Environmental Modeling & Assessment - ENVIRON MODEL ASSESS, 2000
This paper presents two simple methods for the estimation of the instantaneous background air pol... more This paper presents two simple methods for the estimation of the instantaneous background air pollution level in a study area around an emitting point source. The methods allow estimation of concentrations non-inclusive of the contribution of the local emitting source. Hourly records of several monitoring stations located around the point source and results of the diagnostic Lagrangian particle dispersion model LADISMO are used in the calculations. A hypothetical case study is used to demonstrate the application of the two methods.
Determinación de la máxima capacidad de adsorción de la tierra de Arriera en la eliminación de fo... more Determinación de la máxima capacidad de adsorción de la tierra de Arriera en la eliminación de fosfatos en soluciones acuosas 1 Infografía:. Proceso de adsorción utilizando tierra de arriera en soluciones acuosas (aguas eutrofizadas).
... Ms. Víctor Córdova Asociación Chilena de seguridad, Chile. ... de la Incidencia de Patologías... more ... Ms. Víctor Córdova Asociación Chilena de seguridad, Chile. ... de la Incidencia de Patologías Respiratorias por Exposición al Polvo de Madera en los Carpinteros del Quindío ... Física para el Control Ergonómico de Factores Humanos Vinculados al Dolor Lumbar Solari G, Solari B ...
Study characterized and analyzed form factor, elementary composition and particle size of wood du... more Study characterized and analyzed form factor, elementary composition and particle size of wood dust, in order to understand its harmful health effects on carpenters in Quindío (Colombia). Once particle characteristics (size distributions, aerodynamic equivalent diameter (D(α)), elemental composition and shape factors) were analyzed, particles were then characterized via scanning electron microscopy (SEM) in conjunction with energy dispersive X-ray analysis (EDXRA). SEM analysis of particulate matter showed: 1) cone-shaped particle ranged from 2.09 to 48.79 µm D(α); 2) rectangular prism-shaped particle from 2.47 to 72.9 µm D(α); 3) cylindrically-shaped particle from 2.5 to 48.79 µm D(α); and 4) spherically-shaped particle from 2.61 to 51.93 µm D(α). EDXRA reveals presence of chemical elements from paints and varnishes such as Ca, K, Na and Cr. SEM/EDXRA contributes in a significant manner to the morphological characterization of wood dust. It is obvious that the type of particles sampled is a complex function of shapes and sizes of particles. Thus, it is important to investigate the influence of particles characteristics, morphology, shapes and D(α) that may affect the health of carpenters in Quindío.
The re-use of sewage sludge without any treatment as primary material-mixed with clays-in order t... more The re-use of sewage sludge without any treatment as primary material-mixed with clays-in order to obtain structural ceramics for buildings has been successfully improved. In the Ecobrick 1 project, the firing of a mixture of specific percentages of three components (clays, sludges and forest debris) resulted in a lighter and more thermal and acoustic insulating brick, compared with conventional clay-bricks. Volatile organic compounds (VOC) emission from the manufacturing of ceramics is the most important aspect to control. In the Ecobrick 1 project VOC emissions were monitored by using a bench-scale furnace. The study was conducted using an EPA recommended sampling train and portable sampling tubes that were thermally desorbed and analyzed by gas chromatography/mass spectrometry. Drying of raw sewage-sludge and firing processes were considered separately. In this paper, we present VOC emissions coming from the firing step of the Ecobrick 1 production. #
This paper compares two multi-criteria decision making (MCDM) approaches based on linguistic labe... more This paper compares two multi-criteria decision making (MCDM) approaches based on linguistic label assessment. The first approach consists of a modified fuzzy TOPSIS methodology introduced by Kaya and Kahraman in 2011. The second approach, introduced by Agell et al. in 2012, is based on qualitative reasoning techniques for ranking multi-attribute alternatives in group decision-making with linguistic labels. Both approaches are applied to a case of assessment and selection of the most suitable types of energy in a geographical area.
Several tests using water as effluent are used to analyse the performance of three types of micro... more Several tests using water as effluent are used to analyse the performance of three types of microfiltration cross-flow ceramic membranes. Two of these membranes are commercial (Atech and Membralox/US Filter) and the third one is experimental. The main differences between them lie in their chemical composition (different origin of raw materials) and in their manufacturing process.
Use of sewage sludge from wastewater treatment plants as a raw material for making clay bricks ha... more Use of sewage sludge from wastewater treatment plants as a raw material for making clay bricks has been analyzed to be an option to dumping sludges into landfills. This alternative has been shown feasible and interesting due to the high rate of use of ceramic materials in the building sector. However, it meets with some environmental issues and some prejudices on the part of users.
Removal of sludges from Wastewater Treatment Plants (WWTP) represents a serious worldwide environ... more Removal of sludges from Wastewater Treatment Plants (WWTP) represents a serious worldwide environmental problem for which alternatives other than their simple incineration are investigated. In this work the treatment of raw sludge from urban WWTP by means of a minimization process through spraydrying is analyzed as well as some proposals for revaluating the resulting dry product. Analysis is supported by some experimental results obtained with a laboratory spray dryer. The experimental procedure at laboratory scale is extrapolated to an industrial plant scale. An economic analysis of the proposal in relation to other possible sludge treatments is presented, taking into account in this case the comparison between the costs of the processes of sludge thickening, stabilization and dehydratation and the costs of spray-drying (especially power consumption), minimization of the final waste and reuse options. Finally, an environmental balance of the process is presented. In contrast with the classical treatment line, this alternative allows transforming sludges, i.e., a waste, into a valuable product with several applications.
We conducted a study of the health and working conditions in 10 carpenter&amp... more We conducted a study of the health and working conditions in 10 carpenter's workshops in the municipality of Armenia (Colombia). In these workshops, all the most exposed workers to wood dust were surveyed at the areas of sanding, brushing, immunization and painting (workers with the highest risk to get chronic respiratory disease). They were 177 workers. The use of hard and soft woods for furniture was detected. Besides, some pesticides, volatile organic solvents, synthetic epoxy resins glues and paintings, were used for finishes, which increases the risk of acquiring some neurological diseases and damage to the nervous system. Occurrence of cancer in nostrils mainly due to the use of hardwoods is an additional risk. With regard to the basic lighting conditions, it was found that half of workshops had deficiencies in special carving areas, because they were below the minimum allowable lighting limit level (500 lux). With relation to noise, all the workshops exceeded the permissible maximum limit value (85 dBA). With respect to the occurrence of occupational events, no data were found in the companies, or analysis of employee absenteeism due to the exposure to particulate matter.
Relationship between volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions and the... more Relationship between volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions and the chemical production of tropospheric ozone is studied through mathematical simulation. The study is applied to the Aburrá Valley, in the Colombian Andes, which is a practically unknown area from the point of view of ozone formation. The model used for this application is the European modelling of atmospheric constituents (EUMAC) zooming model (EZM) which consists of a mesoscale prognostic model (MEMO, mesoscale meteorological model) and a chemical reaction model (MUSE, multiscale for the atmospheric dispersion of reactive species), coupled to the chemical mechanism EMEP (European monitoring and evaluation program). The analysis is performed for a real episode that was characterized by high ozone production and that happened during the 23rd and 24th December, 1999 in Medellín (Colombia). From this real scenario, a sensitivity analysis has been carried out in order to assess the influence of VOC and NOx amounts on ozone production and to extract some conclusions for future ozone abatement policies in Andean regions. As far as ozone air quality is concerned, it is shown that in order to keep current levels the emphasis must be put to avoid increasing NOx emissions, or alternatively, to augment VOC emissions in order to have a high VOC/NOx ratio.
... We firstly used Hanna's scheme (1984) for near neutral conditions but finally, and becau... more ... We firstly used Hanna's scheme (1984) for near neutral conditions but finally, and because of the poor quality of the results obtained, we 15:00 h 4762 4759 4756 4753 4750 E 4747 4744 4741 r 4738 4735 4732 4729 4726 4723 3500 3000 2500 2000 JF HERNANDEZ et al. ...
A Lagrangian particle model has been used to simulate the dispersion of a tall stack plume of a p... more A Lagrangian particle model has been used to simulate the dispersion of a tall stack plume of a power plant located in a complex coastal site at the Spanish Mediterranean coast, under summer meteorological conditions: land and sea breezes and thermal low effects. These are responsible for a particular behavior of plume (rotations greater than 90'). The model is based on the numerical solution of Langevin's equation by following the trajectories of many particles. The displacement of these particles is governed by meteorological parameters resulting from Eulerian wind data adjusted by an objective analysis model based on variational calculus. The adjusted values should satisfy continuity as a strong constraint . The model allows to simulate the atmospheric dispersion both in homogeneous and nonhomogeneous turbulence according to de Baas et al. (1986) and schemes. The numerical results obtained by the dispersion model are compared with experimental data from a measurement campaign developed at the surroundings of Castellon power plant. The model is applied to the problem of predicting the ground level concentration (GLC) (3 m, above ground level) of the SO* emitted by the power plant. Model behavior was evaluated through several statistical indices: relative mean bias, normalized mean square error and the cumulative frequency distribution of the point-by-point ratio between observed and predicted concentrations. Both models were developed at the Instituto de Tecnologia y Modelizacibn Ambiental (ITEMA) of the Universidad PolitCcnica de Catalufia (UPC).
Recent research pointed out the question of missing OH reactivity in a forest system and the ques... more Recent research pointed out the question of missing OH reactivity in a forest system and the question for unknown highly reactive biogenic emissions. In this study we show that coniferous forests are an important source of highly reactive hydrocarbons, the sesquiterpenes. We investigated the seasonality of terpene emissions from Scots pine to work out influences on atmospheric chemistry in different seasons for both mono-and sesquiterpenes. Especially sesquiterpenes (C 15 ) change dramatically in their contribution to the terpene emissions of Scots pine. Fourteen sesquiterpenes and oxygenated compounds were found in the emissions. In spring, the pattern was most complex with all 14 compounds being emitted, whereas in summer and fall it was reduced to 1,8-cineol and camphor. The emission pattern of the monoterpenes varied only slightly. The main compounds emitted were a-pinene, b-pinene, and 3-carene representing up to 90% of the total terpene emission. The total monoterpene emission rates varied from below detection limit to 460 pmol m À2 s À1 with highest emission rates found in June. Standard emission rates of the main compounds calculated from the monthly measured diurnal emission courses varied considerably over the year. Highest values were found in spring and early summer with up to 700 pmol m À2 s À1 .
Environmental Modeling & Assessment - ENVIRON MODEL ASSESS, 2000
This paper presents two simple methods for the estimation of the instantaneous background air pol... more This paper presents two simple methods for the estimation of the instantaneous background air pollution level in a study area around an emitting point source. The methods allow estimation of concentrations non-inclusive of the contribution of the local emitting source. Hourly records of several monitoring stations located around the point source and results of the diagnostic Lagrangian particle dispersion model LADISMO are used in the calculations. A hypothetical case study is used to demonstrate the application of the two methods.
Determinación de la máxima capacidad de adsorción de la tierra de Arriera en la eliminación de fo... more Determinación de la máxima capacidad de adsorción de la tierra de Arriera en la eliminación de fosfatos en soluciones acuosas 1 Infografía:. Proceso de adsorción utilizando tierra de arriera en soluciones acuosas (aguas eutrofizadas).
... Ms. Víctor Córdova Asociación Chilena de seguridad, Chile. ... de la Incidencia de Patologías... more ... Ms. Víctor Córdova Asociación Chilena de seguridad, Chile. ... de la Incidencia de Patologías Respiratorias por Exposición al Polvo de Madera en los Carpinteros del Quindío ... Física para el Control Ergonómico de Factores Humanos Vinculados al Dolor Lumbar Solari G, Solari B ...
Study characterized and analyzed form factor, elementary composition and particle size of wood du... more Study characterized and analyzed form factor, elementary composition and particle size of wood dust, in order to understand its harmful health effects on carpenters in Quindío (Colombia). Once particle characteristics (size distributions, aerodynamic equivalent diameter (D(α)), elemental composition and shape factors) were analyzed, particles were then characterized via scanning electron microscopy (SEM) in conjunction with energy dispersive X-ray analysis (EDXRA). SEM analysis of particulate matter showed: 1) cone-shaped particle ranged from 2.09 to 48.79 µm D(α); 2) rectangular prism-shaped particle from 2.47 to 72.9 µm D(α); 3) cylindrically-shaped particle from 2.5 to 48.79 µm D(α); and 4) spherically-shaped particle from 2.61 to 51.93 µm D(α). EDXRA reveals presence of chemical elements from paints and varnishes such as Ca, K, Na and Cr. SEM/EDXRA contributes in a significant manner to the morphological characterization of wood dust. It is obvious that the type of particles sampled is a complex function of shapes and sizes of particles. Thus, it is important to investigate the influence of particles characteristics, morphology, shapes and D(α) that may affect the health of carpenters in Quindío.
The re-use of sewage sludge without any treatment as primary material-mixed with clays-in order t... more The re-use of sewage sludge without any treatment as primary material-mixed with clays-in order to obtain structural ceramics for buildings has been successfully improved. In the Ecobrick 1 project, the firing of a mixture of specific percentages of three components (clays, sludges and forest debris) resulted in a lighter and more thermal and acoustic insulating brick, compared with conventional clay-bricks. Volatile organic compounds (VOC) emission from the manufacturing of ceramics is the most important aspect to control. In the Ecobrick 1 project VOC emissions were monitored by using a bench-scale furnace. The study was conducted using an EPA recommended sampling train and portable sampling tubes that were thermally desorbed and analyzed by gas chromatography/mass spectrometry. Drying of raw sewage-sludge and firing processes were considered separately. In this paper, we present VOC emissions coming from the firing step of the Ecobrick 1 production. #
This paper compares two multi-criteria decision making (MCDM) approaches based on linguistic labe... more This paper compares two multi-criteria decision making (MCDM) approaches based on linguistic label assessment. The first approach consists of a modified fuzzy TOPSIS methodology introduced by Kaya and Kahraman in 2011. The second approach, introduced by Agell et al. in 2012, is based on qualitative reasoning techniques for ranking multi-attribute alternatives in group decision-making with linguistic labels. Both approaches are applied to a case of assessment and selection of the most suitable types of energy in a geographical area.
Several tests using water as effluent are used to analyse the performance of three types of micro... more Several tests using water as effluent are used to analyse the performance of three types of microfiltration cross-flow ceramic membranes. Two of these membranes are commercial (Atech and Membralox/US Filter) and the third one is experimental. The main differences between them lie in their chemical composition (different origin of raw materials) and in their manufacturing process.
Use of sewage sludge from wastewater treatment plants as a raw material for making clay bricks ha... more Use of sewage sludge from wastewater treatment plants as a raw material for making clay bricks has been analyzed to be an option to dumping sludges into landfills. This alternative has been shown feasible and interesting due to the high rate of use of ceramic materials in the building sector. However, it meets with some environmental issues and some prejudices on the part of users.
Removal of sludges from Wastewater Treatment Plants (WWTP) represents a serious worldwide environ... more Removal of sludges from Wastewater Treatment Plants (WWTP) represents a serious worldwide environmental problem for which alternatives other than their simple incineration are investigated. In this work the treatment of raw sludge from urban WWTP by means of a minimization process through spraydrying is analyzed as well as some proposals for revaluating the resulting dry product. Analysis is supported by some experimental results obtained with a laboratory spray dryer. The experimental procedure at laboratory scale is extrapolated to an industrial plant scale. An economic analysis of the proposal in relation to other possible sludge treatments is presented, taking into account in this case the comparison between the costs of the processes of sludge thickening, stabilization and dehydratation and the costs of spray-drying (especially power consumption), minimization of the final waste and reuse options. Finally, an environmental balance of the process is presented. In contrast with the classical treatment line, this alternative allows transforming sludges, i.e., a waste, into a valuable product with several applications.
We conducted a study of the health and working conditions in 10 carpenter&amp... more We conducted a study of the health and working conditions in 10 carpenter's workshops in the municipality of Armenia (Colombia). In these workshops, all the most exposed workers to wood dust were surveyed at the areas of sanding, brushing, immunization and painting (workers with the highest risk to get chronic respiratory disease). They were 177 workers. The use of hard and soft woods for furniture was detected. Besides, some pesticides, volatile organic solvents, synthetic epoxy resins glues and paintings, were used for finishes, which increases the risk of acquiring some neurological diseases and damage to the nervous system. Occurrence of cancer in nostrils mainly due to the use of hardwoods is an additional risk. With regard to the basic lighting conditions, it was found that half of workshops had deficiencies in special carving areas, because they were below the minimum allowable lighting limit level (500 lux). With relation to noise, all the workshops exceeded the permissible maximum limit value (85 dBA). With respect to the occurrence of occupational events, no data were found in the companies, or analysis of employee absenteeism due to the exposure to particulate matter.
Relationship between volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions and the... more Relationship between volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions and the chemical production of tropospheric ozone is studied through mathematical simulation. The study is applied to the Aburrá Valley, in the Colombian Andes, which is a practically unknown area from the point of view of ozone formation. The model used for this application is the European modelling of atmospheric constituents (EUMAC) zooming model (EZM) which consists of a mesoscale prognostic model (MEMO, mesoscale meteorological model) and a chemical reaction model (MUSE, multiscale for the atmospheric dispersion of reactive species), coupled to the chemical mechanism EMEP (European monitoring and evaluation program). The analysis is performed for a real episode that was characterized by high ozone production and that happened during the 23rd and 24th December, 1999 in Medellín (Colombia). From this real scenario, a sensitivity analysis has been carried out in order to assess the influence of VOC and NOx amounts on ozone production and to extract some conclusions for future ozone abatement policies in Andean regions. As far as ozone air quality is concerned, it is shown that in order to keep current levels the emphasis must be put to avoid increasing NOx emissions, or alternatively, to augment VOC emissions in order to have a high VOC/NOx ratio.
... We firstly used Hanna's scheme (1984) for near neutral conditions but finally, and becau... more ... We firstly used Hanna's scheme (1984) for near neutral conditions but finally, and because of the poor quality of the results obtained, we 15:00 h 4762 4759 4756 4753 4750 E 4747 4744 4741 r 4738 4735 4732 4729 4726 4723 3500 3000 2500 2000 JF HERNANDEZ et al. ...
A Lagrangian particle model has been used to simulate the dispersion of a tall stack plume of a p... more A Lagrangian particle model has been used to simulate the dispersion of a tall stack plume of a power plant located in a complex coastal site at the Spanish Mediterranean coast, under summer meteorological conditions: land and sea breezes and thermal low effects. These are responsible for a particular behavior of plume (rotations greater than 90'). The model is based on the numerical solution of Langevin's equation by following the trajectories of many particles. The displacement of these particles is governed by meteorological parameters resulting from Eulerian wind data adjusted by an objective analysis model based on variational calculus. The adjusted values should satisfy continuity as a strong constraint . The model allows to simulate the atmospheric dispersion both in homogeneous and nonhomogeneous turbulence according to de Baas et al. (1986) and schemes. The numerical results obtained by the dispersion model are compared with experimental data from a measurement campaign developed at the surroundings of Castellon power plant. The model is applied to the problem of predicting the ground level concentration (GLC) (3 m, above ground level) of the SO* emitted by the power plant. Model behavior was evaluated through several statistical indices: relative mean bias, normalized mean square error and the cumulative frequency distribution of the point-by-point ratio between observed and predicted concentrations. Both models were developed at the Instituto de Tecnologia y Modelizacibn Ambiental (ITEMA) of the Universidad PolitCcnica de Catalufia (UPC).
Recent research pointed out the question of missing OH reactivity in a forest system and the ques... more Recent research pointed out the question of missing OH reactivity in a forest system and the question for unknown highly reactive biogenic emissions. In this study we show that coniferous forests are an important source of highly reactive hydrocarbons, the sesquiterpenes. We investigated the seasonality of terpene emissions from Scots pine to work out influences on atmospheric chemistry in different seasons for both mono-and sesquiterpenes. Especially sesquiterpenes (C 15 ) change dramatically in their contribution to the terpene emissions of Scots pine. Fourteen sesquiterpenes and oxygenated compounds were found in the emissions. In spring, the pattern was most complex with all 14 compounds being emitted, whereas in summer and fall it was reduced to 1,8-cineol and camphor. The emission pattern of the monoterpenes varied only slightly. The main compounds emitted were a-pinene, b-pinene, and 3-carene representing up to 90% of the total terpene emission. The total monoterpene emission rates varied from below detection limit to 460 pmol m À2 s À1 with highest emission rates found in June. Standard emission rates of the main compounds calculated from the monthly measured diurnal emission courses varied considerably over the year. Highest values were found in spring and early summer with up to 700 pmol m À2 s À1 .
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Papers by Lazaro Cremades