Multilayer adsorption of Cu(II) and Cd(II) over Brazilian Orchid Tree (Pata-de-vaca) and its adsorptive properties

Author(s)

Jorgetto, Alexandre de O. ^[1] ; da Silva, Adrielli C. P. ^[1] ; Wondracek, Marcos H. P. ^{[1, 2]} ; Silva, Rafael I. V. ^[1] ; Valini, Edivaldo D. ^[3] ; Saeki, Margarida J. ^[1] ; Pedrosa, Valber A. ^[1] ; Castro, Gustavo R. ^[1]

Affiliation

^[1] IB UNESP, Dept Quim & Bioquim, BR-18618000 Botucatu, SP - Brazil

^[2] FACET UFGD, BR-79804970 Dourados, MS - Brazil

^[3] FCA UNESP, Nucleo Pesquisas Avancadas Matol Nupam, BR-18610307 Botucatu, SP - Brazil

• Document type: Journal article
• Source: Applied Surface Science; v. 345, p. 81-89, AUG 1 2015.
• Web of Science Citations: 15

Abstract

Through very simple and inexpensive processes, pata-de-vaca leaves were turned into a powder and applied as an adsorbent for the uptake of Cu(II) and Cd(II) from water. The material was characterized through SEM, EDX, FTIR and surface area measurement. The material had its point of zero charge determined (5.24), and its adsorption capacity was evaluated as a function of time, pH and metal concentration. The material presented fast adsorption kinetics, reaching adsorption equilibrium in less than 5 min and it had a good correlation with the pseudo-second order kinetic model. Optimum pH for the adsorption of Cu(II) and Cd(II) were found to be in the range from 4 to 5, approximately. In the experiment as a function of the analyte concentration, analogously to gas adsorption, the material presented a type II isotherm, indicating the formation of multilayers for both species. Such behavior was explained with basis in the alternation between cations and anions over the material's surface, and the maximum adsorption capacity, considering the formation of the multilayers were found to be 0.238 mmol L-1 for Cu(II) and 0.113 mmol L-1 for Cd(II). (C) 2015 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 12/21795-9 - Incorporation of 4-Amino-3-hydrazino-5-mercapto-1,2,4-triazole onto mesoporous silica surface for trace Cu(II), Cd(II), Ni(II), Pb(II) e Co(II) determination in Tietê River water samples
• Grantee: Gustavo Rocha de Castro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/22955-2 - Synthesis of silica-titania and silica-titania-magnetite hybrids and their functionalization and sensitization with Fe3+ ions for the photodegradation of 4-chlorophenol under UV and visible light
• Grantee: Alexandre de Oliveira Jorgetto
• Support Opportunities: Scholarships in Brazil - Doctorate