The production of biofuels from algal biomass is one of the most ambitious task to fulfill a sust... more The production of biofuels from algal biomass is one of the most ambitious task to fulfill a sustainable ecological balance worldwide. The main goal is the reduction of environmental contamination by recycling part of the CO2, produced through energy generation by fossil fuels and use it for bio-oil production. Recently, the possibility of
ABSTRACT Wet limestone scrubbing is the most common flue gas desulphurization (FGD) process. In t... more ABSTRACT Wet limestone scrubbing is the most common flue gas desulphurization (FGD) process. In this process, oxidation of calcium bisulphite plays a major role both by determining the dewatering properties of the obtained sludge and the production of gypsum of high quality. In order to contribute to the simulation of the wet limestone FGD process, in the present paper a comprehensive model for isothermal gas–liquid stirred tank reactors has been used. Based on the assumption that the reactions are zeroth order with respect to gaseous reactants, the model requires appropriate physico-chemical parameters which are taken from the literature. The model was used to quantitatively interpret some literature experimental data concerning uncatalysed calcium bisulphite oxidation performed in a continuous stirred tank reactor. In particular, the model is capable of confidently predicting the transition from chemically to mass transfer controlled regime occurring when changing the operating conditions.
European Journal of Biology and Biotechnology, 2022
Cell cycle and its progression play a crucial role in the life of all living organisms, in tissue... more Cell cycle and its progression play a crucial role in the life of all living organisms, in tissues and organs of animals and humans, and therefore are the subject of intense study by scientists in various fields of biomedicine, bioengineering and biotechnology. Effective and predictive simulation models can offer new development opportunities in such fields. In the present paper a comprehensive mathematical model for simulating the cell cycle progression in batch systems is proposed. The model includes a structured population balance with two internal variables (i.e., cell volume and age) that properly describes cell cycle evolution through the various stages that a cell of an entire population undergoes as it grows and divides. The rate of transitions between two subsequent phases of the cell cycle are obtained by considering a detailed biochemical model which simulates the series of complex events that take place during cell growth and its division. The model capability for simula...
The Role of Mathematical Modeling and Genetic Engineering for the Microalgae Based Technology Ale... more The Role of Mathematical Modeling and Genetic Engineering for the Microalgae Based Technology Alessandro Concas*, Cristina Costelli, Veronica Malavasi, Massimiliano Orsini, Roberto Cusano, Andrea Angius, Massimo Pisu, Giacomo Cao a Center for Advanced Studies, Research and Development in Sardinia (CRS4), Loc. Piscina Manna, Building 1, 09010 Pula (CA), Italy b Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124 Cagliari, Italy c Institute of Genetic and Biomedical Research (IRGB), CNR, Monserrato (CA), 09042 Italy d Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Piazza d’Armi, 09123 Cagliari, Italy aconcas@crs4.it
A novel mathematical model to simulate the size-structured growth of microalgal strains dividing ... more A novel mathematical model to simulate the size-structured growth of microalgal strains dividing by multiple fission is proposed. The model is validated by comparison with literature experimental data. Then, the implications of such division mode on crucial aspects of microalgae cultivation and processing, such as time for steady state achievement, biomass productivity and flocculant dosage, were assessed through proper numerical simulations. The model well captured the experimental results and thus represents a suitable tool for the simulation of the growth of microalgae strains dividing by multiple fission.
a Center for Advanced Studies, Research and Development in Sardinia (CRS4), Loc. Piscina Manna, B... more a Center for Advanced Studies, Research and Development in Sardinia (CRS4), Loc. Piscina Manna, Building 1, 09010 Pula (CA), Italy b Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124 Cagliari, Italy c Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Piazza d’Armi, 09123 Cagliari, Italy aconcas@crs4.it; giacomo.cao@dimcm.unica.it;
Mechano-chemical treatment has been recognized to be a promising technology for the immobilizatio... more Mechano-chemical treatment has been recognized to be a promising technology for the immobilization of heavy metals (HMs) in contaminated soils without the use of additional reagents. Despite this, very few studies aiming to investigate the applicability of this technology at full scale have been published so far. In this study, a quantitative approach was developed to provide process design information to scale-up from laboratory- into pilot-scale mechano-chemical reactors for immobilizing heavy metals in contaminated mining soil. In fact, after preliminary experiments with laboratory-scale ball mills, experiments have been carried out by taking advantage of milling devices suited for pilot-scale applications. The experimental data of this work, along with literature ones, have been quantitatively interpreted by means of a mathematical model allowing to describe the effect of milling dynamics on the HM immobilization kinetics for applications at different scales. The results suggest that the mechanical process can trigger specific physico-chemical phenomena leading to a significant reduction of HMs leached from mining soils. Specifically, after suitably prolonged processing time, HM concentration in the leachate is lowered below the corresponding threshold limits. The observed behavior is well captured by the proposed model for different HMs and operating conditions. Therefore, the model might be exploited to infer design parameters for the implementation of this technique at the pilot and full scale. Moreover, it represents a valuable tool for designing and controlling mechano-chemical reactors at productive scale.
Mechanochemical processing to immobilize heavy metals in contaminated soils has been proposed few... more Mechanochemical processing to immobilize heavy metals in contaminated soils has been proposed few years ago. The corresponding experimental results have shown that, under specific operating conditions, the mechanical energy provided by suitable ball mills, can greatly reduce heavy metals mobility without the addition of any reactant. Such results, together with the extreme simplicity of the proposed technique, are still very promising in view of its industrial transposition. Along these lines, the use of suitable mathematical models might represent a valuable tool which would permit to design and control mechano-chemical reactors for field applications. In this work, a simple albeit exhaustive model is proposed for the first time to quantitatively describe the effects of the dynamics of milling process, such as impact frequency and energy, on the immobilization kinetics. Model results and experimental data obtained so far are successfully compared in terms of leached heavy metals and immobilization efficiency evolution with treatment time. Finally, the potential capability of the model to contribute to the industrial scale transposition of the proposed technique is addressed.
A novel mathematical model for the quantitative assessment of the effect of dissolved nitrogen on... more A novel mathematical model for the quantitative assessment of the effect of dissolved nitrogen on the autotrophic batch-growth and lipid accumulation of Chlorella sorokiniana, is proposed in this work. Model results have been validated through comparison with suitable experimental data performed in lab photobioreactors. Further experiments have been then performed using the BIOCOIL photobioreactor operated in fed-batch mode. The experimental results, which show that a maximum growth rate of 0.52day(-1) and a lipid content equal to 25%wt can be achieved with the BIOICOIL, have been successfully predicted through the proposed model. Therefore, the model might represent a first step toward the development of a tool for the scale-up and optimization of the operating conditions of BIOCOIL photobioreactors. Finally, the fatty acid methyl esters obtained by trans-esterification of lipids extracted from C. sorokiniana, have been analyzed in view of the assessment of their usability for prod...
The production of biofuels from algal biomass is one of the most ambitious task to fulfill a sust... more The production of biofuels from algal biomass is one of the most ambitious task to fulfill a sustainable ecological balance worldwide. The main goal is the reduction of environmental contamination by recycling part of the CO2, produced through energy generation by fossil fuels and use it for bio-oil production. Recently, the possibility of
ABSTRACT Wet limestone scrubbing is the most common flue gas desulphurization (FGD) process. In t... more ABSTRACT Wet limestone scrubbing is the most common flue gas desulphurization (FGD) process. In this process, oxidation of calcium bisulphite plays a major role both by determining the dewatering properties of the obtained sludge and the production of gypsum of high quality. In order to contribute to the simulation of the wet limestone FGD process, in the present paper a comprehensive model for isothermal gas–liquid stirred tank reactors has been used. Based on the assumption that the reactions are zeroth order with respect to gaseous reactants, the model requires appropriate physico-chemical parameters which are taken from the literature. The model was used to quantitatively interpret some literature experimental data concerning uncatalysed calcium bisulphite oxidation performed in a continuous stirred tank reactor. In particular, the model is capable of confidently predicting the transition from chemically to mass transfer controlled regime occurring when changing the operating conditions.
European Journal of Biology and Biotechnology, 2022
Cell cycle and its progression play a crucial role in the life of all living organisms, in tissue... more Cell cycle and its progression play a crucial role in the life of all living organisms, in tissues and organs of animals and humans, and therefore are the subject of intense study by scientists in various fields of biomedicine, bioengineering and biotechnology. Effective and predictive simulation models can offer new development opportunities in such fields. In the present paper a comprehensive mathematical model for simulating the cell cycle progression in batch systems is proposed. The model includes a structured population balance with two internal variables (i.e., cell volume and age) that properly describes cell cycle evolution through the various stages that a cell of an entire population undergoes as it grows and divides. The rate of transitions between two subsequent phases of the cell cycle are obtained by considering a detailed biochemical model which simulates the series of complex events that take place during cell growth and its division. The model capability for simula...
The Role of Mathematical Modeling and Genetic Engineering for the Microalgae Based Technology Ale... more The Role of Mathematical Modeling and Genetic Engineering for the Microalgae Based Technology Alessandro Concas*, Cristina Costelli, Veronica Malavasi, Massimiliano Orsini, Roberto Cusano, Andrea Angius, Massimo Pisu, Giacomo Cao a Center for Advanced Studies, Research and Development in Sardinia (CRS4), Loc. Piscina Manna, Building 1, 09010 Pula (CA), Italy b Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124 Cagliari, Italy c Institute of Genetic and Biomedical Research (IRGB), CNR, Monserrato (CA), 09042 Italy d Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Piazza d’Armi, 09123 Cagliari, Italy aconcas@crs4.it
A novel mathematical model to simulate the size-structured growth of microalgal strains dividing ... more A novel mathematical model to simulate the size-structured growth of microalgal strains dividing by multiple fission is proposed. The model is validated by comparison with literature experimental data. Then, the implications of such division mode on crucial aspects of microalgae cultivation and processing, such as time for steady state achievement, biomass productivity and flocculant dosage, were assessed through proper numerical simulations. The model well captured the experimental results and thus represents a suitable tool for the simulation of the growth of microalgae strains dividing by multiple fission.
a Center for Advanced Studies, Research and Development in Sardinia (CRS4), Loc. Piscina Manna, B... more a Center for Advanced Studies, Research and Development in Sardinia (CRS4), Loc. Piscina Manna, Building 1, 09010 Pula (CA), Italy b Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124 Cagliari, Italy c Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Piazza d’Armi, 09123 Cagliari, Italy aconcas@crs4.it; giacomo.cao@dimcm.unica.it;
Mechano-chemical treatment has been recognized to be a promising technology for the immobilizatio... more Mechano-chemical treatment has been recognized to be a promising technology for the immobilization of heavy metals (HMs) in contaminated soils without the use of additional reagents. Despite this, very few studies aiming to investigate the applicability of this technology at full scale have been published so far. In this study, a quantitative approach was developed to provide process design information to scale-up from laboratory- into pilot-scale mechano-chemical reactors for immobilizing heavy metals in contaminated mining soil. In fact, after preliminary experiments with laboratory-scale ball mills, experiments have been carried out by taking advantage of milling devices suited for pilot-scale applications. The experimental data of this work, along with literature ones, have been quantitatively interpreted by means of a mathematical model allowing to describe the effect of milling dynamics on the HM immobilization kinetics for applications at different scales. The results suggest that the mechanical process can trigger specific physico-chemical phenomena leading to a significant reduction of HMs leached from mining soils. Specifically, after suitably prolonged processing time, HM concentration in the leachate is lowered below the corresponding threshold limits. The observed behavior is well captured by the proposed model for different HMs and operating conditions. Therefore, the model might be exploited to infer design parameters for the implementation of this technique at the pilot and full scale. Moreover, it represents a valuable tool for designing and controlling mechano-chemical reactors at productive scale.
Mechanochemical processing to immobilize heavy metals in contaminated soils has been proposed few... more Mechanochemical processing to immobilize heavy metals in contaminated soils has been proposed few years ago. The corresponding experimental results have shown that, under specific operating conditions, the mechanical energy provided by suitable ball mills, can greatly reduce heavy metals mobility without the addition of any reactant. Such results, together with the extreme simplicity of the proposed technique, are still very promising in view of its industrial transposition. Along these lines, the use of suitable mathematical models might represent a valuable tool which would permit to design and control mechano-chemical reactors for field applications. In this work, a simple albeit exhaustive model is proposed for the first time to quantitatively describe the effects of the dynamics of milling process, such as impact frequency and energy, on the immobilization kinetics. Model results and experimental data obtained so far are successfully compared in terms of leached heavy metals and immobilization efficiency evolution with treatment time. Finally, the potential capability of the model to contribute to the industrial scale transposition of the proposed technique is addressed.
A novel mathematical model for the quantitative assessment of the effect of dissolved nitrogen on... more A novel mathematical model for the quantitative assessment of the effect of dissolved nitrogen on the autotrophic batch-growth and lipid accumulation of Chlorella sorokiniana, is proposed in this work. Model results have been validated through comparison with suitable experimental data performed in lab photobioreactors. Further experiments have been then performed using the BIOCOIL photobioreactor operated in fed-batch mode. The experimental results, which show that a maximum growth rate of 0.52day(-1) and a lipid content equal to 25%wt can be achieved with the BIOICOIL, have been successfully predicted through the proposed model. Therefore, the model might represent a first step toward the development of a tool for the scale-up and optimization of the operating conditions of BIOCOIL photobioreactors. Finally, the fatty acid methyl esters obtained by trans-esterification of lipids extracted from C. sorokiniana, have been analyzed in view of the assessment of their usability for prod...
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