Coffee Grounds May Help Get Heavy Metals Out Of The Water

 For the savvy savers, dumping coffee grounds out every morning is a waste: after all, they are known to have a lot of practical uses - from marinating meats to facial scrubs, to plant fertilizers. However, it seems that they have an even more important use: help removes lead and mercury from drinking water.

A team of Italian scientists said that powder made from used coffee grounds could be helpful for water remediation. Mechanical engineer Constantine Megaridis of the University of Chicago shared on Chemical and Engineering News, "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."

In their study, the Italian scientists turned used espresso coffee grounds into a powder and combined it with sugar and silicon. Once dried, the solid was dipped in water, dissolving the sugar in the mix and leaving behind little holes. This then created blocks of foam that acted like filters, which successfully managed to filter out 99 percent of the mercury and lead in the water in only 30 hours.

However, the experiment was in a still water, which is a different scenario compared to the running water we have in pipes. Yet, in that scenario, the team found that as much as 67 percent of lead can still be removed, which is a good thing, considering that lead-poisoned water is considered a major health hazard.

As noted by The New York Times, the metals needed some time to interact with the coffee, explaining why significantly lesser metals were filtered out in running water. Then, there is also the issue of maxing out absorption over time. According to Dr. Despina Fragouli, lead author of the study and a materials scientist at the Istituto Italiano di Tecnologia, if this technology is to be used practically in the future, water will have to move very slowly through a very thick layer of foam, or be contained in a large, foam-filled tank for hours on end.