ATP	Adenosine triphosphate
BRT	Biomass retention time
GOGAT	Glutamate synthase
GS	Glutamine synthase
HRT	Hydraulic retention time
MF	Microfiltration
MPBR	Membrane photobioreactor
OD	Optical density
OEC	Oxygen-evolving complex
PBR	Photobioreactor
PSI	Photosystem I
PSII	Photosystem II
PSBR	Porous substrate photobioreactors
SVR	Surface area to volume ratio
TN	Total nitrogen
TP	Total phosphorus
Symbol	Entity	Unit
P area	Area productivity	g m−2 day−1
I phin	Average light intensity	μmolph m−2·s−1
X	Biomass concentration	g L−1
X R	Biomass concentration in the recovered volume	g L−1
BRT	Biomass retention time	day
β	Biomass productivity	g L−1 day−1
Chl a	Chlorophyll a concentration	mg L−1
I phin24	Daily integral light intensity	molph·m−2·day−1
D	Dilution rate	h−1
η	Harvesting efficiency	%
HRT	Hydraulic retention time	day
q	Liquid flow	L day−1
C N	Nitrogen concentrations	mg L−1
N	OD of a predetermined wavelength	abs
p N	Percentage removal of nitrogen	%
Y ph	Photosynthetic efficiency	g molph−1
A r	Reactor surface area	m2
r N	Removal rate of nitrogen	mg L−1 day−1
μ	Specific growth rate	h−1
SVR	Surface to volume ratio	m−1
t	Time	day (or h)
V R	Volume of the recovered solution	L