similar way to activated charcoal. In order to find a way to separate the grounds from the water, lead scientist at the Instituto Italiano di Tecnologia, Despina Fragouli, says that she and her team simplified this process by combining the coffee grounds with sugar and silicone. The sugar and silicone helped create a foamy brick that held together and thus made it easy to use as a filter.


When testing the efficacy of this new coffee brick filter, Fragouli and her team placed a 200 milligram piece of foam (about the size of an almond) in still water, and found that 99% of the heavy metal toxins, such as lead and mercury, were removed in 30 hours. When placed in flowing water, or water with a concentration of metal ions that exceeded 200 parts per billion, the foam filter removed between 50-60% of the lead ions. That is about as efficient as most commercially available filters. 

The foam brick absorbed 5 times as much metal ions by weight as used coffee grounds alone. This makes it quite possible to use spent coffee grounds in a large scale, and by using enough foam it is possible to filter water to the point of meeting drinking water standards. Fragouli and her team are currently working on improving the composition of the filter so that it becomes the only filter one needs, as well as experimenting with other waste from agricultural and food industries that may remove other chemicals based on their different chemical composition. “It’s very important that we find new resources to make polymers-materials that are reusable and that can replace the petroleum-based materials we currently use,” says Fragouli.

“Millions of tons of spent coffee wind up in landfills every year, so the proposed method not only reduces the solid waste stream but removes dangerous heavy metal pollutants from water,” says Constantine M. Megardis, a mechanical engineer at the University of Illinois, Chicago. He adds, “collecting enough coffee grounds for large-scale application of this technology could be difficult and doing it cost effectively would require a system to be set up with commercial users like hotels and restaurants.” 

Although this product is still being developed, it seems to us like it could in time be incredibly influential in reducing waste and cleaning up the environment. This is just another reason why coffee is so great! So go make yourself a cup of coffee and save your coffee grounds as they might come in handy. And remember, a good cup of coffee is full of great ideas, so go buy some Bristol Coffee, why don’t you?

Leave your comment