Dear Dr. Universe: What happens to the world’s garbage? -Presley, 8, Spokane, Wash.
How exactly do you recycle an object into another object? -Brianna, 12, New York
Dear Presley and Brianna,
While a lot of our trash goes in a landfill, we can also recycle all kinds of stuff on our planet. Depending on what the object is made of, we might grind it up, mix it up or melt it down before we turn it into something new.
Let’s start with paper. When you recycle paper, it usually ends up at a recycling center where it gets washed with soapy water and mixed into a huge, thick slurry.
Sometimes we add a few other ingredients if we want a specific kind of product, like cardboard or printer paper. The slurry is poured out onto a big table and flattened with big rollers. After it dries, it can be cut into different sizes and shipped to stores. Recycling is a great way to help us make new paper without cutting down more trees.
Melting down materials
We can also recycle things like glass, plastic and aluminum. A lot of these materials are mixed together in a recycling bin, so the first step when they arrive at a recycling center is to wash and sort them. Engineers have built conveyer belts and equipment to help divide up the different items into groups.
Once they are divided up, they can be melted down, cooled and shaped into flat sheets or new objects. A glass bottle might become a jar, a plastic bottle might become part of recycled clothing and a soda can might become another soda can.
While different objects go through different recycling processes, most of the time we break them down before we build them up into something new. But some materials that we want to recycle don’t break down quite as easily.
Breaking it down with Dr. Zhang
While most of us put smaller items into the recycle bin, we also have lots of really huge stuff we need to recycle, too. Things like airplane wings and giant blades from windmills often end up in landfills. My friend Jinwen Zhang, a scientist at Washington State University, is helping research ways to recycle the lightweight materials and keep these big objects out of landfills.
This kind of lightweight material, carbon fiber plastic, they work with in the lab can’t melt down like a lot of other things we recycle. Zhang and his team figured out a different way to break them down using just the right environmentally-friendly chemical mix.
Exactly what kinds of objects those wings and blades will become is a question that we are still looking to answer. It will inspire more research and help us understand how to recycle things that couldn’t really be recycled before we learned to break them down.
These are great questions you ask, Brianna and Presley. Thank you for being curious. We can help make the planet a safer and healthier place to live when we recycle.