Hi Mark, David et al.
I would add to Mark's comments that a significant difference between
anaerobic and aerobic digestion organisms is that aerobic organisms
put 9 times more energy into reproduction, which translates into
solid waste at the point that the dead bodies of these organisms are
left behind.
Since anaerobic digestion organisms produce methane and methane is a
combustible gas, the energy required for the digestion process can
be derived from the process itself, rather than require expensive
energy inputs for oxygenation (i.e. turning aerators).
>> Why are these systems not in use to solve the manures and waste
>> problem in the US?
They are, in terms of waste water treatment. (Manure digestors are
generally anaerobic digestion processes). But the most promising
processes combine anaerobic and aerobic digestion organisms in a
train that feeds itself, and these are patented processes. If my
memory serves me, the municipality of Fayetteville, AR had one of
these trains installed during the 80's. Another may have been done
in Dade County FL.
I agree with Mark´s statement:
MM> But I would advocate for the proper use of manure rather than
MM> trying to make it disappear (and sending more greenhouse gases
MM> into the atmosphere).
but re-emphasize that methane production is a viable option in some
third world (i.e. India) where it's used extensively in small scale
applications (it's collected for use by consumers, not let escape).
The process used can be tailored to the goal, using traditional (non
GMO) microorganisms that convert for free (if we feed them).
Compost production itself is a process using aerobic organisms,
since their bodies retain carbon and other elements and form an
important part of the fertilizer. And we don't want to forget using
(working with) earthworms for making compost.
Douglas
*********** REPLY SEPARATOR ***********
Thursday, May 11, 2000, 6:38:57 AM, you wrote:
MM> David,
MM> Aerobic digestion is the breakdown of organic material with
MM> oxygen-consuming bugs, while anaerobic digestion uses bugs that
MM> don't like oxygen, and so it requires an air-tight container.
MM> Ideally, aerobic digestion breaks organics into carbon dioxide
MM> and water, while anaerobic digestion also produces methane.
MM> If feedlots were considered a point source, then they would have
MM> to treat the manure, and their costs would skyrocket. But I
MM> would advocate for the proper use of manure rather than trying
MM> to make it disappear (and sending more greenhouse gases into the
MM> atmosphere).
MM> best wishes,
MM> Mark
MM> At 07:29 AM 05/11/2000 -0400, David Drexler wrote:
>>
>>Could someone please tell me the basic differences between anaerobic and
>>aerobic digestion. Why are these systems not in use to solve the
>>manures and waste problem in the US?
>>Thanks
>>David D/
>>
>>
MM> Mark Muller
MM> Institute for Agriculture and Trade Policy
MM> 2105 First Avenue South
MM> Minneapolis, Minnesota 55404
MM> phone: (612) 870-3420
MM> fax: (612) 870-4846
MM> email: mmuller@iatp.org
MM> website: http://www.iatp.org/
Douglas Hinds, Dir. Gral. - CeDeCoR, A.C.
Centro para el Desarrollo Comunitario y Rural, Asociacion Civil
(Center for Rural and Community Development,
a Mexican non-profit organization)
Cordoba, Veracruz; Cd. Guzman, Jalisco; Loma Bonita, Oaxaca
& Reynosa, Tamaulipas Mexico
Mail: Apdo. Postal No. 171
Fortin de las Flores, Veracruz
94471 Mexico
Tel: 011 522 713 2888 (Direct at present)
U.S. Fax Mailbox (email linked) 630 300 0555
dmhinds@acnet.net, cedecor@acnet.net,
dhinds@prodigy.net.mx
Río revolcado, ganancia de pescadores
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