Papers by Yoshinori Kawase
Environmental Science and Pollution Research, Dec 31, 2022
Highlights Constructed wetlands (CWs) showed the remarkable potential for removing the PhACs. The... more Highlights Constructed wetlands (CWs) showed the remarkable potential for removing the PhACs. The removal of carbamazepine was significantly enhanced in planted CWs compared to unplanted CWs. Cyperus alternifolius can tolerate and uptake certain PhACs. Tolerance to PhACs could be related to photosynthesis and antioxidative defence. The removal of PhACs in CWs was divided into two stages.
Design and Scale-Up of Bioreactors for Dense Suspension Broths
Recent Advances in Biotechnology, 1992
The effects of rheological complexity of dense suspension broths on the design and scale-up of bi... more The effects of rheological complexity of dense suspension broths on the design and scale-up of bioreactors are discussed. On the basis of the surface renewal concept. a theoretical model for liquid-phase mass transfer coefficient, is developed. The validity of the proposed model is examined using a wide range of experimental results. The scale-up strategy for bioreactors is also discussed.
Hydroxyl radical generation linked with iron dissolution and dissolved oxygen consumption in zero-valent iron wastewater treatment process
Chemical Engineering Journal, 2016
Abstract In zero-valent iron (ZVI) wastewater treatments, organic pollutants are degraded by hydr... more Abstract In zero-valent iron (ZVI) wastewater treatments, organic pollutants are degraded by hydroxyl radical (OH radical) generated via the Fenton reaction besides by the reductive reaction. The generation of OH radical is initiated by the dissolution of ZVI. The strong linkage of OH radical generation by ZVI with eluted ferrous ion and dissolved oxygen (DO) through the iron dissolution and the formation of passive iron oxide/hydroxide layer on the ZVI surface was found. While OH radicals were gradually generated by microscale ZVI (mZVI) until the termination of iron dissolution, the OH radical generation by nanoscale ZVI (nZVI) was very quick at the initial phase, subsequently slowed down and terminated. Although the rate of OH radical generation with nZVI was much faster than that with mZVI, the amount of generated OH radical with nZVI was less than mZVI under the same iron dosage conditions. With increasing ZVI dosage and controlled solution pH value, the amount of generated OH radical for both mZVI and nZVI increased and decreased, respectively. For nZVI under the oxic condition, the quick depletion of DO at the initial phase accompanied with the sequential recovery to the saturation concentration was found. A reaction kinetic model was developed to quantify a linkage of OH radical generation with the iron dissolution and the formation of passive iron oxide/hydroxide layer on the ZVI surface. The linkage could be reasonably simulated by the proposed kinetic model with the correlation coefficient of >0.828.
Powder Technology, 1998
Measurements have been taken of the relationship between Ilow rate and pressure drop Ibr non-Newt... more Measurements have been taken of the relationship between Ilow rate and pressure drop Ibr non-Newtonian Iluid,, in two-and three-phase Iluidized beds and the minimum Iluidization vel~.'ities have been determined. Aqueous sLflutions of carboxymethyl cellulose and xanthan gum have been used as the nnn-Newlonian liquid~. The ineasureinents cm,'ered Reyn~flds numbers at nfinimum Ih.lidizalion from 0,0337 to 540 and Ih)w indices in a power-lay, model from 11.4891o I. The mininmm Iluidization veh~.-it~, decreased with an increase in the gas velocity and the magnitude of this decrease became sinaller as particle size decreased. The increase of the viscous not,-Newtonian flow behaviour or pseudoplasticity led to a decrease of the mininlum Iluidization velocity, "]'he results I'w the milfimun) hq.id lluidizatinn veh~.'ity ti)r two-phase systems have been ex:m)ined using the c()rrclation based on the Irce-surface cell model, The predicted minimum tluidization velocities were in reasnnahle agreelllenl with the experimental data Inr iii)n-Newttlniall liquid-s~flid IW'u-phase s)'Meinx over the whole Reynolds number reginn.
KAGAKU KOGAKU RONBUNSHU, 1975
Environmental Science and Pollution Research, 2017
Mechanisms for removal of anionic surfactant sodium dodecyl benzene sulfonate (SDBS) in wastewate... more Mechanisms for removal of anionic surfactant sodium dodecyl benzene sulfonate (SDBS) in wastewaters by zerovalent iron (ZVI) were systematically examined. The contributions of four removal mechanisms, i.e., reductive degradation, oxidative degradation, adsorption, and precipitation, changed significantly with solution pH were quantified and the effective removal of SDBS by ZVI was found to be attributed to the adsorption capability of iron oxides/hydroxides on ZVI surface at nearly neutral pH instead of the degradation at acidic condition. The fastest SDBS removal rate and the maximum TOC (total organic carbon) removal efficiency were obtained at pH 6.0. The maximum TOC removal at pH 6.0 was 77.8%, and the contributions of degradation, precipitation, and adsorption to TOC removal were 4.6, 14.9, and 58.3%, respectively. At pH 3.0, which is an optimal pH for oxidative degradation by the Fenton reaction, the TOC removal was only 9.8% and the contributions of degradation, precipitation, and adsorption to TOC removal were 2.3, 4.6, and 2.9%, respectively. The electrostatic attraction between dodecyl benzene sulfate anion and the iron oxide/hydroxide layer controlled the TOC removal of SDBS. The kinetic model based on the Langmuir-Hinshelwood/Eley-Rideal approach could successfully describe the experimental results for SDBS removal by ZVI with the averaged correlation coefficient of 0.994. ZVI was found to be an efficient material toward the removal of anionic surfactant at nearly neutral pH under the oxic condition.
Heat transfer in bioreactors with dense suspension broths
The Chemical Engineering Journal, 1989
Abstract A theoretical correlation for heat transfer in bioreactors, i.e. stirred tanks and bubbl... more Abstract A theoretical correlation for heat transfer in bioreactors, i.e. stirred tanks and bubble columns, with dense suspension broths having a yield stress has been developed. The theoretical predictions show that an increase in yield stress causes a decrease in heat transfer coefficient. At a fairly high degree of turbulence, however, the influence of yield stress is insignificant and the decrease in heat transfer coefficient is mainly attributed to the increase in plastic viscosity. Reasonable agreement is obtained between the predicted and experimental values of the heat transfer coefficient in stirred tanks and bubble columns.
Bed expansion in liquid–solid two-phase fluidized beds with Newtonian and non-Newtonian fluids over the wide range of Reynolds numbers
Powder Technology, 2001
Bed expansion characteristics in Newtonian and non-Newtonian fluid–solid two-phase fluidized bed ... more Bed expansion characteristics in Newtonian and non-Newtonian fluid–solid two-phase fluidized bed have been examined. Bed expansion measurements were carried out for a bed of glass beads fluidized in Newtonian liquids (water and glycerol solutions) and non-Newtonian liquids (aqueous solutions of carboxymethyl cellulose (CMC) and xanthan gum). Measurements of bed voidage covered a terminal particle Reynolds number from 8.14 to 3947
Chemical Engineering Science, 2001
Gas holdup and bed expansion measurements were carried out for a bed of glass beads uidized in Ne... more Gas holdup and bed expansion measurements were carried out for a bed of glass beads uidized in Newtonian liquids and non-Newtonian liquids with gas. The value of gas holdup increased and decreased with increasing particle size and liquid velocity, respectively. The e ect of rheological properties on gas holdup was insigniÿcant and therefore the gas holdup data for both Newtonian and non-Newtonian uids were reasonably ÿtted by the available correlation which had no liquid viscosity term. The bed voidage increased with increasing superÿcial liquid velocities and superÿcial gas velocities. The increase of the viscous non-Newtonian ow behaviours resulted in an increase of the bed voidage. The correlation for the bed voidage in three-phase uidized beds was developed for gas-Newtonian or non-Newtonian liquid-solid three-phase systems by combining the generalized wake model and the correlation for liquid-solid two-phase systems proposed previously by the authors. The predictions for bed voidage were in reasonable agreement with the present experimental data for three-phase systems with Newtonian and non-Newtonian liquids in a wide range of Reynolds numbers.
Process Biochemistry, 2007
For the minimization of excess sludge in activated sludge process, the photo-Fenton reaction was ... more For the minimization of excess sludge in activated sludge process, the photo-Fenton reaction was applied as a novel technique and its effectiveness was experimentally examined. A batch study was conducted to elucidate parameters governing the activated sludge integration by the photo-Fenton process such as the concentrations of sludge, Fe ion and hydrogen peroxide. It was found that the chemical oxidation sludge disintegration by photo-Fenton reaction could be divided into two phases. At the beginning of the photo-Fenton process the dissolved chemical oxygen demand (COD) increased. This is due to the discharge of organic compounds occurred by oxidative decomposition of the cell wall of a microbe in the sludge. The COD reached the maximum and then decreased. In this phase, mineralization of dissolved organic substances by the photo-Fenton reaction might be dominant. The occurrence of mineralization was suppressed as the initial MLSS increased. The Fe dosage enhanced the sludge disintegration by the photo-Fenton reaction as well as the H 2 O 2 dosage. The soluble total organic carbon (TOC) of the solution increased monotonously. The results suggest that Fe ions might be entrapped into the activated sludge. It may be concluded that photo-Fenton reaction is one of feasible processes for disintegration of excess activated sludge.
International Communications in Heat and Mass Transfer, 1990
Theoretical correlations based on the energy dissipation rate concept are developed for turbulent... more Theoretical correlations based on the energy dissipation rate concept are developed for turbulent heat and mass transfer in dragreducing fluids. Applicability of the proposed correlations is examined using the available experimental data. A physical interpretation of the energy dissipation rate concept is also discussed.
International Communications in Heat and Mass Transfer, 1985
A simple analytical technique for turbulent natural convection heat transfer from an isothermal v... more A simple analytical technique for turbulent natural convection heat transfer from an isothermal vertical plate to a power-law fluid is developed. The model is based on the assumption that the turbulent heat transfer rate is controlled by the flow characteristic near the surface in the limit of large Prandtl numbers. The formulation proposed in this work agrees well with the correlations available in the literature.
Heat transfer in bubble column reactors with newtonian and non-Newtonian fluids
Chemical Engineering Research & Design, 1987
Modele mathematique base sur le concept des trois zones de Levich et sur la theorie de la turbule... more Modele mathematique base sur le concept des trois zones de Levich et sur la theorie de la turbulence isotrope de Kolmogoroff. Il predit l'accroissement de transfert de chaleur du a l'effet d'amincissement par cisaillement du fluide. L'accord est bon entre ce modele et les correlations des donnees experimentales, pour un large domaine de conditions operatoires
Evaluation of bubble removing performance in a TV glass furnace. Part 2. Verification using real furnace data
Glass Science and Technology, 1998
In part 2, a furnace for melting TV panel glass is studied to examine the effectiveness of the si... more In part 2, a furnace for melting TV panel glass is studied to examine the effectiveness of the simulator developed by the authors. Because panel glass is used as a part of a cathodic ray tube where the TV image is projected and its defect is easily recognizable, bubble-free glass quality is definitely required. If the bubble quality becomes worse, a heap of rejected products is piled up, which leads to tremendous economical loss. In order to avoid such trouble designing and operating a TV glass furnace and inspecting glass quality are conducted with great care, and therefore, lots of field data have been accumulated so far. Accordingly, it is meaningful to utilize a TV glass furnace to verify the effectiveness of such simulating technology. The values and phenomena predicted by the simulator and the data having been observed in real furnaces were found to be in reasonable agreement. Therefore, it may be concluded that the proposed simulator is useful as a method of scale-up and trouble-shooting for glass furnaces.
Removal of cationic dye methylene blue by zero-valent iron: Effects of pH and dissolved oxygen on removal mechanisms
Journal of Environmental Science and Health, Part A, 2015
Effects of pH and dissolved oxygen on mechanisms for decolorization and total organic carbon (TOC... more Effects of pH and dissolved oxygen on mechanisms for decolorization and total organic carbon (TOC) removal of cationic dye methylene blue (MB) by zero-valent iron (ZVI) were systematically examined. Decolorization and TOC removal of MB by ZVI are attributed to the four potential mechanisms, i.e. reduction, degradation, precipitation and adsorption. The contributions of four mechanisms were quantified at pH 3.0, 6.0 and 10.0 in the oxic and anoxic systems. The maximum efficiencies of decolorization and TOC removal of MB were found at pH 6.0. The TOC removal efficiencies at pH 3.0 and 10.0 were 11.0 and 17.0%, respectively which were considerably lower as compared with 68.1% at pH 6.0. The adsorption, which was favorable at higher pH but was depressed by the passive layer formed on the ZVI surface at alkaline conditions, characterized the effects of pH on decolorization and TOC removal of MB. The efficiencies of decolorization and TOC removal at pH 6.0 under the anoxic condition were 73.0 and 59.0%, respectively, which were comparable to 79.9 and 55.5% obtained under the oxic condition. In the oxic and anoxic conditions, however, the contributions of removal mechanisms were quite different. Although the adsorption dominated the decolorization and TOC removal under the oxic condition, the contribution of precipitation was largely superior to that of adsorption under the anoxic condition.
Adsorption capacities of poly-γ-glutamic acid and its sodium salt for cesium removal from radioactive wastewaters
Journal of Environmental Radioactivity, 2016
Cesium removal from radioactive wastewaters was examined using water-insoluble poly-γ-glutamic ac... more Cesium removal from radioactive wastewaters was examined using water-insoluble poly-γ-glutamic acid (γ-PGA) and water-soluble sodium salt form poly-γ-L-glutamic acid (γ-PGANa) as biosorbents. The maximum adsorption capacities at equilibrium of γ-PGA and γ-PGANa for Cs were 345 mg-Cs(g-γ-PGA)-1 at pH 6.0 and 290 mg-Cs(g-γ-PGANa)-1 at pH 9.0, respectively. At lower pH < pKa, the carboxyl groups of γ-PGA primarily remained in the protonated form and adsorption of Cs only slightly occurred. At higher pH > pKa, the adsorption of Cs was significantly facilitated due to ionization of carboxyl groups to carboxylate ion. Adsorption of Cs at pH > 9.0 was inhibited due to the hydrolysis of Cs. The Langmuir model could successfully describe the isotherm data. For γ-PGA and γ-PGANa, the maximum adsorption capacities at equilibrium in the Langmuir model were 446 and 333 mg-Cs(g-adsorbent)-1, respectively. The high adsorption capacities confirmed a potential utilization of γ-PGA and γ-PGANa for Cs removal. The adsorption of Cs by both γ-PGA and γ-PGANa attained the equilibrium within 0.5 min. The very quick equilibration is a benefit from the viewpoint of practical application. The spectra of FT-IR and XPS before and after adsorption confirmed the adsorption of Cs onto γ-PGA and γ-PGANa via electrostatic interaction with carboxylate anions.
Journal of Environmental Chemical Engineering, 2019
Cloud computing systems have become widely used for Big Data processing, providing access to a wi... more Cloud computing systems have become widely used for Big Data processing, providing access to a wide variety of computing resources and a greater distribution between multi-clouds. This trend has been strengthened by the rapid development of the Internet of Things (IoT) concept. Virtualization via virtual machines and containers is a traditional way of organization of cloud computing infrastructure. Containerization technology provides a lightweight virtual runtime environment. In addition to the advantages of traditional virtual machines in terms of size and flexibility, containers are particularly important for integration tasks for PaaS solutions, such as application packaging and service orchestration. In this paper, we overview the current state-ofthe-art of virtualization and containerization approaches and technologies in the context of Big Data tasks solution. We present the results of studies which compare the efficiency of containerization and virtualization technologies to solve Big Data problems. We also analyze containerized and virtualized services collaboration solutions to support automation of the deployment and execution of Big Data applications in the cloud infrastructure.
A phenomenological reaction kinetic model for Cu removal from aqueous solutions by zero-valent iron (ZVI)
Chemosphere, 2018
Zero-valent iron (ZVI) being an inexpensive and eco-friendly catalyst has drawn great attention i... more Zero-valent iron (ZVI) being an inexpensive and eco-friendly catalyst has drawn great attention in removal of heavy metals from wastewaters. However, quantitative understandings of ZVI processes are significantly deficient. To compensate for the lack of quantitative analyses of removal of heavy metals by ZVI, a phenomenological reaction kinetic model was newly developed for removal of Cu chosen as a typical heavy metal from acidic aqueous solutions by ZVI. The novel kinetic model is based on the adsorption of Cu2+ and H+ onto ZVI surface and subsequent Cu2+ reduction on ZVI surface and Fe2+ elution from ZVI. Batch experiments were conducted to elucidate effects of pH and Cu loading on Cu removal by ZVI in acidic aqueous solutions and to validate the proposed phenomenological reaction kinetic model. The quick and complete removals of 1.57 mM Cu were established in the rage of pH 2-5. Although the maximum Cu removal rate was obtained at pH 4, effects of pH were insignificant. In the range of Cu loading from 0.393 to 4.72 mM, almost complete Cu removals were obtained at pH 4 within 35 min. The changes in concentrations of Cu2+, Fe2+, H+ and dissolved oxygen were strongly linked with each other. They could be successfully simulated by the proposed model with the average correlation coefficient of 0.979. The capability of the phenomenological reaction kinetic model for dynamic simulation of Cu removal by ZVI under acidic conditions was confirmed.
Hydroxyl radical generation by zero-valent iron/Cu (ZVI/Cu) bimetallic catalyst in wastewater treatment: Heterogeneous Fenton/Fenton-like reactions by Fenton reagents formed in-situ under oxic conditions
Chemical Engineering Journal, 2018
Abstract Zero-valent iron (ZVI) has been recognized as a heterogeneous Fenton/Fenton-like catalys... more Abstract Zero-valent iron (ZVI) has been recognized as a heterogeneous Fenton/Fenton-like catalyst generating hydroxyl radical (OH radical). ZVI bimetallic catalysts modified by the deposition of transition metals on the ZVI surface have been proposed as alternatives to enhance the reactivity of ZVI catalyst. However, it is not clear from the literature whether OH radical is actively generated via the Fenton/Fenton-like reactions in ZVI bimetallic catalyst systems. To quantify the generation of OH radical by ZVI/Cu bimetallic catalysts, the amount of generated OH radical was measured under the oxic condition. Although the maximum amount of generated OH radical by ZVI/Cu bimetallic catalysts was obtained at pH 3 being an optimal pH for the Fenton reaction, OH radical generation by ZVI/Cu bimetallic catalysts was considerably restricted by the inadequate in-situ generation of H2O2 and the generation of OH radical was inhibited due to Cu deposition on ZVI surface. While the deposition of Cu on the ZVI surface enhanced the removal of Orange II via the facilitation of reductive degradation and the increase in adsorption capability on the surface of ZVI/Cu bimetallic catalysts, it could not stimulate the OH radical generation or the oxidative reactivity of heterogeneous Fenton/Fenton-like catalyst. The present study confirmed that the passivation of ZVI surface accelerated by the deposition of Cu on ZVI surface inhibited the OH radical generation. The kinetic models for OH radical generation by ZVI/Cu bimetallic catalysts were developed by considering the linkage of OH radical generation with eluted Fe and Cu ions. The model predictions could simulate the experimental results reasonably.
Zero-valent iron treatment of dark brown colored coffee effluent: Contributions of a core-shell structure to pollutant removals
Journal of Environmental Management, 2016
The decolorization and total organic carbon (TOC) removal of dark brown colored coffee effluent b... more The decolorization and total organic carbon (TOC) removal of dark brown colored coffee effluent by zero-valent iron (ZVI) have been systematically examined with solution pH of 3.0, 4.0, 6.0 and 8.0 under oxic and anoxic conditions. The optimal decolorization and TOC removal were obtained at pH 8.0 with oxic condition. The maximum efficiencies of decolorization and TOC removal were 92.6 and 60.2%, respectively. ZVI presented potential properties for pollutant removal at nearly neutral pH because of its core-shell structure in which shell or iron oxide/hydroxide layer on ZVI surface dominated the decolorization and TOC removal of coffee effluent. To elucidate the contribution of the core-shell structure to removals of color and TOC at the optimal condition, the characterization of ZVI surface by scanning electron microscopy (SEM) with an energy dispersive X-ray spectroscope (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) was conducted. It was confirmed that the core-shell structure was formed and the shell on ZVI particulate surface and the precipitates formed during the course of ZVI treatment consisted of iron oxides and hydroxides. They were significantly responsible for decolorization and TOC removal of coffee effluent via adsorption to shell on ZVI surface and inclusion into the precipitates rather than the oxidative degradation by OH radicals and the reduction by emitted electrons. The presence of dissolved oxygen (DO) enhanced the formation of the core-shell structure and as a result improved the efficiency of ZVI treatment for the removal of colored components in coffee effluents. ZVI was found to be an efficient material toward the treatment of coffee effluents.
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Papers by Yoshinori Kawase