Symbol
Explanation
Dimension
Unit,
See
for example
page
XB,PAO
biomass of phospho- M· L- 3
kgSS(B)/m 3
98
rus accumulating bacteria
Xcoo
sludge concentration M· L- 3
kgCOD(B)/m 3
(biomass concentration) measured in COD
Xr
suspended biological M· L-3
kg COD(S)/m 3
43
inert organic matter
Xr,N
suspended inert
MNL- 3
kgN/m 3
49
nitrogen
Xorg,P
suspended organic
Mp · L- 3
kgP/m 3
49
phosphorus
XpHA
polyhydroxyMpHA· L- 3
kgCOD/m 3
49
alkanoate
XP,a
adsorbed phosphorus Mp·M
mg P /kg soil
330
XP,p
amount of phosphorus M·L- 3
gP/m 3 water
327
in primary particles
per volume of water
XR
non-diffusible matter M· L- 3
g/m3
184
Xs
suspended biological- M· L- 3
kg/m 3 , kg COD(S)/m 3
43
ly, slowly degradable
organic rna tter
Xs,N
suspended organic,
MN· L- 3
kgN/m 3
49
slowly degradable
nitrogen
Xo.s
sludge concentration M· L- 3
g/l,kg/m 3
in activated sludge
after 1 12 hour's settling
y
yield constant
M·~l
kg VSS/kg substrate or
kg COD(B) /kg COD(S)
368