RT Journal Article
T1 Removal of Cd(II), Pb(II) and Cr(III) from water using modifed residues of Anacardium occidentale L
A1 Coelho, Gustavo Ferreira
A1 Gonçalves Jr., Afonso Celso
A1 Schwantes, Daniel
A1 Álvarez Rodríguez, Esperanza
A1 Tarley, César Ricardo Teixeira
A1 Dragunski, Douglas
A1 Conradi Junior, Élio
K1 Biosorbent
K1 Biosorption
K1 Metal adsorption
K1 Remediation
K1 Water pollution
AB The pollution of water has been one of the greatest problems faced by the modern society, due to industrialization and urban growth. Rivers, lakes and seas have been continually suffering from the rising concentration of various pollutants, especially toxic elements. This study aimed to evaluate the use of cashew nut shell (Anacardium occidentale) (CNS), after chemical modification with H2O2, H2SO4 and NaOH, as an new and renewable adsorbent material, for the removal of metals Cd2+, Pb2+ and Cr3+ in aqueous medium. The adsorbents were characterized by its chemical constitution, structure, infrared spectroscopy, morphology, by means of scanning electron microscopy, determination of the point of zero charge, thermogravimetrical analysis and porosimetry assessments. Tests were conducted to determine the optimal conditions (pH vs. adsorbent mass) for adsorption, by means of multivariate analysis using a central composite design. The adsorption kinetics was evaluated by models of pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion, while adsorption isotherms were linearized by Langmuir, Freundlich and Dubinin–Radushkevich. The effect of initial concentration, temperature and desorption was also performed. The adsorbents exhibited irregular, spongy and heterogeneous structure. FTIR analysis confirms the presence of hydroxyl, aliphatic, phenolic and carboxylic acid groups, which are favorable adsorption characteristics. The pHPZC of adsorbent is 4.35, 2.50 e 6.92, respectively, for CNS H2O2, H2SO4 and NaOH. The optimum adsorption conditions were as follows: pH 5.0; relation of adsorbent mass/volume of water: 4 g L−1; 40 min of contact time for reaching the equilibration. Results suggest the predominance of chemisorption of Cd2+ and Cr3+. Most of biosorbents exhibited good fit by Langmuir and Freundlich, suggesting the occurrence of adsorption on mono- and multilayers. The adsorbents of cashew nut shell exhibited high removal efficiency of Cd, Pb and Cr from waters
PB Springer
SN 2190-5487
YR 2018
FD 2018
LK http://hdl.handle.net/10347/22281
UL http://hdl.handle.net/10347/22281
LA eng
NO Coelho, G.F., Gonçalves, A.C., Schwantes, D. et al. Removal of Cd(II), Pb(II) and Cr(III) from water using modified residues of Anacardium occidentale L.. Appl Water Sci 8, 96 (2018). https://doi.org/10.1007/s13201-018-0724-8
NO To Capes and CNPq for the funding of this research
DS Minerva
RD 28 abr 2026