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Advances in Environmental Research Volume 1, Number 3, September 2012 , pages 223-236 DOI: https://doi.org/10.12989/aer.2012.1.3.223 |
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Coconut husk as a biosorbent for methylene blue removal and its kinetics study |
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Shailesh R. Dave, Vaishali A. Dave and Devayani R. Tipre
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| Abstract | ||
| Biosorption of methylene blue (MB) from aqueous solution was studied with respect to the point of zero charge of coconut husk, dye concentration, particle size, pH, temperature, as well as adsorbent and NaCl concentration using coconut husk biomass. Amongst Langmuir and Freundlich adsorption isotherms studied, Langmuir adsorption isotherm showed better agreement. Pseudo second order kinetics model was found to be more suitable for data presentation as compared to pseudo first order kinetics model. Also, involvement of diffusion process was studied using intraparticle diffusion, external mass transfer and Boyd kinetic model. Involvement of intraparticle diffusion model was found to be more relevant (prominent) as compared to external mass transfer (in) for methylene blue biosorption by the coconut husk. Moreover, thermodynamic properties of MB biosorption by coconut husk were studied. Desorption of methylene blue from biomass was studied with different desorbing agents, and the highest desorption achieved was as low as 7.18% with acetone, which indicate stable immobilization. Under the experimental conditions MB sorption was not significantly affected by pH, temperature and adsorbent concentration but low sorption was observed at higher NaCl concentrations. | ||
| Key Words | ||
| methylene blue; biosorption; adsorption isotherm; coconut husk; kinetic models | ||
| Address | ||
| Shailesh R. Dave, Vaishali A. Dave and Devayani R. Tipre: Department of Microbiology and Biotechnology, School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat, India | ||
