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Daryl R. Williams - One of the best experts on this subject based on the ideXlab platform.

  • a comparison of frontal and nonfrontal methods for determining solid liquid Adsorption isotherms using inverse liquid chromatography
    Langmuir, 2007
    Co-Authors: Pirre P Ylamaihaniemi, Daryl R. Williams
    Abstract:

    Inverse liquid chromatography (ILC) has been used to determine experimental isotherms for the equilibrium Adsorption of cyclohexanone onto a silica (61.8 m2/g) from hexane using the peak maximum (PM), elution by characteristic point (ECP), frontal analysis (FA), and frontal analysis by characteristic point (FACP) methods. Isotherms obtained using these four approaches gave good internal agreement, as well as being in good agreement with classically determined isotherms. Columns were successfully packed using a dry powder packing method with 9 μm diameter silica particles, and excellent intercolumn and instrument to instrument reproducibility was obtained for PM isotherms. The theoretical background to the PM, ECP, FA, and FACP methods, as well as the practical facets of isotherm determination using these methods, is outlined in this work.

  • Novel inverse liquid chromatography detector configuration for studying Solid-Liquid Adsorption.
    Journal of Chromatography A, 2006
    Co-Authors: Pirre P. Ylä-mäihäniemi, Daryl R. Williams
    Abstract:

    Abstract Inverse liquid chromatography (ILC) is a physicochemical chromatographic technique for studying solid–liquid interactions and surface properties of unknown solid materials. However, such studies are dependant on the ability to self pack the sample powder into a LC column in a reliable and robust manner. In practise, this is often difficult and anomalous chromatograms can be encountered quite frequently. Results obtained with a novel LC system configuration utilising both pre and post-column UV–vis detectors for ILC studies are reported here which greatly assist in our attempts to interpret such chromatograms. The operational issues for using a two detector system are discussed including the use of both detectors in the linear concentration regime; with the choice of an optimal detector wavelength being the most critical factor. The two detector system was demonstrated to be capable of verifying reversible Adsorption processes, as well as assisting in the interpretation of complex or problematic chromatograms. This paper demonstrates that the two detector ILC system can offer a number of practical benefits in the study of complex chromatographic phenomena.

  • Novel inverse liquid chromatography detector configuration for studying Solid-Liquid Adsorption.
    Journal of chromatography. A, 2006
    Co-Authors: Pirre P. Ylä-mäihäniemi, Daryl R. Williams
    Abstract:

    Inverse liquid chromatography (ILC) is a physicochemical chromatographic technique for studying Solid-Liquid interactions and surface properties of unknown solid materials. However, such studies are dependent on the ability to self pack the sample powder into a LC column in a reliable and robust manner. In practise, this is often difficult and anomalous chromatograms can be encountered quite frequently. Results obtained with a novel LC system configuration utilising both pre and post-column UV-vis detectors for ILC studies are reported here which greatly assist in our attempts to interpret such chromatograms. The operational issues for using a two detector system are discussed including the use of both detectors in the linear concentration regime; with the choice of an optimal detector wavelength being the most critical factor. The two detector system was demonstrated to be capable of verifying reversible Adsorption processes, as well as assisting in the interpretation of complex or problematic chromatograms. This paper demonstrates that the two detector ILC system can offer a number of practical benefits in the study of complex chromatographic phenomena.

Pirre P. Ylä-mäihäniemi - One of the best experts on this subject based on the ideXlab platform.

  • Novel inverse liquid chromatography detector configuration for studying Solid-Liquid Adsorption.
    Journal of Chromatography A, 2006
    Co-Authors: Pirre P. Ylä-mäihäniemi, Daryl R. Williams
    Abstract:

    Abstract Inverse liquid chromatography (ILC) is a physicochemical chromatographic technique for studying solid–liquid interactions and surface properties of unknown solid materials. However, such studies are dependant on the ability to self pack the sample powder into a LC column in a reliable and robust manner. In practise, this is often difficult and anomalous chromatograms can be encountered quite frequently. Results obtained with a novel LC system configuration utilising both pre and post-column UV–vis detectors for ILC studies are reported here which greatly assist in our attempts to interpret such chromatograms. The operational issues for using a two detector system are discussed including the use of both detectors in the linear concentration regime; with the choice of an optimal detector wavelength being the most critical factor. The two detector system was demonstrated to be capable of verifying reversible Adsorption processes, as well as assisting in the interpretation of complex or problematic chromatograms. This paper demonstrates that the two detector ILC system can offer a number of practical benefits in the study of complex chromatographic phenomena.

  • Novel inverse liquid chromatography detector configuration for studying Solid-Liquid Adsorption.
    Journal of chromatography. A, 2006
    Co-Authors: Pirre P. Ylä-mäihäniemi, Daryl R. Williams
    Abstract:

    Inverse liquid chromatography (ILC) is a physicochemical chromatographic technique for studying Solid-Liquid interactions and surface properties of unknown solid materials. However, such studies are dependent on the ability to self pack the sample powder into a LC column in a reliable and robust manner. In practise, this is often difficult and anomalous chromatograms can be encountered quite frequently. Results obtained with a novel LC system configuration utilising both pre and post-column UV-vis detectors for ILC studies are reported here which greatly assist in our attempts to interpret such chromatograms. The operational issues for using a two detector system are discussed including the use of both detectors in the linear concentration regime; with the choice of an optimal detector wavelength being the most critical factor. The two detector system was demonstrated to be capable of verifying reversible Adsorption processes, as well as assisting in the interpretation of complex or problematic chromatograms. This paper demonstrates that the two detector ILC system can offer a number of practical benefits in the study of complex chromatographic phenomena.

K. Vasanth Kumar - One of the best experts on this subject based on the ideXlab platform.

  • Modelling the Solid-Liquid Adsorption processes using artificial neural networks trained by pseudo second order kinetics
    Chemical Engineering Journal, 2009
    Co-Authors: K. Vasanth Kumar, K. Porkodi
    Abstract:

    Abstract A three-layer feed forward neural network was constructed and tested to analyze the second order kinetics of solid–liquid Adsorption process. The pseudo second order kinetics of auramine O onto activated carbon was used to train the artificial neural network (ANN) to model the sorption system for various operating conditions. The operating variables studied are the contact time, initial dye concentration, agitation speed, temperature, initial solution pH and activated carbon mass. The studied operating variables were used as the input to the constructed neural network to predict the dye uptake by pseudo second order kinetics at any time as the output or the target. The dye uptake predicted by ANN trained by pseudo second order kinetics was found to be precise in representing the experimental kinetics of auramine O uptake by activated carbon. The constructed network was also found to be precise in predicting the sorption kinetics of auramine O by activated carbon for the new input data which are kept unaware of the trained neural network showing its applicability to determine the dye uptake rate for any operating conditions under interest. The ANN was also trained using pseudo second order kinetics of sorption of divalent metal ions onto peat particles and also using the second order kinetics of cadmium ions onto tree fern particles. The ANN and pseudo second order kinetics compliment each other to model the studied sorption systems for a wide range of operating conditions.

  • Comments on “Equilibrium studies for the Adsorption of Acid dye onto modified hectorite”
    Journal of hazardous materials, 2006
    Co-Authors: K. Vasanth Kumar
    Abstract:

    The present letter discusses the significance of the dimensionless separation factor of solid/liquid Adsorption systems. The present letter also explain citing the original paper for using the term separation factor 'R'.

Pirre P Ylamaihaniemi - One of the best experts on this subject based on the ideXlab platform.

  • a comparison of frontal and nonfrontal methods for determining solid liquid Adsorption isotherms using inverse liquid chromatography
    Langmuir, 2007
    Co-Authors: Pirre P Ylamaihaniemi, Daryl R. Williams
    Abstract:

    Inverse liquid chromatography (ILC) has been used to determine experimental isotherms for the equilibrium Adsorption of cyclohexanone onto a silica (61.8 m2/g) from hexane using the peak maximum (PM), elution by characteristic point (ECP), frontal analysis (FA), and frontal analysis by characteristic point (FACP) methods. Isotherms obtained using these four approaches gave good internal agreement, as well as being in good agreement with classically determined isotherms. Columns were successfully packed using a dry powder packing method with 9 μm diameter silica particles, and excellent intercolumn and instrument to instrument reproducibility was obtained for PM isotherms. The theoretical background to the PM, ECP, FA, and FACP methods, as well as the practical facets of isotherm determination using these methods, is outlined in this work.

Sachin A. Mandavgane - One of the best experts on this subject based on the ideXlab platform.

  • Batch and packed bed techniques for adsorptive aqueous phase removal of selected phenoxyacetic acid herbicide using sugar industry waste ash
    International Journal of Chemical Reactor Engineering, 2020
    Co-Authors: Sunil K. Deokar, Pooja G. Theng, Sachin A. Mandavgane
    Abstract:

    AbstractBatch and packed bed Adsorption of 4-chloro-2-methylphenoxyacetic acid (MCPA) herbicide was performed using bagasse fly ash (BFA) as an adsorbent. In batch process, characteristics of adsorbent, and the influence of adsorbent dosage, initial herbicide concentration, time, pH, particle size of adsorbent and temperature on Adsorption were studied. Results disclose higher removal of MCPA on bigger particles of BFA owing to higher specific surface area because of greater carbon and lesser silica percentage in bigger particles. Application of isotherm models in present study indicates the best fitting of Langmuir and Temkin isotherms whereas the kinetic models suggest the suitability of pseudo second order and Elovich models. Thermodynamic study specifies the temperature preferred Adsorption process. In packed bed technique, the effect of influent concentration, flow rate and bed height were investigated. The deactivation kinetic model which was previously considered only for studies in gas-solid Adsorption is applied in this study to Solid-Liquid Adsorption along with conventional packed bed models. In packed bed study, Bohart-Adams and Wolborska models are appropriate to explain the experimental data upto 60% saturation of the column. The deactivation kinetic model is found the best to elucidate the nature of breakthrough curves till the complete saturation of column. Batch capacity and packed bed capacity per m2 specific surface area of BFA is found about two and three times greater than the previously used adsorbents for MCPA respectively.

  • Adsorptive removal of 2,4-dichlorophenoxyacetic acid from aqueous solution using bagasse fly ash as adsorbent in batch and packed-bed techniques
    Clean Technologies and Environmental Policy, 2016
    Co-Authors: Sunil K. Deokar, Sachin A. Mandavgane, Bhaskar D. Kulkarni
    Abstract:

    Among the several synthetic herbicides available currently, 2,4-D is a commonly used herbicide to control broadleaf weeds in agriculture and forestry. However, its increasing use in agricultural and nonagricultural activities has resulted in increasing concentrations of 2,4-D being detected in water bodies. Thus, there is a need to identify methods to remove 2,4-D to protect the environment. Among the various methods used for 2,4-D removal, Adsorption is found to be effective, and several adsorbents have been studied to remove 2,4-D from aqueous solutions. In this study, we used bagasse fly ash (BFA), a common industrial waste generated in large amount worldwide, for 2,4-D removal from aqueous solution using batch and continuous packed-bed Adsorption. In the batch Adsorption process, the effects of initial concentration, contact time, temperature, pH, and particle size of BFA were studied. The packed-bed performance of BFA was investigated by varying the influent concentration (50–150 mg/L), flow rate (1.2–4 mL/min), and bed height (4.5–9 cm). Isotherm and thermodynamic parameters are determined for batch Adsorption, whereas the performance of continuous Adsorption is evaluated by different packed-bed models. The particle-size effect indicated the higher removal of 2,4-D on the bigger particles of BFA due to greater BET surface area and carbon-to-silica ratio than smaller particles. The maximum percentage removal (37.04) is achieved for an influent concentration of 50 mg/L, flow rate of 1.2 mL/min, and bed height of 6.5 cm. For the first time ever, the deactivation kinetic model was applied for the solid–liquid Adsorption system and it showed the best fit among the selected models. The bed capacity (m^2/g) of BFA is three times greater than synthetic activated carbon for Adsorption of 2,4-D. This informs that the BFA can be used as an adsorbent for 2,4-D removal from aqueous solution.

  • Estimation of packed-bed parameters and prediction of breakthrough curves for adsorptive removal of 2,4-dichlorophenoxyacetic acid using rice husk ash
    Journal of Environmental Chemical Engineering, 2015
    Co-Authors: Sunil K. Deokar, Sachin A. Mandavgane
    Abstract:

    Abstract In this paper, we studied the physicochemical characteristics of rice husk ash (RHA). Our results show higher surface area, smaller silica-to-carbon ratio, and consequently higher batch Adsorption capacity for bigger RHA particles. Packed-bed performance of bigger particles (0.500–0.354 mm) was investigated for influent concentration (50–400 mg/L), flow rate (1–10 mL/min), and bed height (7–13 cm). The maximal removal (53.86%) was achieved for an influent concentration of 50 mg/L, flow rate of 7 mL/min, and bed height of 9 cm. For minimal removal (34.60%), the corresponding parameters were 100 mg/L, 7 mL/min, and 7 cm. Various mathematical models, including bed depth service time, Bohart–Adams, Wolborska, Thomas, Clark, Yoon–Nelson, and deactivation kinetic, are applied to experimental data for breakthrough curve prediction and to determine the optimal bed parameters. According to the bed depth service time model, 10% and 90% breakthrough capacities were determined to be 2628.10 and 7400.03 mg/L, respectively. The deactivation kinetic model for the solid–liquid Adsorption system is found to best elucidate the packed-bed data. Packed-bed Adsorption capacity (mg/m2) for RHA is 2.7 times higher than synthetic activated carbon.