When plants and animals die, elements like carbon and nitrogen return to the earth to support new life. Natural systems are closed, which means nothing is lost.
However, humans do not deal with waste as effectively. The way we deal with our garbage and emissions often leads to pollution and damage to the planet.
We produce huge amounts of waste such as plastics, devices, food scraps and harmful emissions, and most of it is not recycled.
Currently, less than 10% of the estimated 7 billion tonnes of plastic waste is recycled. As a result, our waste is filling landfills, polluting the environment and damaging ecosystems.
Scientists at the U.S. Department of Energy's (DOE) Argonne National Laboratory are working to change that through what's called the circular economy.
In a circular economy, products are designed to have a second useful life. This approach ensures that waste becomes a valuable resource for creating new products.
Turning waste into treasure
Argonne researchers are developing methods to recycle valuable materials from batteries and electronic devices.
They are also collaborating with industry and local communities to extend the reach of these technologies. For example, Argonne scientists use special chemical tools called catalysts to turn plastic waste into higher-value products, such as lubricants and waxes.
One method, being developed in partnership with Cornell University, is aimed at recycling high-density polyethylene (HDPE), known as Type 2 plastic. This new technique allows the plastic to be recycled repeatedly without losing its quality.
Battery recycling is another major focus for Argonne. The ReCell Center, based in Argonne, is a national center for advancing battery recycling technologies.
Recycled materials such as lithium, cobalt and nickel can be reused, reducing the need to mine new materials and lowering the cost of electric vehicle batteries.
"It's fascinating to start with something that looks like garbage and end up with brilliant reusable materials," said Jeffrey Spangenberger, director of the ReCell Center.
Turning organic waste into energy
Argonne researchers are also tackling society's more stinky wastes - food scraps and sludge from wastewater treatment.
Scientist Meltem Urgun Demirtash is working with colonies of microorganisms to break down these waste streams and turn them into valuable fuels, such as renewable methane and sustainable jet fuel.
Residual nutrients from these processes can be used as fertilizers, preventing harmful algal blooms in the environment.
Another project at Argonne involves capturing carbon dioxide (CO2) from emissions and converting it into valuable chemicals.
Chemist Di-Jia Liu is leading a team to create a device called an electrolyzer that uses renewable energy to convert CO2 into useful products such as ethanol and acetic acid.
This method traps CO2 in a closed loop, reducing its presence in the atmosphere and turning it into something useful.
Water is essential not only for life but also for the production of many products. Argonne's Junhong Chen is leading the effort to create a circular blue economy focused on water. This initiative, called Great Lakes ReNEW, aims to develop better technologies to treat wastewater and extract valuable materials from it. The team is working on a network of sensors to monitor wastewater quality in real time, which will help treatment plants operate more efficiently.
Researchers are also thinking about the future to ensure that their solutions are environmentally friendly. They are developing plastics and catalysts that will not harm the environment if they break down. They are finding cost-effective ways to recycle batteries and other electronic devices using machines such as shredders, magnets and sorting robots.
With these efforts, scientists are turning trash into treasure, reducing our impact on the planet, and making valuable materials more affordable.
"With dedicated science, education and partnership, it's only a matter of time before we achieve our vision of a more sustainable energy future," says Urgun Demirtash. | BGNES
