Abstract
In this study, Moringa oleifera seed extract was applied as coagulant under different pH values (2.5 - 9.5), coagulant dosages
(200-600 mg/L), initial dye concentrations (50-300 mg/L) and different settling times (0- 60 minutes) for R. Blue 19 and R. Red
120 dyes removal. Results revealed that with increase in pH (from 2.5 to 9.5), removal efficiency decreased from 95% to 87.3%
for R. Blue 19 and from 97.2% to 62% for R. Red 120. By increasing coagulant dosage to 400 mg/L, removal efficiencies
increased up to 93% for both dyes. Higher dosages (more than 400 mg/L) could not achieve more than 93% removal of the dyes.
No suspension of formed flocs nor desorption of the dyes was observed after long settling times up to 24 hours. Moringa oleifera
did not change the pH of solution through experiments. This natural coagulant revealed a high capacity in reactive dyes removal.