TY - JOUR
T1 - Alkaline Modification of Arabica-Coffee and Theobroma-Cocoa Agroindustrial Waste for Effective Removal of Pb(II) from Aqueous Solutions
AU - Lavado-Meza, Carmencita
AU - De la Cruz-Cerrón, Leonel
AU - Asencios, Yvan J.O.
AU - Marcos, Francielle Candian Firmino
AU - Dávalos-Prado, Juan Z.
N1 - Publisher Copyright:
© 2023 by the authors.
PY - 2023/1
Y1 - 2023/1
N2 - Arabica-coffee and Theobroma-cocoa agroindustrial wastes were treated with NaOH and characterized to efficiently remove Pb(II) from the aqueous media. The maximum Pb(II) adsorption capacities, qmax, of Arabica-coffee (WCAM) and Theobroma-cocoa (WCTM) biosorbents (qmax = 303.0 and 223.1 mg·g−1, respectively) were almost twice that of the corresponding untreated wastes and were higher than those of other similar agro-industrial biosorbents reported in the literature. Structural, chemical, and morphological characterization were performed by FT-IR, SEM/EDX, and point of zero charge (pHPZC) measurements. Both the WCAM and WCTM biosorbents showed typical uneven and rough cracked surfaces including the OH, C=O, COH, and C-O-C functional adsorbing groups. The optimal Pb(II) adsorption, reaching a high removal efficiency %R (>90%), occurred at a pH between 4 and 5 with a biosorbent dose of 2 g·L−1. The experimental data for Pb(II) adsorption on WACM and WCTM were well fitted with the Langmuir-isotherm and pseudo-second order kinetic models. These indicated that Pb(II) adsorption is a chemisorption process with the presence of a monolayer mechanism. In addition, the deduced thermodynamic parameters showed the endothermic (ΔH0 > 0), feasible, and spontaneous (ΔG0 < 0) nature of the adsorption processes studied.
AB - Arabica-coffee and Theobroma-cocoa agroindustrial wastes were treated with NaOH and characterized to efficiently remove Pb(II) from the aqueous media. The maximum Pb(II) adsorption capacities, qmax, of Arabica-coffee (WCAM) and Theobroma-cocoa (WCTM) biosorbents (qmax = 303.0 and 223.1 mg·g−1, respectively) were almost twice that of the corresponding untreated wastes and were higher than those of other similar agro-industrial biosorbents reported in the literature. Structural, chemical, and morphological characterization were performed by FT-IR, SEM/EDX, and point of zero charge (pHPZC) measurements. Both the WCAM and WCTM biosorbents showed typical uneven and rough cracked surfaces including the OH, C=O, COH, and C-O-C functional adsorbing groups. The optimal Pb(II) adsorption, reaching a high removal efficiency %R (>90%), occurred at a pH between 4 and 5 with a biosorbent dose of 2 g·L−1. The experimental data for Pb(II) adsorption on WACM and WCTM were well fitted with the Langmuir-isotherm and pseudo-second order kinetic models. These indicated that Pb(II) adsorption is a chemisorption process with the presence of a monolayer mechanism. In addition, the deduced thermodynamic parameters showed the endothermic (ΔH0 > 0), feasible, and spontaneous (ΔG0 < 0) nature of the adsorption processes studied.
KW - Pb(II) removal
KW - agroindustrial waste
KW - biosorption
KW - heavy metals
UR - http://www.scopus.com/inward/record.url?scp=85146766464&partnerID=8YFLogxK
U2 - 10.3390/molecules28020683
DO - 10.3390/molecules28020683
M3 - Original Article
C2 - 36677741
AN - SCOPUS:85146766464
SN - 1420-3049
VL - 28
JO - Molecules
JF - Molecules
IS - 2
M1 - 683
ER -