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Instant water cleaning method ‘millions of times’ better: study

cardiff.ac.uk

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Re: Instant water cleaning method ‘millions of times’ better: study

#61

Post by lugged »

perihelions wrote: post #37
slownews45 wrote: post #5

Anytime you read things like 100,000,000 times more effective - you should be asking, what was the numerator or denominator in this. Or are they just describing some tiny part of the system. For example, normally you need to filter, do settling for sediment etc - how did they solve all this? Given the orders of magnitude involved here a 5 MGD plant could produce 500 trillion gallons per day of "commercial approach" w…

If I've understood correctly, the denominator being compared against isn't a "best available alternative" treatment solution of H2O2. It's against the concentration that's an " equivalent amount "-- which is actually a pretty dilute concentration (for H2O2), that *isn't* effectively bactericidal. > "...are over 10^7 times more potent than an equivalent amount of preformed hydrogen peroxide..." Per fig. 2(c,d), the "c…

> The team showed that as the catalyst brought the hydrogen and oxygen together to form hydrogen peroxide, it simultaneously produced a number of highly reactive compounds, known as reactive oxygen species (ROS), which the team demonstrated were responsible for the antibacterial and antiviral effect, and not the hydrogen peroxide itself.

> The catalyst-based method was shown to be 10,000,000 times more potent at killing the bacteria than an equivalent amount of the industrial hydrogen peroxide, and over 100,000,000 times more effective than chlorination, under equivalent conditions.

Basically, I'm getting the highly reactive ROS are the key point here, they're creating them in situ so they're able to be exploited where as standing h2o2 is likely much less reactive.

The order of magnitude gains are easy to grasp if you take into consideration the literal hours you need to wait for chlorine or similar to sterilize water. If there is a way to speed that up to near instant your gains are going to be relatively immeasurable.

Re: Instant water cleaning method ‘millions of times’ better: study

#62

Post by lugged »

dalbasal wrote: post #46
slownews45 wrote: post #5

Anytime you read things like 100,000,000 times more effective - you should be asking, what was the numerator or denominator in this. Or are they just describing some tiny part of the system. For example, normally you need to filter, do settling for sediment etc - how did they solve all this? Given the orders of magnitude involved here a 5 MGD plant could produce 500 trillion gallons per day of "commercial approach" w…

"millions of times more effective at killing viruses and bacteria than traditional commercial methods.." "..revolutionise water disinfection technologies" I don't think this is comparable to a water treatment plant. No sediment settling, biofiltration etc. It's comparable to sterilising water using hydrogen peroxide or boiling it, in a camping context. Not sure what the "millions of times" measures.

I'm curious how well it does with dirty water, one of the big issues in the camping context is sediment in the water ruin the efficacy of all forms of water treatment.

Re: Instant water cleaning method ‘millions of times’ better: study

#63

Post by TaylorAlexander »

wanderingmind wrote: post #51
icegreentea2 wrote: post #14

Earlier quoted context omitted.

The specific measure appears to be in CFU/mL of E. Coli in their test sample before and after. As you suspected, this does not include filtering or settling, just clearing out bacterial contamination. I haven't read the paper yet (paywall)- just looked at their supplementary data. The increased effectiveness appears (guessing here a bit) to be in terms of bacteria load reduction given similar concentration of bacteri…

This is the trouble with most academic research which focuses on trying to maximize one aspect of the problem while a useful commercial application needs to simultaneously optimize multiple conflicting aspects. A similar stream of useless papers also are published in energy storage (beyond Li-ion batteries) which are not likely to be ever commercialized.

I don't see the problem. Isolating one variable per experiment is helpful to ensure you are appropriately testing your thesis. It makes sense to me that not all science is immediately commercializable and that many of the papers never directly contribute to commercial application. It seems to me that commercialization is a distinct step in the process of discovery and production, which must often come after the initial process of scientific exploration.

Re: Instant water cleaning method ‘millions of times’ better: study

#64

Post by azinman2 »

Kaibeezy wrote: post #59
rdiddly wrote: post #53

Earlier quoted context omitted.

Remember science is still just science; it's not necessarily for commercializing.

The researcher himself is directly quoted saying things like “revolutionising water disinfection technologies around the world”. If that’s not backed up by it being feasible or valuable commercially, then the criticism is spot on.

I think the point is the science can be useful in that endeavor by demonstrating a new approach one can take. That’s not to say it’s all that would be required. It’s unreasonable and incorrect to expect a full commercial solution to come directly out of a set of lab experiments.

Re: Instant water cleaning method ‘millions of times’ better: study

#65

Post by wanderingmind »

TaylorAlexander wrote: post #63
wanderingmind wrote: post #51

Earlier quoted context omitted.

This is the trouble with most academic research which focuses on trying to maximize one aspect of the problem while a useful commercial application needs to simultaneously optimize multiple conflicting aspects. A similar stream of useless papers also are published in energy storage (beyond Li-ion batteries) which are not likely to be ever commercialized.

I don't see the problem. Isolating one variable per experiment is helpful to ensure you are appropriately testing your thesis. It makes sense to me that not all science is immediately commercializable and that many of the papers never directly contribute to commercial application. It seems to me that commercialization is a distinct step in the process of discovery and production, which must often come after the initi…

Unfortunately scientific research at this point is not trying to solve difficult problems but just do a small step change improvement that can be published. Most of the kinetics and thermodynamics of these catalyst behaviors have been well understood for decades. The logical next step in scientific exploration would have been to untangle and understand the interactions of the different processes of interest and how they impact one another. Instead most of the research in these areas are to use fancy tools to create patterns like nanostructures that can never be done at scale and create a contest to show delta improvement in the reactivity while providing minimal fundamental insights to either understanding, explaining or solving the problem.

Re: Instant water cleaning method ‘millions of times’ better: study

#66

Post by [deleted] »

wanderingmind wrote: post #45
tristor wrote: post #4

Wow, that’s incredible. Since it uses electricity for it’s energy input, this could be readily adapted for use in remote areas powered by solar plus battery. Even in Western nations this is a boon to treat well water sources instead of shock chlorination. This combined with GAC filtration can produce very clean water anywhere you can get sunlight.

It needs gold and platinum catalyst. The trouble would be there would be no catalyst in the plant to process water, the day after it is deployed in a remote area.

[deleted]

Re: Instant water cleaning method ‘millions of times’ better: study

#67

Post by jcranmer »

slownews45 wrote: post #5

Anytime you read things like 100,000,000 times more effective - you should be asking, what was the numerator or denominator in this. Or are they just describing some tiny part of the system. For example, normally you need to filter, do settling for sediment etc - how did they solve all this? Given the orders of magnitude involved here a 5 MGD plant could produce 500 trillion gallons per day of "commercial approach" w…

> For example, normally you need to filter, do settling for sediment etc - how did they solve all this?

The key sentence should be this:

> In their study, the team tested the disinfection efficacy of commercially available hydrogen peroxide and chlorine compared to their new catalytic method.

In other words, no, this doesn't replace coagulation+flocculation, sedimentation, and filtration; it's only replacing the specific disinfectant in use.

Re: Instant water cleaning method ‘millions of times’ better: study

#68

Post by sp332 »

rmah wrote: post #20

Yeah, the use of "millions of times better" just doesn't pass the sniff test. Given that current commercial methods kill 90%+ bacteria in water, thus, nothing can be even 2x better...and makes me suspicious of any claim in the article. Hopefully it can help people in areas that are currently without clean water, but I'm not holding my breath.

It's comparing the needed concentrations of the disinfectant chemicals. You can use many orders of magnitude less of this than of chlorine.

Re: Instant water cleaning method ‘millions of times’ better: study

#69

Post by sp332 »

_0ffh wrote: post #56

Nice, but it seems the method is not exactly new. Here's a short nature article from the 2nd of March 2016 talking about the same research programme on catalysts at Cardiff University. https://www.nature.com/articles/531011b

What's new is the discovery that it's not the H2O2 that's doing the disinfection.

Re: Instant water cleaning method ‘millions of times’ better: study

#70

Post by Algol »

wanderingmind wrote: post #45
tristor wrote: post #4

Wow, that’s incredible. Since it uses electricity for it’s energy input, this could be readily adapted for use in remote areas powered by solar plus battery. Even in Western nations this is a boon to treat well water sources instead of shock chlorination. This combined with GAC filtration can produce very clean water anywhere you can get sunlight.

It needs gold and platinum catalyst. The trouble would be there would be no catalyst in the plant to process water, the day after it is deployed in a remote area.

*palladium

Though I guess that is also a precious metal.

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