Mealworms can compost styrofoam | Hacker News Reader

Mealworms can compost styrofoam

livingearthsystems.com

157 pointsrrauenza127 comments

Here in The Netherlands we collect styrofoam with the recycling, it is then turned into a high value insulation product used to help insulate our housing stock.

I had a ton of extra styrofoam (I live in the SF Bay Area). It was hard to find out what to do with it, but finally found out that SF will take styrofoam waste for free and compact it with a densifier. Their site says "Our densifier converts Styrofoam into ingots, which can be re-manufactured into door and crown moldings, picture frames, and side and deck board."

'Can be'... I'd be curious what percentage actually is re-purposed and how much ends up in a landfill

so am I. It seemed that out of all the alternatives, this was the best option since it was free, and ostensibly recycled where all the other options were to throw it in landfill.

At the very least, those ingots will occupy less space in a landfill...

Also, we might have a far better recycling technology in 100 years and will know where to find the material. Perhaps it is better to simply store it somewhere for the future. Only now we should make sure it doesn't find its way to the oceans.

Store-and-use-later is underrated...

Most trash heaps from 100+ years ago have something of value in for people today (antiques, museum artifacts, leftover gold/metals in mine waste, etc.).

It seems unlikely that today's trash heaps won't have something of value for future people.

The only challenge is how to stop leaching of poisonous stuff...

I had an odd experience taking styrofoam to the dump in SF. On most days I would be told to just put it in some random dumpster, no receipt written up and no vehicle weigh in/out or anything. I figured that was just the process until one day I was told to take it to a specific place where there was other styrofoam being collected, my vehicle was weighed in/out and a receipt generated. Who knows what they were doing with it on those other days?

Yes, I also had to go through weighing and getting a receipt (but it was still free), and dropped off the foam right in front of the densifier. I've never been through that transfer station before, it's probably just covid rearrangement.

Turning the waste into building & construction materials is definitely going to be one of the major industrial ways of low-carbon polymer recycling.

Its already Here and its not necessarily industrial scale either its called EPSCrete [1] Yep no need to transport your styrofoam to a recycler and buy back some insulation product when you can make it yourself [2]

[1] https://en.wikipedia.org/wiki/Expanded_polystyrene_concrete

[2] http://www.norishouse.com/archives/582

Reduce is better than re-use - I don't think I've seen styrofoam for the last few years in the UK. Cups and food containers are paper and packaging for things like TVs is now shaped cardboard. What are you still getting in styrofoam over there?

Every monitor and tv i have ever bought used it for transport. (Germany)

It's very common in the packaging for computers and monitors that we order, although shout out to HP for transitioning to almost full cardboard packaging for their desktop PCs.

The new Dell monitor I just bought was also all-cardboard packaging, with some impressive engineering with layered compartments and accordion-spring folded reinforcement sections to keep the whole thing nicely sturdy.

I recently received a M1 Mini and I was impressed with Apple's packaging. The white box the computer was in had plastic wrap around it but everything else was cardboard or paper. The cable was secured with paper, not twist-ties. The white box fits neatly into the brown cardboard box and is protected at the corners.

Also happy with the M1 Mini, which has 16GB but I don't do virtualization. Mostly too many tabs.

Apples packaging is better than most but I doubt they would be able to ship a monitor in the same hard cardboard they ship small products in.

You mean, like the iMac?

I think the iMac packaging involves styrofoam and not just the paper parts used on their laptops and the Mac Mini.

I've ordered a bunch of DELL monitors over the last few years. All came in cardboard packaging with no styrofoam.

it's rare to get anything styrofoam in Oregon, but the last time I visited Florida, it was all over the place - take out containers, everything.

it really depends on the state, since those regulations are currently at the state level. a lot of states frown on federal mandates, and a lot of cities frown on state mandates. we're a huge country.

I just opened an LG product that had quite a bit of styrofoam in the box.

It is infrequent enough now that I often remark when I do see it.

LG started as a chemicals company producing plastics, and LG Chem still does that, so I guess they'd be one of the last to switch. There is always a certain preference for buying from your own company :)

Some companies are getting better at this, but I still see computer parts padded with styrofoam.

> Cups and food containers are paper

Paper covered with PFAS? Not sure whether that's any better than styrofoam.

Any good sources about that?

Some recent discussion here, and it the pages linked from that discussion: https://news.ycombinator.com/item?id=25557113

> in the UK ... packaging for things like TVs is now shaped cardboard.

Shaped cardboard packaging is not universal. I see as much styrofoam as those.

Styrofoam is terrible as 1) the council don't want it in the recycling bins. 2) inevitably it breaks, scattering little foamed plastic beads that disperse easily in wind. So it eventually contributes to the environmental microplastics

>Reduce is better than re-use...

I'm not so sure, reducing often does involve carbon release. In this case half the carbon in the styrofoam is released by the mealworms as CO2. If we can delay that a few decades why wouldn't we? Also re-use doesn't preclude eventual reduction, and by delaying it we may also be able to take advantage of more advanced reduction options. I think we need to look at these things on a case by case basis.

The phrase is "reduce, reuse, recycle, in that order" (each being better than the next). In this context, reduction means not buying styrofoam in the first place. I think you're confusing reduction with recycling.

Does styrofoam introduce any extra fire risk?

I would say that's a yes: https://www.abc.net.au/news/2019-02-21/cladding-crisis-sprea...

https://www.irishtimes.com/news/environment/insulation-blame...

The city where I live is recycling styrofoam to produce lightweight concrete as well as injected insulation foam.

"Fed with Styrofoam as the sole diet, the larvae lived as well as those fed with a normal diet (bran) over a period of 1 month"

I do not believe this claim.

Polystyrene has only carbon and hydrogen - so where are the mealworms getting nitrogen for protein synthesis? If they are getting it from the air, that's pretty major, and I highly doubt it.

Another problematic claim:

"and the rest into mineralized organic material"

What mineral exactly are they making that is usable for plants? Carbon and Hydrogen would leave just CO2 and water as waste products. What could they possibly be making?

> I do not believe this claim.

The biomass didn't increase for the Styrofoam eating mealworms. It did for the bran eating meal worms.

Would that fit?

10.1021/acs.est.5b02661

It makes sense. It implies the mealworms can use it for energy, but not for growth. It's basically a carbohydrate, they would need some protein, fat, and trace elements for proper growth.

Now I just need to know if these worms would harm my chickens. They (the chickens) already try and eat foam packing material that gets blown out of trash cans on windy days. The worms can't be worse, right?

We don't eat the chickens and barely eat the eggs (they're pets), so no risk to us.

Why don't you eat the eggs? I have ducks as pets and I love the eggs.

Wife is vegan, kid doesn't really like them and I just don't eat a lot of food. Nobody is really all that interested. We eat some but the chickens are free range and since the last move, we haven't found their nesting ground. We get one a day is a predictable place and the rest are who knows where. Even with one a day, we give about half away.

Huh, I thought chickens were more predictable and nested. Ducks sometimes just drop and egg while they're walking around, but mine stay in a pretty small area so they're easy to find if they haven't broken them.

>The mealworms are able to do this due to their gut bacteria (Exiguobacterium sp. strain YT2) that actually breaks down the polystyrene.

> The fact that these worms are converting about half of the styrofoam they eat into carbon dioxide and the rest into mineralized organic material suggest that it has come full circle.

The bacteria breaks the molecules and shouldn't harm the animals that eat them.

Is the next step to breed and harvest the bacteria?

And use that to just break down the styrofoam?

I don't know about industrial processes involving bacteria, but the mealworms might be providing a lot of value. First they chew up the styrofoam, and then they provide an environment (pH, nutrients, enzymes) for the bacteria to be effective. Mealworms are also fairly easy to breed.

If you isolated the bacteria, you might need to provide those other functions in an alternative way that's more cost effective than putting some worms in a bucket.

True, but at industrial volumes it might be more space/cost/time effective to directly use the bacteria, combined with a mechanical or chemical pre-processing step.

You don't buy fire, you buy a furnace. The mealworms really are the functional tool here, even if the bacteria is what's doing the work.

It’s gonna be quite some time before we can make better bioreactors than nature.

Tell that to the brewing and cheese industries.

Each of which being thousands of years old.

Tricks that work for airborne yeasts don't necessarily work for microbes that like digestive tracts.

Would you need to feed the mealworms anything other than just styrofoam? i.e. can you just have a giant vat of mealworms that you through styrofoam into?

My recollection of the original stanford writeup was that you actually couldn't feed the worms anything else. If given any options, they picked styrofoam last.

If you already have the styrofoam in one area it's way way way way more efficient to just burn it.

The only benefit of the mealworms is they go and find the styrofoam on their own.

How are you defining efficiency? Time to “disappear” the styrofoam? If yes, that’s not the problem to solve here. Health concerns are to be reduced from used styrofoam. Burning reacts it with air, and as another has commented, that produces harmful byproducts. Decomposing into CO2 (perhaps which can be captured) and manure is perhaps a better alternative?

> Burning reacts it with air, and as another has commented, that produces harmful byproducts.

It does not. Burning in an incinerator is completely clean and releases only water and CO2. If you burn it badly you can make smoke, so don't do that.

Also, it does not make manure, that's false info. It makes CO2 and water, nothing else, even with mealworms.

> It does not. Burning in an incinerator is completely clean and releases only water and CO2. If you burn it badly you can make smoke, so don't do that.

I suppose I should have been more careful with my terms - "burning" was meant as a layman's "making fire" rather than in a controlled process within an incinerator as you mentioned.

If this is clean, why are people so motivated to look for alternatives for its disposal, giving up and resorting to landfill? Is incineration cost-prohibitive? Or is the transport to the incinerators inefficient?

Because people are not rational and incineration "seems" dirty somehow, even though it is - by far - the mostly environmentally friendly way to deal with plastic. Far outclassing recycling.

It just looks bad, and recycling is about feeling good, not the environment.

Incineration not only disposes of the plastic, it also gives you back the energy embodied in the raw material used to make it. Then you can avoid burning some other oil, and use that other oil to make fresh plastic.

You can think of it as recycling with extra steps :)

But the byproduct is CO2, so without some math we don’t know if it’s better than burning and/or burying the foam

The danger from Styrofoam comes when the smoke from burning it releases harmful amounts of PAH (Polycyclic Aromatic Hydrocarbons). According to the Illinois Department of Public Health, it is known that PAH stays in the environment for years; has been linked to short-term symptoms like eye irritation, nausea, vomiting, diarrhea and confusion, and long-term symptoms like kidney and liver damage and cataracts.

https://www.atsdr.cdc.gov/phs/phs.asp?id=120&tid=25

I did a science fair project once in elementary school. My project was to see what materials would break down styrofoam. I took a big chunk and broke it into pieces, leaving each in a jar of different liquid (and burning one). As one would expect, burning it worked really well, but of course let off a ton of black smoke.

But you know what else fully dissolved the styrofoam? Coke. One week in a jar of coke and it was gone.

What does it turn into?

Polymer degradation of polystyrene through chain scission, if I recall correctly. Phosphoric acid results in a whole bunch of H+ ions floating around in the coke. Those can attach to the C of both ends of each piece of a broken polymer chain or to the aromatic rings on the chain. So the styrofoam breaks into shorter and shorter chains until they are simply floating in solution invisible to the naked eye.

I wonder if that makes it easier for the mealworms to digest it.

Coke is a fairly strong acid, and somewhat notorious for its cleaning properties viz: https://www.airtasker.com/blog/15-ways-clean-coca-cola/

This admittedly might be pedantic however when it comes to acids "weak" and "strong" are reserved words, if you will, in chemistry; phosphoric is a weak acid. This may be a confusing notion at the outset as hydrofluoric acid, for example, is terrifically corrosive yet considered "weak".

The distinction lies in whether the acid's molecules fully disassociate into ions in solution, or only partially.

What is a better way to describe acids with higher or lower pH in a non-technical context?

Apparently the USDA uses "strongly acidic" to mean soil pH of 5–5.5 https://en.wikipedia.org/wiki/PH#Classification_of_soil_pH_r...

Yes, but "strongly acidic soil" and a "strong acid" are not the same thing.

Coke contains phosphoric acid whic is a weak acid. It is just an acid that is pretty good at removing rust and other oxides in a relatively safe way. Phosphoric acid is also really good at decalcifying your teeth... Leave a tooth in coke for a few days if you want to see what I mean.

To which the head scientist of Coke responded in the 70's - don't keep coke in your mouth for days on end.

Apparently acetone or any organic solvent work well to dissolve styrofoam also.

https://sciencing.com/acetone-styrofoam-experiment-2768.html

Though, that's probably not elementary school safe.

It doesn't remove the Styrofoam though. The Styrofoam is broken down into long chains of molecules which remain in the solvent.

Could this mean it's a bad idea to drink Coke from a styrofoam cup?

Only if you plan to leave the coke in there for a week beforehand.

Don't these cups have some kind of inner coating?

They do not. You are thinking of paper cups with a plastic or wax coating.

They used to have a wax coating, in just the past decade that has disappeared almost entirely and any recently manufactured cups have a polyethylene (not styrene) lining. Many cups made for hot drinks have polystyrene on the outside, some are multi-layer paper and some have a cardboard sleeve.

It's generally a bad idea to drink coke, or to drink from a styrofoam cup.

>It's generally a bad idea to drink coke

Not really, it's not worse compared to many other things people consume.

> Not really, it's not worse compared to many other things people consume.

Yes really. Other things being worse is whataboutism to derail from the issue.

Coke, specifically, from can bottle. If you drink the brown sugar suspension that is fountain soda, you are just marching toward diabetes. The chemistry is unique between these products.

Coke isn't limited to sugary coke.

> Could this mean it's a bad idea to drink Coke from a styrofoam cup?

> It's generally a bad idea to drink coke

All coke colas (and most other products) are insanely high in fructose. The distinction to "drinking coke" is that it's a coke carbonated cola product. The conversation isn't nuanced that a distinction is being made.

>All coke colas (and most other products) are insanely high in fructose

by "Coke isn't limited to sugary coke.", I'm guessing the parent commenter was talking about the sugar free variants eg. diet coke or coke zero.

Yep.

Uhhh no, diet coke and the various kinds of coke zero are NOT high in fructose.

Why is this downvoted. I'm quite sure that many soft drinks like "coke no sugar" use aspartame instead.

If you look at my posts, I seem to be on the "downvoted every post list" from a few unhappy members as I frequently find my posts instantly downvoted for no reasons...

Most fruit juices sold have very similar amounts of sugar to non-diet sodas.

Some people I know lecture me about drinking too much soda while their kid chugs cup after cup of orange/apple/grape juice.

https://www.forbes.com/sites/nancyhuehnergarth/2015/12/14/wa....

Coke doesn't contain acetone or alkanes like in gasoline so you will be fine. You should be more worried about your teeth and blood sugar.

Gasoline works great. And with enough styrofoam you get the Anarchist’s Cookbook version of napalm as a bonus.

If you want to dissolve polystyrene (styrofoam) then acetone or any other organic solvent (even gasoline) does a much faster job. And because the foam is mostly air you can get rid of quite a lot of it before the solution becomes completely saturated. This solution can be used as a sealant, or to fill molds and produce plastic parts, although it's advisable to use a vacuum chamber to recycle your solvent and help with the degassing.

I once tried to spray-paint styrofoam black for a school project. The solvent in the paint ate away at the plastic and left it not foamy immediately.

Next time put a thin layer of plaster of paris on the styrofoam first before painting.

Or PVA (aka "wood") glue. You can even thin it with water fairly substantially to make a poor "sealer."

12 year old me made napalm with the dissolved styrofoam

I was just melting styrofoam with acetone sprayed from syringe.

Fun ended when I decided to include lego minifigure and found out that acetone also dissolves abs plastic. Legos were expensive, hard to get and treasured when I was a kid so result was much undesired.

>Legos were expensive, hard to get and treasured when I was a kid so result was much undesired.

By the time I had children of my own, they were cheap enough to be used as caltrops.

Solvent-based methods have some unfortunate side-effects, and are difficult to scale [1]. Low and slow heat appears to work. I'm still trying to find reports of anyone who takes end user styrofoam and turns it back into desired styrofoam shapes with carbon dioxide as a foaming agent, entraining it into the closed cells. I've yet to hear of people who reduce styrofoam into polystyrene being able to turn it back into styrofoam again, but can't tell if that is an outcome of the chemistry/thermochemistry (very difficult to address), or lack of foaming equipment (addressable with enough expertise, space and capital).

Ideally, I'd like to figure out a way to take all styrofoam entering say a neighborhood as end user packing gets continuously turned into standardized insulation interlocking blocks that is continuously, incrementally installed into buildings that are pre-built with say, 2-4 meter thick wall cavities for incrementally build up the insulation over time. The styrofoam that enters our lives as packing material for a brief period and becomes unwanted detritus ends up in multi-decade and hopefully multi-century building insulation.

I want to do the same with the polyethylene used for most bags, though for those I'd want to turn them into sheets and use them for endlessly making Kaizen foam to organize, protect and store my tooling.

[1] https://davehakkens.nl/community/forums/topic/has-anyone-tri...

Styrofoam isn't safe for household insulation. It's very flamable and produces heavy black toxic smoke.

Is it not the same thing as ubiquitous foam board insulation? https://www.homedepot.com/b/Building-Materials-Insulation-Fo...

Somewhat. There's multiple types of foam board used for insulation in buildings. The most common types are EPS, XPS, and polyisocyanurate. EPS and XPS are Expanded and eXtruded PolyStyrene, respectively. Both are closed-cell foams.

EPS is styrofoam, and is made by putting a bunch of polystyrene beads in a container, and then heating it up so they expand into a big block either in the desired final shape, or later cut into the desired size and shape.

XPS is foamed up with a blowing agent, previously an hyrdoflourocarbon gas (I don't know what's used currently), and then extruded into its desired shape.

Polyiso is its own animal, but I know little about it, other than it's not polystyrene.

What synthetic chemicals remain in bodies & excrement of the mealworms?

Assuming synthetic chemicals are not somehow metabolized into natural chemicals, then the problem remains.

Since polystyrene has only carbon and hydrogen in it, the number of problematic chemicals you can make from it is quite limited.

Not zero certainly, I'm sure a chemist could find some, but starting from polystyrene (which is very stable) and ending up at a problematic chemical is unlikely because the mealworms are using the polystyrene for energy, so I would assume they fully oxidize it, leaving just CO2 and Water.

You mean like for instance the known carcinogen styrene?

https://en.m.wikipedia.org/wiki/Styrene

That's exactly the point: You're not going to go from polystyrene to styrene without inputting energy (like in a fire).

These mealworms are not going to generate it, they can't.

Isn't polystyrene just styrene blocks chained together, meaning going from polystyrene to styrene should be quite doable?

Full disclaimer, my chemistry knowledge is very shallow (advanced high school level I guess).

Doable, yes, but as the parent said you need lots of energy, because you need to tear the chemical bond apart again, and that is quite strong in polystyrene and thus doesn't easily depolymerize. If I remember right the industrial process for it is at a few hundred degrees C and high pressure.

(solvents etc will do all kinds of weird things to polystyrene, but it won't just fall apart into styrene molecules again easily)

Thanks, makes sense then :-)

So is the answer then that some synthetic chemicals remain?

If so, do you know approximately which ones and in which amounts? Just curious.

> So is the answer then that some synthetic chemicals remain?

That's the opposite of what he said. He said other chemicals can not be created.

Not making Styrofoam in the first place is a better answer.

Among other problems, Wikipedia states: "The EPA and International Agency for Research on Cancer reported limited evidence that styrene is carcinogenic for humans and experimental animals, meaning that there is a positive association between exposure and cancer and that causality is credible, but that other explanations cannot be confidently excluded." (with links to EPA reports)

A quick search found NoMoreStyrofoam.org http://nomorestyrofoam.org, which says a lot more.

That's a pretty cool article. Would be limited to potentially fertilizing gardens with their leavings. Couldn't eat the worms since there would be plastic particles still in their guts.

You could just transfer them to a non-plastic medium prior to consumption and let them flush out their digestive tract.

True!

"each worm can eat 0.127mg per day" That sounds too less to be considered a feasible recycling method

Keeping hundreds of thousands of worms is pretty practical. Commercial mealworm growers are storing at least that many. You could easily keep a couple thousand at home. The real barrier to styrofoam recycling is transporting it (it takes up so much volume) and cleaning off food from it. This can be easily done at home and requires no washing of the styrofoam so it eliminates both of those issues.

Anybody knows if those are sold online? I would grow them and feed them all the stuff i get in the mail!

Mealworm’s gut bacteria break down the styrofoam into usable organic matter!

- Click to Tweet

Anybody have a TLDR?

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very cool!

[deleted]

Reading the article and your comment afterwards brought Simpsons to mind:

Skinner: Well, I was wrong; the lizards are a godsend.

Lisa: But isn't that a bit short-sighted? What happens when we're overrun by lizards?

Skinner: No problem. We simply release wave after wave of Chinese needle snakes. They'll wipe out the lizards.

Lisa: But aren't the snakes even worse?

Skinner: Yes, but we're prepared for that. We've lined up a fabulous type of gorilla that thrives on snake meat.

Lisa: But then we're stuck with gorillas!

Skinner: No, that's the beautiful part. When wintertime rolls around, the gorillas simply freeze to death.

Funny, the comment I posted was one line: "Used to feed mealworms to pet chameleons as a kid." Got immediately dinged with a DV. I was merely recalling a childhood memory of "mealworms". Maybe someone thought I was suggesting some kind of remedy to a potential invasive species problem? Nothing of the sort. I am all too familiar with real world invasive species problems and the historical remedial failures associated therewith. Totally different subject.

Who knows why you got downvoted, but please don't be so sensitive that you delete comments you'd stand by. It's annoying to find deleted/edited comments that have replies.

I did not downvote you, but I figured I’d let you know that based on what you said I’m pretty sure you were downvoted because your comment brings nothing to the conversation. People on HN tend to prefer informative contributions to the discussion, just for future reference.

I think that's it. Cheers! I guess if I told some entertaining story the result might have differed.

Article link is returning a 403 so haven't read it; Does this release carbon in the form of CO₂? If so it's better to leave it as-is, or recycle it into other products in ways that don't release carbon.

Since they emit CO2 anyways, is this much more efficient than just burning the foam?

The answer to which question, though? Sure, some organisms can eat styrofoam, and raising vast quantities of them is one outbreak away from a massive invasive species problem. So yeah, in the lab this is "a" way to get rid of a small amount of styrofoam, but it doesn't solve the styrofoam problem. Banning styrofoam is half the solution there, and the other half is un-economically expensive.

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