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Sara J Couperthwaite - One of the best experts on this subject based on the ideXlab platform.

  • Determination of an engineering model for exchange kinetics of strong acid Cation Resin for the ion exchange of sodium chloride & sodium bicarbonate solutions
    Journal of water process engineering, 2017
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Gavin L. Miller, Scott A. Dalzell, David Macfarlane
    Abstract:

    Abstract This study identified an appropriate engineering model which described the exchange kinetics of sodium ions with a strong acid Cation Resin. Synthetic Resins have potential appliCation for the demineralization of coal seam (CS) water prior to beneficial reuse. However, there is limited data regarding the kinetic behaviour of strong acid Cation (SAC) Resin for the removal of sodium ions, the most prevalent ions in the water collected from coal seams (produced water) during natural gas extraction. In particular, exchange kinetics need to be understood in relation to estimating how full scale columns of Resin may perform. Kinetic analysis revealed that the exchange of sodium ions from both sodium chloride and sodium bicarbonate solutions with SAC Resin reached equilibrium within minutes at ambient temperature. Optimal simulation of the kinetic data for both chloride and bicarbonate containing solutions was achieved by appliCation of the Brouers, Weron and Sotolongo (BWS) fractal equation; and this should be used as the basis for development of an engineering model. The model parameters varied depending upon the ratio of Resin to liquid employed in the tests, with rates showing substantial enhancement once an excess of Resin exchange sites were present. The exchange process was apparently controlled in part by intraparticle diffusion, with three phases inferred for sodium chloride solutions and two for sodium bicarbonate solutions. Other rate limiting phenomena such as film diffusion appeared to play a role under certain conditions.

  • BDST modelling of sodium ion exchange column behaviour with strong acid Cation Resin in relation to coal seam water treatment
    Journal of environmental chemical engineering, 2016
    Co-Authors: Nathan Pember, Sara J Couperthwaite, Graeme J Millar, Mitchell De Bruyn, Kenneth Nuttall
    Abstract:

    Abstract Reverse osmosis is the dominant technology utilized for desalination of saline water produced during the extraction of coal seam gas. Alternatively, ion exchange is of interest due to potential cost advantages. However, there is limited information regarding the column performance of strong acid Cation Resin for removal of sodium ions from both model and actual coal seam water samples. In particular, the impact of bed depth, flow rate, and regeneration was not clear. Consequently, this study applied Bed Depth Service Time (BDST) models to reveal that increasing sodium ion concentration and flow rates diminished the time required for breakthrough to occur. The loading of sodium ions on fresh Resin was calculated to be ca . 71.1 g Na/kg Resin. Difficulties in regeneration of the Resin using hydrochloric acid solutions were discovered, with 86% recovery of exchange sites observed. The maximum concentration of sodium ions in the regenerant brine was found to be 47,400 mg/L under the conditions employed. The volume of regenerant waste formed was 6.2% of the total volume of water treated. A coal seam water sample was found to load the Resin with only 53.5 g Na/kg Resin, which was consistent with not only the co-presence of more favoured ions such as calcium, magnesium, barium and strontium, but also inefficient regeneration of the Resin prior to the coal seam water test.

  • factors influencing kinetic and equilibrium behaviour of sodium ion exchange with strong acid Cation Resin
    Institute for Future Environments; Science & Engineering Faculty, 2016
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Gavin L. Miller, Shannon Papworth
    Abstract:

    This study reports an investigation of the ion exchange treatment of sodium chloride solutions in relation to use of Resin technology for appliCations such as desalination of brackish water. In particular, a strong acid Cation (SAC) Resin (DOW Marathon C) was studied to determine its capacity for sodium uptake and to evaluate the fundamentals of the ion exchange process involved. Key questions to answer included: impact of Resin identity; best models to simulate the kinetics and equilibrium exchange behaviour of sodium ions; difference between using linear least squares (LLS) and non-linear least squares (NLLS) methods for data interpretation; and, effect of changing the type of anion in solution which accompanied the sodium species. Kinetic studies suggested that the exchange process was best described by a pseudo first order rate expression based upon non-linear least squares analysis of the test data. AppliCation of the Langmuir Vageler isotherm model was recommended as it allowed confirmation that experimental conditions were sufficient for maximum loading of sodium ions to occur. The Freundlich expression best fitted the equilibrium data when analysing the information by a NLLS approach. In contrast, LLS methods suggested that the Langmuir model was optimal for describing the equilibrium process. The Competitive Langmuir model which considered the stoichiometric nature of ion exchange process, estimated the maximum loading of sodium ions to be 64.7 g Na/kg Resin. This latter value was comparable to sodium ion capacities for SAC Resin published previously. Inherent discrepancies involved when using linearized versions of kinetic and isotherm equations were illustrated, and despite their widespread use, the value of this latter approach was questionable. The equilibrium behaviour of sodium ions form sodium fluoride solution revealed that the sodium ions were now more preferred by the Resin compared to the situation with sodium chloride. The solution chemistry of hydrofluoric acid was suggested as promoting the affinity of the sodium ions to the Resin.

  • ion exchange treatment of saline solutions using lanxess s108h strong acid Cation Resin
    Institute for Future Environments; Science & Engineering Faculty, 2015
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Mitchell De Bruyn, Chun Wing Leung
    Abstract:

    Common to many types of water and wastewater is the presence of sodium ions which can be removed by desalination technologies, such as reverse osmosis and ion exchange. The focus of this investigation was ion exchange as it potentially offered several advantages compared to competing methods. The equilibrium and column behaviour of a strong acid Cation (SAC) Resin was examined for the removal of sodium ions from aqueous sodium chloride solutions of varying normality as well as a coal seam gas water sample. The influence of the bottle-point method to generate the sorption isotherms was evaluated and data interpreted with the Langmuir Vageler, Competitive Langmuir, Freundlich, and Dubinin-Astakhov models. With the constant concentration bottle point method, the predicted maximum exchange levels of sodium ions on the Resin ranged from 61.7 to 67.5 g Na/kg Resin. The general trend was that the lower the initial concentration of sodium ions in the solution, the lower the maximum capacity of the Resin for sodium ions. In contrast, the constant mass bottle point method was found to be problematic in that the isotherm profiles may not be complete, if experimental parameters were not chosen carefully. Column studies supported the observations of the equilibrium studies, with maximum sodium loading of ca. 62.9 g Na/kg Resin measured, which was in excellent agreement with the predictions of the data from the constant concentration bottle point method. Equilibria involving coal seam gas water were more complex due to the presence of sodium bicarbonate in solution, albeit the maximum loading capacity for sodium ions was in agreement with the results from the more simple sodium chloride solutions.

  • Equilibrium and column studies of iron exchange with strong acid Cation Resin
    Journal of environmental chemical engineering, 2015
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Aaron Schot, Amy Shilling, Kenneth Nuttall, Mitchell De Bruyn
    Abstract:

    Abstract The exchange of iron species from iron(III) chloride solutions with a strong acid Cation Resin has been investigated in relation to a variety of water and wastewater appliCations. A detailed equilibrium isotherm analysis was conducted wherein models such as Langmuir–Vageler, Competitive Langmuir, Freundlich, Temkin, Dubinin–Astakhov, Sips and Brouers–Sotolongo were applied to the experimental data. An important conclusion was that both the bottle-point method chosen and solution normality used to generate the ion exchange equilibrium isotherm influenced which sorption model fitted the isotherm profiles optimally. Invariably, the calculated value for the maximum loading of iron on strong acid Cation Resin was substantially higher than the value of 47.1 g/kg of Resin which would occur if one Fe3+ ion exchanged for three “H+” sites on the Resin surface. Consequently, it was suggested that above pH 1, various iron complexes sorbed to the Resin in a manner which required less than 3 sites per iron moiety. Column trials suggested that the iron loading was 86.6 g/kg of Resin when 1342 mg/L Fe(III) ions in water were flowed at 31.7 BV/h. Regeneration with 5–10% HCl solutions reclaimed approximately 90% of exchange sites.

Graeme J Millar - One of the best experts on this subject based on the ideXlab platform.

  • Determination of an engineering model for exchange kinetics of strong acid Cation Resin for the ion exchange of sodium chloride & sodium bicarbonate solutions
    Journal of water process engineering, 2017
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Gavin L. Miller, Scott A. Dalzell, David Macfarlane
    Abstract:

    Abstract This study identified an appropriate engineering model which described the exchange kinetics of sodium ions with a strong acid Cation Resin. Synthetic Resins have potential appliCation for the demineralization of coal seam (CS) water prior to beneficial reuse. However, there is limited data regarding the kinetic behaviour of strong acid Cation (SAC) Resin for the removal of sodium ions, the most prevalent ions in the water collected from coal seams (produced water) during natural gas extraction. In particular, exchange kinetics need to be understood in relation to estimating how full scale columns of Resin may perform. Kinetic analysis revealed that the exchange of sodium ions from both sodium chloride and sodium bicarbonate solutions with SAC Resin reached equilibrium within minutes at ambient temperature. Optimal simulation of the kinetic data for both chloride and bicarbonate containing solutions was achieved by appliCation of the Brouers, Weron and Sotolongo (BWS) fractal equation; and this should be used as the basis for development of an engineering model. The model parameters varied depending upon the ratio of Resin to liquid employed in the tests, with rates showing substantial enhancement once an excess of Resin exchange sites were present. The exchange process was apparently controlled in part by intraparticle diffusion, with three phases inferred for sodium chloride solutions and two for sodium bicarbonate solutions. Other rate limiting phenomena such as film diffusion appeared to play a role under certain conditions.

  • BDST modelling of sodium ion exchange column behaviour with strong acid Cation Resin in relation to coal seam water treatment
    Journal of environmental chemical engineering, 2016
    Co-Authors: Nathan Pember, Sara J Couperthwaite, Graeme J Millar, Mitchell De Bruyn, Kenneth Nuttall
    Abstract:

    Abstract Reverse osmosis is the dominant technology utilized for desalination of saline water produced during the extraction of coal seam gas. Alternatively, ion exchange is of interest due to potential cost advantages. However, there is limited information regarding the column performance of strong acid Cation Resin for removal of sodium ions from both model and actual coal seam water samples. In particular, the impact of bed depth, flow rate, and regeneration was not clear. Consequently, this study applied Bed Depth Service Time (BDST) models to reveal that increasing sodium ion concentration and flow rates diminished the time required for breakthrough to occur. The loading of sodium ions on fresh Resin was calculated to be ca . 71.1 g Na/kg Resin. Difficulties in regeneration of the Resin using hydrochloric acid solutions were discovered, with 86% recovery of exchange sites observed. The maximum concentration of sodium ions in the regenerant brine was found to be 47,400 mg/L under the conditions employed. The volume of regenerant waste formed was 6.2% of the total volume of water treated. A coal seam water sample was found to load the Resin with only 53.5 g Na/kg Resin, which was consistent with not only the co-presence of more favoured ions such as calcium, magnesium, barium and strontium, but also inefficient regeneration of the Resin prior to the coal seam water test.

  • factors influencing kinetic and equilibrium behaviour of sodium ion exchange with strong acid Cation Resin
    Institute for Future Environments; Science & Engineering Faculty, 2016
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Gavin L. Miller, Shannon Papworth
    Abstract:

    This study reports an investigation of the ion exchange treatment of sodium chloride solutions in relation to use of Resin technology for appliCations such as desalination of brackish water. In particular, a strong acid Cation (SAC) Resin (DOW Marathon C) was studied to determine its capacity for sodium uptake and to evaluate the fundamentals of the ion exchange process involved. Key questions to answer included: impact of Resin identity; best models to simulate the kinetics and equilibrium exchange behaviour of sodium ions; difference between using linear least squares (LLS) and non-linear least squares (NLLS) methods for data interpretation; and, effect of changing the type of anion in solution which accompanied the sodium species. Kinetic studies suggested that the exchange process was best described by a pseudo first order rate expression based upon non-linear least squares analysis of the test data. AppliCation of the Langmuir Vageler isotherm model was recommended as it allowed confirmation that experimental conditions were sufficient for maximum loading of sodium ions to occur. The Freundlich expression best fitted the equilibrium data when analysing the information by a NLLS approach. In contrast, LLS methods suggested that the Langmuir model was optimal for describing the equilibrium process. The Competitive Langmuir model which considered the stoichiometric nature of ion exchange process, estimated the maximum loading of sodium ions to be 64.7 g Na/kg Resin. This latter value was comparable to sodium ion capacities for SAC Resin published previously. Inherent discrepancies involved when using linearized versions of kinetic and isotherm equations were illustrated, and despite their widespread use, the value of this latter approach was questionable. The equilibrium behaviour of sodium ions form sodium fluoride solution revealed that the sodium ions were now more preferred by the Resin compared to the situation with sodium chloride. The solution chemistry of hydrofluoric acid was suggested as promoting the affinity of the sodium ions to the Resin.

  • ion exchange treatment of saline solutions using lanxess s108h strong acid Cation Resin
    Institute for Future Environments; Science & Engineering Faculty, 2015
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Mitchell De Bruyn, Chun Wing Leung
    Abstract:

    Common to many types of water and wastewater is the presence of sodium ions which can be removed by desalination technologies, such as reverse osmosis and ion exchange. The focus of this investigation was ion exchange as it potentially offered several advantages compared to competing methods. The equilibrium and column behaviour of a strong acid Cation (SAC) Resin was examined for the removal of sodium ions from aqueous sodium chloride solutions of varying normality as well as a coal seam gas water sample. The influence of the bottle-point method to generate the sorption isotherms was evaluated and data interpreted with the Langmuir Vageler, Competitive Langmuir, Freundlich, and Dubinin-Astakhov models. With the constant concentration bottle point method, the predicted maximum exchange levels of sodium ions on the Resin ranged from 61.7 to 67.5 g Na/kg Resin. The general trend was that the lower the initial concentration of sodium ions in the solution, the lower the maximum capacity of the Resin for sodium ions. In contrast, the constant mass bottle point method was found to be problematic in that the isotherm profiles may not be complete, if experimental parameters were not chosen carefully. Column studies supported the observations of the equilibrium studies, with maximum sodium loading of ca. 62.9 g Na/kg Resin measured, which was in excellent agreement with the predictions of the data from the constant concentration bottle point method. Equilibria involving coal seam gas water were more complex due to the presence of sodium bicarbonate in solution, albeit the maximum loading capacity for sodium ions was in agreement with the results from the more simple sodium chloride solutions.

  • Equilibrium and column studies of iron exchange with strong acid Cation Resin
    Journal of environmental chemical engineering, 2015
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Aaron Schot, Amy Shilling, Kenneth Nuttall, Mitchell De Bruyn
    Abstract:

    Abstract The exchange of iron species from iron(III) chloride solutions with a strong acid Cation Resin has been investigated in relation to a variety of water and wastewater appliCations. A detailed equilibrium isotherm analysis was conducted wherein models such as Langmuir–Vageler, Competitive Langmuir, Freundlich, Temkin, Dubinin–Astakhov, Sips and Brouers–Sotolongo were applied to the experimental data. An important conclusion was that both the bottle-point method chosen and solution normality used to generate the ion exchange equilibrium isotherm influenced which sorption model fitted the isotherm profiles optimally. Invariably, the calculated value for the maximum loading of iron on strong acid Cation Resin was substantially higher than the value of 47.1 g/kg of Resin which would occur if one Fe3+ ion exchanged for three “H+” sites on the Resin surface. Consequently, it was suggested that above pH 1, various iron complexes sorbed to the Resin in a manner which required less than 3 sites per iron moiety. Column trials suggested that the iron loading was 86.6 g/kg of Resin when 1342 mg/L Fe(III) ions in water were flowed at 31.7 BV/h. Regeneration with 5–10% HCl solutions reclaimed approximately 90% of exchange sites.

Chun Wing Leung - One of the best experts on this subject based on the ideXlab platform.

  • ion exchange treatment of saline solutions using lanxess s108h strong acid Cation Resin
    Institute for Future Environments; Science & Engineering Faculty, 2015
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Mitchell De Bruyn, Chun Wing Leung
    Abstract:

    Common to many types of water and wastewater is the presence of sodium ions which can be removed by desalination technologies, such as reverse osmosis and ion exchange. The focus of this investigation was ion exchange as it potentially offered several advantages compared to competing methods. The equilibrium and column behaviour of a strong acid Cation (SAC) Resin was examined for the removal of sodium ions from aqueous sodium chloride solutions of varying normality as well as a coal seam gas water sample. The influence of the bottle-point method to generate the sorption isotherms was evaluated and data interpreted with the Langmuir Vageler, Competitive Langmuir, Freundlich, and Dubinin-Astakhov models. With the constant concentration bottle point method, the predicted maximum exchange levels of sodium ions on the Resin ranged from 61.7 to 67.5 g Na/kg Resin. The general trend was that the lower the initial concentration of sodium ions in the solution, the lower the maximum capacity of the Resin for sodium ions. In contrast, the constant mass bottle point method was found to be problematic in that the isotherm profiles may not be complete, if experimental parameters were not chosen carefully. Column studies supported the observations of the equilibrium studies, with maximum sodium loading of ca. 62.9 g Na/kg Resin measured, which was in excellent agreement with the predictions of the data from the constant concentration bottle point method. Equilibria involving coal seam gas water were more complex due to the presence of sodium bicarbonate in solution, albeit the maximum loading capacity for sodium ions was in agreement with the results from the more simple sodium chloride solutions.

  • an examination of isotherm generation impact of bottle point method upon potassium ion exchange with strong acid Cation Resin
    Separation and Purification Technology, 2015
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Chun Wing Leung
    Abstract:

    This paper relates to the importance of impact of the chosen bottle-point method when conducting ion exchange equilibria experiments. As an illustration, potassium ion exchange with strong acid Cation Resin was investigated due to its relevance to the treatment of various industrial effluents and groundwater. The “constant mass” bottle-point method was shown to be problematic in that depending upon the Resin mass used the equilibrium isotherm profiles were different. Indeed, appliCation of common equilibrium isotherm models revealed that the optimal fit could be with either the Freundlich or Temkin equations, depending upon the conditions employed. It could be inferred that the Resin surface was heterogeneous in character, but precise conclusions regarding the variation in the heat of sorption were not possible. Estimation of the maximum potassium loading was also inconsistent when employing the “constant mass” method. The “constant concentration” bottle-point method illustrated that the Freundlich model was a good representation of the exchange process. The isotherms recorded were relatively consistent when compared to the “constant mass” approach. UnifiCation of all the equilibrium isotherm data acquired was achieved by use of the Langmuir Vageler expression. The maximum loading of potassium ions was predicted to be at least 116.5 g/kg Resin.

Shannon Papworth - One of the best experts on this subject based on the ideXlab platform.

  • factors influencing kinetic and equilibrium behaviour of sodium ion exchange with strong acid Cation Resin
    Institute for Future Environments; Science & Engineering Faculty, 2016
    Co-Authors: Graeme J Millar, Sara J Couperthwaite, Gavin L. Miller, Shannon Papworth
    Abstract:

    This study reports an investigation of the ion exchange treatment of sodium chloride solutions in relation to use of Resin technology for appliCations such as desalination of brackish water. In particular, a strong acid Cation (SAC) Resin (DOW Marathon C) was studied to determine its capacity for sodium uptake and to evaluate the fundamentals of the ion exchange process involved. Key questions to answer included: impact of Resin identity; best models to simulate the kinetics and equilibrium exchange behaviour of sodium ions; difference between using linear least squares (LLS) and non-linear least squares (NLLS) methods for data interpretation; and, effect of changing the type of anion in solution which accompanied the sodium species. Kinetic studies suggested that the exchange process was best described by a pseudo first order rate expression based upon non-linear least squares analysis of the test data. AppliCation of the Langmuir Vageler isotherm model was recommended as it allowed confirmation that experimental conditions were sufficient for maximum loading of sodium ions to occur. The Freundlich expression best fitted the equilibrium data when analysing the information by a NLLS approach. In contrast, LLS methods suggested that the Langmuir model was optimal for describing the equilibrium process. The Competitive Langmuir model which considered the stoichiometric nature of ion exchange process, estimated the maximum loading of sodium ions to be 64.7 g Na/kg Resin. This latter value was comparable to sodium ion capacities for SAC Resin published previously. Inherent discrepancies involved when using linearized versions of kinetic and isotherm equations were illustrated, and despite their widespread use, the value of this latter approach was questionable. The equilibrium behaviour of sodium ions form sodium fluoride solution revealed that the sodium ions were now more preferred by the Resin compared to the situation with sodium chloride. The solution chemistry of hydrofluoric acid was suggested as promoting the affinity of the sodium ions to the Resin.

  • exploration of the fundamental equilibrium behaviour of calcium exchange with weak acid Cation Resins
    Desalination, 2014
    Co-Authors: Graeme J Millar, Shannon Papworth, Sara J Couperthwaite
    Abstract:

    This study evaluated the complexity of calcium ion exchange with sodium exchanged weak acid Cation Resin (DOW MAC-3). Exchange equilibria recorded for a range of different solution normalities revealed profiles which were represented by conventional “L” or “H” type isotherms at low values of equilibrium concentration (Ce) of calcium ions, plus a superimposed region of increasing calcium uptake was observed at high Ce values. The loading of calcium ions was determined to be ca. 53.5 to 58.7 g/kg of Resin when modelling only the sorption curve created at low Ce values, which exhibited a well-defined plateau. The calculated calcium ion loading capacity for DOW MAC-3 Resin appeared to correlate with the manufacturer's recommendation. The phenomenon of super equivalent ion exchange (SEIX) was observed when the “driving force” for the exchange process was increased in excess of 2.25 mmol calcium ions per gram of Resin in the starting solution. This latter event was explained in terms of displacement of sodium ions from sodium hydroxide solution which remained in the Resin bead following the initial conversion of the as supplied “H+” exchanged Resin sites to the “Na+” version required for softening studies. Evidence for hydrolysis of a small fraction of the sites on the sodium exchanged Resin surface was noted. The importance of carefully choosing experimental parameters was discussed especially in relation to appliCation of the Langmuir–Vageler expression. This latter model which compared the ratio of the initial calcium ion concentration in solution to Resin mass, versus final equilibrium loading of the calcium ions on the Resin; was discovered to be an excellent means of identifying the progress of the calcium–sodium ion exchange process. Moreover, the Langmuir–Vageler model facilitated standardization of various calcium–sodium ion exchange experiments which allowed systematic experimental design.

Patrick Sharrock - One of the best experts on this subject based on the ideXlab platform.