Gyorgy Patzay | Budapest University of Technology and Economics (original) (raw)

Papers by Gyorgy Patzay

Research paper thumbnail of ILT15 - A Computer Program for Evaluation of Accelerated Leach Test Data of LLW in the Hungarian NPP Paks

Periodica Polytechnica Chemical Engineering, Dec 20, 2018

Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste f... more Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste forms in the Hungarian NPP Paks. The program is designed to be used as a tool for performing the calculations necessary to analyse leach test data, a modelling program to determine if diffusion is the operating leaching mechanism (and, if not, to indicate other possible mechanisms), and a means to make extrapolations using the diffusion models. The ILT15 program contains four mathematical models that can be used to represent the data, diffusion through a semi-infinite medium, diffusion through a finite cylinder, diffusion plus partitioning of the source term and solubility limited leaching. The program is written in C++ in the Borland C++ Builder programming environment. A detailed description of application of this modelling computer program is given.

Research paper thumbnail of ILT15 - A Computer Program for Evaluation of Accelerated Leach Test Data of LLW in the Hungarian NPP Paks

Periodica Polytechnica Chemical Engineering, Dec 20, 2018

Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste f... more Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste forms in the Hungarian NPP Paks. The program is designed to be used as a tool for performing the calculations necessary to analyse leach test data, a modelling program to determine if diffusion is the operating leaching mechanism (and, if not, to indicate other possible mechanisms), and a means to make extrapolations using the diffusion models. The ILT15 program contains four mathematical models that can be used to represent the data, diffusion through a semi-infinite medium, diffusion through a finite cylinder, diffusion plus partitioning of the source term and solubility limited leaching. The program is written in C++ in the Borland C++ Builder programming environment. A detailed description of application of this modelling computer program is given.

Research paper thumbnail of Health and environmental benefits from air pollution reductions in Hungary

Sci Total Envir, 1998

The aim of this study was to assess the cost and benefit of the implementation of a specific ener... more The aim of this study was to assess the cost and benefit of the implementation of a specific energy saving program in Hungary. We have considered the possible reduced damage to public health, building materials and agricultural crops that may be obtained from reducing emissions of important air pollutants and also how the program contributes to reduced emissions of greenhouse gases. The measures are described in the National Energy Efficiency Ž . Improvement and Energy Conservation Programs NEEIECP , elaborated by the Hungarian Ministry of Industry and Trade and accepted by the Government in 1994. The energy saving expected from the program is approximately 64 PJryear. The benefits were estimated using monitoring data and populationrrecipient data from urban and rural areas in Hungary together with exposure᎐response functions and valuation estimates mainly from western studies. Our analysis indicates that the main benefit from reducing the concentrations of pollutants relates to public health and that reduced prevalence of chronic respiratory diseases is an important effect. Reduced premature mortality is also important and the estimated attributable risk of air pollution to excess mortality at present is approximately 6%. The estimated annual benefit of improved health conditions alone is likely to exceed the investments needed to implement the program. In addition there are significant benefits due to reduced replacement and maintenance costs Ž . for building materials 30᎐35 million US$ annually in Budapest only . The damage to crops due to ozone is large, but a significant improvement in Hungary depends upon concerted actions in several countries. ᮊ 1998 Elsevier Science B.V.

Research paper thumbnail of The environmental evaluation of utilising geothermal energy with the life-cycle method

Periodica Polytechnica Chemical Engineering, 2010

Research paper thumbnail of The environmental evaluation of utilising geothermal energy with the life-cycle method

Periodica Polytechnica Chemical Engineering, 2010

Research paper thumbnail of Health and environmental benefits from air pollution reductions in Hungary

The Science of The Total Environment, 1998

The aim of this study was to assess the cost and benefit of the implementation of a specific ener... more The aim of this study was to assess the cost and benefit of the implementation of a specific energy saving program in Hungary. We have considered the possible reduced damage to public health, building materials and agricultural crops that may be obtained from reducing emissions of important air pollutants and also how the program contributes to reduced emissions of greenhouse gases. The measures are described in the National Energy Efficiency Ž . Improvement and Energy Conservation Programs NEEIECP , elaborated by the Hungarian Ministry of Industry and Trade and accepted by the Government in 1994. The energy saving expected from the program is approximately 64 PJryear. The benefits were estimated using monitoring data and populationrrecipient data from urban and rural areas in Hungary together with exposure᎐response functions and valuation estimates mainly from western studies. Our analysis indicates that the main benefit from reducing the concentrations of pollutants relates to public health and that reduced prevalence of chronic respiratory diseases is an important effect. Reduced premature mortality is also important and the estimated attributable risk of air pollution to excess mortality at present is approximately 6%. The estimated annual benefit of improved health conditions alone is likely to exceed the investments needed to implement the program. In addition there are significant benefits due to reduced replacement and maintenance costs Ž . for building materials 30᎐35 million US$ annually in Budapest only . The damage to crops due to ozone is large, but a significant improvement in Hungary depends upon concerted actions in several countries. ᮊ 1998 Elsevier Science B.V.

Research paper thumbnail of Health and Environmental Benefits from the Implementation of an Energy Saving Program in Hungary

Research paper thumbnail of Transport of NaCl, MgSO_4, MgCl_2 and Na_2SO_4 across DL type nanofiltration membrane

Periodica Polytechnica Chemical Engineering, 2010

Abstract The separation of inorganic ions by membrane filtration of aqueous solutions through NF-... more Abstract The separation of inorganic ions by membrane filtration of aqueous solutions through NF-membranes was investigated. The single and binary salt solutions of NaCl, MgCl2, Na2SO4 and MgSO4 were used in this study. These salts are the most commonly ...

Research paper thumbnail of Transport of NaCl, MgSO_4, MgCl_2 and Na_2SO_4 across DL type nanofiltration membrane

Periodica Polytechnica Chemical Engineering, 2010

Abstract The separation of inorganic ions by membrane filtration of aqueous solutions through NF-... more Abstract The separation of inorganic ions by membrane filtration of aqueous solutions through NF-membranes was investigated. The single and binary salt solutions of NaCl, MgCl2, Na2SO4 and MgSO4 were used in this study. These salts are the most commonly ...

Research paper thumbnail of New EDTA determination method based on ion chromatography with suppressed conductimetric detection

Journal of Radioanalytical and Nuclear Chemistry, 2014

Research paper thumbnail of New EDTA determination method based on ion chromatography with suppressed conductimetric detection

Journal of Radioanalytical and Nuclear Chemistry, 2014

Research paper thumbnail of Limitation of hardness from thermal water by means of nanofiltration

Water Science & Technology, 2013

Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of ... more Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of the territory of the country, with a lowest temperature of 30°C. For energetic purposes, it can be utilized in two different ways: for supplying heat or generating electricity. In relation to utilization, one of the most serious problems derives from the chemical composition of thermal water. The present paper investigates the opportunities of preventing scaling by nanofiltration. Experiments were performed on a Thin Film NF DK membrane, thermostated at 50°C and at a pressure of 3.5 MPa with four different samples (from four Hungarian cities - Eger, Mezőkövesd, Bogács, Miskolc-Tapolca) using batch plant. Reproducibility of experiments was also investigated using water samples from Komárom at 50 and 60°C. The results showed that NF DK could achieve high retention of divalent ions. The results of the second phase of the experiments proved that water flux and rejections were very stable. After filtration, the scaling properties of thermal water were simulated with the help of chemical equilibrium modelling software, called Visual MINTEQ 3.0. The results of the permeate samples prove that nanofiltration is a successful process in preventing scaling of thermal water for further use.

Research paper thumbnail of Limitation of hardness from thermal water by means of nanofiltration

Water Science & Technology, 2013

Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of ... more Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of the territory of the country, with a lowest temperature of 30°C. For energetic purposes, it can be utilized in two different ways: for supplying heat or generating electricity. In relation to utilization, one of the most serious problems derives from the chemical composition of thermal water. The present paper investigates the opportunities of preventing scaling by nanofiltration. Experiments were performed on a Thin Film NF DK membrane, thermostated at 50°C and at a pressure of 3.5 MPa with four different samples (from four Hungarian cities - Eger, Mezőkövesd, Bogács, Miskolc-Tapolca) using batch plant. Reproducibility of experiments was also investigated using water samples from Komárom at 50 and 60°C. The results showed that NF DK could achieve high retention of divalent ions. The results of the second phase of the experiments proved that water flux and rejections were very stable. After filtration, the scaling properties of thermal water were simulated with the help of chemical equilibrium modelling software, called Visual MINTEQ 3.0. The results of the permeate samples prove that nanofiltration is a successful process in preventing scaling of thermal water for further use.

Research paper thumbnail of Radioactive wastewater treatment using a mixture of TANNIX sorbent and VARION mixed bed ion exchange resin

International Journal of Nuclear Energy Science and Technology, 2006

ABSTRACT A wastewater treatment system has been developed by using a mixture of ammonium-insolubl... more ABSTRACT A wastewater treatment system has been developed by using a mixture of ammonium-insoluble tannin (TANNIX, this is the trademark of an adsorbent made by Mitsubishi Nuclear Fuel Co. Ltd) and mixed (strong acid cation exchanger and strong base anion exchanger) ion exchange resin (MIX) for the selective separation of transuranium isotopes, including Pu, Am, Cm, and U, as well as fission and radioactive corrosion products from boric acid solution (pH ∼ 4.1). The equilibrium and fixed bed sorption experiments resulted in K<sub align="right"> d values of 10<sup align="right"> 4 –10<sup align="right"> 5 ml/g, and decontamination factors of 1,000, with a breakthrough point between 1500 BV and 5000 BV of accumulated volume.

Research paper thumbnail of Radioactive wastewater treatment using selective ion exchangers

2010 1st International Nuclear & Renewable Energy Conference (INREC), 2010

It is well known that in the Hungarian PWR-type nuclear power plant Paks the radioactive waste wa... more It is well known that in the Hungarian PWR-type nuclear power plant Paks the radioactive waste waters are collected in common tanks. These water streams contain radioactive isotopes in ultra-low concentration and inactive compounds as major components (borate 1.7 g/dm3, sodium-nitrate 0.4 g/dm3, sodium-hydroxide 0.16 g/dm3, and oxalate 0.25 g/dm3). These low salinity solutions were evaporated by adding sodium-hydroxide, until

Research paper thumbnail of Preliminary investigations of scaling and corrosion in high enthalpy geothermal wells in Hungary

Geothermics, 2003

A solubility equilibrium program GEOPROF was applied to the determination of the bubble-point dep... more A solubility equilibrium program GEOPROF was applied to the determination of the bubble-point depth, pressure and temperature, as well as the partial pressure profiles of the gases CO2, CH4 and N2 between the bubble-point depth and the wellhead, in two high enthalpy geothermal wells, NSZ-2 and FAB-4 in southern Hungary. The pH, alkalinity, total carbonates, and equilibrium solubility for CaCO3, CaSO4, BaSO4, and SrSO4 along the well depth profile in the Na–K–Mg–Ca–H–Ba–Sr–Cl–Br–SO4–OH–HCO3–CO3–CO2–H2O system were also determined and the concentrations of Ca2+, Ba2+, Sr2+, H+, OH−, HCO3−, CO32−, and H2CO3* were computed at the actual temperature and CO2 pressure using the Davies and Pitzer activity calculation methods. The calculated amounts of CaCO3 scaling along the wells and at the surface were used in estimating service life. The results for well FAB-4 contain high uncertainties because of the estimated gas separation analysis data.

Research paper thumbnail of Development of selective cobalt and cesium removal from the evaporator concentrates of the PWR Paks

Radiochimica Acta, 2003

ABSTRACT At the PWR Paks (Hungary) the diluted radioactive waste water is converted to a concentr... more ABSTRACT At the PWR Paks (Hungary) the diluted radioactive waste water is converted to a concentrate by evaporation and the concentrate is stored in tanks. The most important radionuclides in these solutions are Cs-134, Cs-137 and Co-60. In this research we studied granular potassium nickel hexacyanoferrate(II) as a Cs-selective ion-exchanger. Its capacity depended on the preparation method, temperature of pretreatment and age of the ion exchanger. We investigated also the effect of metal ions (Fe2+, Fe3+, Mn2+, Mg2+, Ca2+, Co2+, Ni2+, Cu2+) on the Cs-capacity in the presence of complex forming compounds citrate, oxalate and EDTA. The cesium ion exchange capacity increased with addition of inactive cobalt or nickel salts. Additionally we studied filtration, adsorption and ultrafiltration separation processes for cobalt removal. The results showed that only adsorption by active carbon could be successfully used for the cobalt removal from evaporation concentrates. Experiments were performed both in the laboratory and at the PWR Paks.

Research paper thumbnail of Study of calcite scaling and corrosion processes in geothermal systems

Geothermics, 2000

Prediction of scaling in geothermal systems is important in order to be able to take preventive a... more Prediction of scaling in geothermal systems is important in order to be able to take preventive action. Scaling and corrosion processes are correlated in geothermal systems so that the factors influencing both processes are discussed in this paper. Pilot-scale equipment to model dissolution and scaling, and investigate corrosion, has been constructed. The construction of the pilot-scale equipment and the design of the experiments were based on the results of earlier laboratory model experiments. In order to check the measurement results we used a computer programe that was developed earlier, and which is suitable for the calculation of the equilibrium solubilities. Based on the results of the equilibrium experiments, we developed a modelling method for scaling in the pilot-scale equipment, and studied corrosion during scaling on the surfaces of five different structural materials.

Research paper thumbnail of Cobalt(III) EDTA complex removal from aqueous alkaline borate solutions by nanofiltration

Desalination, 2005

At the PWR Paks diluted low-level radioactive waste water (LLW) contains the long-lived 60Co isot... more At the PWR Paks diluted low-level radioactive waste water (LLW) contains the long-lived 60Co isotope in EDTA complex form, which has no simple separation procedure. In this research nanofiltration(NF) was studied for selective removal of the cobalt(III) EDTA complex from a drain waste water model solution, which contains mainly sodium borate at an alkaline pH. A suitable NF membrane was chosen to separate the cobalt complex from the borate solution. The NF experiments were performed at constant temperature (25°C) and pressure range 1–10 bar. The cobalt complex and the borate ion rejection (R) as well as the permeate flux of the membrane was investigated as a function of pH. The rejection of the cobalt(III) EDTA complex ion and especially the borate were strongly pH dependent. The rejection of the complex ion and the borate was increased at alkaline pH (at pH 8, R = 73%; at pH 11.5, R = 96% for the cobalt complex; at pH 8, R = 7%; at pH 11.5, R = 59% for borate). NF seems to be a suitable separation method for the removal of the Co(III) EDTA complex from nuclear power plant waste streams. The removal of the cobalt complex ion from an alkaline borate solution by NF is possible in two ways: at slightly alkaline pH by a two-step separation, or at a more alkaline pH (pH > 9.5) by a one-step separation.

Research paper thumbnail of A simplified numerical solution method for the Nernst-Planck multicomponent ion exchange kinetics model

Reactive & Functional Polymers, 1995

A simplified solution for multispecies ion exchange kinetics based on the Nernst-Planck model has... more A simplified solution for multispecies ion exchange kinetics based on the Nernst-Planck model has been developed. The numerical solution has been tested by simple isotopic exchange and binary ion exchange kinetic solutions as well as with the Hwang's computed three-component ion exchange kinetic curves. All of these tests resulted in good agreement. The computational algorithm has been built in a program for the computation of multicomponent fixed bed ion exchange breakthrough and co- and counter-current elution curve. The details of this program will be reported elsewhere.

Research paper thumbnail of ILT15 - A Computer Program for Evaluation of Accelerated Leach Test Data of LLW in the Hungarian NPP Paks

Periodica Polytechnica Chemical Engineering, Dec 20, 2018

Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste f... more Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste forms in the Hungarian NPP Paks. The program is designed to be used as a tool for performing the calculations necessary to analyse leach test data, a modelling program to determine if diffusion is the operating leaching mechanism (and, if not, to indicate other possible mechanisms), and a means to make extrapolations using the diffusion models. The ILT15 program contains four mathematical models that can be used to represent the data, diffusion through a semi-infinite medium, diffusion through a finite cylinder, diffusion plus partitioning of the source term and solubility limited leaching. The program is written in C++ in the Borland C++ Builder programming environment. A detailed description of application of this modelling computer program is given.

Research paper thumbnail of ILT15 - A Computer Program for Evaluation of Accelerated Leach Test Data of LLW in the Hungarian NPP Paks

Periodica Polytechnica Chemical Engineering, Dec 20, 2018

Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste f... more Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste forms in the Hungarian NPP Paks. The program is designed to be used as a tool for performing the calculations necessary to analyse leach test data, a modelling program to determine if diffusion is the operating leaching mechanism (and, if not, to indicate other possible mechanisms), and a means to make extrapolations using the diffusion models. The ILT15 program contains four mathematical models that can be used to represent the data, diffusion through a semi-infinite medium, diffusion through a finite cylinder, diffusion plus partitioning of the source term and solubility limited leaching. The program is written in C++ in the Borland C++ Builder programming environment. A detailed description of application of this modelling computer program is given.

Research paper thumbnail of Health and environmental benefits from air pollution reductions in Hungary

Sci Total Envir, 1998

The aim of this study was to assess the cost and benefit of the implementation of a specific ener... more The aim of this study was to assess the cost and benefit of the implementation of a specific energy saving program in Hungary. We have considered the possible reduced damage to public health, building materials and agricultural crops that may be obtained from reducing emissions of important air pollutants and also how the program contributes to reduced emissions of greenhouse gases. The measures are described in the National Energy Efficiency Ž . Improvement and Energy Conservation Programs NEEIECP , elaborated by the Hungarian Ministry of Industry and Trade and accepted by the Government in 1994. The energy saving expected from the program is approximately 64 PJryear. The benefits were estimated using monitoring data and populationrrecipient data from urban and rural areas in Hungary together with exposure᎐response functions and valuation estimates mainly from western studies. Our analysis indicates that the main benefit from reducing the concentrations of pollutants relates to public health and that reduced prevalence of chronic respiratory diseases is an important effect. Reduced premature mortality is also important and the estimated attributable risk of air pollution to excess mortality at present is approximately 6%. The estimated annual benefit of improved health conditions alone is likely to exceed the investments needed to implement the program. In addition there are significant benefits due to reduced replacement and maintenance costs Ž . for building materials 30᎐35 million US$ annually in Budapest only . The damage to crops due to ozone is large, but a significant improvement in Hungary depends upon concerted actions in several countries. ᮊ 1998 Elsevier Science B.V.

Research paper thumbnail of The environmental evaluation of utilising geothermal energy with the life-cycle method

Periodica Polytechnica Chemical Engineering, 2010

Research paper thumbnail of The environmental evaluation of utilising geothermal energy with the life-cycle method

Periodica Polytechnica Chemical Engineering, 2010

Research paper thumbnail of Health and environmental benefits from air pollution reductions in Hungary

The Science of The Total Environment, 1998

The aim of this study was to assess the cost and benefit of the implementation of a specific ener... more The aim of this study was to assess the cost and benefit of the implementation of a specific energy saving program in Hungary. We have considered the possible reduced damage to public health, building materials and agricultural crops that may be obtained from reducing emissions of important air pollutants and also how the program contributes to reduced emissions of greenhouse gases. The measures are described in the National Energy Efficiency Ž . Improvement and Energy Conservation Programs NEEIECP , elaborated by the Hungarian Ministry of Industry and Trade and accepted by the Government in 1994. The energy saving expected from the program is approximately 64 PJryear. The benefits were estimated using monitoring data and populationrrecipient data from urban and rural areas in Hungary together with exposure᎐response functions and valuation estimates mainly from western studies. Our analysis indicates that the main benefit from reducing the concentrations of pollutants relates to public health and that reduced prevalence of chronic respiratory diseases is an important effect. Reduced premature mortality is also important and the estimated attributable risk of air pollution to excess mortality at present is approximately 6%. The estimated annual benefit of improved health conditions alone is likely to exceed the investments needed to implement the program. In addition there are significant benefits due to reduced replacement and maintenance costs Ž . for building materials 30᎐35 million US$ annually in Budapest only . The damage to crops due to ozone is large, but a significant improvement in Hungary depends upon concerted actions in several countries. ᮊ 1998 Elsevier Science B.V.

Research paper thumbnail of Health and Environmental Benefits from the Implementation of an Energy Saving Program in Hungary

Research paper thumbnail of Transport of NaCl, MgSO_4, MgCl_2 and Na_2SO_4 across DL type nanofiltration membrane

Periodica Polytechnica Chemical Engineering, 2010

Abstract The separation of inorganic ions by membrane filtration of aqueous solutions through NF-... more Abstract The separation of inorganic ions by membrane filtration of aqueous solutions through NF-membranes was investigated. The single and binary salt solutions of NaCl, MgCl2, Na2SO4 and MgSO4 were used in this study. These salts are the most commonly ...

Research paper thumbnail of Transport of NaCl, MgSO_4, MgCl_2 and Na_2SO_4 across DL type nanofiltration membrane

Periodica Polytechnica Chemical Engineering, 2010

Abstract The separation of inorganic ions by membrane filtration of aqueous solutions through NF-... more Abstract The separation of inorganic ions by membrane filtration of aqueous solutions through NF-membranes was investigated. The single and binary salt solutions of NaCl, MgCl2, Na2SO4 and MgSO4 were used in this study. These salts are the most commonly ...

Research paper thumbnail of New EDTA determination method based on ion chromatography with suppressed conductimetric detection

Journal of Radioanalytical and Nuclear Chemistry, 2014

Research paper thumbnail of New EDTA determination method based on ion chromatography with suppressed conductimetric detection

Journal of Radioanalytical and Nuclear Chemistry, 2014

Research paper thumbnail of Limitation of hardness from thermal water by means of nanofiltration

Water Science & Technology, 2013

Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of ... more Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of the territory of the country, with a lowest temperature of 30°C. For energetic purposes, it can be utilized in two different ways: for supplying heat or generating electricity. In relation to utilization, one of the most serious problems derives from the chemical composition of thermal water. The present paper investigates the opportunities of preventing scaling by nanofiltration. Experiments were performed on a Thin Film NF DK membrane, thermostated at 50°C and at a pressure of 3.5 MPa with four different samples (from four Hungarian cities - Eger, Mezőkövesd, Bogács, Miskolc-Tapolca) using batch plant. Reproducibility of experiments was also investigated using water samples from Komárom at 50 and 60°C. The results showed that NF DK could achieve high retention of divalent ions. The results of the second phase of the experiments proved that water flux and rejections were very stable. After filtration, the scaling properties of thermal water were simulated with the help of chemical equilibrium modelling software, called Visual MINTEQ 3.0. The results of the permeate samples prove that nanofiltration is a successful process in preventing scaling of thermal water for further use.

Research paper thumbnail of Limitation of hardness from thermal water by means of nanofiltration

Water Science & Technology, 2013

Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of ... more Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of the territory of the country, with a lowest temperature of 30°C. For energetic purposes, it can be utilized in two different ways: for supplying heat or generating electricity. In relation to utilization, one of the most serious problems derives from the chemical composition of thermal water. The present paper investigates the opportunities of preventing scaling by nanofiltration. Experiments were performed on a Thin Film NF DK membrane, thermostated at 50°C and at a pressure of 3.5 MPa with four different samples (from four Hungarian cities - Eger, Mezőkövesd, Bogács, Miskolc-Tapolca) using batch plant. Reproducibility of experiments was also investigated using water samples from Komárom at 50 and 60°C. The results showed that NF DK could achieve high retention of divalent ions. The results of the second phase of the experiments proved that water flux and rejections were very stable. After filtration, the scaling properties of thermal water were simulated with the help of chemical equilibrium modelling software, called Visual MINTEQ 3.0. The results of the permeate samples prove that nanofiltration is a successful process in preventing scaling of thermal water for further use.

Research paper thumbnail of Radioactive wastewater treatment using a mixture of TANNIX sorbent and VARION mixed bed ion exchange resin

International Journal of Nuclear Energy Science and Technology, 2006

ABSTRACT A wastewater treatment system has been developed by using a mixture of ammonium-insolubl... more ABSTRACT A wastewater treatment system has been developed by using a mixture of ammonium-insoluble tannin (TANNIX, this is the trademark of an adsorbent made by Mitsubishi Nuclear Fuel Co. Ltd) and mixed (strong acid cation exchanger and strong base anion exchanger) ion exchange resin (MIX) for the selective separation of transuranium isotopes, including Pu, Am, Cm, and U, as well as fission and radioactive corrosion products from boric acid solution (pH ∼ 4.1). The equilibrium and fixed bed sorption experiments resulted in K<sub align="right"> d values of 10<sup align="right"> 4 –10<sup align="right"> 5 ml/g, and decontamination factors of 1,000, with a breakthrough point between 1500 BV and 5000 BV of accumulated volume.

Research paper thumbnail of Radioactive wastewater treatment using selective ion exchangers

2010 1st International Nuclear & Renewable Energy Conference (INREC), 2010

It is well known that in the Hungarian PWR-type nuclear power plant Paks the radioactive waste wa... more It is well known that in the Hungarian PWR-type nuclear power plant Paks the radioactive waste waters are collected in common tanks. These water streams contain radioactive isotopes in ultra-low concentration and inactive compounds as major components (borate 1.7 g/dm3, sodium-nitrate 0.4 g/dm3, sodium-hydroxide 0.16 g/dm3, and oxalate 0.25 g/dm3). These low salinity solutions were evaporated by adding sodium-hydroxide, until

Research paper thumbnail of Preliminary investigations of scaling and corrosion in high enthalpy geothermal wells in Hungary

Geothermics, 2003

A solubility equilibrium program GEOPROF was applied to the determination of the bubble-point dep... more A solubility equilibrium program GEOPROF was applied to the determination of the bubble-point depth, pressure and temperature, as well as the partial pressure profiles of the gases CO2, CH4 and N2 between the bubble-point depth and the wellhead, in two high enthalpy geothermal wells, NSZ-2 and FAB-4 in southern Hungary. The pH, alkalinity, total carbonates, and equilibrium solubility for CaCO3, CaSO4, BaSO4, and SrSO4 along the well depth profile in the Na–K–Mg–Ca–H–Ba–Sr–Cl–Br–SO4–OH–HCO3–CO3–CO2–H2O system were also determined and the concentrations of Ca2+, Ba2+, Sr2+, H+, OH−, HCO3−, CO32−, and H2CO3* were computed at the actual temperature and CO2 pressure using the Davies and Pitzer activity calculation methods. The calculated amounts of CaCO3 scaling along the wells and at the surface were used in estimating service life. The results for well FAB-4 contain high uncertainties because of the estimated gas separation analysis data.

Research paper thumbnail of Development of selective cobalt and cesium removal from the evaporator concentrates of the PWR Paks

Radiochimica Acta, 2003

ABSTRACT At the PWR Paks (Hungary) the diluted radioactive waste water is converted to a concentr... more ABSTRACT At the PWR Paks (Hungary) the diluted radioactive waste water is converted to a concentrate by evaporation and the concentrate is stored in tanks. The most important radionuclides in these solutions are Cs-134, Cs-137 and Co-60. In this research we studied granular potassium nickel hexacyanoferrate(II) as a Cs-selective ion-exchanger. Its capacity depended on the preparation method, temperature of pretreatment and age of the ion exchanger. We investigated also the effect of metal ions (Fe2+, Fe3+, Mn2+, Mg2+, Ca2+, Co2+, Ni2+, Cu2+) on the Cs-capacity in the presence of complex forming compounds citrate, oxalate and EDTA. The cesium ion exchange capacity increased with addition of inactive cobalt or nickel salts. Additionally we studied filtration, adsorption and ultrafiltration separation processes for cobalt removal. The results showed that only adsorption by active carbon could be successfully used for the cobalt removal from evaporation concentrates. Experiments were performed both in the laboratory and at the PWR Paks.

Research paper thumbnail of Study of calcite scaling and corrosion processes in geothermal systems

Geothermics, 2000

Prediction of scaling in geothermal systems is important in order to be able to take preventive a... more Prediction of scaling in geothermal systems is important in order to be able to take preventive action. Scaling and corrosion processes are correlated in geothermal systems so that the factors influencing both processes are discussed in this paper. Pilot-scale equipment to model dissolution and scaling, and investigate corrosion, has been constructed. The construction of the pilot-scale equipment and the design of the experiments were based on the results of earlier laboratory model experiments. In order to check the measurement results we used a computer programe that was developed earlier, and which is suitable for the calculation of the equilibrium solubilities. Based on the results of the equilibrium experiments, we developed a modelling method for scaling in the pilot-scale equipment, and studied corrosion during scaling on the surfaces of five different structural materials.

Research paper thumbnail of Cobalt(III) EDTA complex removal from aqueous alkaline borate solutions by nanofiltration

Desalination, 2005

At the PWR Paks diluted low-level radioactive waste water (LLW) contains the long-lived 60Co isot... more At the PWR Paks diluted low-level radioactive waste water (LLW) contains the long-lived 60Co isotope in EDTA complex form, which has no simple separation procedure. In this research nanofiltration(NF) was studied for selective removal of the cobalt(III) EDTA complex from a drain waste water model solution, which contains mainly sodium borate at an alkaline pH. A suitable NF membrane was chosen to separate the cobalt complex from the borate solution. The NF experiments were performed at constant temperature (25°C) and pressure range 1–10 bar. The cobalt complex and the borate ion rejection (R) as well as the permeate flux of the membrane was investigated as a function of pH. The rejection of the cobalt(III) EDTA complex ion and especially the borate were strongly pH dependent. The rejection of the complex ion and the borate was increased at alkaline pH (at pH 8, R = 73%; at pH 11.5, R = 96% for the cobalt complex; at pH 8, R = 7%; at pH 11.5, R = 59% for borate). NF seems to be a suitable separation method for the removal of the Co(III) EDTA complex from nuclear power plant waste streams. The removal of the cobalt complex ion from an alkaline borate solution by NF is possible in two ways: at slightly alkaline pH by a two-step separation, or at a more alkaline pH (pH > 9.5) by a one-step separation.

Research paper thumbnail of A simplified numerical solution method for the Nernst-Planck multicomponent ion exchange kinetics model

Reactive & Functional Polymers, 1995

A simplified solution for multispecies ion exchange kinetics based on the Nernst-Planck model has... more A simplified solution for multispecies ion exchange kinetics based on the Nernst-Planck model has been developed. The numerical solution has been tested by simple isotopic exchange and binary ion exchange kinetic solutions as well as with the Hwang's computed three-component ion exchange kinetic curves. All of these tests resulted in good agreement. The computational algorithm has been built in a program for the computation of multicomponent fixed bed ion exchange breakthrough and co- and counter-current elution curve. The details of this program will be reported elsewhere.