[HN Gopher] Plastic-Eating Enzyme Could Eliminate Billions of To...
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Plastic-Eating Enzyme Could Eliminate Billions of Tons of Landfill
Waste
Author : FrankyHollywood
Score : 104 points
Date : 2022-05-18 20:04 UTC (2 hours ago)
(HTM) web link (news.utexas.edu)
(TXT) w3m dump (news.utexas.edu)
| rootusrootus wrote:
| 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 off focusing research on reducing the waste
| rather than improving disposal.
| faitswulff wrote:
| This could theoretically treat free-floating microplastics in,
| e.g., the ocean, which you can't plausibly isolate in
| landfills.
| rootusrootus wrote:
| 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.
| faitswulff wrote:
| Yeah, good point. Theoretically, a more optimized enzyme
| might be able to do it at ambient temperatures, which they
| mention in the article as a target. Assuming the search
| space for enzyme mutations isn't already exhausted.
| nomel wrote:
| > a more optimized enzyme might be able to do it at
| ambient temperatures
|
| Releasing this into the ocean, in any appreciable amount,
| seems like a very bad idea. I think collection from
| plastic "hot spots", and then separate processing, would
| make more sense. I think it's best to reduce the number
| of foreign chemicals in the environment.
| [deleted]
| noizejoy wrote:
| > IMO we'd be better off focusing research on reducing the
| waste rather than improving disposal.
|
| And IMO there's much upside to pursue multiple avenues to
| desired solutions, rather than making choices to eliminate
| potentially contending solutions too early.
|
| Mother nature herself provides pretty much exactly that
| template for evolution. So if we want to save nature, why not
| use that same approach? It seems to have served the survival of
| life on our planet rather well.
| sschueller wrote:
| We should be focusing on reducing trash and getting raw
| materials back out of trash. The rest should be burned or
| processed cleanly and maybe generate electricity while at it.
| [deleted]
| sudden_dystopia wrote:
| Neat. Hope it can scale and soon!
| FredPret wrote:
| We use plastic in many places with the idea that it'll never rot.
|
| Obviously we want plastic to eventually biodegrade, but I wonder
| what sorts of chaos would be caused by it.
| Areading314 wrote:
| Wouldn't this be extremely dangerous if a form of "plastic rot"
| was created? Things like PVC sewer pipes, or any long-lived
| plastic parts in cars/equipment could now degrade over time,
| which could create huge costs to find alternative materials.
| After all plastic is pretty useful _because_ it is biologically
| and chemically inert.
| ars wrote:
| 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 may work in a lab, but I doubt
| they can turn it into an industrial process.
|
| I take issue with this:
|
| "The most common method for disposing of plastic, besides
| throwing it in a landfill, is to burn it, which is costly, energy
| intensive and spews noxious gas into the air."
|
| This is utterly false, and I don't see how they can claim to be
| scientific if they publish falsehoods. It makes me wonder about
| the accuracy of the rest of the press release.
| mistrial9 wrote:
| https://no-burn.org and others.. incinerator waste to energy
| has been a battle for at least fifty years..
| ars wrote:
| Another organization we can blame for terrible environmental
| outcomes?
|
| Why is it so common for people to pretend to be
| environmentalists and advocate for things that directly harm
| the environment?
| mistrial9 wrote:
| > we can blame for terrible environmental outcomes
|
| who is "we" here ?
|
| > to pretend to be environmentalists
|
| that is wildly defamatory, with no evidence, right?
| ars wrote:
| We is you and me.
|
| > that is wildly defamatory, with no evidence, right?
|
| The evidence is right on their own website. Their
| advocacy that they are so proud of is actively harming
| the planet and they are sitting there proud of it.
| Geezus-42 wrote:
| ars wrote:
| Exactly. Everyone thinks there will be black smoke, but
| actually plastic burns very clean in a proper incinerator.
| kube-system wrote:
| They're dirtier than natural gas power plants, however.
| (and the pollution that they do create can be particularly
| nasty) We're better off in terms of emissions-per-watt by
| burying the plastic and using natural gas instead.
| ars wrote:
| > They're dirtier than natural gas power plants, however
|
| That is not true.
|
| > and the pollution that they do create can be
| particularly nasty
|
| That is also not true.
|
| Plastic is made of the exact same atoms as natural gas,
| plus oxygen. Plastic burns very very clean, with no waste
| except for water and CO2.
|
| PVC has chlorine, but is rare in trash, and the small
| amount of chlorine is easily filtered out of the exhaust.
|
| > We're better off in terms of emissions-per-watt by
| burying the plastic and using natural gas instead.
|
| This is also not true because it costs energy to extract
| the natural gas. The plastic is already there, and needs
| to be dealt with one way or another. Plastic makes about
| the same CO2/watt as gasoline.
| kube-system wrote:
| Plastic that goes into the trash is not pure plastic, it
| is trash and it has a lot of other junk in it. i.e. heavy
| metals and other stuff. That's one of the biggest reasons
| we have trouble recycling it. Are there even any WTE
| plants that burn only plastic?
| r00fus wrote:
| Isn't the problem with plastic burning the fact that most
| plastic waste is actually contaminated with food/non-plastics
| that burn differently?
| williamtwild wrote:
| Yes. I see quite a few three letter accounts advocating for
| burning plastic. Let them throw some in their fireplace of
| the chimnea while relaxing with the family and see how that
| goes.
| ars wrote:
| PET burns very clean with enough air. I use it as a fire
| starter for outdoor fires.
|
| A fireplace is a smoky thing, without enough air (even the
| wood makes a lot of smoke). An incinerator makes sure to
| supply enough air.
| SoftTalker wrote:
| Industrial waste incineration is not at all the same thing
| as burning trash in a backyard fire.
| williamtwild wrote:
| Which part is false? There is at least one part of that
| statement that is absolutely true.
| ars wrote:
| The only part that is true is that burning is the most common
| method, with recycling being a close third.
|
| > which is costly
|
| Burning is not costly it is cheaper than all other methods.
| It's so cheap it's actually profitable.
|
| > energy intensive
|
| It actually provides extra energy, and reduces energy waste
| (because now we have to pump less oil.)
|
| > and spews noxious gas into the air.
|
| It spews nothing except water and CO2.
| thfuran wrote:
| I wouldn't exactly call it noxious, but C02 isn't exactly
| something we want to be spewing more of. Isn't a landfill
| full of plastic pretty much just a big pile of captured
| carbon?
| not2b wrote:
| 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.
| BurningFrog wrote:
| Yeah, landfills are not major environmental problems, AFAIK,
| but they offend the neat freak within all of us.
|
| And, as you say, they're pretty good carbon deposits, which is
| supposed to be The Most Important Thing.
| [deleted]
| j-bos wrote:
| Or those of us who don't like microplatics in our fish,
| water, and bodies
| stjohnswarts wrote:
| Those microplastics aren't coming from landfills. They're
| coming from your everyday interactions with plastic and
| people dumping plastic in rivers and oceans.
| noja wrote:
| > Yeah, landfills are not major environmental problems
|
| ... yet?
| google234123 wrote:
| If you are worried about space i recommend that you look at
| the surface area of earth and the volume of space that's
| accessible to us underneath the surface.
| DANK_YACHT wrote:
| What would cause them to be an environmental issue? As far
| as I know they can be built in a safe manner and there is
| plenty of space for them.
| candiddevmike wrote:
| Most landfills contain icky things like heavy metals or
| arsenic. Having that leak into an aquifer Would Be Bad.
| DANK_YACHT wrote:
| That's why they're sealed with clay and plastic and
| constantly monitored for leakage.
| mschuster91 wrote:
| In the Western world maybe, but outside of it... hell
| even in the Western world we have regular reports of
| mismanagement and corruption, just look at Italy.
|
| We need to reduce the amount of trash we produce, not
| hope for a miracle technology.
| DANK_YACHT wrote:
| Landfills are not a miracle technology. They exist
| already and are technologically sound. It'd be way more
| of a miracle if we somehow managed to greatly reduce
| waste.
| paulryanrogers wrote:
| How sustainable are landfills? There's limited land for
| farming, residences, manufacturing, and everything else
| we use it for. And trucking trash to deserts to landfill
| there isn't carbon neutral either. Trash also doesn't
| breakdown as quickly in covered landfills (for better or
| worse depending on what one dumps).
| stjohnswarts wrote:
| People love to "what if" landfills. Best to not bother
| arguing with them. We have tons of problems with
| emissions, plastics pollution, industrial dumping.
| However landfills ain't one of them, but people won't
| give up. I've learned to not bother discussing anything
| with them if they don't know a few basics of how modern
| landfills are run (at least in western nations).
| not2b wrote:
| As others have mentioned they are a major source of
| methane emission, though this can be addressed (do a
| better job separating out food waste and compost it).
| xxr wrote:
| Is there enough raw material on earth for landfills to
| become major environmental problems? (genuinely curious)
| BurningFrog wrote:
| Maybe this makes me sounds like a jerk, but:
|
| All material that can end up in landfills is already on
| Earth.
| drew-y wrote:
| I wouldn't go that far.
|
| > Per the most recent Inventory Report, U.S. landfills
| released an estimated 109.3 million metric tons of carbon
| dioxide equivalent (MMTCO2e) of methane into the atmosphere
| in 2020; this represents 16.8 percent of the total U.S.
| anthropogenic methane emissions across all sectors.
|
| https://www.epa.gov/lmop/frequent-questions-about-
| landfill-g....
| Baeocystin wrote:
| Sure. That's almost all due to food waste, though. FWIW.
|
| https://www.epa.gov/sustainable-management-
| food/sustainable-...
| not2b wrote:
| Yes, for that reason Santa Clara County (Silicon Valley)
| is pushing hard to divert food waste out of the garbage
| and get it composted instead: it's supposed to go in with
| yard waste, not the regular trash. Not sure how
| successful this is as it counts on people putting things
| in the correct bin.
| snek_case wrote:
| I think the main problem is that the average Joe/Jane
| confuses all types of pollution as equally bad. The real,
| most imminent threat is really CO2. That's what we have to
| spend the most money/energy on, because it could have
| absolutely catastrophic consequences in the next few decades.
|
| Plastic in a landfill is just... Stuck there. It's unnatural,
| sure, but it's not immensely harmful, not nearly on the same
| scale as CO2, and realistically, in the future, we'll be able
| to mine it out of there and refine it into something usable
| if we need it.
| therealdrag0 wrote:
| Garbage is also a problem in the environment like plastics
| in oceans, but the problem is not enough (well run and
| used) land fills (in Asia) not too many!
| zackees wrote:
| We've had the solution to fossil fuels for over a century
| in the form of nuclear. By the numbers, it's the safest
| large scale energy source ever invented. The new ones even
| eat nuclear waste as fuel.
|
| The will to solve the CO2 question is done and we have the
| means. The people controlling the media won't allow it.
| This is common knowledge.
|
| Also, the very premise that more CO2 is existential is
| contradicted by historical record: 250 million years ago
| earth was 15 degrees warmer than it is now and CO2 was a
| lot more abundant.
|
| Now if we go 15 degrees colder then we are in an ice age
| and a mass extinction event. If anything, we want to kick
| up the temperature to buffer against an ice age.
| paulryanrogers wrote:
| Nuclear fuel must first be mined, correct? That's not
| renewable and could offset the benefits somewhat. That
| said I imagine it may be better as a base load than dirty
| coal.
| shepherdjerred wrote:
| We're not running out of fissionable material any time
| soon
| paulryanrogers wrote:
| What are the limiting inputs? Because I imagine there is
| a lot to do to go from the ground to the reactor and back
| again?
| lkbm wrote:
| The article talks about using it for environmental cleanup, but
| the paper seems more focused on recycling back into fresh
| PET[0]:
|
| > ...and a circular carbon economy for PET is theoretically
| attainable through rapid enzymatic depolymerization followed by
| repolymerization or conversion/valorization into other products
|
| > Finally, we demonstrate a closed-loop PET recycling process
| by using FAST-PETase and resynthesizing PET from the recovered
| monomers. Collectively, our results demonstrate a viable route
| for enzymatic plastic recycling at the industrial scale.
|
| [0] https://www.nature.com/articles/s41586-022-04599-z
| wyager wrote:
| I would infinitely rather have a bit more gaseous carbon than a
| 10,000 year source of endocrine disruptor microplastics
| leaching into the water.
| flaviut wrote:
| It's a good thing we're all rich here, able to move to places
| with better climates or buy air conditioners, not the
| billions of poor people who have no way to survive
| intensifying extreme weather events.
| hprotagonist wrote:
| So, uh, what are the CO2 emissions like on eating that much
| sequestered carbon?
| bobbylarrybobby wrote:
| What would be really cool is if we got something that could eat
| plastic and produce as a waste product some environmentally
| neutral substance like (say) some kind of alcohol. Is there
| anything like that on the horizon?
| ars wrote:
| Please define environmentally neutral. Because alcohol will
| just oxidize into water and CO2.
|
| Do you want to just sequester the Carbon? Something very
| environmentally neutral would be .... plastic. Anything
| biodegradable would eventually become CO2 and water.
|
| Best option is to burn it and capture the energy for a useful
| purpose, instead of letting that energy be wasted when it
| biodegrades.
| paulryanrogers wrote:
| Can plastic combustion be done with releasing CO2 into the
| atmosphere? Or worse chemicals?
| motohagiography wrote:
| Or rather, how will governments and NGOs manage the problem
| (and by extension, the economy) if someone invents a technology
| that actually just solves it?
| superjan wrote:
| 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.
| mistrial9 wrote:
| 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
| noizejoy wrote:
| The phrase "single use" is doing some heavy lifting there, and
| I have no idea why that particular product is made to be
| patient zero for this.
|
| A pen presumably gets hundreds or thousands of uses, depending
| on how you count. For example, one way product packaging is
| much more of a single use plastic.
|
| That being said, I'd hate to lose plastics for bulk food
| packaging, unless there's an equally food safe successor.
| nikanj wrote:
| I've read this headline monthly since the 90s.
| icefox11 wrote:
| You happen to read anything related to removing salt from
| seawater as well?
| jimmySixDOF wrote:
| DeepMind's AlphaFold capabilities to model protein-folding is
| going to accelerate this kind of discovery at a quantum leap
| order of magnitude. The featured article notes a custom CNN was
| used here - but AlphaFold is a game changer in synthetic biology
| in general even though the first goals were human medical
| application focused.
|
| BBC Science in Action [1] interviewed Prof John McGeehan of the
| Centre for Enzyme Innovation at Portsmouth University working on
| Bacteria breaking down Plastic in landfills. He explained his
| workflow of maybe selecting one candidate very carefully and
| occasionally out of many due to the cost/time involved & how
| DeepMind gave him more results in a single weekend (for free)
| than he had expected to see over his entire reasearch career.
|
| [1] https://www.bbc.co.uk/sounds/play/w3ct1l3y
| tda wrote:
| 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 as we can much better
| burn the old and make fresh new plastic from the fossil fuels we
| didn't have to burn because of that.
|
| When we are not relying on fossil fuels anymore for heat and
| power (which is hopefully sooner than later), only then we need
| to start looking into plastic recycling
| seoaeu wrote:
| Whether we should burn, recycle, or dump plastic into a
| landfill depends entirely on the relative amount of energy
| generated and CO2 emitted by those different options. Just
| because plastic and natural gas both are/come from hydrocarbons
| doesn't mean that burning them produces anywhere near the same
| amount of emissions per MWh, or that the economics would be at
| all close.
|
| And if you are proposing the construction of new power plants
| to burn trash, your justification also has to explain why that
| would be preferable to building wind/solar instead
| mistrial9 wrote:
| this is widely promoted (incinerator to energy) and widely
| disliked (state of the air in industrial locations around the
| world) .. not a new idea
| tda wrote:
| I think just about all household trash in the Netherlands is
| incinerated. And as far as I know the exhoust fumes are
| manageable, but definitely not something to live next to.
| Just like any other fossil fuel run powerplant by the way.
| r00fus wrote:
| Doesn't burning plastic produce large amounts of toxic off
| gassing?
| [deleted]
| Nydhal wrote:
| My understanding is that incinerators don't just release the
| output. The exhaust is pumped back into the system and dealt
| with somehow. The extent to which the release is "dealt with"
| is the tricky part.
| Workaccount2 wrote:
| I'm going to guess that large amounts of CO2 is a byproduct
| and is vented.
| ars wrote:
| No, they produce water and CO2. Nothing toxic, unless you
| don't give enough air (so obviously make sure to give enough
| air).
|
| This isn't some theory - right now, today, lost of plastic is
| being burned, and it works just fine. They try to keep is off
| the radar because of misinformed people thinking it's bad.
| williamtwild wrote:
| Yes , it does. Burning plastic without somehow accounting for
| that is a terrible idea.
| MetaWhirledPeas wrote:
| Is there a way to mitigate this, or make use of the waste
| gasses?
| devops_monkey wrote:
| See my other comment as well as this HN thread:
| https://news.ycombinator.com/item?id=20551946
| devops_monkey wrote:
| 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.
| wang_li wrote:
| Why do we want to put the plastic's carbon into the
| atmosphere instead of back into the ground where it came
| from?
| ars wrote:
| Because then we can avoid pumping oil out of the ground and
| burning that.
|
| The hydrocarbons are going to get burned one way or
| another, you can just trade one type for another types.
| Supermancho wrote:
| > you can just trade one type for another types
|
| You cannot replace most oil-based fuel with incinerators.
| So I'll disagree there.
|
| The utility of oil-based fuels is the energy density in
| combustion. Burning plastic doesn't come close to the
| same exchange.
| zrail wrote:
| I remember reading about this in middle school.
|
| https://www.goodreads.com/book/show/86452.Ill_Wind
| d--b wrote:
| How much co2 does this release? Humanity needs to pick its
| battles carefully...
| BLanen wrote:
| I've been hearing this for 20 years.
|
| I assume nothing will happen while this "news" will be used by
| fossil fuel companies to virtue signal "technological progress"
| in the plastic problem.
| powerbroker wrote:
| 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.
| coryrc wrote:
| I thought it's usually just natural clay, but I bet it varies
| based on local conditions.
| kube-system wrote:
| 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...
| abcc8 wrote:
| I was thinking the same. Worst case scenario with a solution
| like this one is that these organisms get into the wild, gain
| more mutations, and then rapidly release a large volume of
| carbon, currently sequestered as plastic, into the atmosphere.
| Or, plastic-tropic organisms used as a weapon, sprayed over
| cities, etc.
| netizen-936824 wrote:
| Did I miss something? What organism are you referring to?
|
| An enzyme is a protein not an organism
| bitwize wrote:
| An enzyme is a protein molecule, not a living thing. Probably
| the biggest risk is that some wildlife or fish may be
| allergic to it.
| CameronNemo wrote:
| Perhaps plastic should start being compressed into bricks for
| long term storage that does not lead to leaching.
| faitswulff wrote:
| Note: the article talks about an enzyme, which is a simple
| protein. They might manufacture it via organic means, but the
| enzyme by itself has no capacity to reproduce or mutate.
| abcc8 wrote:
| That is true, but the best and easiest way to make a huge
| mass of a specific enzyme is to grow it in something,
| either bacteria or yeast. If it is in an organism, the
| organism can escape into the wild.
| faitswulff wrote:
| That's a much smaller threat than if the organism itself
| were to be applied directly to plastics.
|
| Designer organisms aren't generally well-suited to
| spreading in the wild and even if they were, they could
| be engineered to require a certain dependency that they
| would die without. But yes, still theoretically it's
| possible.
| [deleted]
| scohesc wrote:
| I wonder what the potential harm to infrastructure would be if
| this bacteria were to escape landfills / remediation sites and
| happen to get into places where PET is used in something
| important.
|
| Not that I'm against finding ways to _actually_ recycle or break-
| down plastics, just it seems like something we need a microscope
| to see might be hard to keep track of.
| hh3k0 wrote:
| > I wonder what the potential harm to infrastructure would be
| if this bacteria were to escape landfills
|
| At the very least, I'm sure it won't be as bad as in BioMeat:
| Nectar.
| jy14898 wrote:
| Manufacturers will love that their products break down and
| require replacing more often
| [deleted]
| bhouston wrote:
| And then this escapes and starts to eat plastics in cars and
| other durable goods thus rendering increased near term
| maintenance costs across a large number of industries.... just a
| thought.
| 323 wrote:
| Dumb question, but if plastic eating bacteria starts spreading,
| wouldn't we all be in a lot of trouble?
|
| Will car plastic interior start to rot?
|
| Will PET soda and water bottles start decomposing in the grocery
| store, and will they require refrigeration to prevent that?
|
| Will our computer keyboards require new materials?
| [deleted]
| ars wrote:
| This is for an enzyme, not bacteria, but to answer your
| question bacteria still need water, so if you keep the plastic
| dry it should be fine even in such a world.
|
| PET soda bottles will be sterilized, then sealed. The outside
| is dry and won't decompose. You won't be able to re-close it
| and leave it out though.
|
| For things that need to stay wet, like drain pipes, you would
| add chlorine and use PVC which is unlikely to be edible to
| bacteria.
| kwhitefoot wrote:
| See Doomwatch - Plastic Eaters from 1970:
| https://www.imdb.com/title/tt0564476/
| northisup wrote:
| what are the biproducts?
| Animats wrote:
| That's the real question. It doesn't "eliminate" anything. It
| turns it into - what? Organic sludge? Is that useful for
| something?
|
| Plastic bottle recycling into new plastic pellets works quite
| well. Southern California has a huge plant doing it. Non-bottle
| plastic is more of a problem but less of the volume.
| intrasight wrote:
| Who else things of "Grey Goo"
|
| https://en.wikipedia.org/wiki/Gray_goo
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(page generated 2022-05-18 23:00 UTC)