[Terrapreta] sewage sludge

[Gerald Van Koeverden]

I think the idea of making charcoal out of sewage sludge is a great  
one with much potential.  But the problem of heavy metal and organic  
chemical contamination is a very serious issue, especially in the USA  
which allows 800% higher contamination of soil by heavy metals than  
Canada and Europe.

For those interested in a general overview of heavy metals in sewage  
sludge as fertilizer, check out the following two sites.

"A recent publication from Cornell University's extension service  
recommends that farmers "limit the total cumulative load of metals in  
soil to no more than 1/10 the cumulative loading limits set under  
federal 503 regulations." Why? Because some heavy metals and excesses  
of others ingested by aquatic organisms, wildlife, and humans can  
cause physiological mayhem; troubles like kidney disease,  
hypertension, liver damage, neural damage, structural change in  
tissues, and reproductive problems. On average, the 503 regulations  
for cumulative loading of heavy metals are eight times higher than  
those set in Denmark, Canada, the European Economic Community,  
France, and the Netherlands."

http://www.riles.org/paper2.htm


To check out the Cornell Waste Management Institute, go to:

http://cwmi.css.cornell.edu/

Gerrit
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