Dye removal from aqueous solution by base activated corn cobs powder from adamawa region of Cameroon

The study concerns the adsorption of methylene blue which is an organic dye by the corn cobs activated at the base powder (BACCP). The analysis of the time parameter allowed us to determine the adsorption equilibrium time which is 15min. The maximum adsorption capacity obtained is 11.904 mg / g at a normal pH of 6.5 and at the temperature of 25 °C. Experimental data are analyzed by the Freundlich and Temkin isotherms. The kinetic model of pseudo second order and Elovich were applied with the correlation coefficients of R2 is more than 0.99. The reactions are made according to the models of pseudo second order and Elovich suggesting the hypothesis that the mechanism of the reactions are done in three phases: • The diffusion of the MB towards the surface of the adsorbent; • The diffusion of the MB into pores ; • The interaction between the adsorbate molecules (MB) and the surface of the adsorbent. And that adsorption sites increase exponentially with adsorption, which implies multilayer adsorption. Thermodynamic parameters have shown that MB adsorption on corn cobs is spontaneous (ΔG˂0), endothermic (ΔH˃0) and physical in nature (ΔH˃50 KJ/mol) (Djidel, 2011) in the temperature range of 298K and 338K.