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Products like the LifeStraw/Sawyer/Katadyn won't filter most chemicals. To remove some chemicals you need to use distillation and distillation is only good if t

Products like the LifeStraw/Sawyer/Katadyn won't filter most chemicals. To remove some chemicals you need to use distillation and distillation is only good if the boiling point of a given chemical is higher than that of water. LifeStraw even states >Chemicals, salt water, heavy metals and viruses will not be removed. http://help.lifestraw.com/en/articles/2507813-does-the-lifestraw-filter-out-heavy-metals-and-viruses http://help.lifestraw.com/en/articles/2507813-does-the-lifes... Sawyer states >Taste >The Sawyer filter removes taste that comes from bacteria, dirt, and green matter. >Chemicals >The Sawyer filter does NOT remove iron, sulfur, other chemicals, or simple compounds. Taste can be masked by using flavor additives like Gatorade or crystal light (filter needs to be cleaned immediately after using them). >Heavy Metals >The Sawyer filters are not made with charcoal. While other portable filters have charcoal, they lack in amount of media and adequate dwell time. Therefore, they only remove small amounts of heavy metals, pesticides, etc. (when used in real life applications). Try using better sources of water, if possible. https://sawyer.com/water-filtration/faqs/ https://sawyer.com/water-filtration/faqs/

fredley 7y ago
> distillation is only good if the boiling point of a given chemical is higher than that of water What about fractional distillation?
- ryanmercer 7y ago
  First, I am not a chemist but this is something I've thought aobut a lot as a camper, a "prepper", and someone interested in Mars colonization (perchlorates!). That would work but I imagine it's going to have some amount of inefficiency depending on the contaminant, you'd have to do several passes to get to really low trace levels I imagine as you're going to keep some contamination simply by what collects on the walls of the vessel and runs back down. With some contaminants I imagine you could introduce more chemicals to get a reaction that would make the filtration easier. I imagine some could also be changed sufficiently by heating the sample to a point where you get a chemical change in the contaminant, although, I'm guessing this would be the most 'expensive' method unless energy wasn't an issue (fusion).
  - logfromblammo 7y ago
    Take three fractions, the first being the "heads" or "tops" from the first condensed volume up to 5% of the original volume, the next being the "mains" from the next 90%, and the last being the "tails" or "bottoms" from the final 5%. Wash the packed column and boiling vessel with the heads and then discard them. Discard the tails. Repeat the process with the mains. Your twice-distilled mains are now pure water, discounting contamination from inferior distillation apparatus. Get some food-grade calcium chloride (E509, de-icing salt), magnesium sulfate (Epsom salt), sodium bicarbonate (baking soda), and potassium chloride (NoSalt brand table salt substitute) and add some (known) minerals back into the result for your drinking water, because pure distilled water has a very poor taste profile. The only types of chemical that cannot be easily removed by this distillation process are those that form azeotropes with water, such as ethanol, and those chemicals are unlikely to be present in quantities significant enough to be a problem.
deleted 7y ago
[deleted]
Liquix 7y ago
How would a reverse osmosis filter hooked up in the basement / under the sink compare to distillation? The good ones spit out water that is close to 0 PPM (in most municipal water systems tap water is closer to 60-200). Is PPM a good way of measuring the types of chemicals you mentioned?
- hurxnid 7y ago
  That would almost certainly work but make sure to remineralize the water after.
  - dmm 7y ago
    I have been drinking non-remineralized reverse osmosis water since conception and I'm fine. Plus remineralization isn't as effective as you would think. Most of the minerals removed by RO can't be easily reintroduced as they aren't readily dissolved.
    - ryanmercer 7y ago
      As long as you're eating a varied diet (such as eating a good variety of plants) drinking demineralized water really isn't an issue. I've been eating plant based whole food lately and at 1903 kcals yesterday I managed (per Cronometer): - 646.4mg of calcium - 636.1mg of magnesium - 785.1mg of sodium Which are the 3 big ones in common tap water. Even if you factor in a 25% error margin, through my diet I'm getting way more than I would drinking random tap water.
    - saberience 7y ago
      So as a baby your parents were only giving you RO water? Then during your whole time at high-school and college you only drank RO water? Errr, I don't believe you.
- ryanmercer 7y ago
  RO will still have some chemicals it can't remove. Per the CDC: >Reverse Osmosis Systems will remove common chemical contaminants (metal ions, aqueous salts), including sodium, chloride, copper, chromium, and lead; may reduce arsenic, fluoride, radium, sulfate, calcium, magnesium, potassium, nitrate, and phosphorous. https://www.cdc.gov/healthywater/drinking/home-water-treatment/household_water_treatment.html https://www.cdc.gov/healthywater/drinking/home-water-treatme...
ravenstine 7y ago
Seychelle seems to have more advanced filters: https://www.seychelle.com/water-filters https://www.seychelle.com/water-filters > The Radiological filter removes the four basic zones of contamination: aesthetic (chlorine, taste and odor), chemicals (from industry and agriculture), dissolved solids (heavy metals such as lead, mercury, chromium 6) and up to 99.99% of radiological contaminants such as gross beta, radon 222, alpha radium 226, plutonium, uranium, cesium 134 and 137. Removes up to 90% of fluoride. (Not to be used with salt water.) > The RAD/ADV filter removes up to 99.99% of chlorine, chemicals (VOC’s), heavy metals, radiological contaminants and up to 90% of fluoride. It removes up to 99.9999% of bacteria and viruses, as well as 99.9% of giardia and cryptosporidium. The RAD/ADV filter can be used for emergency preparedness, disaster relief, and radiological contamination. Just like the Advanced filter the RAD/ADV filter is ideal for traveling around the world and used with water of unknown quality. (Not to be used with salt water.) So there's a chance that these might be able to remove other chemicals and perhaps microplastics. The Berkey filter also seems to remove quite a few contaminants: https://www.berkeyfilters.com/pages/filtration-specifications https://www.berkeyfilters.com/pages/filtration-specification... I wonder if there will be a boom in the water filter industry after more mainstream articles come out about the problem and the government eventually starts recommending them openly.

fredley 7y ago

> distillation is only good if the boiling point of a given chemical is higher than that of water What about fractional distillation?

ryanmercer 7y ago
First, I am not a chemist but this is something I've thought aobut a lot as a camper, a "prepper", and someone interested in Mars colonization (perchlorates!). That would work but I imagine it's going to have some amount of inefficiency depending on the contaminant, you'd have to do several passes to get to really low trace levels I imagine as you're going to keep some contamination simply by what collects on the walls of the vessel and runs back down. With some contaminants I imagine you could introduce more chemicals to get a reaction that would make the filtration easier. I imagine some could also be changed sufficiently by heating the sample to a point where you get a chemical change in the contaminant, although, I'm guessing this would be the most 'expensive' method unless energy wasn't an issue (fusion).
- logfromblammo 7y ago
  Take three fractions, the first being the "heads" or "tops" from the first condensed volume up to 5% of the original volume, the next being the "mains" from the next 90%, and the last being the "tails" or "bottoms" from the final 5%. Wash the packed column and boiling vessel with the heads and then discard them. Discard the tails. Repeat the process with the mains. Your twice-distilled mains are now pure water, discounting contamination from inferior distillation apparatus. Get some food-grade calcium chloride (E509, de-icing salt), magnesium sulfate (Epsom salt), sodium bicarbonate (baking soda), and potassium chloride (NoSalt brand table salt substitute) and add some (known) minerals back into the result for your drinking water, because pure distilled water has a very poor taste profile. The only types of chemical that cannot be easily removed by this distillation process are those that form azeotropes with water, such as ethanol, and those chemicals are unlikely to be present in quantities significant enough to be a problem.

deleted 7y ago

[deleted]

Liquix 7y ago

How would a reverse osmosis filter hooked up in the basement / under the sink compare to distillation? The good ones spit out water that is close to 0 PPM (in most municipal water systems tap water is closer to 60-200). Is PPM a good way of measuring the types of chemicals you mentioned?

hurxnid 7y ago
That would almost certainly work but make sure to remineralize the water after.
- dmm 7y ago
  I have been drinking non-remineralized reverse osmosis water since conception and I'm fine. Plus remineralization isn't as effective as you would think. Most of the minerals removed by RO can't be easily reintroduced as they aren't readily dissolved.
  - ryanmercer 7y ago
    As long as you're eating a varied diet (such as eating a good variety of plants) drinking demineralized water really isn't an issue. I've been eating plant based whole food lately and at 1903 kcals yesterday I managed (per Cronometer): - 646.4mg of calcium - 636.1mg of magnesium - 785.1mg of sodium Which are the 3 big ones in common tap water. Even if you factor in a 25% error margin, through my diet I'm getting way more than I would drinking random tap water.
  - saberience 7y ago
    So as a baby your parents were only giving you RO water? Then during your whole time at high-school and college you only drank RO water? Errr, I don't believe you.
ryanmercer 7y ago
RO will still have some chemicals it can't remove. Per the CDC: >Reverse Osmosis Systems will remove common chemical contaminants (metal ions, aqueous salts), including sodium, chloride, copper, chromium, and lead; may reduce arsenic, fluoride, radium, sulfate, calcium, magnesium, potassium, nitrate, and phosphorous. https://www.cdc.gov/healthywater/drinking/home-water-treatment/household_water_treatment.html https://www.cdc.gov/healthywater/drinking/home-water-treatme...

ravenstine 7y ago

Seychelle seems to have more advanced filters: https://www.seychelle.com/water-filters https://www.seychelle.com/water-filters > The Radiological filter removes the four basic zones of contamination: aesthetic (chlorine, taste and odor), chemicals (from industry and agriculture), dissolved solids (heavy metals such as lead, mercury, chromium 6) and up to 99.99% of radiological contaminants such as gross beta, radon 222, alpha radium 226, plutonium, uranium, cesium 134 and 137. Removes up to 90% of fluoride. (Not to be used with salt water.) > The RAD/ADV filter removes up to 99.99% of chlorine, chemicals (VOC’s), heavy metals, radiological contaminants and up to 90% of fluoride. It removes up to 99.9999% of bacteria and viruses, as well as 99.9% of giardia and cryptosporidium. The RAD/ADV filter can be used for emergency preparedness, disaster relief, and radiological contamination. Just like the Advanced filter the RAD/ADV filter is ideal for traveling around the world and used with water of unknown quality. (Not to be used with salt water.) So there's a chance that these might be able to remove other chemicals and perhaps microplastics. The Berkey filter also seems to remove quite a few contaminants: https://www.berkeyfilters.com/pages/filtration-specifications https://www.berkeyfilters.com/pages/filtration-specification... I wonder if there will be a boom in the water filter industry after more mainstream articles come out about the problem and the government eventually starts recommending them openly.