Hurricane crisis inspires teen’s water-cleanup system
PITTSBURGH, Pa. — Last summer, Hurricane Maria hit Puerto Rico hard. High winds lashed the island. During the storm, some spots got more than 30 centimeters (12 inches) of rain in less than an hour. Winds, flooding and landslides caused widespread devastation. Afterward, residents in many areas went without power — and running water — for months. (Some still don't have power or water.) Many people got sick, notes 17-year-old Jeancarlos Meléndez. The crisis inspired him to design a water-filtering system. It can provide drinking water even when the power is out.
The 11th grader from José Rojas Cortes high school in Orocovis, P.R., showcased his new system here, last week at the Intel International Science and Engineering Fair (ISEF).
It’s not easy to go shopping when your neighborhood is devastated. So Jeancarlos decided to make his system from easy-to-find materials.
The filtering system has three steps. Each takes place in a separate plastic bucket. Short lengths of pipe made from PVC, or polyvinyl chloride, join the buckets. That plastic piping, along with valves and L-shaped connectors, are common and low-cost parts used in household plumbing. They also are easy to assemble. Jeancarlos used a simple drill to make holes in the buckets that were the same diameter as the pipes.
He filled the first bucket with gravel, sand and crushed charcoal. He dug up the gravel from a local river bed. He initially collected the sand from a beach. But it had lots of small debris that he couldn’t filter out. So he shifted to using construction-grade sand. The charcoal is the same type used to barbecue food. (The best sort for this filter, Jeancarlos warns, is the type that does not include lighter fluid.)
As he pours dirty water into this first bucket, it flows through the filter materials. Gravel and sand physically hold back large types of debris, but water flows through. The crushed charcoal helps remove potentially toxic chemicals in the water. They can make the water look cloudy, smell bad, taste bad or cause illness.
For his tests, Jeancarlos used a pump — like those found in home aquariums — to move the water into the filter. He powered the pump with electricity. It was generated by a small wheel spun by flowing water, although people could just as easily power it with a small solar panel or battery. If need be, people could simply pour water slowly into the top of the bucket, the teen adds.
Water leaves the filtering system and enters a second bucket. It is simply a big empty space where small particles that escaped the filter can now settle out at the bottom. The hole for the pipe that leads out of here and into the third bucket was drilled near the top of the second bucket. That way, Jeancarlos explains, very little of the material that falls to the bottom of the bucket can flow any farther.
The teen adds chlorine to water entering the third bucket. The chemical kills germs that might cause disease, he explains. That chlorine can come from small tablets, like those used by campers and hikers to treat water in the wilderness. His source: household bleach. About 200 milliliters (7 tablespoons) of bleach will treat about 210 liters (55 gallons) of water, Jeancarlos estimates.
Recently, he took his system to the local water-treatment plant where experts tested its performance. They analyzed water samples from a local spring and a river both before and after it ran through his three-bucket system. Chlorine levels in his system weren’t quite as high as the treatment plant normally uses, Jeancarlos notes. But that’s because the treatment plant uses pure chlorine gas, not household bleach.
Even though the teen’s system is made from simple materials, its filtered water met the standards required for water exiting the treatment plant, the water experts determined.
Almost 1,800 students from 81 nations, regions and territories took part in this year's ISEF. They vied for roughly $5 million is prizes. About one in every three finalists took home some sort of award. Jeancarlos received a scholarship to attend Arizona State University in Tempe.
Society for Science & the Public created ISEF and has been running it since 1950. (The Society also publishes Science News for Students and this blog.) This year’s competition was sponsored by Intel.
Follow Eureka! Lab on Twitter
battery A device that can convert chemical energy into electrical energy.
bleach A dilute form of the liquid, sodium hypochlorite, that is used around the home to lighten and brighten fabrics, to remove stains or to kill germs. Or it can mean to lighten something permanently, such as: Being in constant sunlight bleached most of the rich coloring out of the window drapes.
chemical A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.
chlorine A chemical element with the scientific symbol Cl. It is sometimes used to kill germs in water. Compounds that contain chlorine are called chlorides.
debris Scattered fragments, typically of trash or of something that has been destroyed. Space debris, for instance, includes the wreckage of defunct satellites and spacecraft.
diameter The length of a straight line that runs through the center of a circle or spherical object, starting at the edge on one side and ending at the edge on the far side.
electricity A flow of charge, usually from the movement of negatively charged particles, called electrons.
engineering The field of research that uses math and science to solve practical problems.
filter (in chemistry and environmental science) A device or system that allows some materials to pass through but not others, based on their size or some other feature.
germ Any one-celled microorganism, such as a bacterium or fungal species, or a virus particle. Some germs cause disease. Others can promote the health of more complex organisms, including birds and mammals. The health effects of most germs, however, remain unknown.
high school A designation for grades nine through 12 in the U.S. system of compulsory public education. High-school graduates may apply to colleges for further, advanced education.
hurricane A tropical cyclone that occurs in the Atlantic Ocean and has winds of 119 kilometers (74 miles) per hour or greater. When such a storm occurs in the Pacific Ocean, people refer to it as a typhoon.
Intel International Science and Engineering Fair (Intel ISEF) Initially launched in 1950, this competition is one of three created (and still run) by the Society for Science & the Public. Each year now, approximately 1,800 high school students from more than 80 countries, regions, and territories are awarded the opportunity to showcase their independent research at Intel ISEF and compete for an average of almost $5 million in prizes.
particle A minute amount of something.
plastic Any of a series of materials that are easily deformable; or synthetic materials that have been made from polymers (long strings of some building-block molecule) that tend to be lightweight, inexpensive and resistant to degradation.
polyvinyl chloride (PVC) This is a plastic formed by using heat to turn a liquid resin into a solid. The plastic can be soft and flexible or rigid and hard. The raw ingredients consist primarily of chlorine and carbon.
standards (in regulations) A limit above which something may not be used, sold or considered safe.
toxic Poisonous or able to harm or kill cells, tissues or whole organisms. The measure of risk posed by such a poison is its toxicity.
valve Something that can reduce or shut off the flow of some gas or liquid through a pipe or other passageway. Some specialized valves may allow a liquid or gas to flow in one direction only.