Kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen-doped achatinidae chitin as adsorbent

Emerging contaminants such as chlorhexidine (CHX), pose significant environmental and health-related challenges because of they have high toxicity index and are persistent in water. This study investigates the adsorptive uptake of CHX from an aqueous medium using nitrogen-doped achatinidae chitin ad...

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Main Authors: Marcel I. Ejimofor, Matthew C. Menkiti
Format: Article
Language:English
Published: Elsevier 2025-07-01
Series:Next Materials
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Online Access:http://www.sciencedirect.com/science/article/pii/S2949822825003405
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author Marcel I. Ejimofor
Matthew C. Menkiti
author_facet Marcel I. Ejimofor
Matthew C. Menkiti
author_sort Marcel I. Ejimofor
collection DOAJ
description Emerging contaminants such as chlorhexidine (CHX), pose significant environmental and health-related challenges because of they have high toxicity index and are persistent in water. This study investigates the adsorptive uptake of CHX from an aqueous medium using nitrogen-doped achatinidae chitin adsorbent (N-ASCA), synthesized from discarded achatinidae shells. The N-ASCA was prepared under a nitrogen atmosphere. N-ASCA surface area increased from 2.85 m²/g to 132.15 m²/g after calcination. The FTIR analysis revealed the presence of functional groups such as hydroxyl, carbonyl, and amide. The XRD revealed a strong crystallinity. The maximum adsorption efficiency of 91 % was obtained at a pH of 8. The adsorption process followed pseudo-second-order kinetics with R2 value of 0.999. Langmuir model described the isotherm data with precision. The process thermodynamics infer spontaneity with ΔG = -2.79 kJ/mol at 308 K and endothermicity with ΔH = 75.9 kJ/mol. Electrostatic and π-π interactions were found as the mechanistic pathway for chlorohexidine uptake. Post-adsorption XRD analysis revealed new peaks that show successful uptake of chlorhexidine. This was confirmed by the presence of nitrogen and chlorine peaks in the elemental composition of the spent adsorbent obtained via SEM-EDX. Hence, N-ASCA is a sustainable, cost-effective adsorbent for addressing CHX contamination.
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spelling doaj-art-5347060fc88841cdbf8bd70e42dbf9372025-08-20T03:30:45ZengElsevierNext Materials2949-82282025-07-01810082210.1016/j.nxmate.2025.100822Kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen-doped achatinidae chitin as adsorbentMarcel I. Ejimofor0Matthew C. Menkiti1Corresponding author.; Chemical Engineering Department, Nnamdi Azikiwe University Awka, Anambra State, NigeriaChemical Engineering Department, Nnamdi Azikiwe University Awka, Anambra State, NigeriaEmerging contaminants such as chlorhexidine (CHX), pose significant environmental and health-related challenges because of they have high toxicity index and are persistent in water. This study investigates the adsorptive uptake of CHX from an aqueous medium using nitrogen-doped achatinidae chitin adsorbent (N-ASCA), synthesized from discarded achatinidae shells. The N-ASCA was prepared under a nitrogen atmosphere. N-ASCA surface area increased from 2.85 m²/g to 132.15 m²/g after calcination. The FTIR analysis revealed the presence of functional groups such as hydroxyl, carbonyl, and amide. The XRD revealed a strong crystallinity. The maximum adsorption efficiency of 91 % was obtained at a pH of 8. The adsorption process followed pseudo-second-order kinetics with R2 value of 0.999. Langmuir model described the isotherm data with precision. The process thermodynamics infer spontaneity with ΔG = -2.79 kJ/mol at 308 K and endothermicity with ΔH = 75.9 kJ/mol. Electrostatic and π-π interactions were found as the mechanistic pathway for chlorohexidine uptake. Post-adsorption XRD analysis revealed new peaks that show successful uptake of chlorhexidine. This was confirmed by the presence of nitrogen and chlorine peaks in the elemental composition of the spent adsorbent obtained via SEM-EDX. Hence, N-ASCA is a sustainable, cost-effective adsorbent for addressing CHX contamination.http://www.sciencedirect.com/science/article/pii/S2949822825003405Emerging contaminantChlorohexidineAchatenodaeChitinAdsorption
spellingShingle Marcel I. Ejimofor
Matthew C. Menkiti
Kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen-doped achatinidae chitin as adsorbent
Next Materials
Emerging contaminant
Chlorohexidine
Achatenodae
Chitin
Adsorption
title Kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen-doped achatinidae chitin as adsorbent
title_full Kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen-doped achatinidae chitin as adsorbent
title_fullStr Kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen-doped achatinidae chitin as adsorbent
title_full_unstemmed Kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen-doped achatinidae chitin as adsorbent
title_short Kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen-doped achatinidae chitin as adsorbent
title_sort kinetics and mechanistic modeling of chlorhexidine uptake from aqueous solution using nitrogen doped achatinidae chitin as adsorbent
topic Emerging contaminant
Chlorohexidine
Achatenodae
Chitin
Adsorption
url http://www.sciencedirect.com/science/article/pii/S2949822825003405
work_keys_str_mv AT marceliejimofor kineticsandmechanisticmodelingofchlorhexidineuptakefromaqueoussolutionusingnitrogendopedachatinidaechitinasadsorbent
AT matthewcmenkiti kineticsandmechanisticmodelingofchlorhexidineuptakefromaqueoussolutionusingnitrogendopedachatinidaechitinasadsorbent