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Yoshihiko Matsui - One of the best experts on this subject based on the ideXlab platform.

  • adsorption capacities of activated Carbons for geosmin and 2 methylisoborneol vary with activated Carbon Particle size effects of adsorbent and adsorbate characteristics
    Water Research, 2015
    Co-Authors: Yoshihiko Matsui, Taku Matsushita, Soichi Nakao, Asuka Sakamoto, Takuma Taniguchi, Long Pan, Nobutaka Shirasaki
    Abstract:

    The adsorption capacities of nine activated Carbons for geosmin and 2-methylisoborneol (MIB) were evaluated. For some Carbons, adsorption capacity substantially increased when Carbon Particle diameter was decreased from a few tens of micrometers to a few micrometers, whereas for other Carbons, the increase of adsorption capacity was small for MIB and moderate for geosmin. An increase of adsorption capacity was observed for other hydrophobic adsorbates besides geosmin and MIB, but not for hydrophilic adsorbates. The parameter values of a shell adsorption model describing the increase of adsorption capacity were negatively correlated with the oxygen content of the Carbon among other characteristics. Low oxygen content indicated low hydrophilicity. The increase of adsorption capacity was related to the hydrophobic properties of both adsorbates and activated Carbons. For adsorptive removal of hydrophobic micropollutants such as geosmin, it is therefore recommended that less-hydrophilic activated Carbons, such as coconut-shell-based Carbons, be microground to a Particle diameter of a few micrometers to enhance their equilibrium adsorption capacity. In contrast, adsorption by hydrophilic Carbons or adsorption of hydrophilic adsorbates occur in the inner pores, and therefore adsorption capacity is unchanged by Particle size reduction.

  • geosmin and 2 methylisoborneol removal using superfine powdered activated Carbon shell adsorption and branched pore kinetic model analysis and optimal Particle size
    Water Research, 2013
    Co-Authors: Yoshihiko Matsui, Soichi Nakao, Takuma Taniguchi, Taku Matsushita
    Abstract:

    2-Methylisoborneol (MIB) and geosmin are naturally occurring compounds responsible for musty-earthy taste and odor in public drinking-water supplies, a severe problem faced by many utilities throughout the world. In this study, we investigated adsorptive removal of these compounds by superfine powdered activation Carbon (SPAC, Particle size <1 μm) produced by novel micro-grinding of powdered activated Carbon; we also discuss the optimization of Carbon Particle size to efficiently enhance the adsorptive removal. After grinding, the absorptive capacity remained unchanged for a 2007 Carbon sample and was increased for a 2010 Carbon sample; the capacity increase was quantitatively described by the shell adsorption model, in which MIB and geosmin adsorbed more in the exterior of a Carbon Particle than in the center. The extremely high uptake rates of MIB and geosmin by SPAC were simulated well by a combination of the branched-pore kinetic model and the shell adsorption model, in which intraParticle diffusion through macropores was followed by diffusion from macropore to micropore. Simulations suggested that D40 was on the whole the best characteristic diameter to represent a size-disperse group of adsorbent Particles; D40 is the diameter through which 40% of the Particles by volume pass. Therefore, D40 can be used as an index for evaluating the improvement of adsorptive removal that resulted from pulverization. The dose required for a certain percentage removal of MIB or geosmin decreased linearly with Carbon Particle size (D40), but the dose reduction became less effective as the activated Carbon was ground down to smaller sizes around a critical value of D40. For a 60-min contact time, critical D40 was 2-2.5 μm for MIB and 0.4-0.5 μm for geosmin. The smaller critical D40 was when the shorter the Carbon-water contact time was or the slower the intraParticle mass transfer rate of an adsorbate was.

  • branched pore kinetic model analysis of geosmin adsorption on super powdered activated Carbon
    Water Research, 2009
    Co-Authors: Yoshihiko Matsui, Naoya Ando, Taku Matsushita, Hiroshi Sasaki, Koichi Ohno
    Abstract:

    Super-powdered activated Carbon (S-PAC) is activated Carbon of much finer Particle size than powdered activated Carbon (PAC). Geosmin is a naturally occurring taste and odor compound that impairs aesthetic quality in drinking water. Experiments on geosmin adsorption on S-PAC and PAC were conducted, and the results using adsorption kinetic models were analyzed. PAC pulverization, which produced the S-PAC, did not change geosmin adsorption capacity, and geosmin adsorption capacities did not differ between S-PAC and PAC. Geosmin adsorption kinetics, however, were much higher on S-PAC than on PAC. A solution to the branched pore kinetic model (BPKM) was developed, and experimental adsorption kinetic data were analyzed by BPKM and by a homogeneous surface diffusion model (HSDM). The HSDM describing the adsorption behavior of geosmin required different surface diffusivity values for S-PAC and PAC, which indicated a decrease in surface diffusivity apparently associated with activated Carbon Particle size. The BPKM, consisting of macropore diffusion followed by mass transfer from macropore to micropore, successfully described the batch adsorption kinetics on S-PAC and PAC with the same set of model parameter values, including surface diffusivity. The BPKM simulation clearly showed geosmin removal was improved as activated Carbon Particle size decreased. The simulation also implied that the rate-determining step in overall mass transfer shifted from intraParticle radial diffusion in macropores to local mass transfer from macropore to micropore. Sensitivity analysis showed that adsorptive removal of geosmin improved with decrease in activated Carbon Particle size down to 1 μm, but further Particle size reduction produced little improvement.

  • branched pore kinetic model analysis of geosmin adsorption on super powdered activated Carbon
    Water Research, 2009
    Co-Authors: Yoshihiko Matsui, Naoya Ando, Taku Matsushita, Hiroshi Sasaki, Koichi Ohno
    Abstract:

    Super-powdered activated Carbon (S-PAC) is activated Carbon of much finer Particle size than powdered activated Carbon (PAC). Geosmin is a naturally occurring taste and odor compound that impairs aesthetic quality in drinking water. Experiments on geosmin adsorption on S-PAC and PAC were conducted, and the results using adsorption kinetic models were analyzed. PAC pulverization, which produced the S-PAC, did not change geosmin adsorption capacity, and geosmin adsorption capacities did not differ between S-PAC and PAC. Geosmin adsorption kinetics, however, were much higher on S-PAC than on PAC. A solution to the branched pore kinetic model (BPKM) was developed, and experimental adsorption kinetic data were analyzed by BPKM and by a homogeneous surface diffusion model (HSDM). The HSDM describing the adsorption behavior of geosmin required different surface diffusivity values for S-PAC and PAC, which indicated a decrease in surface diffusivity apparently associated with activated Carbon Particle size. The BPKM, consisting of macropore diffusion followed by mass transfer from macropore to micropore, successfully described the batch adsorption kinetics on S-PAC and PAC with the same set of model parameter values, including surface diffusivity. The BPKM simulation clearly showed geosmin removal was improved as activated Carbon Particle size decreased. The simulation also implied that the rate-determining step in overall mass transfer shifted from intraParticle radial diffusion in macropores to local mass transfer from macropore to micropore. Sensitivity analysis showed that adsorptive removal of geosmin improved with decrease in activated Carbon Particle size down to 1 μm, but further Particle size reduction produced little improvement.

Taku Matsushita - One of the best experts on this subject based on the ideXlab platform.

  • adsorption capacities of activated Carbons for geosmin and 2 methylisoborneol vary with activated Carbon Particle size effects of adsorbent and adsorbate characteristics
    Water Research, 2015
    Co-Authors: Yoshihiko Matsui, Taku Matsushita, Soichi Nakao, Asuka Sakamoto, Takuma Taniguchi, Long Pan, Nobutaka Shirasaki
    Abstract:

    The adsorption capacities of nine activated Carbons for geosmin and 2-methylisoborneol (MIB) were evaluated. For some Carbons, adsorption capacity substantially increased when Carbon Particle diameter was decreased from a few tens of micrometers to a few micrometers, whereas for other Carbons, the increase of adsorption capacity was small for MIB and moderate for geosmin. An increase of adsorption capacity was observed for other hydrophobic adsorbates besides geosmin and MIB, but not for hydrophilic adsorbates. The parameter values of a shell adsorption model describing the increase of adsorption capacity were negatively correlated with the oxygen content of the Carbon among other characteristics. Low oxygen content indicated low hydrophilicity. The increase of adsorption capacity was related to the hydrophobic properties of both adsorbates and activated Carbons. For adsorptive removal of hydrophobic micropollutants such as geosmin, it is therefore recommended that less-hydrophilic activated Carbons, such as coconut-shell-based Carbons, be microground to a Particle diameter of a few micrometers to enhance their equilibrium adsorption capacity. In contrast, adsorption by hydrophilic Carbons or adsorption of hydrophilic adsorbates occur in the inner pores, and therefore adsorption capacity is unchanged by Particle size reduction.

  • geosmin and 2 methylisoborneol removal using superfine powdered activated Carbon shell adsorption and branched pore kinetic model analysis and optimal Particle size
    Water Research, 2013
    Co-Authors: Yoshihiko Matsui, Soichi Nakao, Takuma Taniguchi, Taku Matsushita
    Abstract:

    2-Methylisoborneol (MIB) and geosmin are naturally occurring compounds responsible for musty-earthy taste and odor in public drinking-water supplies, a severe problem faced by many utilities throughout the world. In this study, we investigated adsorptive removal of these compounds by superfine powdered activation Carbon (SPAC, Particle size <1 μm) produced by novel micro-grinding of powdered activated Carbon; we also discuss the optimization of Carbon Particle size to efficiently enhance the adsorptive removal. After grinding, the absorptive capacity remained unchanged for a 2007 Carbon sample and was increased for a 2010 Carbon sample; the capacity increase was quantitatively described by the shell adsorption model, in which MIB and geosmin adsorbed more in the exterior of a Carbon Particle than in the center. The extremely high uptake rates of MIB and geosmin by SPAC were simulated well by a combination of the branched-pore kinetic model and the shell adsorption model, in which intraParticle diffusion through macropores was followed by diffusion from macropore to micropore. Simulations suggested that D40 was on the whole the best characteristic diameter to represent a size-disperse group of adsorbent Particles; D40 is the diameter through which 40% of the Particles by volume pass. Therefore, D40 can be used as an index for evaluating the improvement of adsorptive removal that resulted from pulverization. The dose required for a certain percentage removal of MIB or geosmin decreased linearly with Carbon Particle size (D40), but the dose reduction became less effective as the activated Carbon was ground down to smaller sizes around a critical value of D40. For a 60-min contact time, critical D40 was 2-2.5 μm for MIB and 0.4-0.5 μm for geosmin. The smaller critical D40 was when the shorter the Carbon-water contact time was or the slower the intraParticle mass transfer rate of an adsorbate was.

  • branched pore kinetic model analysis of geosmin adsorption on super powdered activated Carbon
    Water Research, 2009
    Co-Authors: Yoshihiko Matsui, Naoya Ando, Taku Matsushita, Hiroshi Sasaki, Koichi Ohno
    Abstract:

    Super-powdered activated Carbon (S-PAC) is activated Carbon of much finer Particle size than powdered activated Carbon (PAC). Geosmin is a naturally occurring taste and odor compound that impairs aesthetic quality in drinking water. Experiments on geosmin adsorption on S-PAC and PAC were conducted, and the results using adsorption kinetic models were analyzed. PAC pulverization, which produced the S-PAC, did not change geosmin adsorption capacity, and geosmin adsorption capacities did not differ between S-PAC and PAC. Geosmin adsorption kinetics, however, were much higher on S-PAC than on PAC. A solution to the branched pore kinetic model (BPKM) was developed, and experimental adsorption kinetic data were analyzed by BPKM and by a homogeneous surface diffusion model (HSDM). The HSDM describing the adsorption behavior of geosmin required different surface diffusivity values for S-PAC and PAC, which indicated a decrease in surface diffusivity apparently associated with activated Carbon Particle size. The BPKM, consisting of macropore diffusion followed by mass transfer from macropore to micropore, successfully described the batch adsorption kinetics on S-PAC and PAC with the same set of model parameter values, including surface diffusivity. The BPKM simulation clearly showed geosmin removal was improved as activated Carbon Particle size decreased. The simulation also implied that the rate-determining step in overall mass transfer shifted from intraParticle radial diffusion in macropores to local mass transfer from macropore to micropore. Sensitivity analysis showed that adsorptive removal of geosmin improved with decrease in activated Carbon Particle size down to 1 μm, but further Particle size reduction produced little improvement.

  • branched pore kinetic model analysis of geosmin adsorption on super powdered activated Carbon
    Water Research, 2009
    Co-Authors: Yoshihiko Matsui, Naoya Ando, Taku Matsushita, Hiroshi Sasaki, Koichi Ohno
    Abstract:

    Super-powdered activated Carbon (S-PAC) is activated Carbon of much finer Particle size than powdered activated Carbon (PAC). Geosmin is a naturally occurring taste and odor compound that impairs aesthetic quality in drinking water. Experiments on geosmin adsorption on S-PAC and PAC were conducted, and the results using adsorption kinetic models were analyzed. PAC pulverization, which produced the S-PAC, did not change geosmin adsorption capacity, and geosmin adsorption capacities did not differ between S-PAC and PAC. Geosmin adsorption kinetics, however, were much higher on S-PAC than on PAC. A solution to the branched pore kinetic model (BPKM) was developed, and experimental adsorption kinetic data were analyzed by BPKM and by a homogeneous surface diffusion model (HSDM). The HSDM describing the adsorption behavior of geosmin required different surface diffusivity values for S-PAC and PAC, which indicated a decrease in surface diffusivity apparently associated with activated Carbon Particle size. The BPKM, consisting of macropore diffusion followed by mass transfer from macropore to micropore, successfully described the batch adsorption kinetics on S-PAC and PAC with the same set of model parameter values, including surface diffusivity. The BPKM simulation clearly showed geosmin removal was improved as activated Carbon Particle size decreased. The simulation also implied that the rate-determining step in overall mass transfer shifted from intraParticle radial diffusion in macropores to local mass transfer from macropore to micropore. Sensitivity analysis showed that adsorptive removal of geosmin improved with decrease in activated Carbon Particle size down to 1 μm, but further Particle size reduction produced little improvement.

Koichi Ohno - One of the best experts on this subject based on the ideXlab platform.

  • branched pore kinetic model analysis of geosmin adsorption on super powdered activated Carbon
    Water Research, 2009
    Co-Authors: Yoshihiko Matsui, Naoya Ando, Taku Matsushita, Hiroshi Sasaki, Koichi Ohno
    Abstract:

    Super-powdered activated Carbon (S-PAC) is activated Carbon of much finer Particle size than powdered activated Carbon (PAC). Geosmin is a naturally occurring taste and odor compound that impairs aesthetic quality in drinking water. Experiments on geosmin adsorption on S-PAC and PAC were conducted, and the results using adsorption kinetic models were analyzed. PAC pulverization, which produced the S-PAC, did not change geosmin adsorption capacity, and geosmin adsorption capacities did not differ between S-PAC and PAC. Geosmin adsorption kinetics, however, were much higher on S-PAC than on PAC. A solution to the branched pore kinetic model (BPKM) was developed, and experimental adsorption kinetic data were analyzed by BPKM and by a homogeneous surface diffusion model (HSDM). The HSDM describing the adsorption behavior of geosmin required different surface diffusivity values for S-PAC and PAC, which indicated a decrease in surface diffusivity apparently associated with activated Carbon Particle size. The BPKM, consisting of macropore diffusion followed by mass transfer from macropore to micropore, successfully described the batch adsorption kinetics on S-PAC and PAC with the same set of model parameter values, including surface diffusivity. The BPKM simulation clearly showed geosmin removal was improved as activated Carbon Particle size decreased. The simulation also implied that the rate-determining step in overall mass transfer shifted from intraParticle radial diffusion in macropores to local mass transfer from macropore to micropore. Sensitivity analysis showed that adsorptive removal of geosmin improved with decrease in activated Carbon Particle size down to 1 μm, but further Particle size reduction produced little improvement.

  • branched pore kinetic model analysis of geosmin adsorption on super powdered activated Carbon
    Water Research, 2009
    Co-Authors: Yoshihiko Matsui, Naoya Ando, Taku Matsushita, Hiroshi Sasaki, Koichi Ohno
    Abstract:

    Super-powdered activated Carbon (S-PAC) is activated Carbon of much finer Particle size than powdered activated Carbon (PAC). Geosmin is a naturally occurring taste and odor compound that impairs aesthetic quality in drinking water. Experiments on geosmin adsorption on S-PAC and PAC were conducted, and the results using adsorption kinetic models were analyzed. PAC pulverization, which produced the S-PAC, did not change geosmin adsorption capacity, and geosmin adsorption capacities did not differ between S-PAC and PAC. Geosmin adsorption kinetics, however, were much higher on S-PAC than on PAC. A solution to the branched pore kinetic model (BPKM) was developed, and experimental adsorption kinetic data were analyzed by BPKM and by a homogeneous surface diffusion model (HSDM). The HSDM describing the adsorption behavior of geosmin required different surface diffusivity values for S-PAC and PAC, which indicated a decrease in surface diffusivity apparently associated with activated Carbon Particle size. The BPKM, consisting of macropore diffusion followed by mass transfer from macropore to micropore, successfully described the batch adsorption kinetics on S-PAC and PAC with the same set of model parameter values, including surface diffusivity. The BPKM simulation clearly showed geosmin removal was improved as activated Carbon Particle size decreased. The simulation also implied that the rate-determining step in overall mass transfer shifted from intraParticle radial diffusion in macropores to local mass transfer from macropore to micropore. Sensitivity analysis showed that adsorptive removal of geosmin improved with decrease in activated Carbon Particle size down to 1 μm, but further Particle size reduction produced little improvement.

Jing Wang - One of the best experts on this subject based on the ideXlab platform.

  • a number based inventory of size resolved black Carbon Particle emissions by global civil aviation
    Nature Communications, 2019
    Co-Authors: Xi Chen, Xiaole Zhang, Jing Wang
    Abstract:

    With the rapidly growing global air traffic, the impacts of the black Carbon (BC) in the aviation exhaust on climate, environment and public health are likely rising. The Particle number and size distribution are crucial metrics for toxicological analysis and aerosol-cloud interactions. Here, a size-resolved BC Particle number emission inventory was developed for the global civil aviation. The BC Particle number emission is approximately (10.9 ± 2.1) × 1025 per year with an average emission index of (6.06 ± 1.18) × 1014 per kg of burned fuel, which is about 1.3% of the total ground anthropogenic emissions, and 3.6% of the road transport emission. The global aviation emitted BC Particles follow a lognormal distribution with a geometric mean diameter (GMD) of 31.99 ± 0.8 nm and a geometric standard deviation (GSD) of 1.85 ± 0.016. The variabilities of GMDs and GSDs for all flights are about 4.8 and 0.08 nm, respectively. The inventory provides new data for assessing the aviation impacts. Size-resolved Black Carbon (BC) Particle number emission inventory is not available for global civil aviation. Here the authors converted BC mass emission inventory into number emission inventory and found that aviation BC number emission contributes to 1.3% of total ground anthropogenic emissions and 3.6% on global average.

Xiaole Zhang - One of the best experts on this subject based on the ideXlab platform.

  • a number based inventory of size resolved black Carbon Particle emissions by global civil aviation
    Nature Communications, 2019
    Co-Authors: Xi Chen, Xiaole Zhang, Jing Wang
    Abstract:

    With the rapidly growing global air traffic, the impacts of the black Carbon (BC) in the aviation exhaust on climate, environment and public health are likely rising. The Particle number and size distribution are crucial metrics for toxicological analysis and aerosol-cloud interactions. Here, a size-resolved BC Particle number emission inventory was developed for the global civil aviation. The BC Particle number emission is approximately (10.9 ± 2.1) × 1025 per year with an average emission index of (6.06 ± 1.18) × 1014 per kg of burned fuel, which is about 1.3% of the total ground anthropogenic emissions, and 3.6% of the road transport emission. The global aviation emitted BC Particles follow a lognormal distribution with a geometric mean diameter (GMD) of 31.99 ± 0.8 nm and a geometric standard deviation (GSD) of 1.85 ± 0.016. The variabilities of GMDs and GSDs for all flights are about 4.8 and 0.08 nm, respectively. The inventory provides new data for assessing the aviation impacts. Size-resolved Black Carbon (BC) Particle number emission inventory is not available for global civil aviation. Here the authors converted BC mass emission inventory into number emission inventory and found that aviation BC number emission contributes to 1.3% of total ground anthropogenic emissions and 3.6% on global average.