Re: DIG-L: Plants fueled by sludge

[Arthur D Unger <alunger@juno.com>]

Sorry to waste everyone's time by not knowing that there are several
definitions of sludge. The sludge I refer to is the solid material left
after processing municipal sewage. Raw municipal sewage now consists of
human excrement, house hold chemicals and industrial chemicals. Sierra
Club maintains that waste streams should be separated so that raw
municipal sewage consists only of human wastes.  Until ten or so years
ago this sludge was dumped into the ocean;  it killed most life on the
ocean bottom, so ocean dumping was outlawed. Now sludge is land-filled or
used as fertilizer and soil amendment. Many think that microbial
digestion of sludge would reduce the volume and thus facilitate
land-filling. Many are reluctant to spread sludge, with its pathogens,
heavy metals and persistent organic pollutants, on land. 

How many plants in the USA are fueled  by municipal sludge?".

I am aware that animal husbandry operations generate manure that is being
microbially digested to produce methane. I have already burdened this
list enough with my ignorance of that process. 
										Thanks,    Arthur Unger
 

On Thu, 17 May 2001 08:43:24 EDT Vanhauw@aol.com writes:
> Arthur:
> 
> Answering your question "how many plants in the USA are fueled  by 
> sludge?".
> First of all, I do not think (unless a new technology has cropped up 
> very 
> recently) that "sludge", hereby defined as the residue of anaerobic 
> digestion 
> taking place in industrial digesters, is actually used as fuel in 
> any plant. 
> You experts out there may contradict me, and please do.
> This leads us to define the plants under discussion here. What 
> plants do you 
> have in mind. Are you thinking of waste water treatment plants, or 
> industrial 
> plants (fueled by the methane generated during anaerobic digestion). 
> Or 
> plants of a much smaller size as might be found in animal husbandry 
> operations? 
> Give me a little more detail as in "where you are coming from" and I 
> will try 
> to point you in the right direction.
> 
> Best regards,
>     Pierre
> Pierre M. van Hauwaert
> AplusB, Inc.
> 4448 Habersham South - Unit 202
> Cleveland, Ohio 44143 - USA
> Tel (216) 486 1915
> Fax (216) 486 3992
> e-mail: vanhauw@aol.com

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