Thalocean2 wrote:

[ref: spinning human waste before applying it to
fields]

http://www.apfn.org/apfn/waste.htm


Thanks for the reference. It does refer to sewage sludge and states "At
the state-of-the-art West Point Treatment Plant in Seattle, raw sewage
is digested, heated and spun, until it's just right for shipment to the
fields." The article goes on to say that there is some concern being
expressed by Cornell University researchers and describes problems
arising from the practice and in particular from the actions of one
farmer.

A quick check on Google for "heavy metal" sludge spin yielded a large
number of references to rock bands or political spin on sludge
questions. I found no other reference to (physically) spinning the
sludge, although I did not look at all 1000 listed links due to lack of
time.

I would point out that the purpose of spinning is not specified in the
article. I suspect that the purpose is to separate the liquid and solid
components (not necessarily the organic and heavy metal components)
since the stuff that is spread on fields is the solid component. The
liquid component is probably 99% water, and adds weight to the sludge,
so they want to dry it as much as possible before paying someone to
truck it somewhere.




For the record, I am *not* in favor of using sewage sludge on
food-producing land. The reason is that I consider the material
inadequately controlled, particularly in the heavy metal category.
However, I believe that the heavy metals in sewage sludge come from our
hands, not from some other part of our anatomy. It's the other stuff we
put down the drain that is the problem.