UAM | No more microplastic in water!

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In recent decades, one of the biggest ecological problems that has endangered our ecosystems is the accumulation of plastic waste. This waste accumulates around the world, and especially affects marine ecosystems. Plastics generally enter the sea macroscopically, but after undergoing oxidation processes, ultraviolet radiation, and mechanical erosion, they become much smaller fragments, microscopic in size, known as microplastics. The detection of these microplastics and their removal from the environment is essential since, due to their size, these materials are ingested by a wide variety of organisms, putting not only ecosystems at risk, but also human health. These risks have been recognized worldwide by different international institutions, estimating that an adult ingests approximately between 95,000 and 121,000 microplastics annually. For this reason, the group of chemical sensors and biosensors proposes the development of a methodology that allows us not only to observe the amount of microplastics in a water sample, but also to apply a simple and environmentally friendly procedure that allows us to remove a large amount of this waste. In the proposed activity, microplastics contained in a water sample will be marked with an organic dye, to be able to observe it by fluorescence and later to be able to eliminate these residues quickly and easily based on the use of minerals and used vegetable oils. This process is totally compatible with the environment, easy to prepare and simple. The activity will be divided into 3 parts. Part 1. First, there will be a brief explanation of what microplastics are and how they affect our ecosystems. For this, a presentation will be prepared that will be projected on a computer while important and basic concepts about fluorescence are explained in a simple way. In the same way, the staining process of the microplastics will be explained, which will be done directly, on a water sample, and through the use of a suitable beam of light, the fluorescence of these microplastics in the selected sample will be observed. Part 2. Continuing with the presentation previously started, the experiment that will be carried out live in order to carry out the separation of these microplastics will be briefly explained. For this, used vegetable oil and magnetite (iron oxide) will be used. Both will be added to the glass of water and it will be explained that due to the difference in polarity the microplastics will go from the aqueous phase to the apolar phase that contains the mineral. Part 3. Once the ferrofluid has been eliminated along with the microplastics, it will be verified that the water sample has less fluorescence when focused with the appropriate beam of light due to the elimination of these colored microplastics.