4 ms·

I applaud the researchers in their quest, but we do have bleach right now. A crude backcountry filter, or just letting particulate settle, plus the addition of

I applaud the researchers in their quest, but we do have bleach right now. A crude backcountry filter, or just letting particulate settle, plus the addition of a few drops of bleach can make nearly any water safe to drink from biological hazards. Bleach can be easily made onsite from abundant salt and electrolysis. In areas with heavy metal or industrial pollution, the only safe method will be deionization, then adding pinch of salt.

xtiansimon 3y ago
[flagged]
- bombcar 3y ago
  It matches my Boy Scout handbook from 20+ years ago. We had hand pump filters and chlorine tablets. But we weren’t drinking industrial runoff.
  - throwaway173738 3y ago
    Monte Cristo in Washington State is a good example of a backcountry area where you’d be drinking industrial runoff. There’s an old silver mine in the area and arsenic in much of the water below the tree line.
- almog 3y ago
  According to the CDC, bleach is one of the recommended way to treat water in an emergency case: https://www.cdc.gov/healthywater/emergency/making-water-safe.html https://www.cdc.gov/healthywater/emergency/making-water-safe...
  - xtiansimon 3y ago
    I realize the part I was focused on was this: "Bleach can be easily made onsite from abundant salt and electrolysis" I do a fair amount of back country moto-camping and so water purification is on my mind. I'm familiar with many of the water treatment methods for camping and backpacking. But this passage about making bleach is intriguing. I'm genuinely curious if making bleach in this way is commonly used for water treatment. If the OP has this experience or is the OP knowledgeable about chemistry and synthesizing their knowledge to the problem for the sake of discussion. Or is this yet another example of common knowledge that I missed because I was sleeping in high school chemistry class. LOL.
- forgetfreeman 3y ago
  I like this response. It replaces any discussion of existing methods for back country water decontamination with bullshit snark to great effect.
  - dredmorbius 3y ago
    <https://news.ycombinator.com/item?id=35547193 https://news.ycombinator.com/item?id=35547193>
- deleted 3y ago
  [deleted]
- deleted 3y ago
  [deleted]
amluto 3y ago
Kind of. Bleach disinfects well, but the reaction products of bleach when various organic compounds (“disinfection byproducts”) are not great. Modern water treatment in the US takes measures to reduce DBPs. edit: The article also mentions backpackers. Liquid bleach is not amazing for backpacking. Dichlor and trichlor are not amazing disinfectants. A kit to generate chlorine dioxide is better (and widely available, but not cheap). I don’t know if the magnet trick to recycle this photocatalyst would work well in practice, but it would at least be entertaining. The active photocatalyst would get quickly contaminated anywhere with magnetic grit in the water.
- orhmeh09 3y ago
  You don't need to carry liquid bleach. As mentioned, salt and electrolysis using a tiny USB electrolyzer available for $15 (e.g. "PWPAM Sodium Hypochlorite Generator") would do the trick. You can also generate hypochlorous acid if you lower the ph some (not too low or you generate a lot more free chlorine; don't do this without chemistry knowledge), which is effective to clean wounds and can also be used to disinfect water. e: 2020 document hosted by WHO on some of hypochlorous acid's uses: https://cdn.who.int/media/docs/default-source/essential-medicines/2021-eml-expert-committee/applications-for-addition-of-new-medicines/a.18_hypochlorous-acid.pdf https://cdn.who.int/media/docs/default-source/essential-medi...
  - amluto 3y ago
    I guess if you’re backpacking in the sense of carrying a monster backpack around a fun part of the world and staying in hostels, this might make sense. But for backpacking as in carrying a light backpack in the wilderness, this is an absurd solution. (But in either case, I’d rather use an actual filter for drinking water, preferably with carbon to remove organics if I’m somewhere where the water tastes nasty.) I suppose a little USB electrolyzer is handy for making cleaning fluid. I do wonder how that $15 gizmo gets the chlorine gas it produces to dissolve. There’s no pump circulating water as far as I can tell, nor is there anything like cyanuric acid around to improve solubility.
    - 3y ago
adrianmonk 3y ago
Bleach isn't great against certain parasites[1]. Also, bleach breaks down over time[2]. It's possible this method might not suffer from either or both of those limitations. If so, that could be pretty useful. At least for certain purposes like emergency preparedness. --- [1] "Disinfectants can kill most harmful or disease-causing viruses and bacteria, but most disinfectants are not as effective as boiling for killing more resistant germs, such as the parasites Cryptosporidium and Giardia." (https://www.cdc.gov/healthywater/emergency/making-water-safe.html https://www.cdc.gov/healthywater/emergency/making-water-safe...) [2] "When properly stored away from heat and direct sunlight, Clorox® Disinfecting Bleach will last up to a year. After a year, the natural breakdown of the sodium hypochlorite bleach active into salt and water rapidly accelerates, and the active ingredient concentration becomes too low for EPA registered uses like sanitizing or disinfecting." (https://www.clorox.com/learn/how-to-tell-when-a-bleach-bottle-was-made/ https://www.clorox.com/learn/how-to-tell-when-a-bleach-bottl...)
- exabrial 3y ago
  You need to read the fine print on the website you linked as well as independent studies on beach. Start with the MSR field guide with their chlorinator and their whitepapers, which unlike the CDC, actually publishes their scientific results. The cover the use of bleach for other methods of producing free chlorine. Bleach works just fine in those those parasites, which are your main threats everywhere. I’ve followed the field guides on the and drank water from sources known to be contaminated, and despite the CDC, I’m alive, miraculously. The key is to reduce the biological load in the water first. That’s why I had additional information about filtering, which is not listed on the CDCs guide. The CDC is putting protocols out there for the lowest common denominator. If you add bleach to a gallon of muddy water of course it’s not going to do anything.
  - amluto 3y ago
    Not sure which MSR guide you mean, but this one agrees with my recollection: https://www.msrgear.com/blog/water-treatment-101-cryptosporidium/ https://www.msrgear.com/blog/water-treatment-101-cryptospori... Cryptosporidium is relatively easy to remove by filtration, and not so easy to kill with chlorine. Even chlorine dioxide seems to kill cryptosporidium rather slowly: https://www.outdoorgearlab.com/reviews/camping-and-hiking/backpacking-water-filter/aquamira-water-treatment-drops https://www.outdoorgearlab.com/reviews/camping-and-hiking/ba...

xtiansimon 3y ago

[flagged]

bombcar 3y ago
It matches my Boy Scout handbook from 20+ years ago. We had hand pump filters and chlorine tablets. But we weren’t drinking industrial runoff.
- throwaway173738 3y ago
  Monte Cristo in Washington State is a good example of a backcountry area where you’d be drinking industrial runoff. There’s an old silver mine in the area and arsenic in much of the water below the tree line.
almog 3y ago
According to the CDC, bleach is one of the recommended way to treat water in an emergency case: https://www.cdc.gov/healthywater/emergency/making-water-safe.html https://www.cdc.gov/healthywater/emergency/making-water-safe...
- xtiansimon 3y ago
  I realize the part I was focused on was this: "Bleach can be easily made onsite from abundant salt and electrolysis" I do a fair amount of back country moto-camping and so water purification is on my mind. I'm familiar with many of the water treatment methods for camping and backpacking. But this passage about making bleach is intriguing. I'm genuinely curious if making bleach in this way is commonly used for water treatment. If the OP has this experience or is the OP knowledgeable about chemistry and synthesizing their knowledge to the problem for the sake of discussion. Or is this yet another example of common knowledge that I missed because I was sleeping in high school chemistry class. LOL.
forgetfreeman 3y ago
I like this response. It replaces any discussion of existing methods for back country water decontamination with bullshit snark to great effect.
- dredmorbius 3y ago
  <https://news.ycombinator.com/item?id=35547193 https://news.ycombinator.com/item?id=35547193>
deleted 3y ago
[deleted]
deleted 3y ago
[deleted]

amluto 3y ago

Kind of. Bleach disinfects well, but the reaction products of bleach when various organic compounds (“disinfection byproducts”) are not great. Modern water treatment in the US takes measures to reduce DBPs. edit: The article also mentions backpackers. Liquid bleach is not amazing for backpacking. Dichlor and trichlor are not amazing disinfectants. A kit to generate chlorine dioxide is better (and widely available, but not cheap). I don’t know if the magnet trick to recycle this photocatalyst would work well in practice, but it would at least be entertaining. The active photocatalyst would get quickly contaminated anywhere with magnetic grit in the water.

orhmeh09 3y ago
You don't need to carry liquid bleach. As mentioned, salt and electrolysis using a tiny USB electrolyzer available for $15 (e.g. "PWPAM Sodium Hypochlorite Generator") would do the trick. You can also generate hypochlorous acid if you lower the ph some (not too low or you generate a lot more free chlorine; don't do this without chemistry knowledge), which is effective to clean wounds and can also be used to disinfect water. e: 2020 document hosted by WHO on some of hypochlorous acid's uses: https://cdn.who.int/media/docs/default-source/essential-medicines/2021-eml-expert-committee/applications-for-addition-of-new-medicines/a.18_hypochlorous-acid.pdf https://cdn.who.int/media/docs/default-source/essential-medi...
- amluto 3y ago
  I guess if you’re backpacking in the sense of carrying a monster backpack around a fun part of the world and staying in hostels, this might make sense. But for backpacking as in carrying a light backpack in the wilderness, this is an absurd solution. (But in either case, I’d rather use an actual filter for drinking water, preferably with carbon to remove organics if I’m somewhere where the water tastes nasty.) I suppose a little USB electrolyzer is handy for making cleaning fluid. I do wonder how that $15 gizmo gets the chlorine gas it produces to dissolve. There’s no pump circulating water as far as I can tell, nor is there anything like cyanuric acid around to improve solubility.
  - 3y ago

adrianmonk 3y ago

Bleach isn't great against certain parasites[1]. Also, bleach breaks down over time[2]. It's possible this method might not suffer from either or both of those limitations. If so, that could be pretty useful. At least for certain purposes like emergency preparedness. --- [1] "Disinfectants can kill most harmful or disease-causing viruses and bacteria, but most disinfectants are not as effective as boiling for killing more resistant germs, such as the parasites Cryptosporidium and Giardia." (https://www.cdc.gov/healthywater/emergency/making-water-safe.html https://www.cdc.gov/healthywater/emergency/making-water-safe...) [2] "When properly stored away from heat and direct sunlight, Clorox® Disinfecting Bleach will last up to a year. After a year, the natural breakdown of the sodium hypochlorite bleach active into salt and water rapidly accelerates, and the active ingredient concentration becomes too low for EPA registered uses like sanitizing or disinfecting." (https://www.clorox.com/learn/how-to-tell-when-a-bleach-bottle-was-made/ https://www.clorox.com/learn/how-to-tell-when-a-bleach-bottl...)

exabrial 3y ago
You need to read the fine print on the website you linked as well as independent studies on beach. Start with the MSR field guide with their chlorinator and their whitepapers, which unlike the CDC, actually publishes their scientific results. The cover the use of bleach for other methods of producing free chlorine. Bleach works just fine in those those parasites, which are your main threats everywhere. I’ve followed the field guides on the and drank water from sources known to be contaminated, and despite the CDC, I’m alive, miraculously. The key is to reduce the biological load in the water first. That’s why I had additional information about filtering, which is not listed on the CDCs guide. The CDC is putting protocols out there for the lowest common denominator. If you add bleach to a gallon of muddy water of course it’s not going to do anything.
- amluto 3y ago
  Not sure which MSR guide you mean, but this one agrees with my recollection: https://www.msrgear.com/blog/water-treatment-101-cryptosporidium/ https://www.msrgear.com/blog/water-treatment-101-cryptospori... Cryptosporidium is relatively easy to remove by filtration, and not so easy to kill with chlorine. Even chlorine dioxide seems to kill cryptosporidium rather slowly: https://www.outdoorgearlab.com/reviews/camping-and-hiking/backpacking-water-filter/aquamira-water-treatment-drops https://www.outdoorgearlab.com/reviews/camping-and-hiking/ba...