[Terrapreta] sewage sludge charcoal & Living Machines

[David Hirst .com]

My understanding of a good way to manage sewage and other organics waste streams is the
concept of “living machines”, as outlined by John Todd and his wide and students. See
http://www.toddecological.com/ecomachines.html.

The Wikipedia entry also seems comprehensive and authoritative.
http://en.wikipedia.org/wiki/Living_machines, and has references to a variety of
authoritative sources. The book [1] is also helpful, but is not a “design guide”. 

I was initially suspicious about the claims for heavy metal cleanup, as the heavy metals
do not convert to safer elements. But the take up and concentrations of these materials
can be restricted to part of the living machine, so biological concentration may make it
feasible to harvest usable materials from them. Such concentration does perform the
useful service of reducing the materials in the down stream processes.

It seems possible that parts of a living machine can be “evolved” to be effective at
removing other difficult materials, such as the triclosan mentioned.
(http://en.wikipedia.org/wiki/Triclosan suggest that this is a product that has all sorts
of undesirable side effects, and even its intended effects are useful only in pretty
narrow circumstances. Perhaps it would be reasonable to require anybody introducing a new
chemical, or significantly enlarging the uses of an existing chemical) should be required
also to produce ways of getting it out of the environment again. A bit like Europe’s
attempt at recycling old electronics under the WEEE directive.). 

Living machines seem very attractive in a number of ways, but are not (yet?) mainstream,
and seem to be rarely pursued by the utilities. I am not sure why. It may be, of course,
that there are downsides that are unattractive to them, but I have not seen any
criticisms that justifies this slow take up. It seems to present a sound model of good
processing that large industrial process thinking seems to lack. 

Such living machines seem to be a way to capture protein from the nutrients (by growing
fish) as well as a good source of biomass.

It seems probable that this biomass could become a useful input to biochar formation,
perhaps better (or safer) than sludge.

It seems to me that this might be a process that could work well on a “village” scale. A
local living machine captures valuable “by-products” from sewage, cleans up the water,
and produces biomass for input to subsequent processes, where both energy products and
biochar could be outputs.

This might be quite similar to the processes that lead to the formation of TP in the
first place. That is, we can “close a loop” of recycling.

I do recommend exploration of the living machines concepts.

Cheers

David

 

David Hirst

 <mailto:david at davidhirst.com> david at davidhirst.com

 

[1]        Todd, N.J. and J. Todd, From Eco-Cities to Living Machines: Principles of
Ecological Design. 1994 North Atlantic Books, 1-55643-150-3.

 

 

 

  _____  

From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Philip Small
Sent: 09 April 2008 14:48
To: Gerald Van Koeverden
Cc: Terra Preta
Subject: Re: [Terrapreta] sewage sludge charcoal

 

Pyrolised sewage sludge is going to happen.  Its up to the folks involved, like myself,
to figure out how to do it responsibly.  To take the high ground and condemn all land
application of all sludge is not constructive.

Heavy metals content, etc. is dependent on the community and the effectiveness of their
pretreatment program. Not all sludge is a candidate for making biochar, but there is a
cleaner end of the spectrum that cannot be dismissed, and that is where the first
experimentation with slludge derived biochar must occur.  

There is a fair amount of it out there.Improved sludge quality is the product of decades
of pre-treatment efforts.  Getting dentists to control their amalgam had a huge effect on
mercury levels in sludge in the 70's.  Printers were discouraged from using heavy metal
laden ink.  The list is long and it comes down to tracking and identifying individual
sources.  It was a huge effort, and hugely successful, but you don't hear anything about
it anymore.  

There is much improvement left to be made in land applied sludge quality, still some low
hanging fruit left to gather. Like triclosan. Playing on peoples fear to sell them
millions of pounds a year of an unneeded antibacterial compound, one which doesn't break
down in waste treatment, is pretty offensive. Sure the soil has an amazing capacity to
deal with such, but why burden the soil with something that can be eliminated at the
source?

I particularly like the idea of biochar as a way to finish sludge prior to land
application.  It deals nicely with the disease component.

On Wed, Apr 9, 2008 at 6:00 AM, Gerald Van Koeverden <vnkvrdn at yahoo.ca> wrote:

What's the problem with sewage sludge?  Folke has a very good point!

 

"Problems associated with the agricultural use of sewage sludge include groundwater,
soil, and crop contamination with pathogens, heavy metals, nitrate, and toxic and
carcinogenic organic compounds. <http://weblife.org/humanure/references.html#5_34> 34
Sewage sludge is a lot more than organic human refuse. It can contain DDT, PCBs, mercury,
and other heavy metals. <http://weblife.org/humanure/references.html#5_35> 35 One
scientist alleges that more than 20 million gallons of used motor oil are dumped into
sewers every year in the United States.
<http://weblife.org/humanure/references.html#5_36> 36

America's largest industrial facilities released over 550 million pounds of toxic
pollutants into US sewers in 1989 alone, according to the US Public Interest Research
Group. Between 1990 and 1994, an additional 450 million pounds of toxic chemicals were
dumped into sewage treatment systems, although the actual levels of toxic discharges are
said to be much higher than these. <http://weblife.org/humanure/references.html#5_37> 37

Of the top ten states responsible for toxic discharges to public sewers in 1991, Michigan
took first prize with nearly 80 million pounds, followed in order by New Jersey,
Illinois, California, Texas, Virginia, Ohio, Tennessee, Wisconsin and Pennsylvania
(around 20 million pounds from PA).38 <http://weblife.org/humanure/references.html#5_38>
"

For the complerte chapter, go to:

http://weblife.org/humanure/chapter5_10.html

Gerrit

 

On 9-Apr-08, at 5:11 AM, MFH wrote:

Folke

 

Hang on. The Chinese in particular have been using human waste in agriculture for
thousands of years. What's different to their poo?

 

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

 

 


  _____  


Jag använder en gratisversion av SPAMfighter för privata användare.
16402 spam har blivit blockerade hittills.
Betalande användare har inte detta meddelande i sin e-post.
Hämta gratis SPAMfighter <http://www.spamfighter.com/lsv>  idag! 

_______________________________________________

Terrapreta mailing list

Terrapreta at bioenergylists.org

http://tech.groups.yahoo.com/group/biochar/

http://terrapreta.bioenergylists.org

http://info.bioenergylists.org

 


_______________________________________________
Terrapreta mailing list
Terrapreta at bioenergylists.org
http://tech.groups.yahoo.com/group/biochar/
http://terrapreta.bioenergylists.org
http://info.bioenergylists.org




-- 
Land Profile, Inc. * PO Box 2175 * Spokane, WA 99210
509-844-2944 cell * 509-838-4996 fax * 509-838-9860 office
Profile: http://www.linkedin.com/in/philipsmall 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: /attachments/20080409/32b3e381/attachment.html