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Gordon Mckay - One of the best experts on this subject based on the ideXlab platform.
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Effect of Bone Char application on Pb bioavailability in a Pb-contaminated soil.
Environmental Pollution, 2005Co-Authors: Shi-bao Chen, Yong-guan Zhu, Gordon MckayAbstract:Abstract The effects of Bone Char (BC) application on the bioavailability of Pb in a polluted soil from Hunan Province, China were examined. The Pb-contaminated soil was treated with two types of Bone Char, one from the UK and the other from China. The bioavailability of Pb was determined in terms of the uptake by Chinese cabbage ( Brassica chinensis L.), sequential extraction and X-ray diffraction analysis. The results indicate that the Pb concentrations in both shoots and roots decreased with increasing quantities of added Bone Char, and the application of BC from the UK at the rate of 1.6% (w:w) had the largest effect. Lead Pb concentrations in the shoots and roots decreased by 56.0% and 75.9%, respectively, whereas the application of BC from Zhejiang Province, China at the rate of 1.6% (w:w) reduced Pb concentrations in the shoots and roots to 2.04 mg kg −1 and 8.42 mg kg −1 , respectively, only 45.8% and 30.2% compared to the control treatment. Sequential extraction results indicate that the addition of Bone Char, as a metal-immobilizing agent, substantially transforms soil Pb from non-residual fractions to the residual fraction. The transformation was further confirmed using X-ray diffraction studies.
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Sorption of metal ions from aqueous solution using Bone Char.
Environment International, 2005Co-Authors: Keith K.h. Choy, Gordon MckayAbstract:The sorption of cadmium, copper and zinc from aqueous solutions onto Bone Char has been studied in both single and binary multi-component systems. Equilibrium experimental studies have been performed to determine the sorption capacity of Bone Char for each metal ion. The isotherm results have been analysed using single and multi-component equilibrium models. The rate of sorption of the metal ions onto Bone Char has been studied using an agitated batch adsorber. The concentration versus time decay curves have been measured and a number of mass transfer models have been developed and tested based on diffusion controlled sorption. The results of the equilibrium and rate studies are presented and discussed in the paper. The possible mechanisms of metal sorption are also discussed. Finally a series of fixed bed column studies have been performed and analysed using a diffusion mass transport model. The experimental results show a displacement effect for the binary metal ion breakthrough curves.
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Sorption of cadmium, copper, and zinc ions onto Bone Char using Crank diffusion model
Chemosphere, 2005Co-Authors: Keith K.h. Choy, Gordon MckayAbstract:Abstract The rates of adsorption of cadmium, copper and zinc ions onto Bone Char have been studied in three single component systems using an agitated batch adsorber. The effects of initial metal ion solution concentration and Bone Char mass have been studied. The capacities of the three metals on Bone Char are 0.477, 0.709 and 0.505 mmol g −1 for cadmium, copper and zinc respectively which are much higher than most other adsorbents reported in the literature for these three metals. In order to model the experimental concentration decay curves, a film-surface diffusion equation proposed by Crank (1979) has been solved. The model results correlate the experimental better than a previously applied film-pore diffusion model. However, the results indicate that the surface diffusion coefficient was a variable function of initial metal ion concentration. The surface diffusivities vary from 3.00 × 10 −9 to 8.80 × 10 −9 cm 2 s −1 , 2.11 × 10 −9 cm 2 s −1 to 5.4 × 10 −9 cm 2 s −1 and 3.10 × 10 −9 to 8.49 × 10 −9 cm 2 s −1 for cadmium, copper and zinc respectively, for metal ion solution concentrations of 2.10–5.40 mmol dm −3 .
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Multicomponent mass transport model for the sorption of metal ions on Bone Char
Aiche Journal, 2004Co-Authors: John F Porter, Gordon MckayAbstract:The sorption of binary mixtures of copper/cadmium and copper/zinc ions onto Bone Char was studied in fixed beds. The effects of solution flow rate, initial dye concentration, and Bone Char particle size range were investigated. A mass transport model based on film-surface diffusion and the IAS model for the equilibrium relationship was used to develop theoretical fixed-bed breakthrough curves. The model incorporates the Sips isotherm for the first time in fixed-bed predictions, since this isotherm gives an excellent correlation of the experimental equilibrium data. The model was used to determine the optimum surface diffusivities as 7.37 × 10−10 and 2.73 × 10−9 cm2/s for copper and cadmium in the Cu/Cd system; and 1.61 × 10−9 and 2.43 × 10−9 cm2/s for copper and zinc in the Cu/Zn system. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2130–2141, 2004
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Mass Transport Model for the Fixed Bed Sorption of Metal Ions on Bone Char
Industrial & Engineering Chemistry Research, 2003Co-Authors: John F Porter, Gordon MckayAbstract:The ability for the sorption of the three metals onto Bone Char was demonstrated by a series of equilibrium isotherm studies. The Sips isotherm equation was found to give the most accurate correlation of the equilibrium relationship between these metal ions and Bone Char, and the equilibrium adsorption capacities of Bone Char for copper, zinc, and cadmium ion were determined to be approximately 0.80, 0.50, and 0.55 mmol/g, respectively. A film surface diffusion model, which is based on the assumption that the sorbate penetration rate is controlled by the external film diffusion and surface diffusion within the sorbent, has been developed to simulate the fixed bed sorption of copper, zinc, and cadmium ions onto Bone Char. A computer program based on a numerical solution using the finite difference method has been constructed and successfully simulated the metal ion−Bone Char column behavior. A new external mass transfer correlation was proposed and applied in the model. The effect of axial dispersion was t...
Wei Gao - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Photocatalytic Performance of ZnO/Bone Char Composite
Materials, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:ZnO/Bone Char (ZnO/BC) composites were successfully synthesized by the precipitation of a ZnO precursor on pyrolytic Bone Char. The effects of Bone Char size, mass ratio of ZnO to BC, and molar ratio of ZnO to triethylamine (TEA) on the microstructure, specific surface area, and light absorbance of ZnO/BC were studied. The photocatalytic property of ZnO/BC was evaluated by the degradation of methylene blue. Results show that with a uniform nano-ZnO particle layer distributed evenly on the Bone Char surface, ZnO/BC has the strongest light absorbance and can effectively degrade methylene blue. The photocatalytic performance of ZnO/BC is related to the light absorbance of the photocatalyst, as well as the amount and distribution state of the loaded ZnO. This study indicates that bovine Bone waste can be used as a nano-photocatalyst carrier to prepare photocatalytic composites, which is not only a good way to clean wastewater but also an ideal solution to utilize animal Bone waste.
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synthesis and photocatalytic performance of zno Bone Char composite
Materials, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:ZnO/Bone Char (ZnO/BC) composites were successfully synthesized by the precipitation of a ZnO precursor on pyrolytic Bone Char. The effects of Bone Char size, mass ratio of ZnO to BC, and molar ratio of ZnO to triethylamine (TEA) on the microstructure, specific surface area, and light absorbance of ZnO/BC were studied. The photocatalytic property of ZnO/BC was evaluated by the degradation of methylene blue. Results show that with a uniform nano-ZnO particle layer distributed evenly on the Bone Char surface, ZnO/BC has the strongest light absorbance and can effectively degrade methylene blue. The photocatalytic performance of ZnO/BC is related to the light absorbance of the photocatalyst, as well as the amount and distribution state of the loaded ZnO. This study indicates that bovine Bone waste can be used as a nano-photocatalyst carrier to prepare photocatalytic composites, which is not only a good way to clean wastewater but also an ideal solution to utilize animal Bone waste.
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Removal of Methylene Blue from Aqueous Solution by Bone Char
Applied Sciences, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:Bone Char was prepared from bovine Bone for the removal of methylene blue from aqueous solution. The effects of particle size, contact time, and adsorption temperature on the removal rate of methylene blue were investigated. It was found that Bone Char particle size had an insignificant effect. The equilibration time was found at approximately 80 min. The removal rate decreased with an increase in temperature. The intraparticle diffusion was the main rate-limiting step. The experimental data was analyzed by kinetic, isotherm, and thermodynamic equations. The results show that the pseudo-second-order kinetic model and Freundlich, Temkin, and Dubinin–Kaganer–Radushkevich isotherm models are true of the adsorption process. The spontaneous and exothermic ion-exchange adsorption process was certified by the negative values of free energy change and enthalpy change, and 13.29 kJ mol−1 of adsorption energy.
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Synthesis, Characterization and photocatalytic property of novel ZnO/Bone Char composite
Materials Research Bulletin, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:Abstract An innovative composite photocatalyst ZnO/Bone Char (ZnO/BC) was prepared using precipitation of ZnO precursor on Bone Char. The UV–vis absorbance spectrum showed that ZnO/BC has strong visible light absorption. The photocatalytic activity of ZnO/BC was evaluated by degradation of methylene blue (MB) under solar simulator irradiation; and the effects of oxygen, pH, holes (h + ) and hydroxyl radicals ( OH) on the photocatalytic efficiency have been studied. Results showed that the dissolved oxygen contributes to the photocatalytic reaction in MB alkaline solution. The photocatalytic process mainly depends on the pH of the solution. In alkaline solution, OH − can be oxidized by h + to form active OH. Meanwhile, the increase of MB on Bone Char enhances the contact to active h + and OH produced on the surface of ZnO, enhancing the photocatalytic efficiency and reaction rate. The photocatalysis of ZnO/BC mainly resulted from direct oxidation of MB caused by photoinduced holes.
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synthesis Characterization and photocatalytic property of novel zno Bone Char composite
Materials Research Bulletin, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:Abstract An innovative composite photocatalyst ZnO/Bone Char (ZnO/BC) was prepared using precipitation of ZnO precursor on Bone Char. The UV–vis absorbance spectrum showed that ZnO/BC has strong visible light absorption. The photocatalytic activity of ZnO/BC was evaluated by degradation of methylene blue (MB) under solar simulator irradiation; and the effects of oxygen, pH, holes (h + ) and hydroxyl radicals ( OH) on the photocatalytic efficiency have been studied. Results showed that the dissolved oxygen contributes to the photocatalytic reaction in MB alkaline solution. The photocatalytic process mainly depends on the pH of the solution. In alkaline solution, OH − can be oxidized by h + to form active OH. Meanwhile, the increase of MB on Bone Char enhances the contact to active h + and OH produced on the surface of ZnO, enhancing the photocatalytic efficiency and reaction rate. The photocatalysis of ZnO/BC mainly resulted from direct oxidation of MB caused by photoinduced holes.
Puqi Jia - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Photocatalytic Performance of ZnO/Bone Char Composite
Materials, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:ZnO/Bone Char (ZnO/BC) composites were successfully synthesized by the precipitation of a ZnO precursor on pyrolytic Bone Char. The effects of Bone Char size, mass ratio of ZnO to BC, and molar ratio of ZnO to triethylamine (TEA) on the microstructure, specific surface area, and light absorbance of ZnO/BC were studied. The photocatalytic property of ZnO/BC was evaluated by the degradation of methylene blue. Results show that with a uniform nano-ZnO particle layer distributed evenly on the Bone Char surface, ZnO/BC has the strongest light absorbance and can effectively degrade methylene blue. The photocatalytic performance of ZnO/BC is related to the light absorbance of the photocatalyst, as well as the amount and distribution state of the loaded ZnO. This study indicates that bovine Bone waste can be used as a nano-photocatalyst carrier to prepare photocatalytic composites, which is not only a good way to clean wastewater but also an ideal solution to utilize animal Bone waste.
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synthesis and photocatalytic performance of zno Bone Char composite
Materials, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:ZnO/Bone Char (ZnO/BC) composites were successfully synthesized by the precipitation of a ZnO precursor on pyrolytic Bone Char. The effects of Bone Char size, mass ratio of ZnO to BC, and molar ratio of ZnO to triethylamine (TEA) on the microstructure, specific surface area, and light absorbance of ZnO/BC were studied. The photocatalytic property of ZnO/BC was evaluated by the degradation of methylene blue. Results show that with a uniform nano-ZnO particle layer distributed evenly on the Bone Char surface, ZnO/BC has the strongest light absorbance and can effectively degrade methylene blue. The photocatalytic performance of ZnO/BC is related to the light absorbance of the photocatalyst, as well as the amount and distribution state of the loaded ZnO. This study indicates that bovine Bone waste can be used as a nano-photocatalyst carrier to prepare photocatalytic composites, which is not only a good way to clean wastewater but also an ideal solution to utilize animal Bone waste.
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Removal of Methylene Blue from Aqueous Solution by Bone Char
Applied Sciences, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:Bone Char was prepared from bovine Bone for the removal of methylene blue from aqueous solution. The effects of particle size, contact time, and adsorption temperature on the removal rate of methylene blue were investigated. It was found that Bone Char particle size had an insignificant effect. The equilibration time was found at approximately 80 min. The removal rate decreased with an increase in temperature. The intraparticle diffusion was the main rate-limiting step. The experimental data was analyzed by kinetic, isotherm, and thermodynamic equations. The results show that the pseudo-second-order kinetic model and Freundlich, Temkin, and Dubinin–Kaganer–Radushkevich isotherm models are true of the adsorption process. The spontaneous and exothermic ion-exchange adsorption process was certified by the negative values of free energy change and enthalpy change, and 13.29 kJ mol−1 of adsorption energy.
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Synthesis, Characterization and photocatalytic property of novel ZnO/Bone Char composite
Materials Research Bulletin, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:Abstract An innovative composite photocatalyst ZnO/Bone Char (ZnO/BC) was prepared using precipitation of ZnO precursor on Bone Char. The UV–vis absorbance spectrum showed that ZnO/BC has strong visible light absorption. The photocatalytic activity of ZnO/BC was evaluated by degradation of methylene blue (MB) under solar simulator irradiation; and the effects of oxygen, pH, holes (h + ) and hydroxyl radicals ( OH) on the photocatalytic efficiency have been studied. Results showed that the dissolved oxygen contributes to the photocatalytic reaction in MB alkaline solution. The photocatalytic process mainly depends on the pH of the solution. In alkaline solution, OH − can be oxidized by h + to form active OH. Meanwhile, the increase of MB on Bone Char enhances the contact to active h + and OH produced on the surface of ZnO, enhancing the photocatalytic efficiency and reaction rate. The photocatalysis of ZnO/BC mainly resulted from direct oxidation of MB caused by photoinduced holes.
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synthesis Characterization and photocatalytic property of novel zno Bone Char composite
Materials Research Bulletin, 2018Co-Authors: Puqi Jia, Hongwei Tan, Kuiren Liu, Wei GaoAbstract:Abstract An innovative composite photocatalyst ZnO/Bone Char (ZnO/BC) was prepared using precipitation of ZnO precursor on Bone Char. The UV–vis absorbance spectrum showed that ZnO/BC has strong visible light absorption. The photocatalytic activity of ZnO/BC was evaluated by degradation of methylene blue (MB) under solar simulator irradiation; and the effects of oxygen, pH, holes (h + ) and hydroxyl radicals ( OH) on the photocatalytic efficiency have been studied. Results showed that the dissolved oxygen contributes to the photocatalytic reaction in MB alkaline solution. The photocatalytic process mainly depends on the pH of the solution. In alkaline solution, OH − can be oxidized by h + to form active OH. Meanwhile, the increase of MB on Bone Char enhances the contact to active h + and OH produced on the surface of ZnO, enhancing the photocatalytic efficiency and reaction rate. The photocatalysis of ZnO/BC mainly resulted from direct oxidation of MB caused by photoinduced holes.
Chun Wai Cheung - One of the best experts on this subject based on the ideXlab platform.
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Binary Metal Sorption on Bone Char Mass Transport Model Using IAST
Langmuir, 2003Co-Authors: Chun Wai Cheung, John F Porter, Gordon MckayAbstract:The binary sorption of Cu−Cd, Cd−Zn, and Cu−Zn onto Bone Char has been studied using an equilibrium and batch agitation system. The sorption capacities and the selectivity of metal ions onto Bone Char follows the order Cu2+ > Cd2+ > Zn2+, which is in the reverse order of the hydrated ionic radii. The binary sorption equilibria were predicted by the ideal adsorbed solution theory (IAST) on the basis of single component isotherm data using a Langmuir or Langmuir−Freundlich isotherm. The overall performance of the IAST provides a reasonable curve fitting to the experimental data. The single component film−pore diffusion model was extended to the multicomponent systems to correlate the batch kinetic data by incorporating the shrinking core model and the IAST. All the diffusivities in the binary systems are similar to or less than the pore diffusivities in single component systems.
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Removal of Cu(II) and Zn(II) Ions by Sorption onto Bone Char Using Batch Agitation
Langmuir, 2002Co-Authors: Chun Wai Cheung, John F Porter, Gordon MckayAbstract:The sorption rate of copper and zinc ions onto Bone Char around pH 5 has been studied using a batch agitation system. The calcium hydroxyapatite, which is the main composition in Bone Char, removes the metal ions by means of adsorption and ion exchange from the solutions. When the pH values of solutions are adjusted to pH 4 or below, the X-ray desorption patterns show the degrees of the crystalline of hydroxyapatite in the Bone Char reducing. Therefore, the sorption process for the metal ions removal from effluent is recommended to control around pH 5 or above to reduce the loss of the sorbent. In addition, the experimental data from the adsorption isotherms and batch kinetics studied were correlated using the Langmuir equation and a film-pore diffusion mass transport model. The Langmuir parameters were incorporated into the film-pore diffusion model to correlate the batch kinetic data. The constant pore diffusivities for the sorption of copper and zinc ions onto Bone Char are equivalent to 6.67 × 10-7 an...
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sorption kinetic analysis for the removal of cadmium ions from effluents using Bone Char
Water Research, 2001Co-Authors: Chun Wai Cheung, John F Porter, Gordon MckayAbstract:Abstract The adsorption of cadmium ions onto Bone Char has been studied using a batch adsorber. The experimental data was analyzed using four sorption kinetic models-the pseudo-first order, the Ritchie second order, the modified second order and the Elovich equations-to determine the best-fit equation for the sorption of metal ions onto Bone Char. The best-fit equation was identified using the sum of the errors squared ( SSE ). Finally, equilibrium studies were used to evaluate the sorption capacity of Bone Char for cadmium ions and experimental results showed this to be 0.57 mmol g −1 at an equilibrium solution concentration of 3.0 mmol dm −3 . Since the sorption capacity is relatively high, Bone Char can be considered as a suitable sorbent for the adsorption of cadmium in wastewater treatment systems.
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The Removal of Metal Ions from Aqueous Solutions by Bone Char Sorption
Environmental Monitoring and Biodiagnostics of Hazardous Contaminants, 2001Co-Authors: Chun Wai Cheung, G. Mckay, J.f. PorterAbstract:The sorption of cadmium and copper onto Bone Char has been studied in single component systems. Bone Char-type Brimac 216 used throughout all the experiments. Two types of experiments were performed, namely, equilibrium sorption isotherm studies and agitated batch kinetic studies. Equilibrium isotherms were determined for the single component sorption of cadmium and copper onto Bone Char. The isotherms were analyzed using the Langmuir, Freundlich and Redlich-Peterson equations and the Redlich-Peterson equation gave the highest correlation coefficients for both systems. The effect of initial metal ion concentration on the rate of metal ion sorption with contact time was studied using an agitated, baffled, 1.7 dm3 sorber vessel. The contact time data were analyzed using the Lagergren first order kinetic model and a pseudo-second order kinetic model. The pseudo-second order kinetic model gives a higher correlation coefficient for a longer contact time period of the sorption process.
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sorption kinetics for the removal of copper and zinc from effluents using Bone Char
Separation and Purification Technology, 2000Co-Authors: Chun Wai Cheung, John F Porter, Gordon MckayAbstract:Abstract The removal of copper and zinc ions from aqueous effluents by Bone Char has been studied in single component sorption systems. The sorption capacity of Bone Char for copper and zinc is 0.75 and 0.53 mmol per g Bone Char, respectively. The values indicate that Bone Char is a suitable sorbent for the two metal ions. The equilibrium isotherms are best described by a Langmuir–Freundlich (L–F) type isotherm equation. The kinetics of sorption of the two metal ions have been analyzed by two kinetic models, namely, the Lagergren pseudo first-order model and the Elovich kinetic model. Kinetic analysis of the two models has been carried out for system variables — initial metal ion concentration and mass of Bone Char. The rate constants for the two models have been determined and the correlation coefficients have been calculated in order to assess which model provides the best fit predicted data with experimental results. The Elovich equation provides the best fit to experimental data.
John F Porter - One of the best experts on this subject based on the ideXlab platform.
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Multicomponent mass transport model for the sorption of metal ions on Bone Char
Aiche Journal, 2004Co-Authors: John F Porter, Gordon MckayAbstract:The sorption of binary mixtures of copper/cadmium and copper/zinc ions onto Bone Char was studied in fixed beds. The effects of solution flow rate, initial dye concentration, and Bone Char particle size range were investigated. A mass transport model based on film-surface diffusion and the IAS model for the equilibrium relationship was used to develop theoretical fixed-bed breakthrough curves. The model incorporates the Sips isotherm for the first time in fixed-bed predictions, since this isotherm gives an excellent correlation of the experimental equilibrium data. The model was used to determine the optimum surface diffusivities as 7.37 × 10−10 and 2.73 × 10−9 cm2/s for copper and cadmium in the Cu/Cd system; and 1.61 × 10−9 and 2.43 × 10−9 cm2/s for copper and zinc in the Cu/Zn system. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2130–2141, 2004
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Mass Transport Model for the Fixed Bed Sorption of Metal Ions on Bone Char
Industrial & Engineering Chemistry Research, 2003Co-Authors: John F Porter, Gordon MckayAbstract:The ability for the sorption of the three metals onto Bone Char was demonstrated by a series of equilibrium isotherm studies. The Sips isotherm equation was found to give the most accurate correlation of the equilibrium relationship between these metal ions and Bone Char, and the equilibrium adsorption capacities of Bone Char for copper, zinc, and cadmium ion were determined to be approximately 0.80, 0.50, and 0.55 mmol/g, respectively. A film surface diffusion model, which is based on the assumption that the sorbate penetration rate is controlled by the external film diffusion and surface diffusion within the sorbent, has been developed to simulate the fixed bed sorption of copper, zinc, and cadmium ions onto Bone Char. A computer program based on a numerical solution using the finite difference method has been constructed and successfully simulated the metal ion−Bone Char column behavior. A new external mass transfer correlation was proposed and applied in the model. The effect of axial dispersion was t...
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Binary Metal Sorption on Bone Char Mass Transport Model Using IAST
Langmuir, 2003Co-Authors: Chun Wai Cheung, John F Porter, Gordon MckayAbstract:The binary sorption of Cu−Cd, Cd−Zn, and Cu−Zn onto Bone Char has been studied using an equilibrium and batch agitation system. The sorption capacities and the selectivity of metal ions onto Bone Char follows the order Cu2+ > Cd2+ > Zn2+, which is in the reverse order of the hydrated ionic radii. The binary sorption equilibria were predicted by the ideal adsorbed solution theory (IAST) on the basis of single component isotherm data using a Langmuir or Langmuir−Freundlich isotherm. The overall performance of the IAST provides a reasonable curve fitting to the experimental data. The single component film−pore diffusion model was extended to the multicomponent systems to correlate the batch kinetic data by incorporating the shrinking core model and the IAST. All the diffusivities in the binary systems are similar to or less than the pore diffusivities in single component systems.
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Removal of Cu(II) and Zn(II) Ions by Sorption onto Bone Char Using Batch Agitation
Langmuir, 2002Co-Authors: Chun Wai Cheung, John F Porter, Gordon MckayAbstract:The sorption rate of copper and zinc ions onto Bone Char around pH 5 has been studied using a batch agitation system. The calcium hydroxyapatite, which is the main composition in Bone Char, removes the metal ions by means of adsorption and ion exchange from the solutions. When the pH values of solutions are adjusted to pH 4 or below, the X-ray desorption patterns show the degrees of the crystalline of hydroxyapatite in the Bone Char reducing. Therefore, the sorption process for the metal ions removal from effluent is recommended to control around pH 5 or above to reduce the loss of the sorbent. In addition, the experimental data from the adsorption isotherms and batch kinetics studied were correlated using the Langmuir equation and a film-pore diffusion mass transport model. The Langmuir parameters were incorporated into the film-pore diffusion model to correlate the batch kinetic data. The constant pore diffusivities for the sorption of copper and zinc ions onto Bone Char are equivalent to 6.67 × 10-7 an...
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Film-pore diffusion model for the fixed-bed sorption of copper and cadmium ions onto Bone Char.
Water Research, 2001Co-Authors: John F Porter, Gordon MckayAbstract:Abstract The sorption of copper and cadmium ions onto Bone Char in single component systems has been studied using fixed-bed column adsorbers. The effects of solution flowrate, initial metal ion concentration and Bone Char particle size have been studied. A film-pore diffusion model has been developed to predict the fixed-bed breakthrough curves for the two metal ions. A sensitivity analysis has been carried out to investigate the influence of the external mass transfer coefficient (film resistance), the effective diffusion coefficient (pore diffusion) and the solid phase loading capacity. It is found that under the experimental conditions employed in the study, film diffusional resistance was low and the Biot numbers were relatively high. Furthermore, a constant effective pore diffusivity was not sufficient to correlate the breakthrough curves accurately and a variable dependent effective diffusivity was required; suggesting a possible contribution from surface diffusion. Since the metal ion–Bone Char systems take a long time to reach equilibrium, the solid phase loading capacity, as predicted by the “best-fit” equilibrium isotherm, was not suitable for use in the diffusional mass transport model and the mass balance solid phase loading was utilised instead.