Introduction:

Coals obtained by "chemical" activation of national production can be used as ion adsorbents with a high technical index.

Objective:

To obtain activated carbon with good adsorptive properties from sugarcane, bamboo and marabou bagasse, which allows the removal of Pb (II) ions from aqueous solutions.

Materials and Methods:

Activated coals with sugarcane bagasse (BC), marabou (M) and bamboo (B) are prepared to adsorb Pb (II). BC, M and B are carbonized at 400 °C for 1 hour, activated with phosphoric acids and modified with nitric acid with subsequent heating. The kinetic and diffusive models of pseudo first order, pseudo second order, Elovich, liquid film diffusion, intraparticle diffusion, Bangham model and effective diffusivity are applied. Thermodynamic parameters are determined as variation of free energy.

Results and Discussion:

For all three products, the pseudo-first order kinetic model adjusts to the applied determination coefficient. The apparent adsorption rate constant is highest in bagasse and lowest in bamboo. The equilibrium constant is the greatest in bamboo and the lowest in marabou. As for the isosteric heat, it is the highest (modular) for bagasse and the lowest for marabou. Marabou has the highest adsorption capacity of 111.15 mg/g.

Conclusions:

Carbon obtained by "chemical" activation of bamboo is the one that presents the best result as an adsorbent, whose adsorption capacity is 111.15 mg/g.

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