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ABSTRACT: Batch and column kinetics of methylene blue adsorption on calcium chloride, zinc chloride, magnesium chloride and sodium chloride treated beech sawdust were simulated, using untreated beech sawdust as control, in order to explore its potential use as a low-cost adsorbent for wastewater dye removal. The adsorption capacity, estimated according to Freundlich's model, the Langmuir constant K(L) and the adsorption capacity coefficient values, determined using the Bohart and Adams' bed depth service model indicate that salts treatment enhanced the adsorption properties of the original material. Since sawdust is an industrial waste/byproduct and the salts used can be recovered as spent liquids from various chemical operations, this process of adsorbent upgrading/modification might be considered to take place within an 'Industrial Ecology' framework.
Journal of Hazardous Materials 11/2007; 149(1):8-17. · 4.17 Impact Factor
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ABSTRACT: The batch and column kinetics of methylene blue and red basic 22 adsorption on mild acid-hydrolysed beech sawdust were investigated, using untreated beech sawdust as control, in order to explore its potential use as a low cost adsorbent for wastewater dye removal. The adsorption capacities, estimated according to Freundlich's model, and the adsorption capacity coefficient values, determined using the Bohart and Adams' bed depth service model, indicated that prehydrolysis enhances the adsorption properties of the original material. This enhancement can possibly be attributed to (a) the removal of the hemicelluloses during sulphuric acid treatment, resulting in the 'opening' of the lignocellulosic matrix's structure and the increasing of the BET surface area and (b) the activation of the material's surface owing to an increase in the number of dye binding sites.
Bioresource Technology 05/2007; 98(6):1208-17. · 4.98 Impact Factor
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ABSTRACT: The effect of pH on the batch kinetics of methylene blue adsorption on beech sawdust was simulated, in order to evaluate sawdust potential use as low cost adsorbent for wastewater dye removal. The zero point of charge pH(pzc) of the sawdust, in order to explain the effect of pH in terms of pH(pzc), was measured by the mass titration and the automatic titration methods. The adsorption capacity, estimated according to Freundlich's model, indicate that increase of the pH enhances the adsorption behaviour of the examined material. The lower adsorption of methylene blue at acidic pH is due to the presence of excess H(+) ions that compete with the dye cation for adsorption sites. As the pH of the system increases, the number of positively charged sites decreases while the number of the negatively charged sites increases. The negatively charged sites favour the adsorption of dye cation due to electrostatic attraction. The increase in initial pH from 8.0 to 11.5 increases the amount of dye adsorbed.
Journal of Hazardous Materials 04/2007; 141(3):668-79. · 4.17 Impact Factor
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ABSTRACT: Batch and column kinetics of methylene blue and red basic 22 adsorption on CaCl(2) treated beech sawdust was investigated, using untreated beech sawdust as control, in order to explore its potential use as a low-cost adsorbent for wastewater dye removal. The adsorption capacity, estimated according to Freundlich's model, and the adsorption capacity coefficient values, determined using the Bohart and Adams' bed depth service model indicate that CaCl(2) treatment enhanced the adsorption properties of the original material.
Journal of Hazardous Materials 10/2004; 114(1-3):167-74. · 4.17 Impact Factor
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[show abstract]
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ABSTRACT: Batch and column kinetics of methylene blue adsorption on calcium chloride, zinc chloride, magnesium chloride and sodium chloride treated beech sawdust were simulated, using untreated beech sawdust as control, in order to explore its potential use as a low-cost adsorbent for wastewater dye removal. The adsorption capacity, estimated according to Freundlich's model, the Langmuir constant KL and the adsorption capacity coefficient values, determined using the Bohart and Adams’ bed depth service model indicate that salts treatment enhanced the adsorption properties of the original material. Since sawdust is an industrial waste/byproduct and the salts used can be recovered as spent liquids from various chemical operations, this process of adsorbent upgrading/modification might be considered to take place within an ‘Industrial Ecology’ framework.
Journal of Hazardous Materials.
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[show abstract]
[hide abstract]
ABSTRACT: The effect of pH on the batch kinetics of methylene blue adsorption on beech sawdust was simulated, in order to evaluate sawdust potential use as low cost adsorbent for wastewater dye removal. The zero point of charge pHpzc of the sawdust, in order to explain the effect of pH in terms of pHpzc, was measured by the mass titration and the automatic titration methods. The adsorption capacity, estimated according to Freundlich's model, indicate that increase of the pH enhances the adsorption behaviour of the examined material. The lower adsorption of methylene blue at acidic pH is due to the presence of excess H+ ions that compete with the dye cation for adsorption sites. As the pH of the system increases, the number of positively charged sites decreases while the number of the negatively charged sites increases. The negatively charged sites favour the adsorption of dye cation due to electrostatic attraction. The increase in initial pH from 8.0 to 11.5 increases the amount of dye adsorbed.
Journal of Hazardous Materials.
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ABSTRACT: The Animals (data)Base for Energy Potential Estimation (ABEPE), presented in this paper, is a GIS based biomass resource assessment application using a relational database management system to estimate biogas production from livestock manures. Energy and biogas potential of livestock residues of all major groups of stock-raising animals (cattle, pigs, sheep/goats, poultry, etc.) were evaluated. The calculations were based on geographical and time-depending data of Greece. Typical input data included population of animal groupings, by-product factors, availability factors, energy factors, etc. for the period 1970–1998. Output included manure production, available energy and biogas quantities. Furthermore, ‘ABEPE’ can perform time-depending prediction of all types of output, based on past and present trends. As a case example, the prediction results for the year 2010 are herein presented. The possibility of biogas upgrading in order to be distributed through the national natural gas network is also discussed.
Renewable Energy.
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ABSTRACT: Batch and column kinetics of methylene blue and red basic 22 adsorption on CaCl2 treated beech sawdust was investigated, using untreated beech sawdust as control, in order to explore its potential use as a low-cost adsorbent for wastewater dye removal. The adsorption capacity, estimated according to Freundlich's model, and the adsorption capacity coefficient values, determined using the Bohart and Adams’ bed depth service model indicate that CaCl2 treatment enhanced the adsorption properties of the original material.
Journal of Hazardous Materials.
