Re: Composting WWTPs and composting (Was Re: [compost_tea] Re: MICROBIOLOGY TESTING of COMPOST TEAS

From: <soilfoodweb_at_aol.com>
Date: Sun, 26 Dec 2004 02:31:06 -0500
Ted said:
The temperature requirements do not, as far as I can tell, indicate how to adjust your pile. 

Elaine says:
I never said that temperature requirements indicate how to adjust a pile.   

Ted said:
Too much N is just as bad as too much C for composting purposes but the temperature reading alone will not give you an indication of the imbalance. 

Elaine says:
No one ever said that temperature readings alone were adequate.  No one ever said temperature alone will give you an indication of imbalance. 

What was said was that if you understand the proper mix of starting materials, and put the pile together with your best determination of that mix, that temperature will give you a very good understanding of what is going on.  Use temperature in the first few days to help you understand how the mix might need adjusting.  But you have to start with a reasonable mix, and understand how much of what kind of material to put in, to generally get the biology you want.  Turning, or worms, or moisture or quite a list of other things also have to be understood. 

Rather like making bread; its easy once you have the system down, but it is rare that anyone makes bread right the first time they do it.  Composting is like that as well.  It takes practice. 

Ted said:
There are other readings you can take like CO2 and moisture that give a little more information but you've got to be able to understand your materials to a degree and what their potential is in a compost pile or windrow.  There are lots of books and pamphlets that give a start on this process.

Elaine says:
Yep, I agree.  Take classes from people who can make compost that ends up with good biology in the compost. 

Ted said:
Also, please don't assume than anaerobic digestion is inferior.

Elaine says:
I did not make a statement about inferior, or superior.  There are hundreds of different ways to compost.  You have to understand what you are doing.  Understand your goals, and how to achieve that goal. 

Anaerobic digestion requires strict attention to starting materials.  That mix cannot be varied much.  There are serious problems with the left over sludge.  That is just a fact of anaerobic digestors. 

Does that statement indicate any degree of goodness, or badness?  It does not.  Just facts, please don't add in any  emotions.   

It does frighten me that municipalities are being sold a bill of goods about anaerobic digestion, without being told the drawbacks and problems.  What this means is that those who undestand anaerobic digestion need to be ready to come to the rescue of cities who have built these plants.  Because I have concerns does not make the process of anaerobic digestion inferior.  Just be very aware of the drawbacks, and there are some whoppers. 

Of course, large scale aerobic composting requires some serious expenditure - a pad to compost on, a turner, tractor, chippers or screens, or both, something to cover compost when too dry or too wet, ability to measure temperature and moisture at the very least, and O2 or CO2.  So, the need for all this may be considered serious drawbacks for this approach.

Back-yard composting can be done easily, if you have the time to do it, and the willingness to learn the right mixes.  You need some space, chicken wire, a few slats of wood, a shovel or pitch fork, and a thermometer.  The serious drawback is that only if everyone in a city composted could it take care of the problem.  Roof-top composting is very possible!  But still, quantity of the waste is a serious limitation for this approach.

An anaerobic digestor requires a big building with very specific, and expensive, technology in order to operate it.   As a microbiologist, I am fascinated by anaerobic organisms, they are bizarre critters.  We don't know much about soil organisms, so think about the fact that we know probably 1000-fold LESS about anaerobic organisms than we do about soil organisms.  Uncharted territory is scary.  Does that mean we don't go there?  No, it's just scary.  Be careful, think before leaping in. 

Human wastes are just one more kind of starting material, but require an understanding of the fact that there is the potential presence of human pathogens, pests and parasites in the material.  These potential problems can be dealt with  if proper composting is done. 

Combinations of aerobic composting with anaerobic digestion are very possible.  Each variant comes with good points, and with bad points. 

Education is all important. 

It's good to get recommendations on good composting books to read, but it might be more helpful to get the reason why you think those books you recommend are so good.  I like Howard's book, because it gives information on a number of different scales of simple-to-do composting, as well as worm composting.  The Cornell Handbook is useful because it goes through just about every version of building a pile, from the physical point of the business.  It has the C:N ratios of lots of different materials. 

The NRAS publication is much like the Cornell publication, as I recall.  Does it add some more information?  What are its good points? 

--
Elaine Ingham
President, Soil Foodweb Inc.
SFI Corvallis, OR
SFI Port Jefferson, NY
SFI Lismore, NSW, Australia
SFI Cambridge, New Zealand
SFI Culiacan, Mexico
SFI Jerome, Idaho
SFI South Africa
http://www.soilfoodweb.com


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Received on Sun Dec 26 2004 - 17:41:18 EST

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