Bubble barriers: a smart solution to plastic pollution in rivers | Hacker News Reader

Bubble barriers: a smart solution to plastic pollution in rivers

thegreatbubblebarrier.com

323 pointsdwenzek140 comments

This is fascinating and clever.

But the cynic inside me fears it would never make a difference. First of all, one common statistic is that 90% of trash in the ocean that comes from people dumping it (in rivers) comes from just 10 rivers, all in China/Asia.

And if they cared about the problem, they'd already be doing something about it. But it seems like they don't. Because the real solution there is the same as what is done in the first world -- to implement actual municipal trash pickup and urban trashcans etc. If they can't even do that, I have a hard time believing they'll bother with "bubble barriers".

So this seems like something first-world countries would implement... but that's not where the problem is.

But second, it's also common to hear that a large majority of overall ocean plastic comes from discarded industrial fishing gear -- nets and the like. Which this obviously does nothing for.

So while still very clever, I sadly don't think this could ever make a difference. We need to actually solve the much messier human problems of installing trash collection around the world and figuring out ways to monitor and punish fishers who discard their equipment.

I don't follow. Because China don't even implement a countrywide logistics-heavy service branch, they won't bother with a cheaper, localized solution?

The countrywide logistics-heavy solution provides actual benefits to residents with cleaner cities and rivers.

The catch-it-at-the-mouth-of-the-river one doesn't. It would still be expensive, but benefit only the ocean, not residents.

So sadly, yes -- I can't imagine why they'd bother.

The Chinese do eat seafood. They don’t sacrifice growth for the environment, but passing up something relatively simple (and extremely clever) like this?

I can’t think of why they wouldn’t try it.

This is the opposite of a localized solution. It attempts to do waste collection at an aggregated point. Where does all the waste go that doesn't end up in river with managed waste collection, is the issue

The ten rivers dumping 90% of plastic are in Asia and Africa. But Chinese trash is indeed big factor in more than half of the rivers.

Another big problem is that rivers in the developing world aren't particularly well controlled.

Just this summer, a massive flood in the Yangtze basin displaced over 60 million people and inundated a number of large cities. The flood carries anything that will float downstream, and eventually dumps them in the ocean. As it happens, plastics tend to float pretty well.

So even if the Chinese government declared that they will shoot anyone who throws trash in the rivers effective immediately, the rivers themselves come into people's homes, snatch plastics, and carry them into the ocean every year.

Last year I was swimming in Corsica and every evening when the tide rolled in, the plastic rolled in as well. This is an island in the mediterranean, so lots of the plastic will probably come from first world, European countries, not Asia.

Though I obviously cannot rule out that a lot of the plastic actually comes from the Nile.

Most of the plastic that comes to French shores is from Spanish land fills. They severely under recycle.

Case in point, India: https://www.youtube.com/watch?v=XeDY3I841q0

>First of all, one common statistic is that 90% of trash in the ocean that comes from people dumping it (in rivers) comes from just 10 rivers, all in China/Asia.

>So while still very clever, I sadly don't think this could ever make a difference.

I get what you mean by this, but why can't these solutions be used in places that are willing to make a difference? Anywhere this is deployed is making a difference locally. In the grand scheme of the world, yes we do need some big solutions to get some places up to speed but if a bubble wall cleans up some of the 10% other plastic in the water, then I am all for it. We can't keep our heads in the sand over the 90%, but we need to be happy about the small victories we can get.

I remember hearing about the machine that picks up trash in Baltimore at the Inner Harbor. It would take the current and push the trash into the machines conveyor belt. It was probably pick up a percent of a percent of the total world trash, but it made the harbor area much cleaner.

>I get what you mean by this, but why can't these solutions be used in places that are willing to make a difference?

Our efforts (and resources) might be better allocated in an area that has a bigger impact. This is basically the idea behind cap and trade. Why spend $10 to pick up 1 ton of plastic waste in the first world (made up numbers), when you can spend $10 to pick up 5 tons of plastic waste in asia? A more concrete example would be the water conservation measures in calfiornia a few years ago. The vast majority of the water usage is by agriculture, but residents were asked to engage in water saving practices (not watering laws, short showers, opt-in water at restaurants) at great inconvenience to them, even though any savings would be a drop in the bucket overall.

I see what you mean, but at the same point, the $10 to pick up 5 tons of plastic in Asia doesn't seem to be happening for whatever reason. My reasoning is that $10 to pick up 1 ton of plastic is still a good option since the $10 to pick up 5 tons is not a guarantee.

> First of all, one common statistic is that 90% of trash in the ocean that comes from people dumping it (in rivers) comes from just 10 rivers, all in China/Asia.

> but that's not where the problem is.

Maybe we should stop using them as our factories for 80% of the gadgets, tech, clothes, &c. we consume.

I think there is now a real will from the chinese government to limit plastic pollution.

For example, waste sorting started in Shanghai a year ago and started in Beijing last June [0].

This is not the usual waste sorting we are experiencing in Europe, for example, since you need to decline your identity and not make any mistake while sorting or you may get charged.

Probably a bit too invasive (this is China after all) but more thorough for what I consider a good cause.

Besides, the first bans on plastic use will take effect on January [1]. This is only for small items now, but this is a first step, and it also includes production of these items, which is especially impressive considering China supremacy on the production lines.

[0] https://www.scmp.com/news/china/society/article/3016801/shan...

[1] https://www.scmp.com/business/china-business/article/3101241...

Also:

https://en.wikipedia.org/wiki/China%27s_waste_import_ban

A not insignificant part of the plastic thrown in rivers in South East Asia is consumed in Europe and the USA

> A not insignificant part of the plastic thrown in rivers in South East Asia is consumed in Europe and the USA

I've heard this repeated many times, but every time I go searching for details I always come back with the same results: This is not true.

The garbage in rivers is local.

No one is shipping waste from Europe or USA, but some countries do buy recycling. But of course since they paid for the recycling, they have no interest in then dumping it.

If you have some source showing different I'd be interested in seeing it.

Scientists say otherwise: https://www.europeanscientist.com/en/environment/plastic-for...

If you read the study they don't have great data, so they do a lot of estimating. According to the study itself it's 1% to 7% of recycling that ends up in the ocean.

Obviously any amount is bad, but this isn't a significant source of river plastic.

And to really drive the point home: According to the article the plastic ends up in rivers because of bad local trash management!! (As opposed to deliberate dumping.)

So the solution is exactly as others have said: These countries need modern municipal trash pickup. The problem does not originate in Europe or USA.

BTW: This is a very poor study, for example they use numbers for San Fransisco Bay watershed to estimate numbers for India.

the stat is about oceans and that it comes from those 7-10 rivers

You mentioned Shanghai and Beijing, but note that sorting waste isn't new to the country. I was part of a team that installed a single-stream waste sorting system in China in 2007, prior to the Olympics. It was a very impressive system where all garbage would enter at one end and a large array of machines and people would sort the garbage into recyclables, compost, and the rest for an incinerator. It used all the latest tech, mainly from North America.

Do you have any good links to the machinery / tech that does that kind of sorting? I've search for it in the past and it seems like I was mostly getting hits on European manufacturers.

The systems use lots of clever tricks, like floating paper and plastics away from metals with water or jets of air, or using eddy currents to push metals out of mixed waste. Here's one example: https://www.popsci.com/technology/article/2013-07/how-it-wor...

I think current garbage sorting is waaay too inefficient, and this is fundamentally limits the recyclability rates.

This is especially obvious when you talk about stuff made of a lot of different materials.

Picking such things apart for different material streams is impossible to scale.

I was thinking, what if governments were mandating mandatory chemical tagging of all common materials, so you can just shred everything, and then separate materials using machines which can distinguish chemical tags.

I think it might be easier to just have machines learn to recognize the top 99.9% of all things thrown away and leave the rest to a a small group (or landfill).

This seems like the obvious solution. I bet a database of 100,000 products would cover the vast majority of all waste worldwide. If you can make a machine to sort those things into 100,000 (virtual) piles, you can then have a specific way to handle each type of thing.

Each manufacturer of those goods can decide how to handle their "pile", and if they design for recyclability, it's going to be easier and cheaper for them. If they can just say "combine our product with these other products made from the same material" that'll work out cheapest. If their answer is "our product contains a mix of various toxic stuff" then they're going to have to pay for some specialist to handle it... In every location this 'pile' exists in every city...

The only place this system doesn't work is for products that change state significantly during consumer use - for example a candle gets mostly burnt away, but the remaining blobs of wax are probably untracable to the original manufacturer.

The problem, as I stated above, is that you will be landfilling significantly more than 0.01%.

There are tons of unrecyclable stuff in regular household garbage. For example, a packaging made of two incompatible in recycling methods plastics are a waste.

I'm describing an approach to sorting. Your response isn't about sorting.

What about waste vaporization? There are far fewer things that are sensitive to being vaporized (meaning far less sorting needed) and the outputs are far cleaner.

Who will pay for electricity?

There are ways to generate massive amounts of power with relatively few inputs

Which ones?

Recycling, even plastic bans, are not the most direct or simple fix. The first and key step is to stop dumping it in the river. Getting the plastic into landfills is the first step. Reduction and recycling are the stretch goals.

the first step is DON'T MAKE IT

or make it of something biodegradable

I suspect most the plastic waste I generate is in packaging. I wish shipping companies would use cardboard instead.

This is ignorant; China has in recent years taken a hard line on pollution of various kinds. They already put a moratorium on importing foreign trash (which was a huge source of river pollution) and are banning single use bags and straws: https://www.bbc.com/news/world-asia-china-51171491

Packaging like plastic bags are by far the biggest source of river waste: https://ourworldindata.org/plastic-pollution#plastic-waste-b...

China currently produces ~60% of global oceanic plastic waste: https://ourworldindata.org/plastic-pollution#share-of-global...

So if China currently produces a majority of oceanic plastic waste, how hard a line could it be?

"if I'm hitting the accelerator hard, how could it be that I'm not currently moving fast?"

I guess we'll see when they adopt these bubble barriers, or something similar.

"I've been holding the accelerator down hard for multiple minutes, why am I not moving fast?"

They didn't start just a month or two ago. I share the skepticism of it being a "hard line".

The GP said that China/Asia produces 90%. You say China is at 60%, so if we add India and the rest of Southeast Asia, you are saying essentially the same thing.

And while China might be starting to cleanup its act, India is fast urbanizing and increasing its waste production, with less investment in infrastructure. In a few years, the proportions might be swapped but the problem is not going away soon.

>90% of trash in the ocean that comes from people dumping it (in rivers) comes from just 10 rivers, all in China/Asia

So you're saying with bubble barriers in just 10 places (as opposed to all around the world), we can clean up 90% of ocean trash from dumping? That's amazing. A lot easier than trying to get China et al. to implement more "actual municipal trash pickup and urban trashcans etc." The first world could crowdfund the barriers. I'll help.

If there was a way to setup a nonprofit actually competent enough to carry this out, and maintain it, and fend off any local politicking that is bound to happen then this might be the fastest solution. Of course the difficulty is getting enough buy in from the countries with those rivers since using force is probably not possible.

For all the reasons you've stated, that's why it's simply not going to happen.

Can you think of any major environmental project funded by foreigners that just goes in and successfully helps out?

They don't work because they're seen as an affront to the nation's autonomy. It's not seen as help. It's seen as invasion.

I'm not even joking: in Brazil most of the population believes that any effort by US private citizens/charities to purchase land in the Amazon to protect it is just a front to make a future US military invasion of the Amazon easier. It's ludicrous to Americans, but it's just "common sense" to Brazilians.

The point is that those 10 places don't even need bubble barriers, they just need normal first-world refuse handling.

Isn’t our first world refuse handling to send it to the second world?

No, it is not. Why do so many people believe this?

I've seen it repeated over and over as if it were true, but it's not.

https://www.smithsonianmag.com/science-nature/burning-truth-...

> reporters come here thinking this is the destination for old laptops exported from the United States [..] But this isn’t the destination at all. The computer shops are.

> According to the United Nations Environment Programme, 85 percent of the e-waste dumped in Ghana and other parts of West Africa is produced in Ghana and West Africa

I think "produced" is a massive misnomer here. For as far as I know, there are no high-tech electronics factories in Africa. What the 85% figure refers to, I guess, is the part of the waste that was part of the local economy before ending up at the dump. But from the first quote, that still means the site is filled with discarded items from the US and Europe, just not directly.

So .... discarded items from the US and Europe are given new life and reused in Ghana? And this is bad somehow?

Isn't reuse the ideal situation?

Not to mention e-waste vs plastic trash are rather different topics.

I repeat what I said: First world countries do not deal with trash by sending it to second world countries, despite being oft repeated, this is not actually true.

I haven't claimed anything about right or wrong. I'm just pointing out that the claims "much waste on landfills in Africa comes from first-world countries" and "first-world countries do not dump their trash in Africa" can both be true.

"...[China] which had handled nearly half of the world’s recyclable waste for the past quarter century."

https://e360.yale.edu/features/piling-up-how-chinas-ban-on-i...

It very much is true. In the context of this discussion, the bubble barrier works on plastic pollution, so we're talking about plastics and recyclables.

Except we don't "send" the recycling to China, rather China buys (bought) it from us.

So because they bought it, they value it, which means they are not just dumping it wholesale.

> the bubble barrier works on plastic pollution, so we're talking about plastics and recyclables.

But we are not talking about plastic from the US or Europe, rather we are talking about local plastic. Because, as I said above: China is not dumping random plastic in rivers, they value the plastic because they paid for it.

(Yes, there is some waste mixed in, that needs to be disposed of, however that's a minor amount compared to waste in general, and especially compared to local waste. If you need a ref on that see my other comments in this thread.)

In summary almost zero plastic from the US or Europe ends up in the ocean via a third world country. That's simply not how it happens. If you want to solve this problem you need to look elsewhere instead of blaming first world countries as you did in your earlier post.

>Except we don't "send" the recycling to China, rather China buys (bought) it from us.

And then what happens? I'm sure they don't "use every part of the buffalo," so to speak.

most is put at dumps, ewaste might/used to be shipped internationally. Most cities have a dump. The one that handled New York is currently being turned into a park. https://www.nytimes.com/2020/08/14/nyregion/freshkills-garba...

But the other point is that it's way easier to build 10 barriers than convince thousands (millions?) of people to change their habits. Especially in the short term.

try billions

If the rivers get sufficiently clogged up with trash, the bubble barriers aren't going to do anything. The pressure from the river on a lot of garbage will easily overcome the bubbles. Eventually, somebody is going to need to incinerate the trash or move it to a landfill.

Are you thinking that the bubble barrier is just meant to push the trash to the side, and that's it? Clearly, they are trying to push it to one location for easier collection. Try being a little more open to ideas, and a little more thought about next steps.

It's much easier to collect trash in dump sites in flood-prone areas for example than from a river. Concentrated trash in a smaller body of water won't be much easier to collect than the status quo given how much concentrated trash there already major Asian rivers, especially when you consider how much maintenance a great bubble barrier would require.

We don't need new solutions. Developed countries have already solved the problem of river trash with waste management, but since it's not glamorous enough, people only fund these well meaning flashy projects that could create more environmental harm than they prevent.

> So you're saying with bubble barriers in just 10 places (as opposed to all around the world), we can clean up 90% of ocean trash from dumping?

Careful, this is about hating the inhuman Chinese who enjoy putting rubbish everywhere. If you think to hard the whole idea might fall apart. Facts and thinking things through kill ideas like this.

>the ihuman Chinese

Chinese people as a whole, no, but the Chinese Government is literally putting millions of people in in humane concentration camps. I believe the criticism China gets is well beyond justified.

It comes mainly from Asia because developed countries send their trashes there (in big polluting ships) to be "recycled", so depressing.

This is why feel-good nonsense in 1st world countries like plastic bag taxes and banning plastic straws is infuriating.

Is there a source on that actually being nonsense? I recognize that it might have a trivial effect overall given the global situation, but it still seems like a good step to me. I know next to nothing about this though, so I'm interested to hear more.

I was mildly against it, but now that it’s implemented I feel a little different about it.

I think the main impact is going to be cultural - people are going to start feeling weird about using disposable plastic in everything. It’s going to nudge everyone just a little bit away from plastic.

The kids growing up now, hardly ever seeing a plastic bag, will grow up to be designers in the future. Predisposed against plastic.

I’m now mildly for banning plastic bags. Where paper is not yet optimal, we will eventually iron out the kinks with engineering and science.

You deny the concept of collective impact. One person using a plastic straw isn't a big deal. Three hundred million people using a few dozen straws per year is additive. Same with all disposables.

Furthermore, ocean pollution isn't the only kind. Look at any urban creek/bayou bank after a hard rain and look at the trash that is washed up in the grass.

The right-wing pejorative is "virtue-signalling" but is that always bad? Is it bad to set an example, a cultural marker, that we want to encourage re-use and biodegradable materials?

This is not an either-or.

I agree, but I would say the danger is that people will feel like they have now done their part - "My straw is waxed paper! I'm not destroying the planet!" when in fact plenty of other things in their day-to-day lives have a much larger impact - insulating your home would do more for the world by orders of magnitude (admittedly that doesn't keep straws out of sealife, but choose your battles?)

Throwing someone in a cage for not following your admittedly not very effective "cultural marker" is evil. If you want to use public shaming to convince restaurants to use paper straws, fine, but please leave it at that.

Yes, and taxation is theft and you didn't sign a social contract. /s

Government power can be exercised without jailtime, but you seem to take everything to the logical extreme.

I'm going to be free of your fundamentalist religion and there's nothing you can do about it.

Is there a jurisdiction somewhere where using plastic straws has been made a criminal offence with jail time as a punishment?

Here (Australia) it was implemented as a civil fine and I assumed it would be similar elsewhere. But if that were the case where you live I’d agree that’s awful.

If that’s not true then you’ve just made a straw man argument.

Hell, even if there _was_ a place where they locked someone up for providing plastic straws to customers I’d argue that the issue is that particular law. Not the broader issue of legal ‘nudges’ to foster positive cultural changes.

If we don't comply you'll continue to escalate until we do comply or we're dead. That's what happens if I refuse to pay your unjust civil infraction.

The fundamentalist faith that is evangelical progressivism allows nothing and no one to fall outside its purview. Every aspect of everyone's life must submit to its edicts.

It might seem ridiculous in the grand scheme but we don't live on the grand scale anyway. The first world can sacrifice a little bit while demanding change from larger entities.

Not really. It convinces a lot of people to reuse, and use alternative methods.

What's nice about this solution is that it's not trying to change people's behaviors. Instead, by angling (no pun intended) the bubble barrier across the current the rivers and canals can be used to sort the plastics into recycling bins.

Installing a bubble barrier could be a lot easier than solving plastic pollution all the way along the river in a country with endemic corruption.

I wouldn't call that cynical, just a recognition that the "missing ingredients" in any plan usually turn out to be leadership, courage, compassion etc., not technology.

So if those countries don't care about their rivers spewing plastic into the oceans, could a billionaire simply pay to build one of these things and then pay boats to clean up the waste it collects?

I wonder what it would cost to just put one of these in somewhere and run it. (Including all the bribes/lobbying to allow it to be built in the first place)

It gives me a strong "solar freaking roadway" vibe. I feel like there has to be some details missing that makes a huge difference.

> First of all, one common statistic is that 90% of trash in the ocean that comes from people dumping it (in rivers) comes from just 10 rivers, all in China/Asia.

Just thought I'd factcheck this: turns out this statement is not accurate. The original paper [1] lists the countries, and two of them are in Africa, 4 are in China, 1 is on the China-Russia border. Jurisdictionally, there seems to be a few parties involved and the insinuation that "they" don't care about the problem seems like an oversimplification and a projection.

Secondly, that snapshot was a while ago and assuming that nothing hasn't been done since then is also incorrect [2].

I have to admit I felt uncomfortable with the cultural assumption expressed in the sentiment about "having a hard time believe they'll bother with bubble barriers". It felt a little presumptuous because it assumes a culture is immutable. The sentiment that these types of solutions are something "only first world countries would implement" also seems a little bit dismissive.

I work with people in non-first-world countries every day (I work in a global company) and have often been surprised how ahead of the curve they can be in certain areas, and I've learned not to make assumptions without first informing myself of the true situation on the ground (which is often more complex and nuanced than the tropes we have in our heads).

[1] https://pubs.acs.org/doi/suppl/10.1021/acs.est.7b02368/suppl...

[2] https://www.weforum.org/agenda/2018/06/90-of-plastic-polluti...

Interesting, this claims that fish and other wildlife can pass through but they don't seem to explain how it's different from bubble barriers used to deter fish from passing into underwater construction zones related to drilling or pile driving [1].

[1] https://www.newnybridge.com/protecting-underwater-wildlife-b...

In that article the primary purpose seems to be to reduce soundwaves rather than preventing fish from passing through, so both sources are in agreement there that it lessens soundwaves.

Also the pressures could be different. It's not hard to imagine that higher pressure would act as a bigger deterrent to passing through, so maybe that's what they're using at the construction site?

Both the bubble barrier page and the article you linked are fairly short on specifics though, which is a shame. It wouldn't be that hard to write out some pressures...

Agree, I hope it's a possible solution. Just thought it was interesting after hearing about the technology a few days ago in relation to sound suppression and rocket launches.

How does this let fish past? Dolphins and whales use bubble corrals as a fishing technique specifically because fish don't like crossing it. I believe it's also being tested as an alternative to shark nets. Presumably this would be a more intense bubble wall, which I would expect to seriously impede the free movement of marine species.

Maybe if it were suspended near the surface of the river so fish could swim under it. That probably wouldn't let much plastic through, as this would only really be effective on floating plastics anyway.

See it:

  >|     |
  >|  |  |
  >   |   
  >|  |  |
  >|     |

Yeah, that's clever, it might work.

Although in the video they don’t have breaks and they have it angled to steer the rubbish towards a trap: https://www.youtube.com/watch?v=n_KwF-gf0S0

But they could add breaks:

  > \
  >  \
  >   \   \  
  >        \
  >         \
  >          [rubbishtrap]

The biggest problem I could see is that it also traps leaves etc which you would ideally let past as they surely are needed for the river mouth ecosystem? Edit: also what if most of the trash is during storm events - the system wouldn’t work if that were the case.

I think the best solution to avoid plastic pollution is to tax it heavily where it does not make sense, whether it's single use or not.

Also I believe a nice solution to plastic recycling would be for legislators to implement a standardisation of all the bottles / food packaging / etc. so that they all use the exact same type of plastic.

Then once we stop dropping tons or plastic on our ocean and polluting our soils with it, we might end up with a quite-clean environment in the next 50-70y (and pray that there are no long term effects on plastic contamination).

But in the end, the best solution to plastic is definitely to stop using it.

This is interesting. There's a related "startup" tackling the problem from a different angle: https://theoceancleanup.com/

They did some research and found that something like the top 5 or top 10 rivers in the world are the source of 80+% of the plastic in the ocean. So they came up with this plastic-filtering-barge design with hopes of placing them at key points in all the major rivers. So far four are built and in operation. Absolutely not a solution but a ton of harm reduction.

https://www.youtube.com/user/TheOceanCleanup/videos

Both of them hail from Amsterdam! I imagine the bubble idea might have come out of seeing the ocean cleanup barges in operation - they have the problem of interfering with boat traffic where deployed.

Ocean Cleanup is originally a Delft company that moved to Rotterdam.

They are not "from Amsterdam".

The Ocean Cleanup hails from Delft. It was founded there, and the concept was 'invented' whilst the inventors were busy with an Aerospace Engineering course at the Delft University.

Different province and about an hour's travel south from Amsterdam

I guess the frisian province is 'Amsterdam Lake District', rotterdam is 'Amsterdam Harbour', The Hague is 'Amsterdam Government Plaza', and Delft is just 'Amsterdam - Burials of Royals + that place with the solar boats and cars and the plastic barges dept' :P

NB: I think that "Amsterdam Lake District" thing really is how its marketed from time to time to attempt to distribute tourism more throughout the country. The rest a bit more tongue in cheek.

If this is the main idea, move it further up on the page if it doesn't break your design goals. I skipped the initial text and went right to it.

https://thegreatbubblebarrier.com/wp-content/uploads/2018/03...

Great idea. Has it been tested?

They claim they are working with Deltares which if you are not familiar is a reference research institute in the Netherlands for Waterway management.

On top of the principle you linked I think an important feature of their concept is that the bubble barrier is diagonal to the waterway so that the debrie is accumulated and guided to a single collection point on the river bank.

There is a video [0] on the "more info" page [1] that presents one working implementation in Amsterdam (video is in Dutch but with good subtitles)

[0] https://www.youtube.com/watch?v=n_KwF-gf0S0

[1] http://thegreatbubblebarrier.com/en/amsterdam-en/

I know that big chemical manufacturing facilities with waterway connections use a similar approach to keep chemicals from entering the waterway in case of an accident. So when it works for liquids, I'd assume it'd also work for solid objects such as plastic waste. However, I doubt this is something fishes would pass, I couldn't find anything about that that proves this claim.

> How much energy does a Bubble Barrier use?

> The Bubble Barrier uses compressed air to create the bubble curtain. Depending on the scale and length of the Bubble Barrier, this is done by means of a compressor. The length of the Bubble Barrier has a significant influence on the necessary energy usage. Our Bubble Barrier uses much less energy than bubble curtains that are used to separate fresh from salt water or to prevent oil spills.

Based on them explicitly not wanting to give any numbers and comparing it to much larger and more difficult operations, I'm guessing this is the main issue. It may well work, but costs a lot of energy. Doing that in NW Europe feels like spending a lot to achieve a little, because plastic going into the ocean is a) not primarily from rivers and b) among that which is delivered via rivers, it's not primarily from rivers in Europe.

There are a lot of companies developing river turbines that possible could complement this well. I have no idea if they produce the right amount of power though.

Good point, though you probably need a strong flow for turbines, which will be an issue for the bubble barrier. And for large rivers that are also deep (i.e. any river that is used for larger scale shipping), the infrastructure seems extreme.

It's one thing to handle a 10m wide canal that's 2m deep, it's quite another to install that system on a river that's 800m across and 10m deep. I believe we'll quickly reach a level where it's not economical to do put a lot of energy into it to catch what little waste there is. On the other hand, maybe there are positive side effects, more oxygen in the water?

Interesting Idea! This seems like an elegant but somewhat expensive solution. Does the power consumed by pumping tons of air 24/7 offset the ecological gains by the system? If this can stop microscopic plastic than it would probably also stop microscopic creatures. Are there shore based ecosystems that rely on those creatures coming to shore, or vice versa?

Anyways still seems worth trying.

If it’s wind / solar, absolutely. A compressor for that canal run is probably using 1-2KW/h, comparable to a small shop. If the compressor itself is cooled by the water you’re even putting back some of the sun or wind energy that would have gone into it :)

Could even use tidal as it lies in a river

Your units are wonky. I'll assume you mean 1-2 kW, a unit of power output. kW/h would be a rate of increase of power (e.g. "The generator is producing 500 kW now, and can safely ramp up at a rate of 100 kW/h.")

in the US Kilowatt-hour is commonly used like that, and not as a rate of change - https://en.wikipedia.org/wiki/Kilowatt-hour

The kW*h doesn't make sense in this context, either. It is a unit of energy, and would imply a one-time cost to have bubbles made from then on.

A kWh is not a kW/h. Also, a device used continuously would use a number of kWh over a time period... So kWh/h or kW. If you were discussing a process, you might say it takes so many kWh per cycle, like charging a battery or producing an item, etc.

It would be a kilowatt-hours per hour in this case, also known as kilowatts.

And as soon as the wind stops and the sun gets obscured by clouds or the earth, the bubbles stop, and off goes the plastic :) Apart from that, I'd think that the amount of energy required to move the air down is massive. Also, not sure wear and tear on the (plastic) structure can be handled in a sensible manner over the long-term...

From the FAQ[1]:

> Is it possible to remove microplastics from water by using a Bubble Barrier? During the Berlin Bubble Barrier Pilot, the Bubble Barrier was able to catch plastic as small as 1 millimetre. It depends on the catchment system whether the microplastics are able to be brought ashore. In the pilot at Wervershoof, we are investigating whether we can catch microplastics measuring 20 micrometers up to 500 micrometers (0,5 millimeters).

Only stopping larger plastic could be enough of a win, I think, as this would prevent it from being broken down into microplastic...

[^1]: https://thegreatbubblebarrier.com/en/faq-en/

>Does the power consumed by pumping tons of air 24/7 offset the ecological gains by the system?

I was thinking along the same lines. I'm guessing it would be cheaper to concentrate all the plastic close to the source so it can be easily collected. Compared to sending N boats out to M garbage patches that exist, I'm thinking this will be more efficient.

Future generations will look at our wanton use of single-use plastic like we look at leaded gasoline or cigarettes and wonder what took us so long to legislate banning poisoning our environment. A bubble barrier moves the plastic around, it doesn't decrease its production.

If it helps in some small way relative to decreasing plastic production, great -- no need to let the perfect be the enemy of the good -- but let's keep it in context of decreasing production.

Also, technical solutions to social and behavioral problems tend to create unintended side-effect. Have we considered them?

What's the children's book, by a classic SciFi artist in the 70s-ish with well done living in the future illustrations.

One was an underwater habitat and all the fish were kept in vertical cages made of bubbles?

It makes me laugh my childhood wonder turns out to be real, except it's for rubbish.

[edit] The Usborne Book of the Future (1979) had it, but I'm sure it's not the only one - P16 P17 - http://calameo.download/00081642432fc0bfded26 All new ideas are old.

I wonder how this affects other stuff such as plankton or other kind of nutrients...

It's unfortunate that these "sexy" solutions get more attention than practical ones. Trash localized in a smaller body of water isn't much better than trash in the ocean, especially since a clogged up river will eventually start leaking trash. The most effective way to reduce ocean trash in the ocean is to build proper waste management infrastructure in developing countries. The only NGO I can find that does this is WasteAid.

https://wasteaid.org

The bubbles are only part of the solution. You still need a fairly straightforward extraction method and a landfill or other long term disposal method. This might add up to ~5 dump trucks an hour worth of trash for extreme rivers, but that’s not all that expensive.

I think this may be a good solution for those countries where trash more or less accidentally ends up in rivers. But what percentage of trash ends up accidentally in the sea, and how much trash is intentionally dumped because it's cheaper or easier? I would assume that's far less than the 8 billion kilos per year quoted on the page.

There's already an existing solution for this purpose: https://www.mrtrashwheel.com/

That handles plastic that's already floating, whereas this claims to bring plastic to the surface.

The two solutions seem complementary.

I could see this working in a shallow stream meandering through the countryside. I don't see this being effective in a deep/fast river. What do those bubble nets look like in a river 50+ feet deep and moving a several mph? Remember that the bubbles get bigger as they rise. I don't think many fish will be happy to swim through a maelstrom of compressed air rushing from giant pipes on the bottom.

You could create steps so to speak. So across the river there would be bubble lines that are only 20% or so of the span. Then the plastic would step down until it reaches the other side and fish could swim around the bubble lines.

I realized I probably didn't describe it well... he's a drawing of what I mean https://imgur.com/a/n9PdT0L

Doesn't this just encourage more plastic dumping into waterways? Now you can write it off because "it wont harm fish anymore"

Lets create systems where we don't need to dump plastic in waterways at all.

"Let's create systems where we don't need to use firewalls/authentication/application patches/defensive programming"

The perfect is the enemy of the good. Defense in depth is a winning strategy.

To be clear: we should also not be polluting/littering/etc. That's part of defense in depth.

Would love to see this in action in the chesapeake bay on the east coast.

Interesting! I spent some time recently looking into technical solutions for marine aquaculture industry problems, and I saw the same concept proposed as a preventative measure for salmon farms, to reduce sea lice infestation. It was referred to as a "bubble curtain", or something like that. IIRC, I may have also seen it proposed as a measure against harmful algae blooms (HABs).

Can this be dangerous to swim through? I imagine that bubble-water has a very low specific weight, causing people to go under.

It would be better to have some kind of deposit system.

Any plastic or plastic product importer must pay deposit per weigh of plastic. When used plastic is returned for recycling/burning etc. that deposit is paid to whoever returns it. This way waste plastic would have a price that would make it worth not to throw it away.

Solidly into "why didn't I think of that" territory.

Who's got other examples? I'll go first:

In my kitchen, I have a coffee can full of ordinary plastic clothespegs/pins that I use to clip bags shut. They work so much better than occlupanids or even purpose-made bag clips, whether you fold or spin the bag.

Why not go the extra mile and use wooden pegs. Less plastic!

I am ging to be that guy now: he already has those plastic pegs. Throwing them away and getting wooden ones may look more environmentally friendly, but it isn't.

Avoiding to buy plastic in the future is a good idea. But throwing away perfectly fine plastic stuff you have to replace it with wood stuff isn't.

That's the case in my home. We have some supply of plastic clothespins bought years ago, and some of them just slowly migrated to the kitchen. We aren't planning to buy any kind of new ones any time soon.

I use metal binder clips for holding bags shut. Maybe they'll break eventually but I've been using the same ones for years and haven't had one break yet.

This technology is already implemented and being used in harbors (I've seen it in Florida) to keep the seaweed OUT of the marina. It was very impressive how well it worked

You can see it work in this video: https://youtu.be/n_KwF-gf0S0

If it blocks plastic, what else might it block?

Inspired by a Sonic the Hedgehog level.

How does it compare or complement the "river cleaner" from the Ocean Cleanup?

Off topic, why is bubble sort called bubble sort? Is it because bubbles are slow?

Without looking further, I would say it's because elements bubble up as they're sorted.

Edit: Wikipedia [1] seems to agree:

    The algorithm, which is a comparison sort, is named for the way smaller or larger elements "bubble" to the top of the list.

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

Because smaller or larger items bubble up to the top of the list. If you watch a visualization you'll see what I mean.

this rhyme is going to be stuck in my head for a while

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