When a group of Bay Area middle school students looked through their school’s trash, recycling, and compost bins, they found that only about half of the waste ended up in the right bin. They tested a sorting contest to motivate students to do better, but accuracy only improved to 58%. Next, they designed a robot to help: A Raspberry Pi-based device takes a picture of a piece of trash, then uses photo classification to tell someone which bin to use. The tool can improve accuracy to more than 90%.
After noticing how many chip bags ended up in the trash at their Florida middle school, a group of seventh and eighth graders invented Chipsulation, a type of insulation made from shredded bags. Because the bags contain polyethylene, they can’t easily be recycled. But as insulation, in tests, the students found that chip bags were both more effective and cheaper than the standard material used in construction.
FIRF (FOOD INTO RENEWABLE FUEL)
A team of fifth and sixth grade girls created a concept for a home device that turns food scraps and waste into fuel for natural gas appliances. Microorganisms break down the food, making methane gas that can be used in stoves, furnaces, or hot water heaters.
Plastic bags, made from polyethylene plastic, can’t be recycled in most home recycling bins. When they are recycled—as from the bins in front of grocery stores—they’re often « downcycled » into low-grade plastic products like recycled lumber. A team of Canadian students has a different solution: a plastic « composter » that uses bacteria to biodegrade polyethylene over a 15-week period. The process creates CO2, which can be reused in other products, and biomass that can be sold as fertilizer.
HAY BALE WRAP
On farms, hay bales are often wrapped in 8 to 10 layers of plastic film before the hay is stored outside—helping preserve the nutrition in the hay for animals, but adding trash. A group of eighth and ninth graders from a rural community in Canada designed a bioplastic made from plant starch and fiber. After it’s used, the bioplastic can break down into an edible product, or be used as fertilizer.
Plastic packaging usually ends up in the landfill, but a group of five students designed a new type of packaging that can be reused. Made from a material called shape memory polymer (SMP)—which can be easily flattened with heat or light, but later pop back into the original shape—the students envision that packages could be sent back to manufacturers, and used in an endless loop.
WATER-SOLUBLE SIX-PACK RINGS
A team of sixth graders took on the problem of six-pack rings that kill marine animals when the animals are trapped, or when they eat pieces of the plastic. Their solution: plastic that dissolves when it’s submerged in water, or exposed to rain.
Another team of students, now eighth graders, has been working together for three years, and now has a patent-pending process for dealing with Styrofoam waste. Their low-temperature system turns the Styrofoam into activated carbon, which can then be used in water filters.
AEROBICALLY DECOMPOSING PLASTIC DOGGY BAGS
In theory, bioplastics should be compostable. But when a group of Canadian students did research at their local composting plant, they learned that most bioplastics failed tests there, and can cause damage to equipment and costs from lost time. They modified a recipe for a decomposing plastic that can be composted—and then turned it into doggy bags, so pet owners can start composting their dog poop and the bags it ends up in.