Spectroscopic investigation of Cu2+, Pb2+ and Cd2+ adsorption behaviors by chitosan-coated argillaceous limestone: Competition and mechanisms.
Environ Pollut
; 254(Pt A): 112938, 2019 Nov.
Article
em En
| MEDLINE
| ID: mdl-31404731
ABSTRACT
In the present study, the competitive adsorption of Cu2+, Pb2+, and Cd2+ by a novel natural adsorbent (i.e., argillaceous limestone) modified with chitosan (C-AL) was investigated. The results demonstrated that both intraparticle diffusion and chemisorption marked significant contributions to the Cu2+ adsorption process by both raw argillaceous limestone (R-AL) and C-AL in mono-metal adsorption systems. Antagonism was found to be the predominant competitive effect for Cu2+, Pb2+ and Cd2+ adsorptions by C-AL in the multi-metal adsorption system. The three-dimensional simulation and FTIR analysis revealed that the presence of Cu2+ suppressed Pb2+ and Cd2+ adsorptions, while the effect of Cd2+ on Cu2+ and Pb2+ adsorptions was insignificant. The spectroscopic analyses evidenced that amide groups in C-AL played a crucial role in metal adsorption. The preferential adsorptions of Pb2+â¯>â¯Cu2+â¯>â¯Cd2+ were likely due to the different affinities of the metals to the lone pair of electrons on the N atom from the amide groups and/or the O atoms from the -OH and -COO- groups on C-AL. The interactions between C-AL and metal ions and between various metal species influenced their competitive adsorption behaviors. C-AL exhibited a superior metal adsorption capacity in comparison with that the capacities of other natural adsorbents reported during the last decade, suggesting its potential practical applications.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Cádmio
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Carbonato de Cálcio
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Cobre
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Quitosana
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Recuperação e Remediação Ambiental
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Chumbo
Idioma:
En
Revista:
Environ Pollut
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
China