Reverse Osmosis Filter

[Madame]

Hello,
I want to ask about reverse osmosis water filters.
is it true that RO water filters can clean water from viruses and bacteria?

[Ravens_cry]

Hello,
I want to ask about reverse osmosis water filters.
is it true that RO water filters can clean water from viruses and bacteria?

According to the CDC, see link for more info, yes, yes they can. They have "very high effectiveness", in fact.
Why do you ask?

[Tarmor]

Why do you ask?

I'm quite sure if we wait for a few more posts, the OP will link to a site that sells them.
Apart from that, I personally found the CDC filtration stuff mildly interesting. :)

[Rydiro]

Does filtration have an advantage over just cooking the water when it comes to removing bio-hazards?
Aside from filtering some biological toxines.

[Eldan]

Does filtration have an advantage over just cooking the water when it comes to removing bio-hazards?
Aside from filtering some biological toxines.

Not really in any practical sense, no. Might also get rid of some heavy metals, I'd have to look into it.

[Khedrac]

Does filtration have an advantage over just cooking the water when it comes to removing bio-hazards?
Aside from filtering some biological toxines.

Best to do both but yes it does.

I notice from watching TV that explorers now carry filtration water bottles so that they can use water found on the trip rather than having to lug it.
Boiling requires more equipment, a fuel source and time.
Also boiling kills things but doesn't remove them. Many toxins may be denatured by boiling (i.e. the proteins degrade to a non-toxic form), filtration removes things (making it a lot harder for them to affect you).
Yes some things will escape filtration, but it is probably fewer than can escape boiling (and probably much of the same list).

[Brother Oni]

The only other thing to keep an eye out for when using RO water, is don't use it with hot stainless steel as it causes rouging, which is a form of rusting as the ultrapure water strips off the passivation layer.

As for how clean RO water can be, we use it for cleaning pharmaceutical manufacturing equipment and the only bagged alternative to onsite generated RO water is WFI, or water for injection, ie the stuff they use to dilute serums and the like before injecting it into people.

[Ravens_cry]

Just to be clear, simple filtering and reverse osmosis filtering are very different animals with very different things they're best at removing.

[Spacewolf]

Working with both Evaporation type and RO type potable water makers. We're not supposed to use them within 20 nautical miles of land due to higher concentrations of sewage and metals in the water. However I've seen ROs with an exception to this rules allowing them to be used closer. Though it does cause the filters to clog up faster, even with that type.

So I'd say there is a risk of viruses and other undesirable elements carrying over but considering how fine the membrane filters are it's certainly far less likely than Evaporation type distillation where there's a high chance of bacterial and viral carryover due to the low temperatures used.

(Either way we does it with Chlorine before it gets to the taps.)

[Rydiro]

Working with both Evaporation type and RO type potable water makers. We're not supposed to use them within 20 nautical miles of land due to higher concentrations of sewage and metals in the water. However I've seen ROs with an exception to this rules allowing them to be used closer. Though it does cause the filters to clog up faster, even with that type.

So I'd say there is a risk of viruses and other undesirable elements carrying over but considering how fine the membrane filters are it's certainly far less likely than Evaporation type distillation where there's a high chance of bacterial and viral carryover due to the low temperatures used.

(Either way we does it with Chlorine before it gets to the taps.)

Just for clarification: You use low-temp evaporation? Which would be different yet from cooking?

[Spacewolf]

Just for clarification: You use low-temp evaporation? Which would be different yet from cooking?

Yea we create a partial vacuum, then boil off the water at about 65-75C. If you're doing it at home and boil it straight off at 100 it should be good to go.

[wumpus]

The only other thing to keep an eye out for when using RO water, is don't use it with hot stainless steel as it causes rouging, which is a form of rusting as the ultrapure water strips off the passivation layer.

As for how clean RO water can be, we use it for cleaning pharmaceutical manufacturing equipment and the only bagged alternative to onsite generated RO water is WFI, or water for injection, ie the stuff they use to dilute serums and the like before injecting it into people.

I had a job that involved using purified water for testing (which was then specifically impurified with various salts to abuse metals). There are four main grades of "distilled water", and RO will almost always meet the second, and should meet the third if you are careful. I'm under the impression the highest requires more than just simple distillation as well.

RO (even just from whatever is used to clean tapwater) is some seriously pure stuff. To answer the OP, viruses and bacteria can easily eliminated by filters. Stuff at the molecular level (salt, minerals, toxic chemicals, etc) is when you need RO. Also RO is pretty wasteful with water, expect to have "pure water" and "leftover impure water". Not an issue with desalinization and other large scale uses, but it isn't really geared for replacing filters in places with limited water supplies.

[Tyndmyr]

Does filtration have an advantage over just cooking the water when it comes to removing bio-hazards?
Aside from filtering some biological toxines.

Cooking kills things, filtering removes them.

If you have, say, muddy water that you boil, well, now you still have muddy water. Yeah, you killed the disease in it, but it's still gonna be rough to drink. Ideally you would also want to filter it.

That can be a pretty practical advantage when you're relying on whatever water's around. Even rainwater can be surprisingly dirty.