naa a22 4500 510750656 CHVBK 20180411083103.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1007/s11270-013-1466-8 doi (NATIONALLICENCE)springer-10.1007/s11270-013-1466-8 Study of Natural Clay Adsorbent Sepiolite for the Removal of Caffeine from Aqueous Solutions: Batch and Fixed-Bed Column Operation [Elektronische Daten] [José Sotelo, Gabriel Ovejero, Araceli Rodríguez, Silvia Álvarez, Juan García] Sepiolite reveals as a low-cost and efficient adsorbent for the adsorption of caffeine from aqueous solutions. The characterization of this material was carried out by N2 adsorption-desorption at 77K, Fourier transform infrared spectroscopy, thermogravimetric analysis, and electronic microscopy. Initially, batch adsorption experiments were developed in order to determine the equilibrium time and the adsorption isotherm of the system. Pseudo-first-order, Elovich equation, pseudo-second-order, and intra-particle diffusion models were applied to the experimental data to determine the adsorption kinetics. In continuous adsorption, the influence of several operation conditions (initial caffeine concentration, volumetric flow rate, and mass of adsorbent) on the shape of breakthrough curves and the mass transfer resistance was evaluated. Experimental data were fitted to the bed-depth service-time model bed-depth service-time (BDST). Through the calculation of the adsorption, parameters as breakthrough time or caffeine removal percentage can be concluded that the removal of this compound from aqueous solutions by adsorption in sepiolite beds is an alternative technique to the current methods, in order to eliminate this micropollutant. Springer Science+Business Media Dordrecht, 2013 Adsorption nationallicence Caffeine nationallicence Emerging contaminant nationallicence Fixed-bed nationallicence Sepiolite nationallicence α : Elovich model initial adsorption rate, milligrams per gram per hour nationallicence b : Langmuir adsorption equilibrium constant, liters per milligram nationallicence β : Elovich model desorption constant, grams per milligram nationallicence C 0 : Adsorbate inlet concentration, milligrams per liter nationallicence C : Adsorbate concentration at any time, milligrams per liter nationallicence C b : Adsorbate concentration at breakthrough time, milligrams per liter nationallicence C e : Equilibrium adsorbate concentration, milligrams per liter nationallicence D : Diffusion coefficient, square centimeters per hour nationallicence E : Mean free energy of adsorption, kilojoules per mole nationallicence ε : Polanyi potential nationallicence FBU : Fractional bed utilization nationallicence K : Dubinin-Radushkevich constant, moles squared per kilojoules squared nationallicence k AB : BDST model adsorption rate constant, liters per milligram per hour nationallicence K F : Freundlich constant, milligrams per gram nationallicence k 1 : Pseudo-first-order model rate adsorption constant, per hour nationallicence k 2 : Pseudo-second-order model rate adsorption constant, grams per milligram per hour nationallicence k i : Intra-particle diffusion model rate parameter, milligram per gram per half hour nationallicence MTZ : Mass transfer zone, centimeter nationallicence n F : Freundlich constant nationallicence N 0 : BDST model adsorption capacity, milligrams per liter nationallicence Q : Volumetric flow rate, millimeters per minute nationallicence Q m : Dubinin-Radushkevich maximum adsorption capacity, moles per gram nationallicence q : Adsorption capacity at any time, milligrams per gram nationallicence q b : Breakthrough adsorption capacity, milligrams per gram nationallicence q e : Adsorption capacity at equilibrium, milligrams per gram nationallicence q s : Saturation adsorption capacity, milligrams per gram nationallicence q sat : Langmuir maximum adsorption capacity, milligrams per gram nationallicence r 0 : Radius of the adsorbent particle, centimeters nationallicence R : Gas constant, Joules per mole Kelvin nationallicence R L : Separation factor nationallicence t : Operation time, hours nationallicence t b : Column breakthrough time, hours nationallicence t s : Column saturation time, hours nationallicence t 1/2 : Half adsorption time, hours nationallicence T : Absolute temperature, Kelvin nationallicence U : Linear flow velocity, centimeters per hour nationallicence W : Mass of adsorbent, grams nationallicence Z : Column length, centimeters nationallicence Sotelo José Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut Ovejero Gabriel Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut Rodríguez Araceli Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut Álvarez Silvia Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut García Juan Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut Water, Air, & Soil Pollution Springer Netherlands 224/3(2013-03-01), 1-15 0049-6979 224:3<1 2013 224 11270 https://doi.org/10.1007/s11270-013-1466-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11270-013-1466-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sotelo José Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut NATIONALLICENCE 700 1- Ovejero Gabriel Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut NATIONALLICENCE 700 1- Rodríguez Araceli Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut NATIONALLICENCE 700 1- Álvarez Silvia Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut NATIONALLICENCE 700 1- García Juan Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain aut NATIONALLICENCE 773 0- Water, Air, & Soil Pollution Springer Netherlands 224/3(2013-03-01), 1-15 0049-6979 224:3<1 2013 224 11270 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer