[Terrapreta] sewage sludge charcoal

[Kevin Chisholm]

Dear MF

Sewage entering a Domestic Septic tank, or the leachate and septage 
leaving it, would be expected to have much lower levels of toxic heavy 
metals or contaminants than would the discharge from a Municipal Sewage 
system.

Municipal sewage systems also treat Industrial wastes, and storm water 
run-off. I would guess that most of the "nasties" come from Industrial 
waste and storm water run-off.

Best wishes,

Kevin

MFH wrote:
>
> Folke
>
> How come sewage contains high levels of heavy metals.
>
> Theoretically the stuff in the sewage treatment plant has all derived 
> from people’s waste. This ignores all the multitude of other material 
> that is tossed down toilet bowls, but if heavy metals are at abnormal 
> levels in this waste, does this imply that the body concentrates and 
> evacuates these?
>
> M
>
> ------------------------------------------------------------------------
>
> *From:* terrapreta-bounces at bioenergylists.org 
> [mailto:terrapreta-bounces at bioenergylists.org] *On Behalf Of *Folke 
> Günther
> *Sent:* Wednesday, 9 April 2008 6:45 PM
> *To:* 'Michael Antal'; 'Terra Preta'
> *Subject:* Re: [Terrapreta] sewage sludge charcoal
>
> Raw sewage sludge should /never/, under any circumstances, be used in 
> a process involving soil that will be used for food production, 
> because of the high content of heavy metals.
>
> I agree that the charring might destroy (or spread out?) some of the 
> otherwise organic noxious stuff, as medicals and the like.
>
> Thus, if you make char of it, you have to put it in abandoned mines or 
> the like, which implicates a loss of phosphorus.
>
> Much better is to use source-separating toilets, add the urine to 
> char, possibly char the faeces, and then put it in the soil.
>
> It is the “purification” process that destroys this otherwise 
> excellent nutrient stuff.
>
> ------------------------------------------------------------------------------- 
>
>
> Folke Günther
>
> Kollegievägen 19
>
> 224 73 Lund, Sweden
>
> home/office: +46 46 14 14 29
>
> cell: 0709 710306 skype: folkegun
>
> Homepage: http://www.holon.se/folke
> blog: http://folkegunther.blogspot.com/
>
> ------------------------------------------------------------------------
>
> *Från:* terrapreta-bounces at bioenergylists.org 
> [mailto:terrapreta-bounces at bioenergylists.org] *För *Michael Antal
> *Skickat:* den 9 april 2008 00:45
> *Till:* 'Terra Preta'
> *Ämne:* [Terrapreta] sewage sludge charcoal
>
> I am pleased and somewhat surprised to report that raw sewage sludge 
> is a good feedstock for charcoal production. Details are available on 
> the HNEI website below. Regards, Michael.
>
> Michael J. Antal, Jr.
>
> Coral Industries Distinguished Professor of Renewable Energy Resources
>
> Hawaii Natural Energy Institute
>
> POST 109, 1680 East-West Rd.
>
> Honolulu, HI 96822
>
> phone: 808/956-7267
>
> fax: 808/956-2336
>
> _www.hnei.hawaii.edu_
>