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I never could get a straight answer if the activated charcoal filters can remove these. I’m distilling my own water now. Seems about the same price as filterin

I never could get a straight answer if the activated charcoal filters can remove these. I’m distilling my own water now. Seems about the same price as filtering once you factor in the costs of the filters. And you know you’re getting everything out. (I add in my own minerals in case that’s important.)

deleted 4y ago
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lend000 4y ago
I don't think distillation actually works for forever chemicals, as they may be miscible to a certain degree or also vaporize and condense. Don't have the source, but there was a story about PFAS in rain recently. Your best bet would be reverse osmosis, which is unfortunately a pretty big waste of water.
- flangola7 4y ago
  How does reverse osmosis waste water?
  - delecti 4y ago
    You don't get all the water out that you put in. Currently, very efficient systems output about half the input as pure water, and half as doubly-impure. Less efficient systems are more like 1:2 or worse. I'm not an expert and can't explain it much beyond that. This summarizes the math better than I probably could: https://en.wikipedia.org/wiki/Reverse_osmosis#Disadvantages https://en.wikipedia.org/wiki/Reverse_osmosis#Disadvantages
    - cute_boi 4y ago
      maybe those wasted water can be used for other purpose like washing/flushing?
      - BugsJustFindMe 4y ago
        Yes but reclaiming it for reuse makes the installation much more complicated.
  - deleted 4y ago
    [deleted]
  - qbrass 4y ago
    You need pressure on the feed side to overcome the osmotic pressure differential between the dirty and clean sides. The dirtier the dirty side gets, the higher pressure you need to move water from the dirty side to the clean side. Eventually you have to flush the dirty side because the concentration of contaminants is too high and nothing will go through the filter even though there's still water that you could use if you could get it through the membrane. Under-cabinet RO systems are less efficient because they rely on the relatively low-pressure water that's running to the tap and are made to work without electricity.
    - stjohnswarts 4y ago
      but do you really care? The "wasted water" is miniscule vs how much people use daily. You fix the 90% problem before you fix the 3% problem, at least that's been SOP in my engineering life.
      - hgomersall 4y ago
        Yeah, water that is drink is a trivial proportion of water that is used. If water that is drunk goes up by 100%, it's still a trivial proportion.
    - flangola7 4y ago
      So? Just increase chamber pressure
- bilsbie 4y ago
  Interesting. I can’t seem to find any information either way about distillation removing them.
samtho 4y ago
Just curious, why not a reverse osmosis setup?
ars 4y ago
"Filters containing activated carbon or reverse osmosis membranes have been shown to be effective at removing PFAS from water supplies" https://www.health.state.mn.us/communities/environment/hazardous/topics/pfashometreat.html https://www.health.state.mn.us/communities/environment/hazar... Some carbon filters make the claim on the label, some don't. The only difference is some companies pay to test for it, and then they can make the claim on the labeling, there is no actual difference in the filters.
nullc 4y ago
carbon filters remove PFAS but they're relatively ineffective so you need an awful lot of carbon to get a substantial reduction at least compared to the amount needed to remove other things. RO is effective, as the chemicals in question have fairly high molecular weight. But then RO is usually used with a bladder tank which will leach plasticizers so ::shrugs:: (they taste awful at least, so the norm is to follow up the tank with RO).
- fogzen 4y ago
  Relatively ineffective according to what? The study linked in another comment shows a simple Brita carbon faucet filter being very effective.
  - nullc 4y ago
    Compared to it's effectiveness against things carbon is usually used for. E.g. go look at the setup required for whole house filtration for people with actionable levels of PFAS contamination-- it ends up being like four or five 50lb carbon canisters. If you're talking about 'safe' drinking water and want to reduce it from 2ppb to 1ppb or something-- just a 50% reduction-- then perhaps a small carbon filter is adequate. For just drinking water RO is pretty reasonable, it's just not particularly reasonable to use RO for dishes, shower, etc. Thus the huge carbon canisters for people with acute contamination.
- hgomersall 4y ago
  Yeah, standard practice is to filter through carbon to remove the bladder impurities.
jejeyyy77 4y ago
Do you actually want this? I imagine there are probably beneficial minerals and things in water that you want. I stopped only drinking filtered/bottled water exclusively for this reason.
- webmobdev 4y ago
  Honest question - what minerals can you get from water that aren't available in the food we eat?
  - philipkglass 4y ago
    In Israel, where a lot of drinking water is sourced by reverse osmosis, it appears that the lack of magnesium in drinking water may have increased heart disease: https://www.sciencedirect.com/science/article/abs/pii/S001393511830358X https://www.sciencedirect.com/science/article/abs/pii/S00139... There are of course many magnesium rich foods but the lack of magnesium in water could make a difference at the margins.
    - cyberax 4y ago
      I have a RO system at home, and it has a remineralizing cartridge attached to it. It's pretty cheap and seems to do its job well, the water contains healthy levels of minerals (I tested it in a lab). Why isn't Israel doing it at a large scale? It should be pretty straightforward.
      - webmobdev 4y ago
        I am still highly sceptical about this and feel it is more of a "fear mongering" advertising - that this "remineralizing water" thing only started so that the RO filter businesses could create another source of recurring revenue. I also remember reading some study that said vitamins and minerals are better metabolised by our body as chemical compounds, as found naturally in food, than as individual elements in tablet forms. And that is why pharmaceutical companies have now started offering such compounds too - like Calcium + Zinc + Magnesium etc. Which also suggests that we may be better of with such vitamin and mineral supplements, if really required, than "remineralizing cartridges" which release questionable dosages into the water.

deleted 4y ago

[deleted]

lend000 4y ago

I don't think distillation actually works for forever chemicals, as they may be miscible to a certain degree or also vaporize and condense. Don't have the source, but there was a story about PFAS in rain recently. Your best bet would be reverse osmosis, which is unfortunately a pretty big waste of water.

flangola7 4y ago
How does reverse osmosis waste water?
- delecti 4y ago
  You don't get all the water out that you put in. Currently, very efficient systems output about half the input as pure water, and half as doubly-impure. Less efficient systems are more like 1:2 or worse. I'm not an expert and can't explain it much beyond that. This summarizes the math better than I probably could: https://en.wikipedia.org/wiki/Reverse_osmosis#Disadvantages https://en.wikipedia.org/wiki/Reverse_osmosis#Disadvantages
  - cute_boi 4y ago
    maybe those wasted water can be used for other purpose like washing/flushing?
    - BugsJustFindMe 4y ago
      Yes but reclaiming it for reuse makes the installation much more complicated.
- deleted 4y ago
  [deleted]
- qbrass 4y ago
  You need pressure on the feed side to overcome the osmotic pressure differential between the dirty and clean sides. The dirtier the dirty side gets, the higher pressure you need to move water from the dirty side to the clean side. Eventually you have to flush the dirty side because the concentration of contaminants is too high and nothing will go through the filter even though there's still water that you could use if you could get it through the membrane. Under-cabinet RO systems are less efficient because they rely on the relatively low-pressure water that's running to the tap and are made to work without electricity.
  - stjohnswarts 4y ago
    but do you really care? The "wasted water" is miniscule vs how much people use daily. You fix the 90% problem before you fix the 3% problem, at least that's been SOP in my engineering life.
    - hgomersall 4y ago
      Yeah, water that is drink is a trivial proportion of water that is used. If water that is drunk goes up by 100%, it's still a trivial proportion.
  - flangola7 4y ago
    So? Just increase chamber pressure
bilsbie 4y ago
Interesting. I can’t seem to find any information either way about distillation removing them.

samtho 4y ago

Just curious, why not a reverse osmosis setup?

ars 4y ago

"Filters containing activated carbon or reverse osmosis membranes have been shown to be effective at removing PFAS from water supplies" https://www.health.state.mn.us/communities/environment/hazardous/topics/pfashometreat.html https://www.health.state.mn.us/communities/environment/hazar... Some carbon filters make the claim on the label, some don't. The only difference is some companies pay to test for it, and then they can make the claim on the labeling, there is no actual difference in the filters.

nullc 4y ago

carbon filters remove PFAS but they're relatively ineffective so you need an awful lot of carbon to get a substantial reduction at least compared to the amount needed to remove other things. RO is effective, as the chemicals in question have fairly high molecular weight. But then RO is usually used with a bladder tank which will leach plasticizers so ::shrugs:: (they taste awful at least, so the norm is to follow up the tank with RO).

fogzen 4y ago
Relatively ineffective according to what? The study linked in another comment shows a simple Brita carbon faucet filter being very effective.
- nullc 4y ago
  Compared to it's effectiveness against things carbon is usually used for. E.g. go look at the setup required for whole house filtration for people with actionable levels of PFAS contamination-- it ends up being like four or five 50lb carbon canisters. If you're talking about 'safe' drinking water and want to reduce it from 2ppb to 1ppb or something-- just a 50% reduction-- then perhaps a small carbon filter is adequate. For just drinking water RO is pretty reasonable, it's just not particularly reasonable to use RO for dishes, shower, etc. Thus the huge carbon canisters for people with acute contamination.
hgomersall 4y ago
Yeah, standard practice is to filter through carbon to remove the bladder impurities.

jejeyyy77 4y ago

Do you actually want this? I imagine there are probably beneficial minerals and things in water that you want. I stopped only drinking filtered/bottled water exclusively for this reason.

webmobdev 4y ago
Honest question - what minerals can you get from water that aren't available in the food we eat?
- philipkglass 4y ago
  In Israel, where a lot of drinking water is sourced by reverse osmosis, it appears that the lack of magnesium in drinking water may have increased heart disease: https://www.sciencedirect.com/science/article/abs/pii/S001393511830358X https://www.sciencedirect.com/science/article/abs/pii/S00139... There are of course many magnesium rich foods but the lack of magnesium in water could make a difference at the margins.
  - cyberax 4y ago
    I have a RO system at home, and it has a remineralizing cartridge attached to it. It's pretty cheap and seems to do its job well, the water contains healthy levels of minerals (I tested it in a lab). Why isn't Israel doing it at a large scale? It should be pretty straightforward.
    - webmobdev 4y ago
      I am still highly sceptical about this and feel it is more of a "fear mongering" advertising - that this "remineralizing water" thing only started so that the RO filter businesses could create another source of recurring revenue. I also remember reading some study that said vitamins and minerals are better metabolised by our body as chemical compounds, as found naturally in food, than as individual elements in tablet forms. And that is why pharmaceutical companies have now started offering such compounds too - like Calcium + Zinc + Magnesium etc. Which also suggests that we may be better of with such vitamin and mineral supplements, if really required, than "remineralizing cartridges" which release questionable dosages into the water.