She assigned homework, students immediately made a water filter for only 23,000 VND

Model of a machine that separates lead from water for 1 USD – Photo: Phys.org

This new ‘invention’ hopes to help improve water availability for many households in the future.

According to the scientific news site Phys.orgup to 10 million households in the US are still using lead-contaminated water, putting the health of many people at risk.

Understanding this, Rebecca Bushway – a science teacher at Barrie High School in Maryland (USA) – has devised an interesting exercise for her students: invent a filter capable of removing lead out of water at low cost.

This is a good and challenging topic, because the cost of installing a water filtration system for a family currently amounts to $600-14,000, making it difficult for many Americans to access clean water.

Surprisingly, Ms. Bushway’s students successfully completed the assignment, when they used 3D printing to create a model that is 7.5cm high and made from biodegradable plastic at a very low price. cheap, only 1 USD/product (about 23,000 VND).

Bushway says the model works by applying chemical precipitation to remove metals from water.

Model includes Ca . powder₃(PO .)₄)₂ (calcium phosphate), which reacts with metals and causes precipitation, also known as the formation of solids after a chemical reaction.

Based on this property, lead metal (Pb) will be precipitated (turned into a solid) and retained in the model. As the precipitated solid becomes larger than the drain hole, it gets trapped inside the model, while the cleaned water flows out.

In addition, the model is also capable of signaling to users when it is time to replace the filter: the group of students placed under calcium phosphate another chemical called potassium iodide. When the calcium phosphate is used up in the filter, a layer of potassium iodide will appear and react with the lead to turn the water yellow – a sign it’s time to change the filter.

Ms. Bushway has introduced the device model at four different conferences, including the prestigious spring conference of the nonprofit American Chemistry Society, and plans to write a journal article to promote the device. assessment experts.

Paul Frail, a chemical engineer, said the model deserves a commendation. However, the student group’s product needs more time to test both for safety and market demand if it is manufactured.

However, the solution of this group of students is very potential. Because the harmful effects of lead poisoning in the United States so far have passed for many decades and there is still no complete solution, although at the moment, US President Joe Biden has pledged billions of dollars to improve. this problem, according to Phys.org.