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 L1
) 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.
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