At age 14, most students are more concerned with the terrifying specter of puberty than with improving drinking water quality worldwide. Not so of Sarina Tajuddin and Urvi Awasthi, two high school sophomores who invented their own water filter in the eighth grade. The filter—comprised of plastic, systems of mesh strainers, antimicrobial colloidal silver nanoparticles, activated carbon crystals and tight-knit cotton—aims to wipe out pathogenic contaminants in drinking water. W&WD Associate Editor Sara Samovalov spoke with Tajuddin and Awasthi about how their filter got them noticed, and about their plans for its future.
Sara Samovalov: What inspired you to design your own water filter?
Sarina Tajuddin: I actually started with a science fair experiment when I was in seventh grade. I was researching about how gold can kill bacteria, and it was really interesting because I got really into learning about oligodynamic metals. I was always into science and biology, so I thought it was really cool to combine this chemistry with biology and introduce a new way of solving a widespread problem, like water filtration, using a combination of the two.
Urvi Awasthi: In eighth grade, Sarina and I decided to put that knowledge to use by creating a water filter.
Samovalov: What happened once you had designed the filter?
Awasthi: In our class, we got to take part in a science fair [IJAS’s State Science Fair] along with the rest of our classmates. People from all over Illinois got to come there.
Tajuddin: We made it to state. That’s where we met the ISAWWA [Illinois Section of the American Water Works Assn.], who invited us to their Watercon in Springfield.
Samovalov: What are your next steps for the filter?
Tajuddin: Recently, we applied for the Stockholm Junior Water Prize. We didn’t make it this year, but we’re planning on applying again next year.
Awasthi: We’re planning on contacting most of the labs that we got in touch with through Watercon. We’re planning on doing more experimentation there and then applying again for the Stockholm Prize.
Samovalov: Are you designing anything else?
Tajuddin: We’re trying to build [our filter] on a bigger scale. We’re seeing if we can incorporate this idea into community water filtration. At Watercon, we talked with different companies about how we could experiment more with water pressure and things like that, so that we could eventually build it on a bigger scale, and a whole community’s water could be filtered using this.
Sarina Tajuddin Urvi Awasthi’s Filter, Explained
As Tajuddin and Awasthi explain in a lab report detailing their findings on their invention, filters for purifying drinking water have, until this point, generally “focused on eliminating chemical or visible contaminants,” while ignoring pathogenic contaminants (e.g., bacteria, fungi and viruses).
Not paying attention to pathogens can have severe consequences, particularly in developing countries, where the illnesses they spread may have “no corresponding vaccinations or cures,” Tajuddin and Awasthi write.
To combat this issue, the filter employs:
- Silver nanoparticles. When silver nanoparticles come in contact with water, a chemical response is triggered. Silver ions intercept pathogens, causing them to “weaken and rapidly self-destruct, resulting in water that is significantly less likely to transmit diseases.”
- Plastic. Plastic provides a sturdy, durable and lightweight filter base, which is easy to wash and transport.
- Mesh strainers. These block large particles of dirt, grime and silt from entering the filter, prolonging its lifetime.
- Activated carbon crystals. These obstruct smaller particles (invisible to the naked eye), while keeping the silver nanoparticles suspended.
- Tight-knit cotton. Located at the bottom of the filter, tight-knit cotton acts as a membrane filter, providing a final process to ensure the water’s purity.
