[Digestion] Relationship between COD and VS

[Leslie Gornall]

Steve, when I measure VS and COD on most organic substrates, animal manures, plant materials etc.  I get the relationship that COD (g) /VS  (g )= 1.1  +/- 0.1.  The exception is chicken manure which can be 0.1 to 0.2 higher.  This could be due to higher nitrogen content or the manure stinks like rotting lawyers when you dry it in the laboratory oven and it tends to be removed quickly for the assay. 

I hope this is useful. 

Best Regards
Les Gornall



> Date: Wed, 13 Feb 2008 11:05:07 +1300
> From: sancreed at hyper.net.nz
> To: DIGESTION at LISTSERV.REPP.ORG
> Subject: [Digestion] Relationship between COD and VS
> 
> Dear List
> Perhaps somebody could confirm whether or not an assumption I have made 
> is correct.
> 
> In this context.
> I am constructing a home scale digestion system, using leaching and 
> methane filter principles. The methane filter is established methanogens 
> on straw / grass fibres. In determining the volume of the filter - other 
> published works state that their systems were fed at certain Organic 
> Load Rates, expressed as COD gms / litre volume.
> 
> Knowing the amount of VS added daily, can I assume that my measure of VS 
> is equivalent to the same amount of COD?
> 
> kia ora
> Steve Rodda
> 
> 
> 
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