GPS-X Technical Reference

291 Digestion Models
ADM1 State Variables Set in the Influent Object
When the influent stream is represented by an influent object, the states influent model
should be used in the influent object. Some of the states are ADM1 states and these need
to be estimated. Some states are not relevant for ADM1 and can be ignored. Some states
form a fraction of an ADM1 state and when added up need to correspond to the values
entered into the influent form of the ADM1 object. More detailed descriptions are given
below:
Table 10-2 – ADM1 State Variables Set in the Influent Object
Parameter
inert inorganic
suspended solids
soluble inert
organic material
readily
biodegradable
substrate
particulate inert
organic material
slowly
biodegradable
substrate
active
heterotrophic
biomass
active autotrophic
biomass
unbiodegradable
particulates from
cell decay
internal cell
storage product
dissolved oxygen
free and ionized
ammonia
soluble
biodegradable
organic nitrogen
Suggestion
Must be measured or estimated. It is not an ADM1 state but will impact
the solids concentration.
Same as the S i state in ADM1
Sum of Monosaccharides, Amino acids, Long chain fatty acids, Total
valerate, Total butyrate, Total propionate, Total acetate, and
Carbohydrates states in ADM1. Make sure this value is the sum of the
values entered for these states in the ADM1 influent stream.
Same as X i state in ADM1.
Sum of composites, proteins, and lipids states in ADM1. Make sure this
value is the sum of the values entered for these states in the ADM1
influent stream.
Set to zero unless you have an estimate of it.
Set to zero unless you have an estimate of it.
Becomes part of X i state in ADM1. Unless you know X u, use X i above
and set this to zero
Not used.
Not in ADM1 but used by GPS-X to estimate the COD demand of the
influent stream. It is assumed that both oxygen and nitrate will be
reduced instantaneously upon entering the anaerobic environment, so
the total incoming COD is reduced by this incoming COD demand to
compensate for the reduction of the electron acceptors present in the
incoming stream.
S in state in ADM1 (inorganic nitrogen). Make sure that correct units
are used.
(nitrogen faction in amino acids = 0.098) amino acids concentration
GPS-X Technical Reference