Reduced Chitosan as a Strategy for Removing Copper Ions from Water
Toxic heavy metals are priority pollutants in wastewater, commonly present in dangerous concentrations in many places across the globe. Although in trace quantities copper is a heavy metal essential to human life, in excess it causes various diseases, whereby its removal from wastewater is a necessi...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-05-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/28/10/4110 |
| _version_ | 1827740564983906304 |
|---|---|
| author | Pedro M. C. Matias Joana F. M. Sousa Eva F. Bernardino João P. Vareda Luisa Durães Paulo E. Abreu Jorge M. C. Marques Dina Murtinho Artur J. M. Valente |
| author_facet | Pedro M. C. Matias Joana F. M. Sousa Eva F. Bernardino João P. Vareda Luisa Durães Paulo E. Abreu Jorge M. C. Marques Dina Murtinho Artur J. M. Valente |
| author_sort | Pedro M. C. Matias |
| collection | DOAJ |
| description | Toxic heavy metals are priority pollutants in wastewater, commonly present in dangerous concentrations in many places across the globe. Although in trace quantities copper is a heavy metal essential to human life, in excess it causes various diseases, whereby its removal from wastewater is a necessity. Among several reported materials, chitosan is a highly abundant, non-toxic, low-cost, biodegradable polymer, comprising free hydroxyl and amino groups, that has been directly applied as an adsorbent or chemically modified to increase its performance. Taking this into account, reduced chitosan derivatives (RCDs 1–4) were synthesised by chitosan modification with salicylaldehyde, followed by imine reduction, characterised by RMN, FTIR-ATR, TGA and SEM, and used to adsorb Cu(II) from water. A reduced chitosan (RCD3), with a moderate modification percentage (43%) and a high imine reduction percentage (98%), proved to be more efficient than the remainder RCDs and even chitosan, especially at low concentrations under the best adsorption conditions (pH 4, <i>R</i><sub>S/L</sub> = 2.5 mg mL<sup>−1</sup>). RCD3 adsorption data were better described by the Langmuir–Freundlich isotherm and the pseudo-second-order kinetic models. The interaction mechanism was assessed by molecular dynamics simulations, showing that RCDs favour Cu(II) capture from water compared to chitosan, due to a greater Cu(II) interaction with the oxygen of the glucosamine ring and the neighbouring hydroxyl groups. |
| first_indexed | 2024-03-11T03:27:35Z |
| format | Article |
| id | doaj.art-a3105c9ab96f425d95c50424adf9a8ac |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-11T03:27:35Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-a3105c9ab96f425d95c50424adf9a8ac2023-11-18T02:39:24ZengMDPI AGMolecules1420-30492023-05-012810411010.3390/molecules28104110Reduced Chitosan as a Strategy for Removing Copper Ions from WaterPedro M. C. Matias0Joana F. M. Sousa1Eva F. Bernardino2João P. Vareda3Luisa Durães4Paulo E. Abreu5Jorge M. C. Marques6Dina Murtinho7Artur J. M. Valente8University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, PortugalUniversity of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, PortugalUniversity of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, PortugalUniversity of Coimbra, CIEPQPF, Department of Chemical Engineering, 3030-790 Coimbra, PortugalUniversity of Coimbra, CIEPQPF, Department of Chemical Engineering, 3030-790 Coimbra, PortugalUniversity of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, PortugalUniversity of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, PortugalUniversity of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, PortugalUniversity of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, PortugalToxic heavy metals are priority pollutants in wastewater, commonly present in dangerous concentrations in many places across the globe. Although in trace quantities copper is a heavy metal essential to human life, in excess it causes various diseases, whereby its removal from wastewater is a necessity. Among several reported materials, chitosan is a highly abundant, non-toxic, low-cost, biodegradable polymer, comprising free hydroxyl and amino groups, that has been directly applied as an adsorbent or chemically modified to increase its performance. Taking this into account, reduced chitosan derivatives (RCDs 1–4) were synthesised by chitosan modification with salicylaldehyde, followed by imine reduction, characterised by RMN, FTIR-ATR, TGA and SEM, and used to adsorb Cu(II) from water. A reduced chitosan (RCD3), with a moderate modification percentage (43%) and a high imine reduction percentage (98%), proved to be more efficient than the remainder RCDs and even chitosan, especially at low concentrations under the best adsorption conditions (pH 4, <i>R</i><sub>S/L</sub> = 2.5 mg mL<sup>−1</sup>). RCD3 adsorption data were better described by the Langmuir–Freundlich isotherm and the pseudo-second-order kinetic models. The interaction mechanism was assessed by molecular dynamics simulations, showing that RCDs favour Cu(II) capture from water compared to chitosan, due to a greater Cu(II) interaction with the oxygen of the glucosamine ring and the neighbouring hydroxyl groups.https://www.mdpi.com/1420-3049/28/10/4110reduced chitosanadsorptioncopper ionswater purification |
| spellingShingle | Pedro M. C. Matias Joana F. M. Sousa Eva F. Bernardino João P. Vareda Luisa Durães Paulo E. Abreu Jorge M. C. Marques Dina Murtinho Artur J. M. Valente Reduced Chitosan as a Strategy for Removing Copper Ions from Water Molecules reduced chitosan adsorption copper ions water purification |
| title | Reduced Chitosan as a Strategy for Removing Copper Ions from Water |
| title_full | Reduced Chitosan as a Strategy for Removing Copper Ions from Water |
| title_fullStr | Reduced Chitosan as a Strategy for Removing Copper Ions from Water |
| title_full_unstemmed | Reduced Chitosan as a Strategy for Removing Copper Ions from Water |
| title_short | Reduced Chitosan as a Strategy for Removing Copper Ions from Water |
| title_sort | reduced chitosan as a strategy for removing copper ions from water |
| topic | reduced chitosan adsorption copper ions water purification |
| url | https://www.mdpi.com/1420-3049/28/10/4110 |
| work_keys_str_mv | AT pedromcmatias reducedchitosanasastrategyforremovingcopperionsfromwater AT joanafmsousa reducedchitosanasastrategyforremovingcopperionsfromwater AT evafbernardino reducedchitosanasastrategyforremovingcopperionsfromwater AT joaopvareda reducedchitosanasastrategyforremovingcopperionsfromwater AT luisaduraes reducedchitosanasastrategyforremovingcopperionsfromwater AT pauloeabreu reducedchitosanasastrategyforremovingcopperionsfromwater AT jorgemcmarques reducedchitosanasastrategyforremovingcopperionsfromwater AT dinamurtinho reducedchitosanasastrategyforremovingcopperionsfromwater AT arturjmvalente reducedchitosanasastrategyforremovingcopperionsfromwater |