Reid Harvey on fri 6 jun 03
Clayart Friends,
In our project, moving towards use of pottery purifiers by the poor, who
are vulnerable to waterborn illnesses, we would like to consider
saturating these filters with silver nitrate. Here in Nepal 40,000 kids
die every year from these illnesses. Upto now we've been saturating
with colloidal silver, but for the nitrate the silver is in solution, so
it may be that more thorough saturation is easier to accomplish. And
silver nitrate may be more accessible than is the case with colloidal
silver. So......
FOLLOWING IS THE QUESTION: The nitrate needs to be burned off at about
475C, the first visible red. Then the pottery purifier is removed from
the kiln, placed in a container with sawdust, and covered with a lid.
The continuing combustion is looking for oxygen, pulling this out as the
nitate, NO3. But the pores of the pottery are filled with carbon.
Here's what we need to know: If we then put the purifier back into the
kiln, to burn off the carbon, will the silver be disturbed? It needs to
remain within the purifier in order to do it's job of killing the
pathogens. Our concern is that black purifiers may be considered
unsightly by prosepective users of the system, especially since the
filters found in the markets tend to be white.
Can someone point me in the direction of those who may have an answer?
Any reponse, please send to me directly at the email address below.
Unfortunately I cannot subscribe to Clayart.
Thanks!
Reid Harvey
Pottery Water Purifier Project, Nepal
http://www.purifier.com.np
pdp1@EARTHLINK.NET on fri 6 jun 03
Hi Reid,
I do not quite understand these 'filters', so forgive me if
I am confused here...but...
Perhaps make the 'filters' some pleasing dark or cheerfully
'speckled' color?...so the remaining carbon is not noticed
as unsightly ( which I take it, does not in itself interfere
with the duties of the Silver?)
I would think that eliminateing any unnecessary steps in
production would benifit productivity.
Or...can the Silver be introduced after the piece is fired?
So long as you have gotten the cintering as best represents
the porosity you intend?
Or...maybe I need to understand these better!
Is there a web-site so I can look?
Phil
lasvegas
----- Original Message -----
From: "Reid Harvey"
To:
Sent: Thursday, June 05, 2003 7:47 PM
Subject: Ever hear of rakuing a water purifier? PLEASE HELP
> Clayart Friends,
> In our project, moving towards use of pottery purifiers by
the poor, who
> are vulnerable to waterborn illnesses, we would like to
consider
> saturating these filters with silver nitrate. Here in
Nepal 40,000 kids
> die every year from these illnesses. Upto now we've been
saturating
> with colloidal silver, but for the nitrate the silver is
in solution, so
> it may be that more thorough saturation is easier to
accomplish. And
> silver nitrate may be more accessible than is the case
with colloidal
> silver. So......
>
> FOLLOWING IS THE QUESTION: The nitrate needs to be burned
off at about
> 475C, the first visible red. Then the pottery purifier is
removed from
> the kiln, placed in a container with sawdust, and covered
with a lid.
> The continuing combustion is looking for oxygen, pulling
this out as the
> nitate, NO3. But the pores of the pottery are filled with
carbon.
> Here's what we need to know: If we then put the purifier
back into the
> kiln, to burn off the carbon, will the silver be
disturbed? It needs to
> remain within the purifier in order to do it's job of
killing the
> pathogens. Our concern is that black purifiers may be
considered
> unsightly by prosepective users of the system, especially
since the
> filters found in the markets tend to be white.
>
> Can someone point me in the direction of those who may
have an answer?
> Any reponse, please send to me directly at the email
address below.
> Unfortunately I cannot subscribe to Clayart.
> Thanks!
> Reid Harvey
>
> Pottery Water Purifier Project, Nepal
> http://www.purifier.com.np
>
>
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Diane Winters on fri 6 jun 03
Hi Reid,
I hope others can help you with the technical issues you raise.
But you also wrote:
>Our concern is that black purifiers may be considered
>unsightly by prosepective users of the system, especially since the
>filters found in the markets tend to be white.
>
Check out first whether the blackness is really a psychological barrier or
not, or could possibly be played up in your "marketing". I'm not sure if
you'd be offering it directly to individuals or to very small rural
communities.
One little present brought to me once by a dinner guest in New York about 20
years ago was a bottle of Monkey Brand Black Tooth Powder that he'd picked
up in an Indian food store in Manhattan. I was absolutely delighted with
it - it still smelled of the Indian spices from the air of the store, but
also I was charmed and amazed at its running so completely counter to all
our instilled American concepts of marketing for dental hygiene. First, the
monkey image of the brand, plus of course the fact that the product was
sooty black, and the clear glass bottle, when taken out of it's box was just
covered with excess black powdery dust. But it "imparts a pearly lustre to
the teeth; accept no imitations". This product is currently available here
in Berkeley at at least one Indian food store, but the packaging is not
quite as charming - the bottle isn't clear to reveal the blackness.
It's obviously mainly powdered charcoal and probably does a pretty good job,
so there may possibly also be strong existing associations of black
charcoaly things as pure and healthy up where you are too.
Good luck with your purifiers
Diane Winters
Tony Olsen on fri 6 jun 03
Phil, (and others interested,)
Here is the link to the water purifiers.
http://www.purifier.com.np/index.html
As I understand it, and may have it wrong, the colloidal silver is run =
through the filter as a last step in preparing the filter.
Tony (Galveston)
Burness Speakman on sat 7 jun 03
In the filters I am familiar with a semi-soft outer shell is made using
Diatomatious Earth. This acts a particulate filter and can be cleaned with
light scrubbing. The interior cavaty is filled with silver impregnated
activated charcoal. The charcoal removes many chemical pulutants and the
silver kill off all the bacteria. The open end is capped with a piece of
fiberglass screen and a porus filter paper membrane. This is mounted in a
bucket, the later flowing through the outer filter into the charcoal center
and drips into a receptical.
In the process you mention, the reduction firing in sawdust is what would
give you the black appearance. In any event charcoal is a necessary part
of any filtration device and makes the best matrix I am aware of to hold
the silver with. Silver nitrate may not be the best way to go since the
silver needs to be in contact with the charcoal to keep the charcoal from
growing bacteria. Perhaps you can also design an outer shell to fit
your "filter" into out of Diatomatious Earth, since it makes for excellant
fire brick and filtration devices.
Who else would know? you might get in touch with the Black Berkey, or
British Berkfeld filtrations systems. (the above is how the British
Berkfeld filters are made)
iandol on sun 8 jun 03
Dear Burness Speakman,
This sounds like an interesting device. But to be useful as a deodoriser =
and substrate which removes organic and chemical contamination, Charcoal =
needs to be treated. Ordinary, run of the mill, barbecue or chicken =
roast charcoal will not do the job. Activation seems like a complex =
process involving steam at up to 900 deg Celsius acting on organic =
matter such as sawdust.
Now I could imagine a clay based substance, composed of clay and sawdust =
and impregnated with Silver nitrate being press formed into cylinders =
then fired in a steam rich atmosphere to 900 deg Celsius. I wonder if =
anyone could estimate the manufacturing cost?Best regards,
Ivor Lewis.=20
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