[Digestion] Digesting MSW

[Jim and Amy Rankin]

Rex,
This ambitious technique to process unsorted MSW as you describe it sounds 
as if it would work well in conjunction with a sewerage treatment plant in 
several of the stages

The water bath might use water from some stage of the sewerage treatment 
plant and the same digesters might be used for the sludges and the 
supernatant that are used for the sewerage.  In effect the organic fraction 
of the MSW could be used to enrich the sewerage for increased gas production 
and increased reactor efficiency.  The aerobic stages that are commonly used 
in sewerage treatment plants could be used in a secondary role to polish the 
digester effluent instead of the primary treatment of sewerage supernatant 
directly.

Couple the recycling of glass and  metal, the digestion of organics and 
incineration or recycling of the plastics and it would seem possible to 
almost completely eliminate the MSW stream to be lanfilled.

Maybe this already exists?

Jim

James R Rankin, DVM
Cedarcrest Farms, Inc
Faunsdale, AL USA


>
> There is an Israeli technology that takes unsorted MSW, sorts the
> "heavies" from the "lights" by dropping the MSW into a water bath -> the
> plastics float off while the heavies are sucked out and subjected metal
> and glass recovery. The organics are broken up by shear in the water
> bath using water jets. The organic laden water is then sent to a two
> stage AD process of which the second stage is a UASB treating filtered
> water from the first stage. This system works remarkably well but, as
> you noted, does not generate as much energy (plastics are not burnt and
> the co-production of CO2 leads to energy loss).
>
> For more information, contact Mel Finstein: see contact details below
>
> Kind regards
> Rex
>