Biosorption of crystal violet from aqueous solution by pearl millet powder: Isotherm modelling and kinetic studies

Environmental pollution caused by industrial effluents is an important issue. Biosorption of crystal violet (CV) from aqueous solution using pearl millet powder (PMP) was investigated in a batch mode. The use of pearl millet powder was as an additional substitution of activated carbon for the adsorption of CV from its aqueous solution. The adsorbent pearl millet powder was productively used for the biosorption of dye from its aqueous solution. The effect of initial concentration for CV, sorption time, dose of adsorbent, pH and temperature on dye removal were studied. The equilibrium sorption isotherms have been analyzed by the Freundlich, Langmuir and Temkin models. Sorption kinetic is quick and the data agree well with pseudo-first order kinetic model. But the kinetics studies were provided with Pseudo second order. The adsorption capacity (Qo) of PMP was found to be 48.535 mg/g. Thermodynamic parameters such as the free energy change (ΔGo), enthalpy change (ΔHo) and entropy change (ΔSo) were determined from Van’t Hoff plot. The data reported shows the adsorption process is endothermic in nature.