Departament d'Enginyeria Minera i Recursos Naturals (fins octubre 2015)
http://hdl.handle.net/2117/4025
2016-12-07T08:44:04ZMeasuring the relevance of factors in the occurrence of events
http://hdl.handle.net/2117/76392
Measuring the relevance of factors in the occurrence of events
Fragnelli, Vito; Freixas Bosch, Josep; Pons Vallès, Montserrat; Sanmiquel Pera, Lluís
A new way to compare the relevance of the different factors intervening in the occurrences of an event is presented and developed in this paper. The idea behind the method comes from cooperative game theory but the focus is slightly different because factors are not necessarily rational decision-makers and because the only data available are obtained by repetition of the event. The concept of relevance measure for a factor in a set of data is introduced, some significant examples are given and the main properties of relevance measures are defined and studied. One of these measures, the fair measure, is proved to have interesting properties which characterize it. Two real world situations, one about traffic accidents and the other one about mining accidents, both of them with real data, are used to show the use of relevance measures to compare factors in each one of these events.
2015-07-30T09:37:01ZFragnelli, VitoFreixas Bosch, JosepPons Vallès, MontserratSanmiquel Pera, LluísA new way to compare the relevance of the different factors intervening in the occurrences of an event is presented and developed in this paper. The idea behind the method comes from cooperative game theory but the focus is slightly different because factors are not necessarily rational decision-makers and because the only data available are obtained by repetition of the event. The concept of relevance measure for a factor in a set of data is introduced, some significant examples are given and the main properties of relevance measures are defined and studied. One of these measures, the fair measure, is proved to have interesting properties which characterize it. Two real world situations, one about traffic accidents and the other one about mining accidents, both of them with real data, are used to show the use of relevance measures to compare factors in each one of these events.Biofiltration of WWTP sludge composting emissions at contact times of 2–10 s by structured/unstructured packing materials
http://hdl.handle.net/2117/76280
Biofiltration of WWTP sludge composting emissions at contact times of 2–10 s by structured/unstructured packing materials
Dorado Castaño, Antonio David; Gabriel, David; Gamisans Noguera, Javier
The performance of a biotrickling filter for the abatement of composting emissions was evaluated at short gas contact times of 2–10 s with a structured and an unstructured packing material. The effect of the gas contact time, pH control and water make-up flowrate were also evaluated during 8 months.
The average elimination capacity was 13 g N m-3 h-1 and 3.3 g C m-3 h-1 for NH3 and VOCs, respectively.
Maximum capacities obtained during an inlet concentration spiking experiment were 45 g N m-3 h-1 and 20 g C m-3 h-1 at a removal efficiency of 92.5 and 46.7%, respectively. A decrease of 40% was detected in the nitrification capacity when the hydraulic residence time increased from 2 to 5 h. Thus, water renewal was identified as a critical parameter to avoid substrate inhibition by nitrite and NH3 accumulation.
Results demonstrate that significant NH3 and VOCs removal efficiencies can be achieved for composting emissions in a biotrickling filter operated at short gas contact times, which entails a substantial reduction of operational and investment costs in comparison to traditional techniques.
2015-07-23T09:13:13ZDorado Castaño, Antonio DavidGabriel, DavidGamisans Noguera, JavierThe performance of a biotrickling filter for the abatement of composting emissions was evaluated at short gas contact times of 2–10 s with a structured and an unstructured packing material. The effect of the gas contact time, pH control and water make-up flowrate were also evaluated during 8 months.
The average elimination capacity was 13 g N m-3 h-1 and 3.3 g C m-3 h-1 for NH3 and VOCs, respectively.
Maximum capacities obtained during an inlet concentration spiking experiment were 45 g N m-3 h-1 and 20 g C m-3 h-1 at a removal efficiency of 92.5 and 46.7%, respectively. A decrease of 40% was detected in the nitrification capacity when the hydraulic residence time increased from 2 to 5 h. Thus, water renewal was identified as a critical parameter to avoid substrate inhibition by nitrite and NH3 accumulation.
Results demonstrate that significant NH3 and VOCs removal efficiencies can be achieved for composting emissions in a biotrickling filter operated at short gas contact times, which entails a substantial reduction of operational and investment costs in comparison to traditional techniques.Numerical simulation of gas migration rules and comparison between U shape and U+L shape ventilation system
http://hdl.handle.net/2117/76217
Numerical simulation of gas migration rules and comparison between U shape and U+L shape ventilation system
Zhang, Haoran; Sanmiquel Pera, Lluís; Zhao, Yaojiang; Vintró Sánchez, Carla; Bascompta Massanes, Marc
This paper offers an overview of numerical simulation with the aim of improving the knowledge and reference of coal mine gas distribution rule, and providing a case study of the optimization of ventilation system and environment protection. The numerical simulation
experiments based on U shape ventilation system and U+L shape ventilation system are performed respectively. The results indicate that U+L shape ventilation system is more effective than its counterpart in terms of accelerating the gas flow, balancing the air pressure,
and lowering the gas content of the upper corner. Besides, the field verification shows that the average gas content of tail airway, upper corner and air outlet have decreased from 1.86%, 0.79% and 0.58% (U shape ventilation system) to 1.68%, 0.75% and 0.55% (U+L
shape ventilation system) respectively, and the average gas drainage rate of special drilling tunnel has increased from 43.4 m3·min-1 (U shape ventilation system) to approximately 51.8 m3·min-1 (U+L shape ventilation system).
2015-07-20T08:12:27ZZhang, HaoranSanmiquel Pera, LluísZhao, YaojiangVintró Sánchez, CarlaBascompta Massanes, MarcThis paper offers an overview of numerical simulation with the aim of improving the knowledge and reference of coal mine gas distribution rule, and providing a case study of the optimization of ventilation system and environment protection. The numerical simulation
experiments based on U shape ventilation system and U+L shape ventilation system are performed respectively. The results indicate that U+L shape ventilation system is more effective than its counterpart in terms of accelerating the gas flow, balancing the air pressure,
and lowering the gas content of the upper corner. Besides, the field verification shows that the average gas content of tail airway, upper corner and air outlet have decreased from 1.86%, 0.79% and 0.58% (U shape ventilation system) to 1.68%, 0.75% and 0.55% (U+L
shape ventilation system) respectively, and the average gas drainage rate of special drilling tunnel has increased from 43.4 m3·min-1 (U shape ventilation system) to approximately 51.8 m3·min-1 (U+L shape ventilation system).Friction factors determination and comparison in potash mines
http://hdl.handle.net/2117/76216
Friction factors determination and comparison in potash mines
Bascompta Massanes, Marc; Sanmiquel Pera, Lluís; Anticoi Sudzuki, Hernán Francisco
Friction factor is a crucial parameter for assessing and modelling the ventilation system in underground mining. However, the development of a mine along its life can complicate the airflow supply required to the working faces, creating setbacks in terms of productivity and production. For this reason, it is very important to determine
all the ventilation parameters. This paper examines data collected from different surveys carried out in two potash mines –both using a room and pillar exploitation method– with the idea of determining the friction factors through the Von Kármán equation, which connects the Atkinson friction factor with roughness of the airways.
Standard values of such type of mining have been obtained, determining the roughness variation along the year due to surface climatic, which influences the shape and geometry of the tunnels in evaporitic exploitations.
2015-07-20T08:08:23ZBascompta Massanes, MarcSanmiquel Pera, LluísAnticoi Sudzuki, Hernán FranciscoFriction factor is a crucial parameter for assessing and modelling the ventilation system in underground mining. However, the development of a mine along its life can complicate the airflow supply required to the working faces, creating setbacks in terms of productivity and production. For this reason, it is very important to determine
all the ventilation parameters. This paper examines data collected from different surveys carried out in two potash mines –both using a room and pillar exploitation method– with the idea of determining the friction factors through the Von Kármán equation, which connects the Atkinson friction factor with roughness of the airways.
Standard values of such type of mining have been obtained, determining the roughness variation along the year due to surface climatic, which influences the shape and geometry of the tunnels in evaporitic exploitations.Gestión de la subsidencia minera en la cuenca minera potásica de Cataluña
http://hdl.handle.net/2117/76214
Gestión de la subsidencia minera en la cuenca minera potásica de Cataluña
Sanmiquel Pera, Lluís; Bascompta Massanes, Marc; Vintró Sánchez, Carla
2015-07-20T08:04:46ZSanmiquel Pera, LluísBascompta Massanes, MarcVintró Sánchez, CarlaModeling hydrodynamics and biochemical reactions in a Flat Plate Bioreactor
http://hdl.handle.net/2117/28543
Modeling hydrodynamics and biochemical reactions in a Flat Plate Bioreactor
Prades Martell, Lledó; Guimerà Villalba, Xavier; Climent, J.; Chiva, S.; Dorado Castaño, Antonio David; Gamisans Noguera, Javier
Modeling the complex interactions between biochemical reactions and hydrodynamics is the key to optimize biofiltration systems performance. In this work, biological kinetics expressions were implemented into Computational Fluid Dynamics (CFD) model as transport equations, including convective and diffusive terms. Previously, activity within the biofilm of a flat plate bioreactor (FPB) was experimentally investigated measuring dissolved oxygen (DO) profiles by means of microsensors and under common operating conditions. Moreover, a mathematical model to describe mass transport and metabolic activity in the FPB was developed and their parameters were fitted from experimental results. Then, a CFD model, combining hydrodynamics and biochemical reactions, was developed and solved to simulate local transient flow and dynamic behaviors of biofilm growth and substrate (glucose) biodregradation in the FPB. The CFD simulation results were evaluated by studying hydrodynamics characterization in the FPB and comparing simulated DO profiles with experimental DO profiles within the biofilm section. The hydraulic behaviour corresponds to a laminar flow and simulated DO profiles illustrate a satisfactory agreement with experimental data for different biofilm densities. Glucose and oxygen biodegradation and biomass growth along the bioreactor were described using the CFD model.
2015-07-08T06:46:48ZPrades Martell, LledóGuimerà Villalba, XavierCliment, J.Chiva, S.Dorado Castaño, Antonio DavidGamisans Noguera, JavierModeling the complex interactions between biochemical reactions and hydrodynamics is the key to optimize biofiltration systems performance. In this work, biological kinetics expressions were implemented into Computational Fluid Dynamics (CFD) model as transport equations, including convective and diffusive terms. Previously, activity within the biofilm of a flat plate bioreactor (FPB) was experimentally investigated measuring dissolved oxygen (DO) profiles by means of microsensors and under common operating conditions. Moreover, a mathematical model to describe mass transport and metabolic activity in the FPB was developed and their parameters were fitted from experimental results. Then, a CFD model, combining hydrodynamics and biochemical reactions, was developed and solved to simulate local transient flow and dynamic behaviors of biofilm growth and substrate (glucose) biodregradation in the FPB. The CFD simulation results were evaluated by studying hydrodynamics characterization in the FPB and comparing simulated DO profiles with experimental DO profiles within the biofilm section. The hydraulic behaviour corresponds to a laminar flow and simulated DO profiles illustrate a satisfactory agreement with experimental data for different biofilm densities. Glucose and oxygen biodegradation and biomass growth along the bioreactor were described using the CFD model.Modelling biotrickling filters to minimize elemental sulfur accumulation during biogas desulfurization under aerobic conditions
http://hdl.handle.net/2117/28542
Modelling biotrickling filters to minimize elemental sulfur accumulation during biogas desulfurization under aerobic conditions
López, L.R.; Dorado Castaño, Antonio David; Mora, M.; Prades Martell, Lledó; Gamisans Noguera, Javier; Lafuente, J.; Gabriel, D.
A mathematical dynamic model describing biological removal of high loads of H2S from biogas streams through a biotrickling filter (BTF) was developed, calibrated and validated to a range of specific experimental conditions of a lab-scale BTF. This model takes into account the main processes occurring in the three phases of the desulfurizing BTF (gas, liquid and biofilm phase) in a co-current configuration flow mode. This model attempts to describe accurately intermediate products obtained from H2S oxidation using kinetic models, previously developed using respirometric techniques with biomass samples obtained from the same BTF set up used here. Previous to the model parameters calibration, a sensitivity analysis was performed in order to focus the parameters estimation on those parameters that showed a highest influence on modelling results over the main process variables. To calibrate the model, an objective function considering the difference between the experimental and the predicted data was minimized. Experimental data for model calibration corresponded to a period of 5 days of operation of the BTF under stepwise increasing H2S concentrations between 2000 and 10000 ppmv. Once the model was calibrated, model was validated by simulating a period of 2 months of operation of the BTF at an average concentration of 2000 ppmv. Validation was successfully achieved since the model also described the reactor performance during a pseudo steady-state period.
2015-07-08T06:41:02ZLópez, L.R.Dorado Castaño, Antonio DavidMora, M.Prades Martell, LledóGamisans Noguera, JavierLafuente, J.Gabriel, D.A mathematical dynamic model describing biological removal of high loads of H2S from biogas streams through a biotrickling filter (BTF) was developed, calibrated and validated to a range of specific experimental conditions of a lab-scale BTF. This model takes into account the main processes occurring in the three phases of the desulfurizing BTF (gas, liquid and biofilm phase) in a co-current configuration flow mode. This model attempts to describe accurately intermediate products obtained from H2S oxidation using kinetic models, previously developed using respirometric techniques with biomass samples obtained from the same BTF set up used here. Previous to the model parameters calibration, a sensitivity analysis was performed in order to focus the parameters estimation on those parameters that showed a highest influence on modelling results over the main process variables. To calibrate the model, an objective function considering the difference between the experimental and the predicted data was minimized. Experimental data for model calibration corresponded to a period of 5 days of operation of the BTF under stepwise increasing H2S concentrations between 2000 and 10000 ppmv. Once the model was calibrated, model was validated by simulating a period of 2 months of operation of the BTF at an average concentration of 2000 ppmv. Validation was successfully achieved since the model also described the reactor performance during a pseudo steady-state period.Application of a novel respirometric methodology to characterize mass transfer and activity of H2S-oxidizing biofilms in biotrickling filter beds
http://hdl.handle.net/2117/28495
Application of a novel respirometric methodology to characterize mass transfer and activity of H2S-oxidizing biofilms in biotrickling filter beds
Bonilla Blanca, Wenceslao; Mora Garrido, Mabel; Revah, Sergio; Baeza Labat, Juan Antonio; Lafuente, Javier; Gamisans Noguera, Javier; Gabriel Buguña, David; González Sanchez, Armando
The elimination capacity of gaseous H2S biofiltration can be limited either by mass transfer or bioreaction in the biofilm. Assessment of the biological activity of immobilized cells (biofilm) usually implies morphological and physiological changes during the adaptation of cells to respirometric devices operated as suspended cultures. In this study, respirometry of heterogeneous media is advised as a valuable technique for characterizing mass transport and biological activity of H2S-oxidizing biofilms attached on two packing materials from operative biotrickling filters. Controlled flows of liquid and H2S-containing air were recirculated through a closed heterogeneous respirometer allowing a more realistic estimation of the biofilm activity by the experimental evaluation of the oxygen uptake rate (OUR). Specific maximum OUR of 23.0 and 38.5 mmol O-2 (g biomass min)(-1) were obtained for Pall rings and polyurethane foam, respectively. A mathematical model for the determination of kinetic-related parameters such as the maximum H2S elimination capacity and morphological properties of biofilm (i.e., thickness and fraction of wetted area of packing bed) was developed and calibrated. With the set of parameters obtained, the external oxygen mass transport to the wetted biofilm was found to limit the global H2S biofiltration capacity, whereas the non-wetted biofilm was the dominant route for the gaseous O-2 and H2S mass transfer to the biofilm. Oxygen diffusion rate was the limiting step in the case of very active biofilms.
2015-07-01T12:03:44ZBonilla Blanca, WenceslaoMora Garrido, MabelRevah, SergioBaeza Labat, Juan AntonioLafuente, JavierGamisans Noguera, JavierGabriel Buguña, DavidGonzález Sanchez, ArmandoThe elimination capacity of gaseous H2S biofiltration can be limited either by mass transfer or bioreaction in the biofilm. Assessment of the biological activity of immobilized cells (biofilm) usually implies morphological and physiological changes during the adaptation of cells to respirometric devices operated as suspended cultures. In this study, respirometry of heterogeneous media is advised as a valuable technique for characterizing mass transport and biological activity of H2S-oxidizing biofilms attached on two packing materials from operative biotrickling filters. Controlled flows of liquid and H2S-containing air were recirculated through a closed heterogeneous respirometer allowing a more realistic estimation of the biofilm activity by the experimental evaluation of the oxygen uptake rate (OUR). Specific maximum OUR of 23.0 and 38.5 mmol O-2 (g biomass min)(-1) were obtained for Pall rings and polyurethane foam, respectively. A mathematical model for the determination of kinetic-related parameters such as the maximum H2S elimination capacity and morphological properties of biofilm (i.e., thickness and fraction of wetted area of packing bed) was developed and calibrated. With the set of parameters obtained, the external oxygen mass transport to the wetted biofilm was found to limit the global H2S biofiltration capacity, whereas the non-wetted biofilm was the dominant route for the gaseous O-2 and H2S mass transfer to the biofilm. Oxygen diffusion rate was the limiting step in the case of very active biofilms.Effect of biomass density on oxygen diffusivity measured inside biofilms with a MEA Sensor
http://hdl.handle.net/2117/28493
Effect of biomass density on oxygen diffusivity measured inside biofilms with a MEA Sensor
Guimerà Villalba, Xavier; Dorado Castaño, Antonio David; Bonsfills Pedrós, Anna; Gabriel, D.; Gamisans Noguera, Javier
The optimization of biofiltration technologies can be addressed improving the knowledge of the process taking place within biofilms, mainly biokinetics and mass transport. Biokinetics are usually defined using different methodologies, such as respirometric and titrimetric tests. Mass transport within biofilms is usually described as diffusion through a homogeneous phase, despite it is accepted that biofilms are very heterogeneous. Thus, a quantitative understanding of how biofilm structure is linked to mass transport is essential to develop reliable models. For this purpose different works have collected the results of various diffusion studies, proposing correlations between biofilm density and mass transport. However the reliability of these correlations, widely used in modeling works, is under suspect because data used in their construction are highly dependent on the experimental conditions where they were obtained. The goal of this paper was to experimentally quantify the effective diffusivity inside biofilms, using a specific microsensor, as function of biomass density, for a specific microbial population and substrate. In addition, biofilm diffusivity was measured at different hydrodynamic conditions. Combining both studies, an equation for the calculation of biofilm diffusivity, considering biomass density and liquid phase velocity, was proposed.
2015-07-01T11:55:07ZGuimerà Villalba, XavierDorado Castaño, Antonio DavidBonsfills Pedrós, AnnaGabriel, D.Gamisans Noguera, JavierThe optimization of biofiltration technologies can be addressed improving the knowledge of the process taking place within biofilms, mainly biokinetics and mass transport. Biokinetics are usually defined using different methodologies, such as respirometric and titrimetric tests. Mass transport within biofilms is usually described as diffusion through a homogeneous phase, despite it is accepted that biofilms are very heterogeneous. Thus, a quantitative understanding of how biofilm structure is linked to mass transport is essential to develop reliable models. For this purpose different works have collected the results of various diffusion studies, proposing correlations between biofilm density and mass transport. However the reliability of these correlations, widely used in modeling works, is under suspect because data used in their construction are highly dependent on the experimental conditions where they were obtained. The goal of this paper was to experimentally quantify the effective diffusivity inside biofilms, using a specific microsensor, as function of biomass density, for a specific microbial population and substrate. In addition, biofilm diffusivity was measured at different hydrodynamic conditions. Combining both studies, an equation for the calculation of biofilm diffusivity, considering biomass density and liquid phase velocity, was proposed.Cartografia geotècnica i amidament dels terraplens de les Granges de l’Olivelles (Abella de la Conca)
http://hdl.handle.net/2117/28133
Cartografia geotècnica i amidament dels terraplens de les Granges de l’Olivelles (Abella de la Conca)
Edo, Joaquim; Parcerisa Duocastella, David; Sanmiquel Pera, Lluís
2015-06-02T07:47:09ZEdo, JoaquimParcerisa Duocastella, DavidSanmiquel Pera, Lluís