Sequestration of Methylene Blue from aqueous solution by cellulose of Sand box (Hura crepitans L.) seed shells

Abstract

The capacity of cellulose from sand box (Hura crepitans) (HC) seed shells for the
removal of Methylene blue dye from aqueous solutions was examined. FTIR and
XRD analysis showed functional groups and crystalline nature of the cellulose.
Utilising Scanning Electron Microscopy (SEM), the porosity of the adsorbent was
examined. Using 0.5 g mass of the adsorbent at pH 12.0, initial dye concentration
of 20 mgL-1, contact period of 120 min and temperature of 25 °C, the adsorption
parameters showed the greatest dye removal effectiveness of 98.41%. The kinetic
models of Pseudo-First order, Pseudo-Second order and Intra-particle diffusion
were used. Whereas the Langmuir, Freundlich, Temkin, and Dubinin-
Radushkevich isotherms were used to fit the equilibrium data. The kinetic data
best suited the Pseudo-Second order model, whereas the Langmuir isotherm most
accurately reflected the equilibrium data. Thermodynamic parameters observed
are ΔHo (1.550 kJmol-1), ΔSo (1.846 Jmol-1K-1) and ΔG° (1.013 kJmol-1),
respectively. Methylene blue adsorption is endothermic and spontaneous,
according to these values. 93.05% of the adsorbent was recovered according to the
desorption study. Thus, cellulose derived from Hura crepitans (HC) is a very
effective choice for adsorbents used in the removal of pollutants and dyes in
solution.