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Research article - Peer-reviewed, 2022

Removal of diphenols using pine biochar. Kinetics, equilibrium, thermodynamics, and mechanism of uptake

Cimirro, Nilton F.G.M.; Lima, Eder C.; Cunha, Mariene R.; Thue, Pascal S.; Grimm, Alejandro; Simões Dos Reis, Glaydson; Rabiee, Navid; Saeb, Mohammad Reza; Keivanimehr, Farhad; Habibzadeh, Sajjad


Thermal pyrolysis synthesized activated biochar from the Pinus elliottii sawdust (PS) at 600 & DEG; C. The obtained activated biochar (PB600) was used for the removal of three diphenols, catechol (CAT), resorci-nol (RES), and hydroquinone (HYD), which are utilized mainly in different industries. The PB600 was characterized by several analytical techniques. The BET surface area of 1473 m(2).g(-1) and a total pore vo-ume of 0.707 cm(3) g(-1) was obtained. The functional groups and amount of acidic and basic groups on the biochar were determined by FTIR and Bohem titration, respectively. From the isotherm studies, it was obtained that the maximum adsorption capacities (Qmax) based on the Liu isotherm model were 419.8 (CAT 45 ?), 263.8 (RES 40 ?), and 500.9 mg g-1 (HYD 25 ?). The values of thermodynamic parameters demonstrated that CAT, RES, and HYD adsorption processes were spontaneous, exothermic, and energet-ically favorable, and the magnitude of DH & DEG; was compatible with physisorption. The CAT, RES, and HYD adsorption mechanism onto the biochar is followed by porous filling, 7C -7C interactions, and hydrogen bonds. Subsequently, PB600 biochar was employed as a potential adsorbent for treating simulated indus-trial effluents in a complex matrix simulating a real industrial effluent, and the overall removal attained up to 95.97 %. In concert with the experimental results, the electronic properties of the developed adsorp-tion systems, including frontier molecular orbitals, charge density difference, and partial density of states, were studied by the density functional theory (DFT) approach to explore the mechanism of adsorption on the activated biochar surface.(c) 2022 Elsevier B.V. All rights reserved.


Diphenols; Biochar; Simulated effluents; DFT calculation

Published in

Journal of Molecular Liquids
2022, Volume: 364, article number: 119979