[Greenbuilding] device to purify human waste, make compost and generate electricity
RT
archilogic at yahoo.ca
Sun Aug 19 08:57:07 CDT 2012
BCJohn wrote:
> China is a good example of a country that has utilized human waste as a
> fertilizer both rurally and within cities
> Systems vary but basically waste is collected from holding tanks in
> buildingsdeposited in large 'ponds' or containment and various
> treatments and amendmentsare used and within 30-90 days typically is
> used as an amendment. Fishponds were
> traditionally used and this was common in germany until the 40's.
To expand a bit on what John has touched upon...
Up until the recent Westernisation of China, in the Pearl River delta
region there were community eco-systems that were pretty close to being
what we might describe as being sustainable.
If one were to plug "Silkworm fish pond farms China" into Google I suspect
that one would get a sufficient number of hits to provide a pretty good
picture of them.
Pretty much every village in that area would traditionally have
built-ponds (build earthen dikes to create containment areas for water
channelled from nearby rivers ) to provide water for their agricultural
activities. (Rainwater harvesting and dug wells would be the sources for
household water). Those ponds would of course also be used for raising
fish, both for their own consumption and to take to market to generate
income.
In the communities that engaged in silkworm production, the pond mud, rich
in nutrients from pooping fish, would be dredged every winter after fish
harvest and that mud would then be used throughout the following growing
season as a slow-release fertiliser and mulch for their mulberry orchards.
The leaves of the mulberry shrubs would be harvested to feed silkworms
(whose cocoons would of course eventually be used for silk production) and
the silkworm poop would be collected to be used as feed for the fish in
the aforementioned ponds. Tilapia, dace and a type of carp thrive in those
pond environments the and the plentiful yields would provide the
invaluable protein supplements for the villagers diets.
All of the village's human, animal and vegetative waste would be fed into
a tank (basically an in-ground stave silo) over which a bladder was placed
to function as a bell-jar to collect the bio-gas produced from the
decompostion of those wastes. Lines (often as simple as vinyl tubing with
an in-line ball-cock valve) would run from the community bio-gas digester
to each dwelling to provide clean-burning fuel for lighting and cooking.
The "spent fuel rods" from the bio-gas digester would be used to fertilise
the vegetable crop fields.
The use of human wastes for agricultural fertiliser was utilised for
millennia in China. More than a few family fortunes were founded upon the
collection and sale of such. Obviously over those millennia, they must
have developed techniques to minimise the spread of disease from potential
pathogens.
In the 1970s, the IDRC ( http://www.idrc.ca ... my neighbour across the
road used to travel around the world for it as an advisor) recognised the
merits of such small-scale, site-built community bio-gas digesters and
implemented a program for their use in Third World countries to the point
that there are currently thousands (ie in the six figures) in use.
OTOH, here in the Effluent (sic) First World where we probably produce
many-fold waste per capita (as compared to Third Worlders) ... well, you
know. And Bill Gate's foundation wants to teach Third Worlders how to do
it right ? Huh.
--
=== * ===
Rob Tom AOD257
Kanata, Ontario, Canada
< A r c h i L o g i c at Y a h o o dot c a >
(manually winnow the chaff from my edress if you hit "reply")
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