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1057254 
Journal Article 
FLY ASH ADSORBENTS FOR MULTI-CATION WASTEWATER TREATMENT 
Visa, M; Isac, L; Duta, A 
2012 
Yes 
Applied Surface Science
ISSN: 0169-4332 
258 
17 
6345-6352 
WOS:000303112100026 
Class "F" fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO2/Al2O3 over 2.4 proved good adsorbent properties, and was further used for obtaining a new substrate with good adsorption capacity for heavy metals from multi-cation wastewater treatment. Firstly, the new adsorbent was characterized by AFM, XRD, DSC, FTIR and the surface energy was evaluated by contact angle measurements. The experimental data suggested that the new type of substrate is predominant crystalline with highly polar surface.



The substrate was used for removing the Pb2+, Cd2+ and Zn2+ cations from mixed solutions. The results show high efficiency and selective adsorption the Pb2+ and Zn2+ cations.



The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The Langmuir and Freundlich models were used to describe the processes. The pseudo-second order kinetics could well model all the processes, indicating a surface concentration of the adsorption sites with the same order of magnitude as the cation concentrations. (C) 2012 Elsevier B.V. All rights reserved. 
Fly ash; Heavy metals; Adsorption; Wastewater treatment