Chitosan/carboxymethylcellulose polyelectrolyte complexes (PECs) are an effective material for dye and heavy metal adsorption from water

Danielle Cristine Mota Ferreira; Thaís Cristina Dos Santos; Jane Sélia Dos Reis Coimbra; Eduardo Basílio de Oliveira

doi:10.1016/j.carbpol.2023.120977

Chitosan/carboxymethylcellulose polyelectrolyte complexes (PECs) are an effective material for dye and heavy metal adsorption from water

Carbohydr Polym. 2023 Sep 1:315:120977. doi: 10.1016/j.carbpol.2023.120977. Epub 2023 May 4.

Authors

Danielle Cristine Mota Ferreira¹, Thaís Cristina Dos Santos², Jane Sélia Dos Reis Coimbra³, Eduardo Basílio de Oliveira⁴

Affiliations

¹ Equipe de Estudo de Materiais Alimentares (E(2)MA), Departamento de Tecnologia de Alimentos (DTA), Universidade de Viçosa (UFV), CEP 36570-900 Viçosa, MG, Brazil. Electronic address: danielle.mota@ufv.br.
² Equipe de Estudo de Materiais Alimentares (E(2)MA), Departamento de Tecnologia de Alimentos (DTA), Universidade de Viçosa (UFV), CEP 36570-900 Viçosa, MG, Brazil.
³ Laboratório de Operações Unitárias (LOP), Departamento de Tecnologia de Alimentos (DTA), Universidade de Viçosa (UFV), CEP 36570-900 Viçosa, MG, Brazil.
⁴ Equipe de Estudo de Materiais Alimentares (E(2)MA), Departamento de Tecnologia de Alimentos (DTA), Universidade de Viçosa (UFV), CEP 36570-900 Viçosa, MG, Brazil. Electronic address: eduardo.basilio@ufv.br.

PMID: 37230616
DOI: 10.1016/j.carbpol.2023.120977

Abstract

Granular macroscopic chitosan/carboxymethylcellulose polyelectrolytic complexes (CHS/CMC macro-PECs) were produced and tested as adsorbents for six pollutants often present in wastewaters: sunset yellow (YS), methylene blue (MB), Congo red (CR) and safranin (S), cadmium (Cd²⁺) and lead (Pb²⁺). The optimum adsorption pH values at 25 °C were 3.0, 11.0, 2.0, 9.0, 10.0, and 9.0 for YS, MB, CR, S, Cd²⁺, and Pb²⁺, respectively. Kinetic studies indicated that the pseudos-econd order model best represented the adsorption kinetics of YS, MB, CR, and Cd²⁺, whereas the pseudo-first order model was the most suitable for S and Pb²⁺ adsorption. The Langmuir, Freundlich, and Redlich-Peterson isotherms were fitted to experimental adsorption data, with the Langmuir model providing the best fit. The maximum adsorption capacity (q_máx) of CHS/CMC macro-PECs for the removal of YS, MB, CR, S, Cd²⁺, and Pb²⁺ was 37.81, 36.44, 70.86, 72.50, 75.43, and 74.42 mg/g, respectively (corresponding to 98.91 %, 94.71 %, 85.73 %, 94.66 %, 98.46 %, and 97.14 %). Desorption assays showed that CHS/CMC macro-PECs can be regenerated after adsorbing any of the six pollutants studied, with possibility of reuse. These results provide an accurate quantitative characterization of the adsorption of organic and inorganic pollutants on CHS/CMC macro-PECs, indicating a novel technological applicability of these two inexpensive, easy-to-obtain polysaccharides for water decontamination.

Keywords: Anionic dyes; Cationic dyes; Charged polysaccharides; Pollutants; Transition metal cations; Wastewater treatment.