In the present study, microalgal bi

In the present study, microalgal biomass term is referred to the
microalgal–bacterial biomass grown in the HRAP. The biomass concentration
of the HRAP mixed liquor ranged from 0.06 to 0.6 g TSS/L over
the year and consisted of consortia of microalgae as well as bacteria,
microalgae accounting for much of the biomass (over 90% of the biomass
according to [19]). Average microalgal biomass production was
9.4 g TSS/m2·day, However, without flocculants, harvested biomass
corresponded to approximately 5 g TSS/m2·day, since 45% of the produced
biomass escaped fromthe settler. The biomasswas characterized
by an average VS/TS ratio of 60% VS/TS, beingmost of the organicmatter
in particulate form as indicated by the low VSS/VS (0.89%) and CODs/
COD (0.72%) ratios. During the experimental period,microalgal population
was mainly composed by green algae belonging to genus
Monoraphidium sp., Scenedesmus sp. and Stigeoclorium sp. and the diatoms
Nitzchia sp., Navicula sp. and Amphora sp. (Fig. 1).