Removal of 2,4-D from aqueous solutions by adsorption processes using two biopolymers: chitin and chitosan and their optical properties
| Autor: | Yahia Boughaleb, M. Rhazi, E. Daoudi, L. El Gaini, H. El Harmoudi, M.A. El Mhammedi, Anna Migalska-Zalas, Mina Bakasse |
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| Rok vydání: | 2014 |
| Předmět: |
Aqueous solution
fungi Organic Chemistry technology industry and agriculture Infrared spectroscopy macromolecular substances engineering.material Chemical reaction Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials carbohydrates (lipids) Inorganic Chemistry Chitosan chemistry.chemical_compound Adsorption Chitin chemistry engineering Organic chemistry Biopolymer Electrical and Electronic Engineering Physical and Theoretical Chemistry Cellulose Spectroscopy Nuclear chemistry |
| Zdroj: | Optical Materials. 36:1471-1477 |
| ISSN: | 0925-3467 |
| DOI: | 10.1016/j.optmat.2014.03.040 |
| Popis: | Chitin, extracted primarily from exoskeleton shellfish, is one of the most abundant biopolymer in the world. It is estimated to be produced annually almost as much as cellulose. The development of fishing activities in Morocco (coastline of 3500 km on both the Atlantic and the Mediterranean) induced an important fish industry waste. The aim of this work is to recover chitin, extracted from shellfish waste, and chitosan, produced by deacetylation of chitin, in the adsorption of organic pesticide 2,4-dichlorophenoxyacetate (2,4-D). The chitosan samples were prepared from chitin from crustacean shells. The chitin deacetylation was carried out in aqueous sodium hydroxide. Characterization of chitin and chitosan was performed by infrared spectroscopy, nuclear magnetic resonance and theoretical calculation of UV–Vis spectra and optical parameters. Analysis of theoretical spectra shows a substantial sensitivity to the hydroxyl and amino groups. The presented hydroxyl group in chitin determines the conformation of the molecule and also the stereochemistry of chemical reactions and kinetics. The presence of functional groups causes the substantial changes of both absorption spectra as well as permanent dipole moment. The adsorption of 2,4-D by chitin and chitosan was performed at different pH values, the pesticide-adsorbent contact time and initial pesticide concentration. The adsorption is described by Langmuir-type isotherm and Freundlich-type isotherm. Recovery tests of 2,4-D confirm the initial interest in using chitin and chitosan as a depolluting agent. |
| Databáze: | OpenAIRE |
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