Microalgae settling was evaluated in settling column tests with and
without flocculant addition. Firstly, a column test was performed without
flocculant (control). Afterwards, two tests per week (one for each
flocculant) were performed over 1 month, obtaining 4 replicates for
each flocculant.Mixed liquor turbidity varied over the experimental period,
average values of 294 and 378 NTU were obtained for Tanfloc and
Ecotan samples, respectively. As described in Section 2 Material and
methods, recovery percentages at different time intervals were calculated
from turbidity measurements before and after settling at different
times and column depths.