Biomass production in waste water
The laboratory experiments indicated that E. gracilis and Selenastrum sp. had a
higher capacity to produce biomass than C. pyrenoidosa. C. pyrenoidosa had
usually higher maximum cell numbers than the two other strains but the cells were
small and thus biomass production remained low. On the other hand, C. pyrenoidosa
was stable in variable culture conditions while the growth of other strains wasmore sensitive. For example, although in a 10% dilution of process water all species
grew well, in a 50% dilution growth of E. gracilis and Selenastrum was poor.
In reject water, survival of E. gracilis cells was very weak.
Our measurements also revealed that Selenastrum was capable of consuming
nutrients very rapidly at the beginning of the cultivation when growth was vigorous.
Thus, algae have potential for waste water purification and the processes of biomass
production and water purification can be combined if the waste water is
otherwise suitable for algae cultivation.