Turning plastic waste into a valuable soil additive
Scientists at the University of California, Riverside are one step closer to finding uses for the hundreds of millions of tons of plastic waste that is generated each year.
In a recent study, Kandis Leslie Abdul-Aziz, assistant professor of chemical and environmental engineering at UCR, and her colleagues identified plastic waste as charcoal, a highly porous form with a whopping surface area of about 400 sq. or detailed how to convert to char. Meters per gram of mass.
Such charcoal traps carbon and may be added to soils to improve soil water retention and agricultural aeration. It can also fertilize the soil because it decomposes naturally. Abdul-Aziz, however, cautioned that more research is needed to demonstrate the usefulness of such char in agriculture.
The plastic-to-char process was developed at the Marlan and Rosemary Bourns College of Engineering at UC Riverside. One of two common types of plastic is mixed with corn waste (remaining stalks, leaves, husks and cobs) and collectively called corn stover. This mixture was then cooked in highly compressed hot water, a process known as hydrothermal carbonization.
The highly porous char is made up of polystyrene, a plastic used in Styrofoam packaging, and polyethylene terephthalate (PET), a material commonly used to make water and soda bottles, among many other products. ) was manufactured using
This study follows on from previous successful efforts to use only corn stover to make activated charcoal used to filter contaminants from drinking water. Charcoal made only from corn stover was able to absorb 98% of the contaminant vanillin from the test water samples.
In a follow-up study, Abdul-Aziz and her colleagues wanted to know whether activated carbon made from a combination of corn stover and plastic would also be an effective water treatment medium. If so, plastic waste has the potential to be reused to clean up water pollution. , she said, was ineffective in purifying water.
“We theorize that there may still be plastic on the surface of the material, which may be preventing the absorption of some of these (vanillin) molecules onto the surface,” she said. I got
Still, the ability to combine plastic and plant-based biomass waste to create porous charcoal is an important discovery, detailed in the paper “Synergistic and antagonistic effects of char and activated carbon by co-pyrolysis of plastic and corn stover.” It has been. It was published in the journal ACS Omega. The lead author is Mark Gale, a former UCR PhD student and now a lecturer at Harvey’s Mad His College. UCR undergraduate Peter Nguyen is the co-author and Abdul-Aziz is the corresponding author.
“It could be a very useful biochar because it’s a very high surface area material,” Abdul-Aziz said. I think there are many useful methods available.”
Plastic is essentially solid petroleum that accumulates in the environment, where it becomes contaminated, entangles, and suffocates fish, birds, and other animals that inadvertently ingest it. Plastic also breaks down into microparticles that can enter the body and damage cells or trigger inflammatory and immune responses.
Unfortunately, it costs more to recycle used plastic than to make new plastic from oil.
Abdul-Aziz’s lab takes a different approach to recycling. We are dedicated to giving back to the economy by upcycling hazardous waste such as plastic and plant biomass waste into valuable commodities.
“If we can put plastic[along with biomass]and use charcoal to improve the soil, I feel like we have a plastic recycling agnostic approach,” she said. “That’s what we think.”
Original: Turning plastic waste into a valuable soil additive
Than: University of California, Riverside
