Water filters, urine, and beer

Dan Kohn dan@dankohn.com
Fri, 12 Apr 2002 13:34:05 -0700

Essentially, this was the point of my experiment.  Eugene, can you
provide any info on the particulate sizes of the chemicals that make
beer and urine beer and urine?  I'm trying to remember my high school
chemistry on the difference between a colloid, suspension, and solution.

The Waterworks can filter 0.2 micron particles.  What is the size of
dissolved salt?  Why does reverse osmosis
<http://www.howstuffworks.com/question29.htm> work when a ceramic filter
doesn't?  Inquiring minds want to know.

          - dan
Dan Kohn <mailto:dan@dankohn.com>
<http://www.dankohn.com/>  <tel:+1-650-327-2600>
Essays announced on <mailto:dankohn-subscribe@yahoogroups.com>=20

-----Original Message-----
From: Eugen Leitl [mailto:eugen@leitl.org]=20
Sent: Friday, April 12, 2002 05:34
To: Luis Villa
Cc: fork@xent.com
Subject: Re: Water filters, urine, and beer

On 12 Apr 2002, Luis Villa wrote:

> Is there a link to the model somewhere, Dan?
> Luis [going to Niger in August]

Um, beer and urine doesn't have relevant particulate size (but for a few
contaminants) which determine the taste. Unless you've got a portable
reverse osmosis device there, all you can hope for is a sterile filter
with some activated charcoal in there. If the filter is fine enough, it
might even get viruses (thought it's doubtful). Salts and small
will pass through.