The feasibility of using the mixture of
seawater and municipal wastewater; (1) the wastewater before activated
sludge tank, just after primary settling (BAS) and (2) the wastewater
after activated sludge tank, just before addition of polymer flocculants
(AAS); as culture medium for the cultivation of marine microalgae Nannochloropsis oculata was investigated.

10%
BAS, 20% BAS and 10% AAS, 20% AAS, 50% AAS, 70% AAS, 100% AAS effluent
loadings were well adapted to used wastewater. Sufficient dry weights
obtained (345–406 mg L⁻¹) with growth rates 0.37–0.45 for
aerated cultures. High TN and TP removals (∼74–90%) were achieved.
Harvesting technique for grown cultures was also studied with natural
sedimentation and pH induced flocculation. By alkalinity induced
flocculation, at pH values of 10.50, high recovery of the cells (∼80%)
achieved with high sedimentation rates in 10 min. The flocculation efficiencies decreased, sedimentation rates increased with the increase of the cell concentration.