Keith Hughes wrote in news:46e8db3d$0$3579
:

Safer than tap water, by a long shot.

I also don't believe this to be true. From the time it was injected with
Chlorine and other chemicals until it reaches your tap is longer than you
think....plenty of time for the chemicals injected into the water to, at
least, KILL the bugs in the water. This is not true in a boat RO system.
If any kind of live organism makes it through the membrane, it's STILL
live when you drink it. It STILL can multiply in the storage tanks,
probably already contaminated by dock water from Smiley's Marina and
Tire's swamp water well out back of the old outhouse.

You could be sure by simply boiling it for a few minutes. That will kill
whatever crap you ingest from RO and that filthy tank you've never seen
the inside of. Of course, for the hermits, that takes power.

Larry
--
The seawater sucked into the RO is loaded with microscopic life the ocean
lives on. The plankton, alone, must represent a huge attack on the
system. Plankton is, probably not, toxic. But, microorganisms have a
tendency to, well, to put it bluntly, ****. That's, probably, a toxic
soup of organic chemistry I'd rather not talk about over dinner. It's
amazing all this doesn't just clog the filter dispite the constant
flushing.....and I keep thinking about all those people on the cruise
ships that got sick from drinking the water on the ship....RO water.
They didn't get sick off tap water.....

On Wed, 12 Sep 2007 23:40:01 -0700, Keith Hughes
wrote:



Richard Casady wrote:
On Wed, 12 Sep 2007 00:44:05 GMT, Jere Lull wrote:

You say that viruses are smaller than sodium or chloride ions? I got
A's in college chemistry, and I have trouble believing it.

Smaller isn't necessarily the issue with retention of ionic species. A
membrane that electrostatically adsorbs ions can still pass much larger
non-polar molecules and materials.

As I understand him from the past, the viruses are broken down to toxic
chemicals that will pass.

Thank you for relaying that little tidbit. I remain skeptical. I may
drop by the local waterworks and look at a few trade magazines. Check
out the ads for the millions of gallons a day RO plants.

Casady

There are a number of studies showing that RO membranes (which are not
absolute porosity filters, but are spiral wound depth filters)

That explains a lot. I have cut open,[ they make a tool just for that]
a number of pleated paper oil filters. With those they seem to either
pass a particle size, or not. Like any sieve, its all or nothing. I
have seen filters made from spiral wound string, for fuel, if I
recall, but they didn't make any claims of micron size. That would be
a spiral wound depth filter? I can see how it could pass some, but not
all, of the same size particles. You could call it an attrition
filter. but clearly it isn't a simple sieve. Photographic filters take
out a percentage, but not all, of the light.I was under the impression
that RO filters were all or nothing,like any sieve. It is good of you
to post some actual information. A newsgroup with news, of all things.

are not 100% viral retentive, or bacterial retentive (especially for Giardia
oocytes, and certainly not for mycoplasma) when challenged with a
significant upstream population. The prevalence of these organisms (and
almost-organisms) in seawater is, however, extremely low, and a 2 to
3-log reduction (about what the literature seems to support) gives a
very high probability of 100% removal. Safer than tap water, by a long shot.

Can you run the stuff through twice and get the same percentage
reduction for the second pass?

Someone mentioned arsenic,and the CRC does list it as a component of
sea water. Three to twenty-four parts per billion. Or mg/ton. About
the same as iron. 1970 edition, your milage may vary.


As for viral proteins being toxic, the only studies I'm aware of have
been done on the common viral pesticides, where no oral toxicity has
ever been observed - doesn't mean it can't happen, but given how rapidly
protein is denature in the stomach, it's pretty unlikely.
That is the reason for having stomach acid isn't it? That and
dissolving "insoluble" heavy metal salts.
For injectables, some hepatotoxicity has been shown in mice injected with
solubilized viral proteins - hence my reluctance to inject RO water
while out sailing...

The DNA/RNA does not appear to be orally toxic either.
0

On Sep 13, 2:39 am, (Richard Casady)
wrote:
On Wed, 12 Sep 2007 23:17:40 -0700, Keith Hughes

wrote:
This, IMO, is the crux of the issue of trying to use engine heat for
evaporation (i.e. distillation), versus just preheating. For an
efficient process, the engine-to-transfer medium exchanger needs to run
with a significant delta-t, and so to does the transfer
medium-to-process exchanger. This two-step cascade would likely require
much higher engine operating temperatures than normal, with all the
attendant maintenance and longevity issues.

There is no escaping the simple fact that equipment for using the
waste heat from an engine for distillation was around for decades. Off
the shelf. It was intended for boats, of all things. RO may have
killed them off, however. Why do you insist that proven, available off
the shelf [ at one time, at least,] equipment cannot work?
Under load, the exhaust headers on my car run yellow hot, with a
ninety MPH breeze cooling them Enough temperature difference?
Something like a quarter of the fuel goes to a hot exhaust. Three
quarters of the fuel burned in a gas engine goes to waste heat.
Diesels do a bit better, and get maybe one third as shaft work.

Casady

Richard Casady wrote:

snip

There are a number of studies showing that RO membranes (which are not
absolute porosity filters, but are spiral wound depth filters)

That explains a lot. I have cut open,[ they make a tool just for that]
a number of pleated paper oil filters. With those they seem to either
pass a particle size, or not. Like any sieve, its all or nothing.

Well, absolute porosity is really a misnomer, even though the term is
used frequently. It's really based on a statistical measure of retention
capability, since all membranes are essentially "mats" of material, not
like you'd expect for, say, sintered metal. And they all depend on
adsorption, impaction, and physical sieving to achieve that porosity rating.

I
have seen filters made from spiral wound string, for fuel, if I
recall, but they didn't make any claims of micron size. That would be
a spiral wound depth filter?

A very common type, yes. A DE pool filter is another example. Depth
filters become *more* effective as they load up, since the accumulated
material provides additional sieving action.

I can see how it could pass some, but not
all, of the same size particles. You could call it an attrition
filter. but clearly it isn't a simple sieve. Photographic filters take
out a percentage, but not all, of the light.I was under the impression
that RO filters were all or nothing,like any sieve.

Unfortunately, all membrane filters have large and small pores, and the
interactions between the mean pore size, the configuration of the pore
pathway (i.e. the more tortuous path provided through the membrane, the
more likely that physical impaction will sequester a particle), membrane
charge, fluid pressure, and fluid velocity, among other esoteric
factors, determines the retention capability of the membrane. So
retention is a statistical measure of performance, rather than an
absolute capability. Depth filters, like wound membranes, have much
larger variability in retention capability, relative to their nominal
pore size, than do most membrane filters.

It is good of you
to post some actual information. A newsgroup with news, of all things.

Well, it's sort of topical at the moment, since I'm currently working on
qualifying a multi-effect still, pure steam generator, and an
ultra-filtration/diafiltration skid.

are not 100% viral retentive, or bacterial retentive (especially for Giardia
oocytes, and certainly not for mycoplasma) when challenged with a
significant upstream population. The prevalence of these organisms (and
almost-organisms) in seawater is, however, extremely low, and a 2 to
3-log reduction (about what the literature seems to support) gives a
very high probability of 100% removal. Safer than tap water, by a long shot.

Can you run the stuff through twice and get the same percentage
reduction for the second pass?

Yes, and no. Since retention is statistical in nature (i.e. the
likelihood of 100% retention is not only directly related to particle
size distribution, but also on upstream particulate concentration), the
retention effectiveness for the second pass would actually be much
greater (with respect to ensuring a clean filtrate) than on the first
pass.

Now, that is if you're talking about dual pass in series. Most
"double-pass" RO systems are designed for water savings, not filtration
effectiveness, and are in a series/parallel configuration where the
rejected water from the first pass goes to the second pass, and that
permeate (filtrate) and is then pooled with the permeate from the first
pass. So the membranes are in series, but water flow is in parallel,
only passing through one membrane, either first pass or second pass.

Someone mentioned arsenic,and the CRC does list it as a component of
sea water. Three to twenty-four parts per billion. Or mg/ton. About
the same as iron. 1970 edition, your milage may vary.

In industrial applications, this isn't an issue, since most systems use
some type of chelating agent or sequestrant that complexes such
materials making them easy to filter. Not real amenable to the cruiser
though, and I don't know off hand how well arsenic is rejected.


As for viral proteins being toxic, the only studies I'm aware of have
been done on the common viral pesticides, where no oral toxicity has
ever been observed - doesn't mean it can't happen, but given how rapidly
protein is denature in the stomach, it's pretty unlikely.

That is the reason for having stomach acid isn't it? That and
dissolving "insoluble" heavy metal salts.

Yep. That it is.

Keith Hughes

Larry wrote:
Keith Hughes wrote in news:46e8db3d$0$3579
:

Safer than tap water, by a long shot.

I also don't believe this to be true. From the time it was injected with
Chlorine and other chemicals until it reaches your tap is longer than you
think....

No, it isn't. In my case, it's long enough for the chlorine level to be
undetectable at my tap. And long enough for plenty of growth to occur.
I've been looking at potable water micro results (total microbial and
coliforms) for 25 years - I know the quality of tap water.

plenty of time for the chemicals injected into the water to, at
least, KILL the bugs in the water. This is not true in a boat RO system.
If any kind of live organism makes it through the membrane, it's STILL
live when you drink it. It STILL can multiply in the storage tanks,
probably already contaminated by dock water from Smiley's Marina and
Tire's swamp water well out back of the old outhouse.

OK, where'd the storage tank slip into the discussion? You think
putting distilled water in a vented storage tank remains sterile?

You could be sure by simply boiling it for a few minutes. That will kill
whatever crap you ingest from RO and that filthy tank you've never seen
the inside of. Of course, for the hermits, that takes power.

I've said it before, and I'll say it again...you were bitten by an RO
unit as a small child weren't you? :-)

Keith Hughes

On Tue, 11 Sep 2007 04:17:23 +0000, Larry wrote:

RO - One pinhole and everyone dies.....
One pinhole and the stuff will be loaded with chloride, dead simple to
detect. Add one drop of silver nitrate solution. Any cloudiness
indicates chloride, and it takes very little. This has long been the
practice on steam ships, with regard to the boiler water. And I don't
paint a rosy picture of RO, other than it takes less than one
hundredth the energy.
So boil the stuff you drink, and use the cheap RO water to wash down
the expensive boat. You can afford distilled drinking water. You ever
figure out what it actually costs for homemade electricity. It ain't
pretty. Salt water showers suck, and so does 25 cent a kwhr juice. The
old quadruple effect evaporators found on steamships used one tenth
the energy of an electric single stage still. Nobody said boats were
cheap.

Keith Hughes wrote in
:

OK, where'd the storage tank slip into the discussion? You think
putting distilled water in a vented storage tank remains sterile?

You could be sure by simply boiling it for a few minutes. That will
kill whatever crap you ingest from RO and that filthy tank you've
never seen the inside of. Of course, for the hermits, that takes
power.

I've said it before, and I'll say it again...you were bitten by an RO
unit as a small child weren't you? :-)

Keith Hughes



Gotta be stored somewhere, making all that water. Distilled isn't going
to make any difference UNLESS it's the ONLY water ever put in one.
Drinking out of someone's filthy water tank is always flirting with
sickness. Who knows what is in there?

No, I was never bitten by RO, myself. I'm not sure of your motives for
the big attack, either, but RO ISN'T as wonderful as the brochures say it
is. In the hands of a sailboat "captain", who's a lawyer, bank
president, with no experience in biology outside of suing doctors for
malpractice, I can't imagine them doing the proper testing and
maintenance these complex filters require to make them safe and reliable.

I'll drink distilled from my 5 gallon sanitary jug.....thanks.

Larry
--
Search youtube for "Depleted Uranium"
The ultimate dirty bomb......

Larry wrote:
Keith Hughes wrote in
:

Snip

Gotta be stored somewhere, making all that water. Distilled isn't going
to make any difference UNLESS it's the ONLY water ever put in one.

Even then it won't make any difference for a typical vented tank, unless
you use a real bacterial retentive vent filter, and do lots of routine
maintenance on the tank and filter.

Drinking out of someone's filthy water tank is always flirting with
sickness. Who knows what is in there?

Well, the point I was making was that you brought up the tank and
storage as though that was strictly an artifact of RO, not distilled.


No, I was never bitten by RO, myself.

I still don't believe it, I bet you tried to pet one when you were
little... :-)

I'm not sure of your motives for
the big attack, either, but RO ISN'T as wonderful as the brochures say it
is.

I had no intention of "attacking" you or distillation. Sorry if it came
off that way. I was responding to your attack on RO as being basically
a death trap, and it just isn't so. If it were, there'd be a lot of dead
people floating around. People by the millions drink RO problems with
out problems.

Also, there are some BS consumer-level stills out there that are not
very effective at all, because of mist and condensate carryover into the
distillate, so you need to be cognizant that there are 'bad' stills out
there, and blind faith in them is not justified. Especially not the
belief that you can basically dump sewage in them and get nice clean
water out. People need to be aware that all purification/sanitization
process results are statistical in nature, and that means being smart
about the feed water as well as the purification method you use.

As for the capturing of engine heat to use for distillation, I just have
a hard time seeing that the engines used by the typical cruiser, as
typically used, would be amenable to that type of modification.

In the hands of a sailboat "captain", who's a lawyer, bank
president, with no experience in biology outside of suing doctors for
malpractice, I can't imagine them doing the proper testing and
maintenance these complex filters require to make them safe and reliable.

Well, personally, for a boat application I would use cellulose acetate
membranes (instead of thin film composite - e.g. polyamide etc.), even
though they are not quite as efficient, so they can be sanitized with a
simple chlorine solution. I also wouldn't use them in most lakes,
estuaries, or inhabited bays.

I'll drink distilled from my 5 gallon sanitary jug.....thanks.

Nothing wrong with that.

Keith Hughes

On Sat, 15 Sep 2007 10:43:37 -0700, Keith Hughes
wrote:


Also, there are some BS consumer-level stills out there that are not
very effective at all, because of mist and condensate carryover into the
distillate, so you need to be cognizant that there are 'bad' stills out
there, and blind faith in them is not justified. Especially not the
belief that you can basically dump sewage in them and get nice clean
water out. People need to be aware that all purification/sanitization
process results are statistical in nature, and that means being smart
about the feed water as well as the purification method you use.

Good advice. Having worked on the steam generating end only, where
the "cool" steam was +600 F, I hadn't given much thought on the
potential distillers have for biological type carryover.
A good boiling of the water, perhaps under pressure, before any
steam/vapor is allowed to process further, and close care with the
carryover and condensing elements of the distiller should solve that,
but the cost and complexity grows greater.
Larry had me a bit concerned about RO quality, and his take on
"toxins" created by RO hydraulic pressure on bacteria, and mass cruise
boat illness is interesting, but I'm not sold on either.
You have raised red flags about distiller feed, design and operation.
Very educational discussion.
Put me down on the RO side.
But I admit I've never been a big drinker of plain water.

--Vic

Keith Hughes wrote in
:

Gotta be stored somewhere, making all that water. Distilled isn't
going to make any difference UNLESS it's the ONLY water ever put in
one.

Even then it won't make any difference for a typical vented tank,
unless you use a real bacterial retentive vent filter, and do lots of
routine maintenance on the tank and filter.



Granted. A couple of years ago, I got in a ****ing contest with an RO
dealer on a web forum. RO was better than distillation, which just isn't
so. So, he and I swapped a quart of our finest product in sanitized
containers. My container was a polycarb jug I meticulously cleaned, then
sanitized in my convection oven for an hour at 220F. Trying to do his
best, his sanitation method was very similar. I took his word he was
sending me RO, not distillate...(c;

The bet was to put each water sample in the sun for a couple of months to
see what grows in it. (I cheated because I'd already set a gallon of
distillate in a sanitized container in the sun for a whole year that
grows nothing...doesn't even change the taste in polycarb containers.

The RO came with a destructive seal I'd forgotten to put on the one I
sent him. I don't think he trusted me. I sat it in the summer South
Carolina sun out on my patio where the daytime temp is in the 90s here on
the river. Two weeks, not a month, later, I returned his RO swamp water
that grew some beautiful algae in a light green color without even taking
a look at it under my microscope to look for bacteria or amoebas. He
never returned my sample and refused to discuss with the group his
findings in my sample.

I told him I thought his membrane had a rip in it....just for laughs.

The algae is harmless, but that wasn't the point. RO isn't the holy
grail the dealers portray it to be. It's FILTERED WATER.

I didn't attack RO, by the way. I only pointed out what I had read of
the bacteria trapped on the high pressure side of the membrane breaking
down, then releasing their toxic load into the feedwater, which WAS small
enough to pass through the membrame into the drinking water on the other
side. It's a serious problem for many drinkers if it's not corrected.
Boaters, the same guys who cannot figure out why the batteries don't
charge, have no training other than the little instruction manual on the
proper maintenance and operation of an RO plant that is complex by its
very nature and REQUIRES this maintenance to be performed at regular
intervals and properly to get safe results. I think THAT is a recipe for
disaster.....not RO, per se.

Larry
--
Search youtube for "Depleted Uranium"
The ultimate dirty bomb......