[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  >
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