A Question For The Hydraulically Inclined And Chemically Clever
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Oh. Thought I might have something to contribute under Chemically Clever, but then I realized you were talking about engineering... :doh:
Christopher Duncan
www.PracticalUSA.com
Author of The Career Programmer and Unite the Tribes
Copywriting Services:laugh: I'm always open to suggestions, if you have some good recipes. :-D
Will Rogers never met me.
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I just instituted a formal water testing and tracking program at work and discovered something disturbing that I can't explain. We have a small development built in the past 6 years, comprised of about a half mile square of fairly new homes. All piping is done with new PVC pipe, EPA approved for potable water. We measure the pH at the inlet to the development, and sample it at 4 homes scattered through the neighborhood. At the inlet the pH is consistently 7.18, but when it is tested at the homes it measures 8.5!!! I wasn't the best chemistry student in college, but I passed and understood more than I let on to the teacher. This shouldn't happen in a chemically neutral pipe! That's an awful lot of hydrion getting in there in a very short run. The testers used the same meter at all locations, and the temperature didn't vary by more than a degree F. Today's quiz has one question: what could cause such a large shift in pH?
Will Rogers never met me.
Do you really think plastic is chemically neutral?
Invisible Empire: A New World Order Defined (High Quality 2:14:01)[^] Watch the Fall of the Republic (High Quality 2:24:19)[^] The Truthbox[^]
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Do you really think plastic is chemically neutral?
Invisible Empire: A New World Order Defined (High Quality 2:14:01)[^] Watch the Fall of the Republic (High Quality 2:24:19)[^] The Truthbox[^]
Of course not, but polymerization makes the molecules very reluctant to form new bonds, and most of the organic radicals aren't very polar to start out...
Will Rogers never met me.
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Reading the other replies (particularly Elaine's) and starting on the day's caffeine intake, I'd be guessing the dissociation of dissolved carbonates, releasing CO2 and leaving bases behind. Try leaving an "input" sample stand for a day or so and see what it registers. Cheers, Peter [might have to amend my sig - so does Roger's PVC ;P ;P ;P ]
Software rusts. Simon Stephenson, ca 1994.
5 for that.
Agh! Reality! My Archnemesis![^]
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Roger Wright wrote:
That's an awful lot of hydrion getting in there
Let's look at it in context. Assume that what you start with is close to 100% H2O. Adding 3 parts per million (by mole) of a fully dissociated[*1] monoacidic base will give you a pH of 8.5 (pOH of 14.0 - 8.5 = 5.5). You can get big changes in pH around the neutral range adding little amounts of "stuff" to non-buffered water. Changing pH 7 to 8 takes very little more than looking at it, but pH 12 to 13 is equivalent to moving a mountain or two. Having said all that, I have no idea what your contaminant is. My point is that it's not very plentiful. [*1]many inorganic and organic bases will be nearly fully dissocated at 3 ppm. Cheers, Peter ps If we want to take this any further, I might invoke my daughter's Chem PhD! ;P
Software rusts. Simon Stephenson, ca 1994.
This might be caused due to the new pipes, the pipes might get exposed to some chemical during transport. My second guess is that if some kind of chemical is used during pipe fitting... The problem get resolved as the time goes... dont worry....
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Urine
Christian Graus Driven to the arms of OSX by Vista. Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.
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Keith Barrow wrote:
Could the problem be filters fitted in the houses?
wouldn't that require one-way valves to be absent or defective? every house is supposed to have one AFAIK. :)
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum
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Luc Pattyn wrote:
every house is supposed to have one AFAIK.
Not in the UK, we have clean tapwater, it's one of the two things that we get right :-).
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Scale buildup is a problem, but it's not lime - iron and manganese are our main problems in this area. The groundwater is saturated with the stuff. Our testing is quite a bit more sensitive than anything a fish store can offer - lab testing is one of our largest expenses, but well worth the cost for safety reasons. We don't scrimp there, ever! Samples are taken on raw water, btw, before entering any filter system.
Will Rogers never met me.
:doh: apologies, I didn't realise you worked for a company testing this stuff!
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I just instituted a formal water testing and tracking program at work and discovered something disturbing that I can't explain. We have a small development built in the past 6 years, comprised of about a half mile square of fairly new homes. All piping is done with new PVC pipe, EPA approved for potable water. We measure the pH at the inlet to the development, and sample it at 4 homes scattered through the neighborhood. At the inlet the pH is consistently 7.18, but when it is tested at the homes it measures 8.5!!! I wasn't the best chemistry student in college, but I passed and understood more than I let on to the teacher. This shouldn't happen in a chemically neutral pipe! That's an awful lot of hydrion getting in there in a very short run. The testers used the same meter at all locations, and the temperature didn't vary by more than a degree F. Today's quiz has one question: what could cause such a large shift in pH?
Will Rogers never met me.
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Is urine not alkaline? Wouldn't that be why it counters/neutralises the acid from jellyfish stings?
Pete
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Is urine not alkaline? Wouldn't that be why it counters/neutralises the acid from jellyfish stings?
Pete
Maybe this[^] helps :-) from the site: Urban myth states that urine works well against jellyfish stings, and this scenario was demonstrated on a Season 4 episode of the NBC-TV show Friends "The One With the Jellyfish", an early episode of the CBS-TV show Survivor and the documentary film The Real Cancun. At best, it is ineffective and in some cases this treatment may make the injury worse
V.
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Urine
Christian Graus Driven to the arms of OSX by Vista. Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.
Christian Graus wrote:
Urine
Good answer. Good answer.
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I just instituted a formal water testing and tracking program at work and discovered something disturbing that I can't explain. We have a small development built in the past 6 years, comprised of about a half mile square of fairly new homes. All piping is done with new PVC pipe, EPA approved for potable water. We measure the pH at the inlet to the development, and sample it at 4 homes scattered through the neighborhood. At the inlet the pH is consistently 7.18, but when it is tested at the homes it measures 8.5!!! I wasn't the best chemistry student in college, but I passed and understood more than I let on to the teacher. This shouldn't happen in a chemically neutral pipe! That's an awful lot of hydrion getting in there in a very short run. The testers used the same meter at all locations, and the temperature didn't vary by more than a degree F. Today's quiz has one question: what could cause such a large shift in pH?
Will Rogers never met me.
Gypsum (CaSO4*2H20). Gypsum is a filler material used in the manufacture of PVC pipe and is an alkali material. Since the PVC piping is new, there is probably some leaching of the filler material exposed on the interior of the pipe. I suspect the pH will rise over time as the leaching declines. Gypsum is also used as a food additive in many foods, especially "Calcium Enriched" foods, and as an additive to soaps and cosmetics, so leaching would probably not be a concern relative to potable water.
modified on Thursday, September 30, 2010 7:51 AM
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Roger Wright wrote:
That's an awful lot of hydrion getting in there
Let's look at it in context. Assume that what you start with is close to 100% H2O. Adding 3 parts per million (by mole) of a fully dissociated[*1] monoacidic base will give you a pH of 8.5 (pOH of 14.0 - 8.5 = 5.5). You can get big changes in pH around the neutral range adding little amounts of "stuff" to non-buffered water. Changing pH 7 to 8 takes very little more than looking at it, but pH 12 to 13 is equivalent to moving a mountain or two. Having said all that, I have no idea what your contaminant is. My point is that it's not very plentiful. [*1]many inorganic and organic bases will be nearly fully dissocated at 3 ppm. Cheers, Peter ps If we want to take this any further, I might invoke my daughter's Chem PhD! ;P
Software rusts. Simon Stephenson, ca 1994.
Sounds to me like you have an open pocket of atmosphere exposion, allowing CO2 in, which would cause this type of alkalinity.
Wikipedia Wrote:
Carbon dioxide is soluble in water, in which it spontaneously interconverts between CO2 and H2CO3 (carbonic acid). The relative concentrations of CO2, H2CO3, and the deprotonated forms HCO−3 (bicarbonate) and CO2−3(carbonate) depend on the pH. In neutral or slightly alkaline water (pH > 6.5), the bicarbonate form predominates (>50%) becoming the most prevalent (>95%) at the pH of seawater, while in very alkaline water (pH > 10.4) the predominant (>50%) form is carbonate. The bicarbonate and carbonate forms are very soluble, such that air-equilibrated ocean water (mildly alkaline with typical pH = 8.2 – 8.5) contains about 120 mg of bicarbonate per liter.
I've had this happen to me on a number of occasions when working with pH sensitive solutions... What is concerning is that it is persistent, because it should decrease over time.. as would any other "contaminants" it seems this is more a structural issue, perhaps a partially crushed supply pipe? or a leaky seal somewhere, that is pulling air, while pushing water. (Negative air pressure inside the pipes, in conjunction with a VERY low pCO2 would cause a CO2 vacuum effect, which would not let water out...)
I'd blame it on the Brain farts.. But let's be honest, it really is more like a Methane factory between my ears some days then it is anything else... -"The conversations he was having with himself were becoming ominous."-.. On the radio...
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Is urine not alkaline? Wouldn't that be why it counters/neutralises the acid from jellyfish stings?
Pete
smells like amoniona and that is alkaline
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Wild guess: static electricity, from friction. I'm not sure how that would cause a pH shift, but it's the only thing I can think of that could happen in those pipes..
I agree. There can be an electricity leak into the ground that somehow changes the pH. A friend has a machine that he uses to raise the pH of his drinking water. I remember someone else who had an electricity leak in an underground line running to his garage. I'd start testing the ground for stray voltage.
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I just instituted a formal water testing and tracking program at work and discovered something disturbing that I can't explain. We have a small development built in the past 6 years, comprised of about a half mile square of fairly new homes. All piping is done with new PVC pipe, EPA approved for potable water. We measure the pH at the inlet to the development, and sample it at 4 homes scattered through the neighborhood. At the inlet the pH is consistently 7.18, but when it is tested at the homes it measures 8.5!!! I wasn't the best chemistry student in college, but I passed and understood more than I let on to the teacher. This shouldn't happen in a chemically neutral pipe! That's an awful lot of hydrion getting in there in a very short run. The testers used the same meter at all locations, and the temperature didn't vary by more than a degree F. Today's quiz has one question: what could cause such a large shift in pH?
Will Rogers never met me.
"The cause must lie elsewhere." This sort of statement insures you will never find the cause. It doesn't matter what you are trying to find. This is right up there with "the alternative is unthinkable." which was bandied about when all the financial firms were collapsing.. When I hear that, I think speak for yourself. Back to the subject at hand, why don't you get some of the pvc pipe, preferably from the same batch that was used in this construction, and soak it in some water from your inlet pipe? At the same time how about you get some of the material used to seal the junctions and soak that in water. Test both water baths periodically and see what happens. Of course one should have a control bath the same as the other two to see what happens when nothing is in the bath. After that report back and we'll tell you what to do next :)
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I just instituted a formal water testing and tracking program at work and discovered something disturbing that I can't explain. We have a small development built in the past 6 years, comprised of about a half mile square of fairly new homes. All piping is done with new PVC pipe, EPA approved for potable water. We measure the pH at the inlet to the development, and sample it at 4 homes scattered through the neighborhood. At the inlet the pH is consistently 7.18, but when it is tested at the homes it measures 8.5!!! I wasn't the best chemistry student in college, but I passed and understood more than I let on to the teacher. This shouldn't happen in a chemically neutral pipe! That's an awful lot of hydrion getting in there in a very short run. The testers used the same meter at all locations, and the temperature didn't vary by more than a degree F. Today's quiz has one question: what could cause such a large shift in pH?
Will Rogers never met me.
B.Sc. Chemistry here. Find a proper lab - the one with a good mass spectrometer - and have them take and analyze water samples at your measuring points. Mass spectroscopy can be the fastest way to get results on unknown samples. Glass pH electrode can get ion interferences, depending on a electrode's glass composition, so you can't know what's wrong if you don't know exact composition of that water.
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I just instituted a formal water testing and tracking program at work and discovered something disturbing that I can't explain. We have a small development built in the past 6 years, comprised of about a half mile square of fairly new homes. All piping is done with new PVC pipe, EPA approved for potable water. We measure the pH at the inlet to the development, and sample it at 4 homes scattered through the neighborhood. At the inlet the pH is consistently 7.18, but when it is tested at the homes it measures 8.5!!! I wasn't the best chemistry student in college, but I passed and understood more than I let on to the teacher. This shouldn't happen in a chemically neutral pipe! That's an awful lot of hydrion getting in there in a very short run. The testers used the same meter at all locations, and the temperature didn't vary by more than a degree F. Today's quiz has one question: what could cause such a large shift in pH?
Will Rogers never met me.
First, you should know that a pH shift from 7.2 to 8.5 is not at all unusual in drinking water within a water system. It is not even unusual for water in an open pond measured over a 24 hr period. Second, the pH changes you are seeing is definitely not due to your pipes. In most water systems, pH is controlled (buffered) by the equilibrium between dissolved carbon dioxide and bicarbonate and carbonate ions. The carbonate and bicarbonate concentrations are affected by calcium carbonate (hard water scale is basically limestone) deposited in the system. As water gets more acidic, hard water scale dissolves. As the pH gets higher, more scale forms. Let me hazard a guess that your water source is groundwater. Groundwater typically has relatively high concentrations of dissolved carbon dioxide and relatively low oxygen concentrations because it is not equilibrated with the levels in the air. Some artesian wells even fizz like soda pop when the water reaches the surface. Aeration of groundwater within the system tends to release the carbon dioxide and increase the oxygenation and the pH by equilibration with the air. So the behavior you are seeing in your system is fairly typical for water of moderate alkalinity and moderate hardness from a groundwater source and sampled at aerated taps.
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Good ideas, but none apply. We know the exact source, have good maps of the installation, and the water is taken from outside taps which no one would apply a filter or treatment system to because of the cost. Inside plumbing might be different - copper, perhaps - but I can't prove it, and it seems unlikely that water taken from 4 randomly chosen homes would show the same pattern. It most likely is something systemic, but it's hard to pin down so far...
Will Rogers never met me.
Roger Wright wrote:
nd the water is taken from outside taps which no one would apply a filter or treatment system to because of the cost
We have a well and treat our own water and we specifically have one outside tap that is filtered and one that isn't because we fill the hot tub from the filtered outlet. We have to do those water tests periodically and take them to a lab here in town and there is a definite procedure for getting a fresh sample but as you say those guys are trained so they must be doing it right....right? :) (What I'm saying is I'd follow them and watch them do it, they must run the water for quite a while before taking a sample else they're sampling what's accumulated in the pipes inside the house)
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