Reportedly, magnesium hydroxide Mg(OH)2 and calcium
hydroxide Ca(OH)2 can flocculate algae culture broth. Thus, the
sedimentation efficiency is shown in (Chen et al., 2013) to achieve
97.4% after 10 min of settling Scenedesmus sp. with pH at 11.5
without flocculants added. Using sodium hydroxide with pH at
11 to flocculate Botryococcus braunii was much more efficient than
the processing with aluminum sulfate and polysaccharide flocculant
of bacterial origin (Lee et al., 1998).