COD removals were recorded for HRT higher than 2 days
(Fig. 11). The optimum HRT was detected as 3 days for the
total sequential system.
The Reactive Black 5 removal efficiencies obtained in
this study are comparable higher than those obtained by
Luangdilok and Panswad [5], Nigam et al. [13], Ganesh
et al. [17] and Beydilli et al. [16]. Nigam et al. [13], found
67% color removal for 50 mg l−1 of Reactive Black 5 dye
within 24 h in a batch reactor containing yeast extract as
the carbon source. A 68% color removal efficiency was
obtained after 48 h of incubation period when glucose is
used as carbon source [16]. A 79% color removal efficiency