- Gazi University Journal of Science
- Vol: 25 Issue: 1
- Removal of Direct Red 81 Dye from Aqueous Solution by Native and Citric Acid Modified Bamboo Sawdust...
Removal of Direct Red 81 Dye from Aqueous Solution by Native and Citric Acid Modified Bamboo Sawdust - Kinetic Study and Equilibrium Isotherm Analyses
Authors : Imran Ali, Sarita Dahiya, Tabrez Khan
Pages : 59-87
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Publication Date : 2012-01-24
Article Type : Other
Abstract :Adsorption of Direct Red 81 (DR81) dye was investigated using Bamboo Sawdust (BSD) and Treated Bamboo Sawdust (TBSD) in a batch system with respect to initial dye concentration, adsorbent dose, pH, temperature and contact time. Maximum adsorption capacity ( q m ) obtained from the Langmuir isotherm plots were 6.43 mg/g (89%) (DR81-BSD) and 13.83 mg/g (92%) (DR81-TBSD) at 303 K. Freundlich and Halsey models described the data more appropriately as compared to Langmuir, Dubinin-Kaganer-Radushkevich (DKR), Harkin-Jura and Temkin models. The adsorption dynamics conformed well to pseudo-second order kinetic equation. The adsorption process was controlled by both liquid-film and intra-particle diffusions. Thermodynamic parameters ( Δ G o , Δ H o and Δ S o ) suggested the adsorption process to be spontaneous, endothermic with increase in randomness at solid-solution interface.Keywords : Treated Bamboo Sawdust, adsorption, isotherm, kinetic, intra-particle diffusion