Table 1.

Model parameters

Parameter	Symbol	Default value	Units	Reference
Internal springs
Spring constant	ks,i	5 × 10−11	N m−1
Filial links (E. coli)
Short spring spring constant	ks,f,short	5 × 10−13	N m−1
Long spring spring constant	ks,f,long	5 × 10−13	N m−1
Stretch limit	df,break	1	μm
Short spring relative length	lf,short	0.5	—
Long spring relative length	lf,long	1.7	—
Filial links (activated sludge)
Short spring spring constant	ks,f,short	2 × 10−11	N m−1
Long spring spring constant	ks,f,long	2 × 10−11	N m−1
Stretch limit	df,break	2	μm
Short spring relative length	lf,short	0.5	—
Long spring relative length	lf,long	1.7	—
Sticking links (activated sludge)
Spring constant	ks,s	1 × 10−11	N m−1
Formation limit	ds,form	0.5	μm
Stretch limit	ds,break	1	μm
Anchoring links (E. coli)
Spring constant	ks,a	1 × 10−11	N m−1
Formation limit	da,form	0.5	μm
Stretch limit	da,break	1	μm
DLVO forces (E. coli)
Electrostatic force grouped constants	CES	1 × 10−22	N m
Van der Waals force grouped constants	CvdW	1 × 10−31	N m2
Inverse Debye length	κ	5 × 107	m−1
Collision response
Cell-cell collision spring constant	kc,c	1 × 10−10	N m−1
Cell-substratum collision spring constant	kc,s	1 × 10−10	N m−1
Other forces
Velocity damping coefficient	kd	1 × 10−13	N s m−1
Bacilli geometry (E. coli)
Cell diameter	Dr	0.75 ± 0.0375	μm	(42)
Initial cell length	Lr,0	3	μm
Final cell length	Lr,div	5.75	μm	(42)
Cell mass at division	mr,div	2.45 × 10−15	kg
Filament-former geometry (activated sludge)
Cell diameter	Dr	0.5	μm	(43)
Initial cell length	Lr,0	1.67	μm
Final cell length	Lr,div	4	μm	(43)
Cell mass at division	mr,div	3.70 × 10−15	kg
Floc former geometry (activated sludge)
Cell diameter	Dr	0.35	μm	(43)
Initial cell length	Lr,0	0.317	μm
Final cell length	Lr,div	1.1	μm	(43)
Cell mass at division	mr,div	6.09 × 10−16	kg
Growth (E. coli)
Growth rate coefficient for bacilli	μ	1.23 ± 0.277	h−1	(44,45)
Growth (activated sludge, low O2 concentration)
Growth rate coefficient for fil. form.	μ	0.217 ± 0.0434	h−1
Growth rate coefficient for floc form.	μ	0.153 ± 0.0306	h−1
Growth (activated sludge, high O2 concentration)
Growth rate coefficient for fil. form.	μ	0.271 ± 0.0542	h−1	(43)
Growth rate coefficient for floc form.	μ	0.383 ± 0.0766	h−1	(43)
Other parameters
Biomass density	ρ	1010	kg m−3