title: Equilibrium and intra-particle diffusion of stabilized landfill leachate onto micro- and meso-porous activated carbon.
abstract: Stabilized landfill leachate has previously been treated with activated carbon (AC); however, information on the selectivity of AC depending upon the pore size is minimal. Isotherm and kinetic experiments were conducted using three commercially available AC products, one micro-porous and two meso-porous. Equilibrium adsorption and intra-particle diffusion of organic matter from stabilized leachate was studied. Isotherm experimental data were fitted to Langmuir, Freundlich, and Redlich-Peterson isotherm models in non-linear forms. Of the three isotherm models, the Redlich-Peterson model provided the best fit to the experimental data and showed a similar organic matter adsorption capacity (approximately 0.2 g total organic carbon (TOC) g(-1) AC) for both micro-porous and meso-porous AC. The organic matter effective intra-particle diffusion coefficients (D(e)) in both AC types were on the order of 10(-10) m(2) s(-1) for AC particle sizes greater than 0.5 mm. Meso-porous ACs showed slightly higher D(e) compared to micro-porous AC. Rapid small-scale tests showed a maximum of 80% TOC removal from leachate by each AC investigated. Fluorescence spectroscopy showed a preferential adsorption of fulvic-type organic matter with an increase in empty bed contact time by each AC.
authors: Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA.
authors: Shrawan K
authors: SK
authors: Singh
authors: Timothy G
authors: TG
authors: Townsend
authors: David
authors: D
authors: Mazyck
authors: Treavor H
authors: TH
authors: Boyer
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D004058:Diffusion; D005431:Florida; D005453:Fluorescence; D008954:Models, Biological; D016062:Porosity; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D002606:Charcoal