The present study shows that the natural shellfish
shells, an abundant low cost prawn waste, can be used
as adsorbent for the removal of MB dye from aqueous
solutions. The findings are: (1) The amount of dye
adsorbed was found as function of initial pH, adsorbent
dose, dye concentration and contact time. (2) The adsorption
equilibrium data were found to fit the Langmuir
isotherm, indicating a monolayer adsorption on a
homogenous surface. (3) Lagergren pseudo-first-order,
second order and intra-particle diffusion models can be
used to predict the adsorption kinetics. (4) The adsorption
mechanism was deduced with the help of mean
free energy E. And (5) The adsorption efficiency of
APR is greater than RPR for adsorption of MB from
aqueous solution.