Scientists achieve more than 98% efficiency removing nanoplastics from water | Hacker News Reader

Scientists achieve more than 98% efficiency removing nanoplastics from water

showme.missouri.edu

66 pointsOzarkian36 comments

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Paper here: https://pubs.acs.org/doi/10.1021/acsaenm.4c00159

Interestingly, there were three chemical systems that worked:

> 1:2 tetrabutylammonium bromide ([N4444]Br):decanoic acid

> 1:2 tetraoctylammonium bromide ([N8888]Br):decanoic acid

> 1:1 thymol:menthol

Unfortunately, none of them are great, and this method is going to be quite limited unless better chemical agents are found. Treating even 0.05% of the ocean's surface water with tetrabutylammonium bromide would require a vast fraction of the world's annual bromine production. It would possibly even call for quantities of bromine that exceed the world's current supply. Besides, bromine leakage could be just as bad -- or worse -- than microplastic contamination, as bromine is biologically active in an obvious and straightforward way, whereas the biological effects of microplastics are still a matter of some debate.

And of course there's not nearly enough thymol or menthol...

So this is interesting for bottled water companies, but not (yet) as an environmental remediation method.

Is it also impractical for treating potable water supplies, or for treating wastewater? (You mentioned only _bottled_ water companies.)

Sounds like 98% effectiveness, not 98% efficiency.

For the non engineer, what's the difference?

They're two different words even for non-engineers.

Effectiveness measures results. A 98% efficient process that never achieves its goal is 0% effective. Focusing on efficiency that is not effective sometimes overlaps with the "missing the forest for the trees" problem. A 1% efficient process that always achieves its goal is 100% effective.

Tangentially related, I'd love to see some form of per product microplastic rating for food and drinks, similar to nutritional facts.

I am finding bread products are often wrapped in two layers of plastic.

That can't be good.

This is an excellent idea. Make the brands accountable to the consumers by giving visibility to what they might consider a health risk.

What legislature or academic institution would fund this against the interests of Dow, Cargill, ADM, PepsiCo, Tyson, Kellog, Unilever…?

I predict someone will start a niche brand advertising plastic free and the FDA will be used to bludgeon them.

Can someone answer a dumb question for me: plastics are made from petroleum, a class of molecules that has been in the ground for hundreds of millions of years, but are bad because plastics take a long time to degrade?

I don't understand. The thing they are made from apparently takes hundreds of millions of years to degrade!

I must be missing something important.

I guess if you are on team carbon sequestration, plastics are better than burn and release into atmosphere. If you are on team plant life, more carbon = more vegetation.

https://www.npr.org/sections/health-shots/2024/05/22/1252831...

How much petroleum does the average human testicle contain?

I'm not an expert, but oil wreaks havoc to nature and life, if it spills. So there is problem nr 1. I don't know how much time nature needs to rebound from such spills, but I know, that (crude) oil on beaches makes them unhabitable for years.

Problem Nr. 2: plastics made from oil are different from, well oil. They're a product, that doesn't occur in nature, as far as I know.

Plastics are hormonally active in the body. There might be thousands of different plastics and nobody really knows how they're reacting with animals, nature and so on.

But the short answer is: petroleum kills, that stuff is dangerous as hell.

Sure, the thing that you're missing is that there's extremely strong evidence that these plastics:

1. Don't degrade quickly (per your point)

2. Are difficult to mitigate/filter (per article's point)

3. Are appearing everywhere, including in our water supply, food supply, adult human tissue, and within fetuses still in their mothers' wombs

4. Critically, and probably the point you're missing, they are disruptive to endocrine systems (hormones) which are extremely important to all sorts of developmental, behavioral, and psychological systems, including negative effects on fertility, e.g. a child born to a microplastic-poisoned mother will have reduced sperm count in adulthood. This is a bad thing, and in combination with points 1-3 is potentially catastrophic for human civilization.

Can you provide some sources for #4?

You can start here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9885170/

Edit, and here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7068600/

Well yeah the problem is that we took it from way way way under ground and put them in your blood stream...

Uranium isn't a problem if it's 100m underground somewhere in Africa, it's a much bigger problem if you have a refined chunk of it under your pillow

Also reads : Even scientists can’t remove all microplastics from water

We can remove all the plastics. 98%. Just not the small ones.

The article is clearly specifically about quote unquote the small ones.

You mean, "the small ones"?

Meanwhile, Starbucks:

https://www.sweetsteep.com/wp-content/uploads/2020/11/starbu...

Teabags are usually silk right?

Some brands have plastic ones. You should never drink tea from plastic bags.

Avoid paper also

care to elaborate?

Paper manufacturing is not devoid of chemicals, it needs bleaching to be white and all the machines to put it in its final shape use mineral oils that find way into the final product. But maybe the quality of the tea itself dwarves the things you find in teabags.

Show me the study that says non-naturally occurring bleach has been observed in human testicles.

https://www.npr.org/sections/health-shots/2024/05/22/1252831...

Bleached paper is probably not a threat to testicles, but it's taking a toll on the environment they're living in. And it's for a frivolous reason: having snow white paper.

Plastic Teabags Release Billions of Microparticles and Nanoparticles into Tea: https://pubs.acs.org/doi/10.1021/acs.est.9b02540

Polypropylene sometimes

Teavana tea bags do contain plastic although it seems it may be plant-sourced biodegradable plastic so not sure it counts for a microplastics thing.

https://ceh.org/yourhealth/plastic-in-my-tea-bag/

I think fancy pyramid-shaped teabags are often nylon (ie plastic) and less often silk (eg I think teapigs might use silk). More old-school flat bags are generally some sort of papery stuff, although that could be bleached with something nasty.

If you worry about plastic and sundry chemicals in drinks you're better off just making loose tea. You get a better cup of tea and you know that tea is all that's in it. (other than anything that was already in the water to start with)

> biodegradable plastic

This is green-washing. It's not really biodegradable in the way that it implies.

Sure. All I'm saying is I don't know enough about the chemistry to know whether this type of biodegradable affects whether there is microplastic residue in the drink.

If Starbucks itself isn’t clearly explaining why its Teavana teabags are safer than other plastic teabags, then the consumer is better off assuming that they’re not.

Premium brands advertise what makes their products premium, so that they can charge more or increase sales. They don’t do it for free out of the goodness of their hearts.

Usually they’re paper, but misguided companies have been pushing plastic. I guess some consultants somewhere think the plastic format looks like it should cost more. Personally, to me the plastic format looks like a hazard, so I avoid it.

Some research has found that plastic teabags robustly dose the tea drinker with not only microplastics but also nanoplastics:

https://www.bbc.com/news/world-us-canada-49845940

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