The temperature, DO and pH were measured with the multiparameter probe ODEON (SNODOEA-0175), an oxygen
sensor (SN-PODOA-0180) and a pH sensor (SN-PPHRA-0144) respectively.
The concentrations of the dissolved nitrogen species (NH4+, NO2, NO3) and PO43 were determined using an Ion Chromatograph (DIONEX LC25-LC20).
The anions were separated using an Ion Pac AS11-HC analytical column and NaOH (30 mM Dionex
LC25) as eluent. The cations were separated using an IonPac CS12A analytical column and methanesulfonic acid (20 mN
Dionex LC20) as eluent.
The particulate nitrogen content (N) of the biomass was determined by elemental analysis (Organic Elemental
Analyzer FLASH 2000CHNS/O, base unit operated with helium).
TSS
and VSS were determined by filtration of the suspension and
heating
the solid at 105
C and at 550
C, respectively.
Microalgal
growth was monitored by measuring the total
chlorophyll
concentration (Chl; mg L
1
) during the experiment.
The
chlorophyll concentration was determined by a modified
method
proposed by Porra [23] with extraction of chlorophyll a
and
b with a 85% methanol aqueous solution containing 1.5 mM of
sodium
dithionite at 40
C. The chlorophyll concentration was
calculated
from the absorbance of the extracted solution at
650
and 664 nm (Spectrophotometer Cary 50 Scan UV–vis). Under
our
conditions, the chlorophyll and biomass (VSS) concentrations
were
well correlated (R
2
= 0.99) over the range observed in our
experiments
(50–400 mg/L).
The
apparentspecificgrowthrate(m)andthealgalbiomass
p