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Removing Microplastics with Magnetism

October 7, 2019 By EarthWise 2 Comments

A new method for removing microplastics from the oceans has emerged from, of all things, a science fair project. An Irish 18-year-old named Fionn Ferreira developed his project for the annual Google Science Fair and it won the grand prize of $50,000 in educational funding.

The teenager was walking on the beach in his hometown and ran across a stone with oil and plastic stuck to it and became focused on the problem of microplastics increasingly entering the environment.

His idea was to make use of ferrofluids, which are nontoxic magnetic fluids made of oil and magnetite, which is an iron-based mineral. In the presence of water, the ferrofluids attract microplastics because both have similar properties.

Ferreira added oil and magnetite to water and mixed in a solution of microplastic particles. When the microplastics latched onto the ferrofluids, he dipped a magnet into the solution several times and the magnet removed both substances, leaving clear water. After almost 1000 tests, he demonstrated the method to be 88% effective in removing a variety of microplastics from water; a result even better than his original hypothesis of an 85% removal rate.

Ferreira is planning to further his education at a prestigious chemistry institute in the Netherlands starting in the fall.

According to a recent study, Americans eat, drink and breathe between 74,000 and 121,000 microplastic particles each year and, if they drink bottle water only instead of tap water, an additional 90,000 particles. So, a science fair project that might provide a way to get rid of most these things is definitely prize-worthy.

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This Irish teenager may have a solution for a plastic-free ocean

Photo, posted April 25, 2016, courtesy of Boe Eide via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Bitter Truth About Caffeine

January 7, 2019 By EarthWise Leave a Comment

Black coffee has a bitter taste. Bitterness evolved as a natural warning system to protect the body from harmful substances. By the logic of evolution, we should therefore want to spit coffee out, but obviously it doesn’t work that way.

Caffeine itself has a particularly bitter taste. Surprisingly, a new study at Northwestern University has found that the more sensitive people are to the bitter taste of caffeine, the more coffee they drink. That sensitivity is actually a genetic variant.

So, one would think that people who are especially sensitive to the bitter taste of caffeine would drink less coffee. The counter intuitive result suggests that coffee consumers acquire a taste or an ability to detect caffeine as a result of the learned positive reinforcement (in other words, the buzz) elicited by caffeine. People with a heightened ability to taste coffee’s bitterness learn to associate good things with it.

The study also found in contrast that people sensitive to the bitter flavor of a different compound called 6-n-propylthiouracil (known as PROP)avoided coffee as well as red wine.

The study made use of applied Mendelian randomization, a technique commonly used in disease epidemiology, to test the causal relationship between bitter taste and beverage consumption in more than 400,000 men and women in the United Kingdom.

These results shed some light on the disdain many coffee drinkers have for decaf coffee. It may not be just the lack of buzz that turns them off. Some of them with the right genes may be missing that extra bit of bitterness that alerts them that something good is about to happen.

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