Equilibrium, kinetics and thermodynamics of lead (II) adsorption in bioadsorvent composed by Caryocar coriaceum Wittm barks

• Published in: Chemosphere (Oxford) Vol. 261; p. 128144
• Main Authors: Menezes, Jorge Marcell Coelho, da Silva Bento, Amanda Maria, da Silva, João Hermínio, de Paula Filho, Francisco José, da Costa, José Galberto M., Coutinho, Henrique Douglas M., Pereira Teixeira, Raimundo Nonato
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2020
• Subjects: Bioadsorption; Bioremediation; Pequi’s bark; Toxic metal; Bioadsorption; Pequi’s bark; Toxic metal; Bioremediation
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.128144

The improper disposal of waste containing toxic metals promotes serious environmental problems. Biosorption stands out as a powerful technique in removing toxic metals from aqueous solutions, making it an efficient and low-cost technique, since it makes use of abundant materials and of natural origins. This work aimed to study the application of the bark of Caryocar coriaceum Wittm, as a possible bioabsorbent for the removal of Lead (II) present in aqueous solutions, for this, residues of this material were collected in a public market, where they were washed and dried, then crushed, sieved (32mesh) and washed again, to then be used in the kinetic, isotherm and thermodynamic tests of lead (II) ions adsorption. After the experiments, it was found that the increase of the temperature disfavored the rate of lead (II) adsorption, ranging from 15.6 to 13.5 mg.L−1, for temperatures of 5 °C and 35 °C, respectively. The pseudo-second order kinetic model best characterizes the adsorption velocity obtaining a linear regression coefficient of 0.9997, while the pseudo-first order obtained a value of 0.7117. Adsorption occurred by chemisorption, with intra-film diffusion. The isothermal model that best represented the adsorption was Langmuir’s (R2 0.99). It was concluded that the bark of Caryocar coriaceum Wittm is a good alternative to be used as a bioabsorbent for solutions containing dissolved lead (II). •Caryocar coriaceum Wittm bark is a good bioadsorbent for solutions with Pb(II) ions.•Caryocar coriaceum Wittm bark has high adsorptive capacity compared to other natural unmodified adsorbents.•The use of Caryocar coriaceum Wittm bark tailings, as adsorbent, can minimize the amount of waste being sent to landfills.•Caryocar coriaceum Wittm bark is an abundant and low-cost material to be used as a absorbent.