Foods and Raw Materials Foods and Raw Materials Foods and Raw Materials 2308-4057 2310-9599 65001 10.21603/2308-4057-2024-1-587 Research Article Research Article Research Article Composite exopolysaccharide-based hydrogels extracted from Nostoc commune V. as scavengers of soluble methylene blue Composite exopolysaccharide-based hydrogels extracted from Nostoc commune V. as scavengers of soluble methylene blue https://orcid.org/0000-0003-0595-8747 Herrera Nora Gabriela Herrera Nora Gabriela nherrera@unfv.edu.pe https://orcid.org/0000-0001-9499-3792 Villacrés Nelson Adrián Villacrés Nelson Adrián https://orcid.org/0000-0001-9358-7688 Aymara Lizbeth Aymara Lizbeth https://orcid.org/0000-0002-6614-3632 Román Viviana Román Viviana https://orcid.org/0000-0002-9143-4060 Ramírez Mayra Ramírez Mayra Federico Villarreal National University Lima Перу Federico Villarreal National University Lima Peru National University of Engineering Lima Перу National University of Engineering Lima Peru Federico Villarreal National University Lima Перу Federico Villarreal National University Lima Peru Federico Villarreal National University Lima Перу Federico Villarreal National University Lima Peru Federico Villarreal National University Lima Перу Federico Villarreal National University Lima Peru 13 02 2024 13 02 2024 12 1 37 46 26 12 2022 07 02 2023 https://jfrm.ru/en/issues/21683/21692/

The industrial water contamination with synthetic dyes is currently a cause for concern. This paper introduces composite hydrogels as alternative scavengers of soluble dyes. This research used kinetic models and adsorption isotherms to test composite exopolysaccharide hydrogels extracted from Nostoc commune V., pectin, and starch for their ability to remove methylene blue from water. The exopolysaccharides demonstrated a rather low extraction yield and a crystallinity percentage of 38.21%. However, the crystallinity increased in the composite hydrogels (48.95%) with heterogeneous surface. The pseudo-second-order kinetic model served to explain the adsorption mechanism at pH 8 and pH 11, while the Elovich model explained the adsorption mechanism at pH 5. When in acid fluid, the hydrogels had a heterogeneous surface, whereas alkaline fluid resulted in a homogeneous surface. The Temkin adsorption model showed a good fit in the treatments. At a basic pH value, composite exopolysaccharide-based hydrogels showed good results as scavengers of low-concentration methylene blue.

The industrial water contamination with synthetic dyes is currently a cause for concern. This paper introduces composite hydrogels as alternative scavengers of soluble dyes. This research used kinetic models and adsorption isotherms to test composite exopolysaccharide hydrogels extracted from Nostoc commune V., pectin, and starch for their ability to remove methylene blue from water. The exopolysaccharides demonstrated a rather low extraction yield and a crystallinity percentage of 38.21%. However, the crystallinity increased in the composite hydrogels (48.95%) with heterogeneous surface. The pseudo-second-order kinetic model served to explain the adsorption mechanism at pH 8 and pH 11, while the Elovich model explained the adsorption mechanism at pH 5. When in acid fluid, the hydrogels had a heterogeneous surface, whereas alkaline fluid resulted in a homogeneous surface. The Temkin adsorption model showed a good fit in the treatments. At a basic pH value, composite exopolysaccharide-based hydrogels showed good results as scavengers of low-concentration methylene blue.

 Hydrogel removal methylene blue adsorption exopolysaccharide Nostoc commune V. Hydrogel removal methylene blue adsorption exopolysaccharide Nostoc commune V. This research was supported by the Vice-Rectorate for Research of the Federico Villarreal National University (UNFV) as part of The Basic and Applied Research Projects Competition CANON 2019, project No. 5784-2019-CU-UNFV. This research was supported by the Vice-Rectorate for Research of the Federico Villarreal National University (UNFV) as part of The Basic and Applied Research Projects Competition CANON 2019, project No. 5784-2019-CU-UNFV.

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