| dc.description.abstract | In this study, the potential use of coconut dregs as the biosorbent for the removal of
Methylene Blue (MB) (basic dye) and Brilliant Red Remazol (BRR) (acidic dye) was
investigated. The effects of adsorption time, adsorbent dosage, pH, and initial dye
concentration on coconut dregs adsorption for MB dye and BRR dye were investigated
during the batch mode adsorption study. The results indicated that the amount of dye
adsorbed on the coconut dregs increased with increasing dye concentration, adsorbent
dosage, and adsorption time. However, both MB and BRR dyes favor different pH for the
adsorption process. The adsorption capacity of MB dye increased with increasing pH while
the adsorption capacity of BRR dye increased with decreasing pH. For Methylene Blue
dye, the most effective of color removal was optimum at pH 11, contact time of 240 min,
dosage of 0.25 g adsorbent, and with initial dye concentration of 50 mg/L. Meanwhile, for
Brilliant Red Remazol dye, the most effective of color removal was optimum at pH 2,
contact time of 180 min, dosage of 0.25 g adsorbent, and with initial dye concentration of
50 mg/L. The Langmuir and Freundlich adsorption models were used to evaluate the
isotherm constants at 25°C. The equilibrium data for both dyes fitted very well with
Langmuir Isotherm equation giving maximum monolayer adsorption capacity as high as
5.7208 mg/g and 3.7636 mg/g for Methylene Blue Dye and Brilliant Red Remazol dye,
respectively. The modeling of the kinetics of dyes adsorption onto coconut dregs was
investigated using two common models; the pseudo-first-order model and pseudo-secondorder
model. Methylene Blue dye follows the second-order-adsorption model while the
Brilliant Red Remazol dye follows the first-order-adsorption model. | en_US |
