Boiling Water for Sterilisation

Bitstring <[email hidden]>, from the wonderful
person -- Paul -- <[email hidden]> said

Quoted message said:

Hi,

I'm having a debate with a mate about water sterilisation. We're both quite
new to this so lack a bit of knowledge.

If you boil the water you loose some of the oxygen from it right. Does this
mean that you get less energy from the oxygen in the water itself?

Personnally I would say that you didn't get any energy from the oxygen in
water and so it dosn't matter if you boil it??

Please help sort this out for us

You get energy from burning (oxidising) food using oxygen in your
bloodstream. 99.99%+ of that oxygen gets there through your lungs. You
lose almost all the oxygen (and nitrogen, and CO2) in water when you
boil it . The result may taste 'flat' but is perfectly fine for
drinking.

Note however that boiling will not remove all poisons and pesticides,
and doesn't even kill 100% of known germs (but if you boil it for a
reasonable time it will kill the ones that are likely to kill you).

--
GSV Three Minds in a Can
8,630 Km walked. 1,677Km PROWs surveyed. 30.5% complete.

On Tue, 8 May 2007 22:58:57 +0100, "-- Paul --" <[email hidden]>
wrote:

|!Hi,
|!
|!I'm having a debate with a mate about water sterilisation. We're both quite
|!new to this so lack a bit of knowledge.

If you boil water you kill pathogenic bugs

|!If you boil the water you loose some of the oxygen from it right. Does this
|!mean that you get less energy from the oxygen in the water itself?

You do not *use* oxygen from water, there is quite enough oxygen in the air
for walking up hills or some people even *run* up hills.

--
Dave Fawthrop <sf hyphenologist.co.uk> 165 *Free* SF ebooks.
165 Sci Fi books on CDROM, from Project Gutenberg
http://www.gutenberg.org/wiki/Main_Page Completely Free to any
address in the UK. Contact me on the *above* email address.

-- Paul -- said:

Hi,

I'm having a debate with a mate about water sterilisation. We're both quite
new to this so lack a bit of knowledge.

If you boil the water you loose some of the oxygen from it right. Does this
mean that you get less energy from the oxygen in the water itself?

When water boils (at whatever temperature - can be much lower than 100C at
high altitude) there are no dissolved gases left in it.

Quoted message said:

Personnally I would say that you didn't get any energy from the oxygen in
water and so it dosn't matter if you boil it??

There's no [useful to people] energy in oxygen as such - it just enables
the process via respiration. Swallowing oxygen just has the obvious effect!

--
Peter.
If you can do it today, you didn't put off enough yesterday.

In message <[email hidden]>, Dave Fawthrop
<[email hidden]> writes

Quoted message said:

On Tue, 8 May 2007 22:58:57 +0100, "-- Paul --" <[email hidden]>
wrote:
|!If you boil the water you loose some of the oxygen from it right. Does this
|!mean that you get less energy from the oxygen in the water itself?

You do not *use* oxygen from water, there is quite enough oxygen in the air
for walking up hills or some people even *run* up hills.

AIUI, oxygen does not provide energy but rather it provides the means
for consuming energy; it permits the conversion of stored energy into
work. For that purpose, oxygen in the air is used because that is the
way the human body has been designed/evolved (cross-out the participle
which doesn't apply).

SFAIK, only fishes have developed ways of extracting dissolved oxygen
from water with any resultant efficiency in the use of energy.

</geriatric pedant>

--
Dave N

N.B. Mail to nospam is rejected. Reply-To does work.

Dave Fawthrop <[email hidden]> writes

Quoted message said:

On Tue, 8 May 2007 22:58:57 +0100, "-- Paul --" <[email hidden]>
wrote:

|!Hi,
|!
|!I'm having a debate with a mate about water sterilisation. We're both quite
|!new to this so lack a bit of knowledge.

If you boil water you kill pathogenic bugs

|!If you boil the water you loose some of the oxygen from it right. Does this
|!mean that you get less energy from the oxygen in the water itself?

You do not *use* oxygen from water, there is quite enough oxygen in the air
for walking up hills or some people even *run* up hills.

Speak for yourself!
--
The man from Atlantis

Dave N said:

SFAIK, only fishes have developed ways of extracting dissolved oxygen
from water with any resultant efficiency in the use of energy.

The OP did not say that they aren't a fish. 🙂

Roos

thanks, I thought as much!

"PeterC" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

-- Paul -- said:

Hi,

I'm having a debate with a mate about water sterilisation. We're both
quite
new to this so lack a bit of knowledge.

If you boil the water you loose some of the oxygen from it right. Does
this
mean that you get less energy from the oxygen in the water itself?

When water boils (at whatever temperature - can be much lower than 100C at
high altitude) there are no dissolved gases left in it.

Quoted message said:

Personnally I would say that you didn't get any energy from the oxygen in
water and so it dosn't matter if you boil it??

There's no [useful to people] energy in oxygen as such - it just enables
the process via respiration. Swallowing oxygen just has the obvious
effect!

--
Peter.
If you can do it today, you didn't put off enough yesterday.

GSV Three Minds in a Can said:

Note however that boiling will not remove all poisons and pesticides,
and doesn't even kill 100% of known germs (but if you boil it for a
reasonable time it will kill the ones that are likely to kill you).

This is true, but note that many highland areas have pure /enough/ water
for the taking anyway. Often the case outside of areas rich in
agro-chemicals that the only effective difference between upland stream
water and bottled mineral water is you're not paying for it. However,
better safe than sorry if you're not confident of the purity.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

GSV Three Minds in a Can said:

Note however that boiling will not remove all poisons and pesticides,
and doesn't even kill 100% of known germs (but if you boil it for a
reasonable time it will kill the ones that are likely to kill you).

This is true, but note that many highland areas have pure /enough/ water
for the taking anyway. Often the case outside of areas rich in
agro-chemicals that the only effective difference between upland stream
water and bottled mineral water is you're not paying for it. However,
better safe than sorry if you're not confident of the purity.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Don't we all have stories of drinking from a burn and then finding a
dead sheep in it 50 yds upstream. It's almost guaranteed in the
Clachaig Gully in Glen Coe. And have we ever suffered? No. Some 25
of us of all ages had no effects at all on one occasion I remember.

My understanding - and no doubt the resident biologist will counter
this - is that if the water is flowing rapidly such that it absorbs
oxygen (and I didn't mean to get back to that again), any pathogens
are unable to survive and the water is potable.

Rob

Rob G said:

Don't we all have stories of drinking from a burn and then finding a
dead sheep in it 50 yds upstream. It's almost guaranteed in the
Clachaig Gully in Glen Coe. And have we ever suffered? No. Some 25
of us of all ages had no effects at all on one occasion I remember.

My understanding - and no doubt the resident biologist will counter
this - is that if the water is flowing rapidly such that it absorbs
oxygen (and I didn't mean to get back to that again), any pathogens
are unable to survive and the water is potable.

I don't think it's necessarily the case that oxygen will directly kill
anything naughty, just that a well aerated mountain stream will be
unlikely to do you any harm.

The one occasion I have got ill (and everyone else who had a drink there
got ill too and others on the same walk that didn't drink were fine, so
I think it was the cause) was a drink at Linn of Dee, which is
/certainly/ rapidly flowing. But probably just a bit bigger, and thus
collecting of "interesting" stuff from many places, than is a good idea
to drink from.

If it were just oxygenation then the water companies could save a lot on
chemicals just by giving supplies a good shake. I don't think it's that
simple.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

GSV Three Minds in a Can said:

Note however that boiling will not remove all poisons and pesticides,
and doesn't even kill 100% of known germs (but if you boil it for a
reasonable time it will kill the ones that are likely to kill you).

This is true, but note that many highland areas have pure /enough/ water
for the taking anyway. Often the case outside of areas rich in
agro-chemicals that the only effective difference between upland stream
water and bottled mineral water is you're not paying for it. However,
better safe than sorry if you're not confident of the purity.

True, but diluting Highland burn water with malt whisky will help.
--
Peter.
If you can do it today, you didn't put off enough yesterday.

Rob G said:

Don't we all have stories of drinking from a burn and then finding a
dead sheep in it 50 yds upstream. It's almost guaranteed in the
Clachaig Gully in Glen Coe. And have we ever suffered? No. Some 25
of us of all ages had no effects at all on one occasion I remember.

I've had this, but at least the sheep was little more tha skeleton and
wool.

Perhaps more risky was our habit of getting the sheep to lick the saucepans
(very good for removing burned-on curry) before we did the washing-up.
--
Peter.
If you can do it today, you didn't put off enough yesterday.

PeterC said:

Perhaps more risky was our habit of getting the sheep to lick the saucepans
(very good for removing burned-on curry) before we did the washing-up.

I once found (by accident I should stress!) that slugs do a pretty good
job on the burned on bits of a cheese fondue if left to work on it
overnight!

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

PeterC said:

Perhaps more risky was our habit of getting the sheep to lick the saucepans
(very good for removing burned-on curry) before we did the washing-up.

I once found (by accident I should stress!) that slugs do a pretty good
job on the burned on bits of a cheese fondue if left to work on it
overnight!

Didn't know that one!
Once left a thin ally saucepan with curry in it for a week - the curry
cleaned the pan on both sides! just wish I hadn't tried to wash it before
finding the holes.
--
Peter.
If you can do it today, you didn't put off enough yesterday.

In message <[email hidden]>, -- Paul --
<[email hidden]> writes

Quoted message said:

If you boil the water you loose some of the oxygen from it right. Does this
mean that you get less energy from the oxygen in the water itself?

Following your "argument" - if your boil it long enough you'll end up
with a lump of hydrogen in the bottom of the pan!

Water evaporates and loses both H2 and O, the remaining liquid is still
water in the correct proportions of H2 and O
--
Bill Grey

Bill Grey said:

Following your "argument" - if your boil it long enough you'll end up
with a lump of hydrogen in the bottom of the pan!

Water evaporates and loses both H2 and O, the remaining liquid is still
water in the correct proportions of H2 and O

More to it than that: you can dissolve all sorts of stuff in water
without changing it from being water: seawater, for example, doesn't
have some weird molecules with salt bonded onto water, the NaCl and H2O
are still distinct molecules.

And in the same way, atmospheric 02 can be dissolved into water. That's
what fish breathe, not the oxygen bonded to the hydrogen. Stagnant
water has no dissolved oxygen, but it's still H2O.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Bill Grey said:

In message <[email hidden]>, -- Paul --
<[email hidden]> writes

Quoted message said:

If you boil the water you loose some of the oxygen from it right. Does this
mean that you get less energy from the oxygen in the water itself?

Following your "argument" - if your boil it long enough you'll end up
with a lump of hydrogen in the bottom of the pan!

Water evaporates and loses both H2 and O, the remaining liquid is still
water in the correct proportions of H2 and O

So use the hydrogen that's left to fuel the stove for boiling the water...

'Boiling point' is when the saturated vapour pressure is equal to [local]
atmospheric pressure (assuming no restriction on ventilation, e.g. a
pressure cooker), so at that point all dissolved gases have come out -
oxygen and CO2 mainly, as water doesn't hold much nitrogen (hence 'the
bends'😉.
Of course, this means that sterilisation will be practically effective if
the water boils at or near 100C, but at high altitude it's a lot lower, so
the bugs just get annoyed.
Water from the stream that's below Everest Base camp, anyone?
--
Peter.
If you can do it today, you didn't put off enough yesterday.

PeterC said:

Water from the stream that's below Everest Base camp, anyone?

With Everest Base Camp's reputation for cleanliness I think I might just
be melting snow that I know where it came from! ;-)

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

In message <[email hidden]>, Peter Clinch
<[email hidden]> writes

Quoted message said:

Bill Grey said:

Following your "argument" - if your boil it long enough you'll end up
with a lump of hydrogen in the bottom of the pan!
Water evaporates and loses both H2 and O, the remaining liquid is
still water in the correct proportions of H2 and O

More to it than that: you can dissolve all sorts of stuff in water
without changing it from being water: seawater, for example, doesn't
have some weird molecules with salt bonded onto water, the NaCl and H2O
are still distinct molecules.

And in the same way, atmospheric 02 can be dissolved into water. That's
what fish breathe, not the oxygen bonded to the hydrogen. Stagnant
water has no dissolved oxygen, but it's still H2O.

Pete.

His question did not involve the chemistry to which you refer.
--
Bill Grey