Résumés
Résumé
L’avancement industriel et technologique à l'échelle mondiale a introduit des polluants de natures diverses dans l'eau. Les polluants peuvent être des contaminants organiques et des métaux lourds. Leur présence dans des effluents industriels où l'eau potable est un problème de santé publique en raison de leur absorption et, par la suite, leur accumulation dans l’organisme humain. Les règlements de pollution de l'eau exigent que les industries textiles réduisent considérablement la quantité de colorants dans leurs rejets. L'adsorption, procédé de traitement des eaux usées, exploite la capacité de quelques solides pour concentrer certaines substances sur leurs surfaces. Généralement, l’adsorbant le plus utilisé pour le traitement des effluents textiles est le charbon activé. La capacité de la bentonite pour enlever la couleur a été reconnue il y a quelque temps. Dans ce travail, nous avons étudié la cinétique d’adsorption d’un colorant acide, le rouge de Congo, en solution aqueuse sur un matériau argileux naturel (bentonite) dans un processus en lots. La concentration initiale du colorant était de 30 mg•L‑1 déterminée par une méthode spectrophotométrique. L’influence de certains paramètres, comme la vitesse d’agitation, la masse d’argile en solution, la concentration initiale du colorant et la granulométrie a été étudiée. Les résultats ont montré pour la vitesse d’adsorption : (i) une augmentation avec la vitesse d’agitation et la masse d’argile et, (ii) une décroissance avec la concentration initiale en colorant et la granulométrie. Cinq modèles de transport externe ont été étudiés et ont montré que l’ordre de grandeur du coefficient, kf, se trouve dans la gamme de 10‑5 à 10‑4•ms‑1.
Mots clés:
- Adsorption,
- Cinétique,
- Transport externe,
- Colorant,
- Argile
Abstract
Industrial growth and technological advancement have led globally to the introduction of pollutants of diverse nature into water bodies. Such pollutants include dyes, organic contaminants and heavy metals. Their presence in industrial effluents or drinking water is a public health problem, due to their absorption and possible accumulation in living organisms. Water pollution regulations require textile dye industries to reduce substantially the amount of colour in their effluents. Adsorption, as a wastewater treatment process, exploits the ability of some solids to concentrate certain substances from solution onto their surface. The most commonly used adsorbent for the treatment of textile effluents is activated carbon. The ability of bentonite to remove colour was recognized some time ago. Batch adsorption experiments are used easily in the laboratory for the treatment of small volumes of effluents. Batch adsorption provides certain preliminary information such as the pH for maximum adsorption, the maximum initial dye concentration, the particle size for optimum adsorption, the mass of adsorbent, the temperature and time of the separation process. Experiments were conducted in this study using bentonite. The dye used in all experiments was Congo red. The initial dye concentration was 30 mg•L‑1 and was determined spectrophotometrically at the wavelength of maximum absorbance. The time required to reach equilibrium was about 2 h. The effect of agitation, initial dye concentration, mass of adsorbent and mean particle diameter were investigated. It appears that the rate of dye removal: (i) increased with the agitation speed and mass of adsorbent and, (ii) decreased with the initial dye concentration and the particle size. Five models for external transport were used to calculate the external mass transfer coefficient, kf, and the results showed that this coefficient is in the range of 10‑5-10‑4•ms‑1.
Key words:
- Adsorption,
- Kinetics,
- External transport,
- Dyes,
- Clay
Parties annexes
Références bibliographiques
- AHMED, A.A. et B.H. HAMEED (2010). Fixed bed adsorption of reactive azo dye onto granular activated carbon prepared from waste. J. Hazard. Mater., 175, 298-303.
- ALIAN, X., Z. SHOUYONG, Z. YIJIANG, L. XIAOPING et H. PINGFAN (2010). Adsorption of reactive dyes from aqueous solution by silylated palygorskite. Appl. Clay Sci., 48, 638-640.
- ALLEN, S.J. et B. KOUMANOVA (2005). Decolourisation of water/wastewater using adsorption. J. Univ. Chem. Technol. Metal., 40, 175-192.
- ALKAN, M., O. DEMIRBAS et M. DOGAN (2007). Adsorption kinetics and thermodynamics of an anionic dye onto sepiolite. Micropor. Mesopor. Mater., 101, 388-396.
- BAGANE, M. et S. GUIZA (2000). Élimination d’un colorant des effluents de l’industrie textile par adsorption. Ann.Chim. Sci. Mater., 25, 615-626.
- BAGANE, M. et S. GUIZA (2002). Étude du transport externe au cours de l’adsorption du bleu de méthylène sur argile naturelle. Entropie, 242, 115-127.
- BALLAY, D. et J.-F. BLAIS (1998). Le traitement des eaux usées. Rev. Sci. Eau, N° spécial, 77-86.
- BHATNAGAR, A. et A.K. MINICHA (2006). Conventional and non-conventional adsorbents for removal of pollutants from water. Indian J. Chem. Technol.,13, 203-217.
- BULUT, E., M. OZACAR et I.A.SENGIL (2008). Equilibrium and kinetic data and process design for adsorption of Congo red onto bentonite. J. Hazard. Mater., 154, 613-622.
- CHI, M.A. et R.A. EGGLETON (1999). Cation exchange capacity of kaolinite. Clays Clay Miner, 47, 174-180.
- CHI EL GEUNDI, M. (1997). Adsorbents for industrial pollution control. Adsorp. Sci. Technol., 15, 777-787.
- CHOY, K.K.H., D.C.K. Ko, C.W. CHUN, J.F. PORTER et G. Mc KAY (2004). Film and intraparticle mass transfer during the adsorption of metal ions onto bone char. J. Colloid Interface Sci., 271, 284-295.
- COONEY, D.O. (1991). Determining external film mass transfer coefficient for adsorption columns. AICHE J., 37, N°8, 1270-1274.
- EL GEUNDI, M. (1990). External mass transport processes during the adsorption of basic dyestuffs onto maize cob. Adsorp. Sci. Technol., 7, 124-132.
- FURUSAWA, T. et J.S. SMITH (1973). Fluid-particle and intraparticle mass transport rates inslurries. Ind. Eng.Chem. Fundam., 12, 197-202.
- FURUSAWA, T. et J.S. SMITH (1973). Diffusivities from dynamic adsorption data. AIChE J., 19, 401-405.
- GEANKOPLIS, C.J. (2003). Transport processes and separationprocesses principles. Prentice Hall, Upper Saddle River, NJ, USA.
- GHOSH, D. et K.G. HATTACHARYYA (2002). Adsorption of methylene blue on kaolinite. Appl. Clay Sci., 20, 295-300.
- GIRARD, P. (1981). Les allergies aux colorants. Schweiz Rundschau Med., Praxis, 70, 1891-1892.
- GORDON, Mc., B.J. MURAD et A. ALTEMIMI (1986). External mass transfer during the adsorption of various pollutants onto activated carbon. Water Res., 20, 435-442.
- GORDON, Mc., M. EL GEUNDI et M.M. NASSER (1987). Equilibrium studies during the removal of dyestuffs from aqueous solutions using bagasse pith. Water Res., 21,1513-1520.
- GORDON, Mc., M. EL GEUNDI et M.M. NASSAR (1996). Pore-diffusion during the adsorption of dyes onto bagasse pith. Proc. Safety Environ. Protec.,Institution of Chemical Engineers (Éditeur), Rugby, Royaume-Uni, 74, 277-288.
- GORDON, Mc. et M. EL GEUNDI (1988). External mass transport processes during the adsorption of dyes onto bagasse pith. Water Res., 22,1527-1533.
- GORDON, Mc. et S.J. ALLEN (1980). Surface mass transfer processes using peat as an adsorbent of dyestuffs. Can J. Chem. Eng., 58, 521-526.
- GUIZA, S. et M. BAGANE (2004). Equilibrium studies for the adsorption of dyes on natural clay. Ann. Chim. Sci. Mater., 29, 615-626.
- GUIZA, S., M. BAGANE, A.H. AL-SOUDANI et H. BEN AMOR (2004). Adsorption of basic dyes onto natural clay. Adsorp. Sci. Technol., 15, 251-270.
- KAOUA, F., A. GAID et H. AIT AMMAR (1987). Cinétique d'adsorption du BM sur différents types d'argiles kaoliniques. Bull. Soc. Chim. Fr., 4, 581-587.
- KHARAB, A. et R.B. UENTHER (2006). An introduction to numerical methods, a matlab approach. Second Edition, Taylor and Francis Group, Chapman et Hall, CRC Press, USA, 608 p.
- KRIFA, F., A. AISSA, M. JERRAY et M. KALLEL (1990). Les colorants utilisés en Tunisie et leurs consommateurs : Étude clinique. Rev. Fr. Allergol. Immunol. Clin., 30, 7-15.
- LIAN, L., L. GUO, C. GUO (2009). Adsorption of Congo red from aqueous solutions onto Ca-bentonite. J. Hazard. Mater., 161, 126-131.
- MALL, I.D., C. SRIVASTAVA et N.K. AGARWAL (2006). Removal of orange-G and methyl violet dyes by adsorption onto bagasse fly ash-kinetic study and equilibrium isotherm analyses. Dyes Pigm., 60, 210-223.
- MATHEWS, A.P. et W.J WEBER (1976). Physical, chemical wastwater treatment. AICHE J., 73, 91-98.
- NEVINE, K.A. (2008). Removal of reactive dye from aqueous solutions by adsorption onto activated carbons prepared from sugarcane bagasse pith. Desalination, 223, 152-161.
- ÖZDEMIR, Y., M. DOGAN et M. ALKAN (2006). Adsorption of cationic dyes from aqueous solutions by sepiolite. Micropor. Mesopor. Mater., 96, 419-427.
- PERINEAU, F., J. MOLINIER et A. GASET (1983). Adsorption de colorants cationiques sur le déchet lainier de carbonisage. Water Res., 17, 559-567.
- RADCLIFF, D.F., L.J. LENG et G. THOMAS (1982). Direct measurement of external mass transfer in packed sorbent beds. AICHE J., 28, 344-442.
- RANZ, W.E. et W.R. MARSHALL (1952). Evaporation from drops. Chem. Ing. Progr., 48, 141-146.
- REYAD, A.S. et M.F. TUTUNJI (2003). Experimental study and modeling of basic dye sorption by diatomaceous clay. Appl. Clay Sci., 24, 111-120.
- RODRIGUEZ, A., J. GARCIA, G. OVEJEROG et M. MESTANZA (2009). Adsorption of anionic dyes on activated carbon from aqueous solution: Equilibrium and kinetics. J. Hazard. Mater., 172, 1311-1320.
- SCHOONHEYDT, R.A et C.T. JOHNSTON (2006). Surface and interface chemistry of clay minerals. Dans : Development in Clay Science. F. Bergaya, B.K.G. Theng et G. Lagaly (Éditeurs), Elsevier, Amsterdam, vol. 1, pp. 87-113.
- TIEN, C. (1994). Adsorption calculations and modelling. Butterworth-Heinemann Series, Chemical Engineering, Oxford, UK, 244 p.
- TREYBAL R.E (1981). Mass transfer operations. 3e édition, Mc Graw-Hill, New York, 35 p.
- UDDIN, M.T., M. RAKUNUZZAMAN, M.M. KHAN et M.A. ISLAM (2009). Adsorption of MB from aqueous solution by jakfruit (Artocarpus heteropyllus) leaf powder: Fixed bed column study. J. Environ. Manage., 60, 3443-3450.
- VIMONSES, V., B. JIN, C.W. CHOW et C. SAINT (2009a). Enhancing removal efficiency of anionic dye by combination and calcination of clay materials and calcium hydroxide. J. Hazard. Mater., 171, 941-947.
- VIMONSES, V., L. SHAMOMIN, B. JIN, C.W.K. CHOW et C. SAINT (2009b). Adsorption of Congo red by three Australian kaolins. Appl. Clay Sci., 43, 465-472.
- ZOHRE, S., S.G. ATALLAH et A. MEHDI (2010). Experimental study of methylene blue adsorption from aqueous solutions onto carbon nano tubes. Int. J. Resour. Environ. Eng., 2, 16-28.