Symbols
a
Specific surface area of supporting media (cm
–1 )
J
Flux of rate-limiting substrate into biofilm (mg/sqcm/day)
J avg
Average substrate flux in biofilm (mg/sqcm/day)
k
Maximum specific rate of substrate use (day
–1 )
S 0
Concentration of rate-limiting substrate in influent (mg/cc)
S w
Effluent substrate concentration (mg/cc)
Ѳ
Empty-bed hydraulic detention time (hr)
Ə c
Mean Cell Residence time or Solid Retention Time (day
–1 )
µ
Specific growth rate of biomass (day
–1
)
b s
Biomass loss rate due to shearing from biofilm (day
–1 )
b d
Biomass decay coefficient (day
–1 )
b t
Total biomass loss rate from biofilm (day
–1 )
K s
Half-velocity coefficient (mg/cc)
Y
Biomass yield coefficient (mg/mg)
X hybrid Concentration of bomass in hybrid bioreactor(mg/cc)
p
Porosity of hybrid reactor
V
Empty-bed volume of hybrid reactor (m
3 )
X
Concentration of suspended biomass in hybrid reactor(mg/cm
3 )
S f
Substrate concentration at any point in the biofilm (mg/cm
3 )
X f
Active biomass density within the biofilm(mg/cm
3 )
D f
Molecular diffusion coefficient of the substrate in the biofilm(cm
2 /day)
S min
Minimum concentration of rate-limiting substrate at biofilm-attachment
surface(mg/cm
3 )
L e
Effective biofilm thickness
L f
Total biofilm thickness
Q w
Waste sludge flow rate (m
3 /hr)
X r
Biomass concentration in waste sludge (mg/cc)
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