Subject: (fwd) Re: Grey Water

From: [email-masked]
Date: Wed, 14 Feb 2001 15:26:29 -0500

On Mon, 12 Feb 2001 10:52:26 GMT, in alt.permaculture "Reedbed"
<[email-masked]> wrote:

Haig <[email-masked]> wrote in message

> Len is spot on about the size of components. I suspect you would need a
> fairly big reed bed or other nutrient removal scheme to do it. Then there
> will be the nutrient imbalance problem. Lotsa phosphates in cleaning
> products but no nitrogen. So the removal bed will only clean up as much P
> as the N will allow, then you will be stuck with high P in your system just
> waiting for some nutrient input to cause an unexpected bloom... probably
> of an unacceptable type like blue-green algae. Could add N I suppose but the
> bed would need to be bigger.

Could you explain how N and P are dependent on each other for removal
???

TIA
Mark

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On Wed, 14 Feb 2001 19:28:01 GMT, in alt.permaculture "Haig"
<[email-masked]> wrote:

Mark,

my understanding is that any biological nutrient system is dependent
on the
food requirements of the species chosen. Apart from the micro
nutrients
(trace elements), living organisms need a balance of their major
nutrients
(N, P, K, C, etc) to grow and reproduce. This introduces the concept
of a
"limiting nutrient", one which is essential to the species and despite
all
the other nutrients being present in abundance, will prevent further
expansion of the species because it is at lower than balance levels. A
typical example is diatoms and their need for silica. Diatom blooms
often
follow an influx of water after rain which has disturbed sediments and
released more dissolved silica.  Getting back to a nutrient removal
system.
Greywater in particular is extremely rich in phosphorous (phosphates
ex
cleaning products) and carbon (sugars, etc from kitchen) and silica
(also ex
cleaning products). Nitrogen is not a big constituent (unless you
include
some toilet waste) and in this type of system becomes a limiting
nutrient.
(remember, even well-treated sewerage contains high P levels even
after
optimised bio-removal through a well-controlled plant).  That is why I
suggest that a recirculating system as Paul proposed can sit there
percolating away with very high nutrient levels but little growth.
Then,
when someone fertilises the garden and excess nitrogen washes in,
bang, a
bloom, but probably of an undesirable species such as algae..... in
short
the green slimey masses you see in drains and stagnant creeks.

But, of course bio-removal can be done. But you have to design a
system with
the right species (those with high requirements for the excess
nutrients),
with the size capacity to cope with the levels (there are bulk
phosphates in
grey water!) and possibly care for the sytem with as much attention as
you
give your swimming pool  -  only NPK etc analyses aren't cheap.

Anyone who takes on such a project gets my full support for
environmental
responsibility and get up and go. Just be aware of the chemistry and
the
hazards associated with grey water aerosols and diffuse pollution
issues,
viz.  high P seeps into water table from Pauls water feature (and
someone
elses septic and someone elses weekly car washing ) and at the spring
in the
next valley to you trails a fetid mass of slime.

Good luck,  Jim

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On Wed, 14 Feb 2001 11:38:25 GMT, in alt.permaculture Ellen Hrebeniuk
<[email-masked]> wrote:

In article <[email-masked]>, "Paul" 
<[email-masked]> asked about grey water systems.

Try looking up back issues of Earth garden and similar magazines, and 
also read Michael Mobbs' book "Sustainable House".  He's managed to 
dispose of his *sewerage* as well as grey water on his property in 
Chippendale!

Ellen Hrebeniuk
Sydney

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