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“Waste” Jute Fiber, an agricultural “waste” by-product was converted into an effective adsorbent and the same was tested for the removal of Malathion pesticide from aqueous solution. The prepared activated Jute fiber carbon (JFC) was characterized by using Scanning Electron microscope (SEM), X-ray diffractometer (XRD), Elemental analyzer and proximate analysis methods. Adsorption equilibrium, kinetics, thermodynamics and mass transfer studies were investigated as a function of agitation time, adsorbent dose, pH and temperature. The adsorption data obtained are found to obey Langmuir isotherm model. The adsorption kinetics was analyzed by using pseudo first order, pseudo second order and Elovich models. Thermodynamic parameters of adsorption process, i.e. ?G, ?S and ?H were computed and their negative values indicate the adsorption was exothermic and spontaneous nature.

A lignocellulose-based waste biopolymer was impregnated with phosphoric acid and used for the removal of two organic dyes, Direct Blue (DB) and Reactive Blue (RB), from aqueous solution. Batch adsorption kinetic studies were carried out at different initial concentrations of the dyes, at different temperatures and various initial pH values (2-10). The equilibrium data obeyed the Langmuir isotherm model with high regression coefficient. The kinetic data were also used to test three different kinetic models. The validity of the kinetic models was analyzed and the pseudo-second-order model may be the best fit to explain the rate-determining step. Adsorption of both dyes follows chemisorption. The effective diffusion coefficient and the activation energy were also calculated at different temperatures to establish the mechanism. Thermodynamic studies suggest that the adsorption of DB and RB is highly endothermic in nature. Mass transfer analysis reveals that the adsorption of DB and RB occurs through a film diffusion mechanism. Based on the Langmuir isotherm equation, the single-stage batch absorber design of the adsorption of DB and RB onto activated carbon was studied.