The presence of lead in tap water is a real public health threat. We can still count millions of households receiving drinking water from pipes containing lead. Even if filtration systems exist, they are not within everyone’s reach. They are far too expensive and their large size can be prohibitive. This is why a group of students and their professor propose a solution to this problem: a new inexpensive filter that attaches to the faucet and removes lead from water who comes out.
the project’s principal investigator, was motivated by the sight of a video of brown water with dissolved metals from the pipes of a Michigan woman’s house. The idea for the project originated in her chemistry class. One day she wondered aloud if there was a small filter made from inexpensive components that would easily remove lead.
The challenge was taken up by the students
Enthusiastic about the idea, the students started thinking about the project and decided to design a filter. They then 3D printed a prototype using biodegradable plastic. It gave a 3″ tall water filter that screws into the end of a sink faucet. The filter contains a mixture of calcium phosphate and potassium iodide powderlying in a series of hexagonal structures through which the water spirals down.
The contaminated water will pass through the device and the lead will first bind to the calcium phosphate to form lead phosphate and free calcium. Calcium is found in water, while lead phosphate is trapped inside the filter by a nylon screen located at the bottom of the device.
A filter that detects the presence of lead in water
When the filter stops working, the lead dissolved in the water reacts with the potassium iodide. This gives the water a yellow color, an indicator of the presence of lead. It means that the filtered must be replaced.
To refine their creation, the students plan to add a tiny spectrophotometer equipped with a single wavelength LED at the bottom of the filter cartridge. The spectrophotometer will detect the yellow color of lead iodide and will trigger the lighting of the LED.
This would indicate the presence of lead even before the color is detectable with the naked eye. The team’s goal would be to manufacture and sell these filters for less than a dollar each. In any case, the researcher believes that she is on her way to achieving this. In addition, the members of the team will present their research at a meeting of theAmerican Chemical Society.
“Ultimately, this experiment showed the students that they can make a difference to someone and that there are problems they can solve through science. »
Rebecca Bushway, Project Principal Investigator