One of the reasons this may be impractical on a large scale is that item re=
ferring to amounts of earthworms per amounts of biosolids. Let's forget th=
e innoculants right now.
For the test, they used a ratio of 1:1. There was approximately 3.6MTons o=
f biosolids and 3.6M tons of earthworms. In subsequent tests, the full sca=
le, there were 1:1.5 biosolids to earthworms. So we have a situation where=
there are more earthworms per tonnage than biosolids. If a WWTP were to i=
ncorporate this type of methodology and the earthworms died for some reason=
, they would be a the mercy of the provider. If the plant chose to raise t=
he earthwoms, they would have a whole different set of problems.
The work looks promising and it has long been known that earthworms, like p=
igs, process human wastes better than almost anything. I think the reason =
nobody has pursued it is simply because the logistics of this on a large sc=
ale of say 200M tons is not feasible. The way WWTPs work is not consistent=
. There are all kinds of factors like weather and food types and heat and =
acid, etc.
In addition, what does the plant do with the worms when there are no biosol=
ids to process? Seventeen percent solids is kind of jelly like. This mean=
s that unless there is a source of O2, there will be anaerobic areas. Now,=
with a 1:1 or 1:1.5 ration, this may be moot but if something happens to t=
he worms, you have zilch.
My ex business partner is the most knowledgeable worm person I have ever me=
t. I asked him once why people didn't use earthworms to process biosolids =
to class A. His response was that it would take too long because even if y=
ou get enough, they will eventually run out of food and leave.
Now, this report was written in 1997. Endrocine disruptors were barely a bl=
ip on anyone's radar at that time. The biosolids being treated now are loa=
ded with hormones such as estrogen and I do not think there has been any wo=
rk done on worm and the processing of hormones.
So again, the report looks promising and I am sure it works. I think logis=
tically, it is still impractical for large scale operations.
I would like to see the same experiment tried at a WWTP with little heavy m=
etals and one close to an industrial area with known heavy metals to see ho=
w that panned out. It seemed that the only interest here were pathogens an=
d the heavy metals were given little attention.
I am always curious when innoculants are used. It bothers me that they cou=
ldn't get the biosolids certified as containing certain elements then proce=
ss from that. To get the numbers they wanted, they had to artifically inno=
culate the windrows. (Actually at 17% solids, there was not much windrowing=
but bedding. There must have been containers to hold the material without=
runnoff.
Anyway, that's my take.
Ted Peterson
EW/SOE
----- Original Message -----
From: Kirk Leonard
To: Compost Tea Group
Sent: Sunday, June 06, 2004 12:12 PM
Subject: [compost_tea] Eastman vermi report
Googling can be wonderful. Found the Bruce R. Eastman, Philip N. Kane,
Clive A. Edwards, Linda Trytek, Bintoro Gunadi, Andrea L. Stermer and
Jacquelyn R. Mobley report of worm tests on pathogen reduction per EPA
biosolids standards:
www.oardc.ohio-state.edu/michel/csu.pdf
And here's an excerpt from a BioCycle story on same:
> ACHIEVING REQUIRED REDUCTION <
> Analytical results showed that all of the pathogen indicators in the te=
st
row had a greater reduction than in the control row. EPA's required three=
-
to fourfold reduction was achieved in all of the pathogen indicators with=
in
144 hours. Fecal coliform, Salmonella sp. and enteric virus achieved the =
EPA
goal in 24 hours, 72 hours and 72 hours, respectively. The helminth ova
achieved this goal within 144 hours. <
Worms are really good. An additional value the worms brought in these
studies was the ability to deal with 80-85% moisture conditions of the
material. And other researchers have shown that worms can handle metal
reduction in organic wastes, too!
So how come there's still no such thing as vermicompost under USNOP?
Kirk
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Received on Sun Jun 06 2004 - 19:57:17 EDT