Adsorption Properties of Mahogani (Swietenia Mahogani) Leaf Powder: Removal of Acid Dyes from Aqueous Solution.

Abstract

The Mahogani (Su'itenic, Mahogani) leaf treated with used as an adsorbent for the sulphuric acid and !'formaldehyde were removal of Reactive yellow C8G and Reactive red MSB de from aqueous solution. The adsorption characteristics of reactive dyes on activated Mahogani leaf powder (MLP) were evaluated as a function of p1-I, adsorbent dose and initial concentration of adsorhate. The amount of dye adsorbed per unit weight of the adsorbent increased with the increase of concentration and contact time. The adsorption was favored by an acidic p1-I range for Reactive red but not significant change for reactive yellow dyes. The adsorption processes were best described by a second-order rate equation. Reactive Yellow and Reactive Red dyes adsorption on MLP agreed with both Langmuir and Freundlich isotherms. The isotherm plots showed that the Freundlich equation gave slightly better linearity than the l.angmuir equation (R 0.94 for Langmuir plots; R 0.99 for Freundlich plots) indicating the MLP surfoce to be heterogeneous in the long range, but having some amount of uniformity locally. Langmuir monolayer adsorption capacity ((1ni) decreased from 67.11 to 11 .93 mg/g br reactive vehlo\v and from 12.39 to 2.09 mg/g for reactive red. MLP amount varying from 0.5 to 1.0 g/L. Ihe adsorption equilibrium parameter, for reactive yellow. h. varied from 0.028 to 0.034 L!mg with the increase in MLP amount and similar trend observed for reactive red. 'l'he adsorption capacity, k fshowed a decrease from 143.52 to 19.76 L/g with increase in MLP amount Irom 0.5 to 1.0 g/L, Similar results found for reactive red dye. The adsorption affinity. 11. lies between 0.21 and 0.27 satisfying the condition a < I for favorable adsorption.