ABSTRACT: Tamarind fruit shell was used as a low-cost biosorbent for the removal of methylene blue from aqueous solution. The various
factors affecting adsorption, such as agitation, pH, initial dye concentration, contact time, and temperature, were investigated.
The dye adsorption capacity was strongly dependent on solution pH as well as temperature. The Langmuir isotherm model showed
good fit to the equilibrium adsorption data, and the maximum adsorption capacity obtained was 1.72mgg−1 at 303K. The kinetics of adsorption followed the pseudo-second-order model and the rate constant increased with increase
in temperature, indicating endothermic nature of adsorption. The Arrhenius equation was used to obtain the activation energy
a) for the adsorption system. The activation energy was estimated to be 19.65kJmol−1. Thermodynamic parameters such as Gibbs free energy (ΔG
0), enthalpy (ΔH
0), and entropy (ΔS
0) were also investigated. Results suggested that adsorption of methylene blue onto tamarind fruit shell was a spontaneous
and endothermic process. The present investigation suggests that tamarind fruit shell may be utilized as a low-cost adsorbent
for methylene blue removal from aqueous solution.
KeywordsTamarind fruit shell-Methylene blue-Isotherm-Kinetics-Thermodynamics
Water Air and Soil Pollution 04/2012; 213(1):287-299. · 1.63 Impact Factor