Eco-friendly and biocompatible cross-linked carboxymethylcellulose hydrogels as adsorbents for the removal of organic dye pollutants for environmental applications.
Environ Technol
; 39(22): 2856-2872, 2018 Nov.
Article
en En
| MEDLINE
| ID: mdl-28805161
ABSTRACT
In this study, new eco-friendly hydrogel adsorbents were synthesized based on carboxymethylcellulose (CMC, degree of substitution [DS] = 0.7) chemically cross-linked with citric acid (CA) using a green process in aqueous solution and applied for the adsorption of methylene blue (MB). Spectroscopic analyses demonstrated the mechanism of cross-linking through the reaction of hydroxyl functional groups from CMC with CA. These CMC hydrogels showed very distinct morphological features dependent on the extension of cross-linking and their nanomechanical properties were drastically increased by approximately 300% after cross-linking with 20% CA (e.g. elastic moduli from 80 ± 15 to 270 ± 50â
MPa). Moreover, they were biocompatible using an in vitro cell viability assay in contact with human osteosarcoma-derived cells (SAOS) for 24â
h. These CMC-based hydrogels exhibited adsorption efficiency above 90% (24â
h) and maximum removal capacity of MB from 5 to 25â
mgâ
g-1 depending on the dye concentration (from 100 to 500â
mgâ
L-1), which was used as the model cationic organic pollutant. The adsorption of process of MB was well-fit to the pseudo-second-order kinetics model. The desorption of MB by immersion in KCl solution (3â
molâ
L-1, 24â
h) showed a typical recovery efficiency of over 60% with conceivable reuse of these CMC-based hydrogels. Conversely, CMC hydrogels repelled methyl orange dye used as model anionic pollutant, proving the mechanism of adsorption by the formation of charged polyelectrolyte/dye complexes.
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Banco de datos:
MEDLINE
Asunto principal:
Contaminantes Químicos del Agua
/
Contaminantes Ambientales
Límite:
Humans
Idioma:
En
Año:
2018
Tipo del documento:
Article