Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Plastic-eating enzyme could eliminate billions of tons of landfill waste

news.utexas.edu

Post reply on HN
Print view View original

41–50 of 294 posts

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#41

Post by rootusrootus »

faitswulff wrote: post #36
rootusrootus wrote: post #34

Can't help but wonder if this is a solution searching for a problem. Landfills already have protections against leeching into the surrounding environment. And we aren't going to plausibly run out of space for landfills in the foreseeable future (images from Wall-E notwithstanding). Isn't plastic basically inert once it gets to a landfill anyway? Even if it takes centuries to break down, who cares? IMO we'd be better…

This could theoretically treat free-floating microplastics in, e.g., the ocean, which you can't plausibly isolate in landfills.

Correct me if I'm wrong, but doesn't this process still assume that the plastic is collected and heated (not super hot, the claim seems to be "less than 50C")? In the case of the ocean, it doesn't seem like this technology would be useful until after we collect all the little bits of plastic. And at that point we could just put it in a landfill anyway.

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#42

Post by [deleted] »

faitswulff wrote: post #36
rootusrootus wrote: post #34

Can't help but wonder if this is a solution searching for a problem. Landfills already have protections against leeching into the surrounding environment. And we aren't going to plausibly run out of space for landfills in the foreseeable future (images from Wall-E notwithstanding). Isn't plastic basically inert once it gets to a landfill anyway? Even if it takes centuries to break down, who cares? IMO we'd be better…

This could theoretically treat free-floating microplastics in, e.g., the ocean, which you can't plausibly isolate in landfills.

[deleted]

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#43

Post by wang_li »

devops_monkey wrote: post #24
tda wrote: post #9

Plastic waste should be burned for heat and/or electricity in an incinerator. Every other usage/disposal method seems like a waste to me. Instead of burning fossil fuels directly, we get much more value from them if we first turn it into some plastic product, and only then burn it. And as long as we keep burning fossil fuels for heat and power, let's not wate out attention on recycling (downcycling actually) plastics…

This is actually the "best" answer for our plastics problem. There was an NPR/Planet Money podcast on it recently here: https://www.npr.org/2020/09/11/912150085/waste-land and there are plenty of other sources that all agree on this premise. I have worked in waste management a few years ago and recycling is not the long-term solution.

Why do we want to put the plastic's carbon into the atmosphere instead of back into the ground where it came from?

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#44

Post by not2b »

Depends on what the waste products are and how they are captured, otherwise you trade one problem for another. The plastic takes up space but if it's in a landfill you have carbon capture, best not to release that carbon into the air as CH4 or CO2.

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#45

Post by mistrial9 »

tda wrote: post #9

Plastic waste should be burned for heat and/or electricity in an incinerator. Every other usage/disposal method seems like a waste to me. Instead of burning fossil fuels directly, we get much more value from them if we first turn it into some plastic product, and only then burn it. And as long as we keep burning fossil fuels for heat and power, let's not wate out attention on recycling (downcycling actually) plastics…

this is widely promoted (incinerator to energy) and widely disliked (state of the air in industrial locations around the world) .. not a new idea

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#46

Post by mistrial9 »

ars wrote: post #3

Even smarter would be to take that plastic and burn it for energy, instead of giving that energy to an enzyme, that will just make waste heat. After reading the article instead of the headline: They imply they can turn the plastic back into a monomer and then rebuild it as a new polymer. Maybe that would work, but I have huge doubts - a monomer is very chemically active, and it really wants to polymerize. That enzyme…

https://no-burn.org and others.. incinerator waste to energy has been a battle for at least fifty years..

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#47

Post by superjan »

The press release points to the paper’s abstract. From that, it appears that it is specific to PET plastic. It can de-polymerase PET for later synthesis in new PET products. PET is already being recycled, the issue there is that recycled PET is not clean enough to reuse as food packaging. I hope this method does not suffer from this limitation.

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#49

Post by mistrial9 »

having done some research on this topic, the problem is not what goes into the landfills.. the problems are in the plastics that do not make it into the landfills, the production of the plastics, and the over-dependence on single-use plastics since the era of the Bic-Pen

Re: Plastic-eating enzyme could eliminate billions of tons of landfill waste

#50

Post by kube-system »

coryrc wrote: post #35
powerbroker wrote: post #11

I understand that the pits, that are the foundation of landfills, are lined with impermeable plastic sheets. Their purpose is to avoid ground-water contamination. So, there may be some redesign of landfills required before this technology can succeed.

I thought it's usually just natural clay, but I bet it varies based on local conditions.

According to this, a municipal landfill in the US requires:

> a flexible membrane (i.e., geo-membrane) overlaying two feet of compacted clay soil lining the bottom and sides of the landfill.

https://www.epa.gov/landfills/municipal-solid-waste-landfill...

Post reply on HN