Revista Internacional de Contaminación Ambiental
Not a member yet
1371 research outputs found
Sort by
Assessment of diesel exhaust pollutants effects in Tillandsia capillaris and Ramalina celastri by laboratory trials
No full textTraffic-related air pollution is one of the most relevant environmental problems in urban areas. Several cryptogams (i.e., lichens and mosses) and vascular species have been employed to monitor urban air pollution since they allow the assessment of air quality in a large number of sampling sites simultaneously at low cost. In large urban cities, vehicle emissions are frequently the major source of air pollution along with residential energy (for cooking and heating), industry, power generation, and waste incineration. Biomonitors in these urban environments are exposed to a mixture of pollutants making it difficult to identify which pollutant causes the greatest damage to organisms. However, studies that analyze the effect of pollutants emitted by vehicle exhaust are scarce and in the particular case of the most used biomonitor species in Argentina, no analysis of how they are affected by vehicle emissions has been carried out so far. So, the aim of this work was to analyze changes in physiochemical parameters (pigment content, pro-oxidant products, and sulfur accumulation) in Ramalina celastri, and heavy metal accumulation in Tillandsia capillaris, exposed to diesel exhausts under laboratory conditions. A strong damage in the photosynthetic apparatus of R. celastri was observed as well as metal concentration in T. capillaris after 20 min of exposure and 48 h of permanence in the exposure chambers. The results indicate that not only the particles and metals cause damage to these two well-known biomonitors, but the interaction of these pollutants with other components of the atmosphere that form different secondary pollutants, together with a longer exposure time, could cause the highest level of damage in them.Traffic-related air pollution is one of the most relevant environmental problems in urban areas. Several cryptogams (i.e., lichens and mosses) and vascular species have been employed to monitor urban air pollution since they allow the assessment of air quality in a large number of sampling sites simultaneously at low cost. In large urban cities, vehicle emissions are frequently the major source of air pollution along with residential energy (for cooking and heating), industry, power generation, and waste incineration. Biomonitors in these urban environments are exposed to a mixture of pollutants making it difficult to identify which pollutant causes the greatest damage to organisms. However, studies that analyze the effect of pollutants emitted by vehicle exhaust are scarce and in the particular case of the most used biomonitor species in Argentina, no analysis of how they are affected by vehicle emissions has been carried out so far. So, the aim of this work was to analyze changes in physiochemical parameters (pigment content, pro-oxidant products, and sulfur accumulation) in Ramalina celastri, and heavy metal accumulation in Tillandsia capillaris, exposed to diesel exhausts under laboratory conditions. A strong damage in the photosynthetic apparatus of R. celastri was observed as well as metal concentration in T. capillaris after 20 min of exposure and 48 h of permanence in the exposure chambers. The results indicate that not only the particles and metals cause damage to these two well-known biomonitors, but the interaction of these pollutants with other components of the atmosphere that form different secondary pollutants, together with a longer exposure time, could cause the highest level of damage in them
Cáscara de naranja como sustrato para sintetizar nanoestructuras de carbón conductivas por un proceso térmico verde
Get PDFOrange (Citrus sinensis L.) peel (OP) has been considered a waste due to its high processing costs and complicated management, resulting in environmental pollution issues. Alternatives have been proposed to generate economic benefits by developing efficient technologies to produce and store electrical energy. Moreover, valorization of OP will bring municipal and agro-industrial waste management reduction. This work aimed to develop a cost-effective and environmentally friendly thermal process to synthesize a conductive carbon from OP using a new methodology herein described. First, the OP was washed using an ultrasonic bath and dried by sun and dehydrated in muffle. Then, dehydrated pieces of OP were covered with fine-grained sea sand to limit air interaction and was carbonized at 1000 °C for one hour. The resulting biocarbon was analyzed by cyclic voltammetry. The electrical double layer capacitance was estimated to assess the electrochemical behavior of the carbon in the electrolyte. Interestingly, with the newly proposed heat treatment, the carbon material showed a specific capacitance of 272 F/g at 20 mV/s. Therefore, the new proposed thermal process allows the synthesis of graphitized carbon with good electrochemical properties at a low cost. The results show the potential for the development of new conductive carbon materials from residual biomass by a simple, economical, and environmentally friendly air-limited heat treatment.La cáscara de naranja (Citrus sinensis L.) se ha considerado como un residuo debido al elevado costo y la compleja gestión de su procesamiento, convirtiéndose en un problema de contaminación ambiental. Por esta razón, se ha prestado gran atención a la valorización de este residuo agroindustrial para obtener beneficios monetarios con una reducción del volumen de residuos orgánicos y la posibilidad del desarrollo de tecnologías eficientes para generar y almacenar energía eléctrica. Este trabajo presenta un proceso térmico ambientalmente amigable para producir un carbón conductivo. Primero las cáscaras de naranja se lavaron por baño ultrasónico y se secaron al sol y en mufla. Posteriormente pedazos de cáscara de naranja deshidratada se cubrieron completamente con arena de mar de grano fino y se carbonizaron a 1000 °C durante 1 hora. Después, el biocarbón fue estudiado por voltametría cíclica. La capacitancia eléctrica de doble capa de la muestra fue estimada para conocer el comportamiento electroquímico del carbono en el electrolito. El material de carbón sintetizado mostró una capacitancia específica de 272 F/g a 20 mV/s. Los resultados observados demostraron que el nuevo proceso térmico propuesto produce carbono grafitizado con buenas propiedades electroquímicas a bajo costo. Además, esta propuesta contribuye con el desarrollo de nuevos materiales conductores de carbón usando un tratamiento térmico simple, económico y respetuoso con el medio ambiente a partir de biomasa residual de bajo valor
Efectos y caracterización de nanopartículas atmosféricas (NP-CuO, ZnO) en plantas
Get PDFAmid the advances in nanotechnology, the use of metal oxide nanoparticles has increased, standing out the use of copper oxide and zinc oxide, due to their abundance and their specific properties of great relevance, such as antimicrobial effects, and the improved electrical conductivity and catalysis. The bioaccumulation and interaction of this type of nanoparticles in the environment are largely unknown, generating concern about potentially toxic effects that have not yet been adequately studied, hence the importance of knowing their effects on the environment. Among the proposals for environmental studies of nanomaterials, plants stand out as bioindicators, especially after the capture of particles from the atmosphere. This review compiles information about different studies on applications of zinc oxide and copper oxide nanoparticles, how they can be detected, and how they can be captured and characterized by using plants. It also highlights the importance of studies on toxicity and the effects that are generated after the interaction with different plant species, which contribute to understanding the diverse mechanisms of toxicity, interaction, and accumulation of metals, as well as their degradation in the environment. Finally, alternatives are mentioned to improve the biocompatibility of nanoparticles with the environment and the organisms. Knowing the current state of the topic will allow to consolidate the information obtained so far and the direction to take, for the efficient and responsible use of nanotechnology, ensuring its continuity and development.Con los avances de la nanotecnología ha aumentado el uso de nanopartículas óxido metálicas, entre las que destacan las de óxido de cobre y óxido de zinc, por su abundancia y por sus propiedades específicas de gran relevancia, tales como efectos antimicrobianos y la mejora de la conductividad eléctrica y la catálisis. La bioacumulación e interacción de este tipo de nanopartículas en el ambiente son desconocidos en gran parte, generando preocupación por los efectos potencialmente tóxicos que aún no han sido estudiados de forma adecuada, de ahí la importancia de conocer sus efectos en el ambiente. Entre las propuestas para los estudios ambientales de los nanomateriales, destacan las plantas como bioindicadores, en especial tras la captación de partículas desde la atmósfera. La presente revisión, recopila información de distintos estudios sobre aplicaciones de nanopartículas de óxido de zinc y óxido de cobre, la manera en que pueden detectarse, y el cómo pueden ser captadas y caracterizadas mediante el uso de plantas. También resalta la importancia de los estudios sobre la toxicidad y los efectos que se generan a través de la interacción con distintas especies de plantas, que contribuyen a entender los diversos mecanismos de toxicidad, interacción y acumulación de metales, así como su degradación en el ambiente. Finalmente, se mencionan alternativas para mejorar la biocompatibilidad de las nanopartículas con el ambiente y los organismos. El conocer el estado actual del tema permitirá consolidar la información obtenida hasta el momento y la dirección a tomar para el uso eficiente y responsable de la nanotecnología, asegurando su continuidad y desarrollo.
Modelación del transporte de sedimentos en el Delta del río Sinú, Colombia
Get PDFVariations in suspended sediment transport rates can cause significant impacts in deltas and estuaries, as river sediments play a fundamental role in the stability of these coastal ecosystems. This work presents the application of a 3D numerical model to simulate sediment transport in the Sinú River Delta, Colombia, and its impact on the adjacent coastal zone, where a significant amount of suspended sediment is transported to the Caribbean Sea. The EFDC Explorer modeling system was implemented, which solves the equations of movement and transport, specifically to determine the dynamics and spatiotemporal distribution of suspended sediments and evaluate the vulnerability of the estuarine zone to hydrodynamic variations and sediment transport. The model was configured with field obtained data and with secondary information from national environmental agencies. The calibration was verified using the index of Agreement, achieving a good fit for the variables considered. The results showed particularities in the distribution and diffusion of sediments, such as the presence of preferential areas of accumulation and dispersion, demonstrating that the coastal zone is vulnerable to sedimentation.Las variaciones en las tasas de transporte de sedimento en suspensión pueden causar impactos significativos en deltas y estuarios, pues los sedimentos fluviales desempeñan un papel fundamental en la estabilidad de estos ecosistemas costeros. Este trabajo presenta la aplicación de un modelo numérico 3D para simular el transporte de sedimentos en el delta del Río Sinú, Colombia y su impacto en la zona costera adyacente, donde se transporta una cantidad importante de sedimento suspendido al mar Caribe. Se implementó el sistema de modelación EFDC Explorer, que resuelve las ecuaciones de movimiento y de transporte, específicamente para: determinar la dinámica y distribución espaciotemporal de los sedimentos suspendidos, y evaluar la vulnerabilidad de la zona estuarina ante variaciones hidrodinámicas y de transporte de sedimentos. El modelo fue configurado con datos obtenidos en campo y con información secundaria de agencias ambientales nacionales. La calibración fue verificada mediante el Índice de Concordancia, logrando un buen ajuste para las variables consideradas. Los resultados mostraron particularidades en la distribución y difusión de los sedimentos, como presencia de áreas preferenciales de acumulación y dispersión, demostrando que la zona costera es vulnerable a la sedimentación
The difference in air pollutants in typical northern and southern China coastal cities-Taking Shenzhen and Qingdao as examples
Get PDFIn 2018, four air pollutants in Qingdao and Shenzhen were comprehensively analyzed and evaluated according to the standards. According to the results, PM2.5 exceeded its standard by multiples of 1.11 and 1.03 in January and February, respectively, in Shenzhen, and the no-exceedance probability was 84.6%. However, the no-exceedance probability in Qingdao was only 50%. When the maximun index of ambient air quality was used to evaluate the above pollutants, the air pollutant in Shenzhen was NO2 from May to September and PM2.5 in other the months, but the pollutants in Qingdao were different each month. The distribution patterns of the monthly average mass concentration of the pollutants in Shenzhen and Qingdao were consistent with the seasonal distribution. The particulate matter in the air was still the focus of the government in Shenzhen. The sources of air pollutants in Qingdao were diverse, and most pollutants were related to energy combustion.In 2018, four air pollutants in Qingdao and Shenzhen were comprehensively analyzed and evaluated according to the standards. According to the results, PM2.5 exceeded its standard by multiples of 1.11 and 1.03 in January and February, respectively, in Shenzhen, and the no-exceedance probability was 84.6%. However, the no-exceedance probability in Qingdao was only 50%. When the maximun index of ambient air quality was used to evaluate the above pollutants, the air pollutant in Shenzhen was NO2 from May to September and PM2.5 in other the months, but the pollutants in Qingdao were different each month. The distribution patterns of the monthly average mass concentration of the pollutants in Shenzhen and Qingdao were consistent with the seasonal distribution. The particulate matter in the air was still the focus of the government in Shenzhen. The sources of air pollutants in Qingdao were diverse, and most pollutants were related to energy combustion
Evaluación de la exposición a arsénico y factores de riesgo de aterogénesis en una población Altoandina en Perú
Get PDFExposure to arsenic (As) through drinking water is a global problem that affects several geographic areas. However, the information related to As exposure and its effects in Peru is limited. In order to estimate the relationship between As exposure and atherogenesis risk markers in residents of Jauja, Peru (3390 msnm), a cross-sectional study was carried out in residents of Apata (n = 31) and Molinos (n = 81) who drink water with As levels between 5 and 47 µg/L, respectively. The concentrations of As in water and urine were evaluated by hydride generation atomic absorption spectroscopy. The lipid profile, paraoxonase 1 aryl ester activity, (PON-ARE) blood pressure, and fasting glucose (Glu) blood levels were also evaluated. The study included 112 adults between 18 and 81 years of age. Median total As concentration in urine (AsT-U) were 4.4 and 28.5 µg/L for Apata and Molinos, respectively. According to the multiple lineal regression analysis, the decrease in PON-ARE activity and the concentration of non-HDL cholesterol were related to a higher concentration of AsT-U (Apata: β = –0.26, IC from –0.93 to –0.17, R2 = 0.07, p < 0.001; Molinos: β = –0.38, IC from –0.797 to –0.295, R2 = 0.15, p < 0.001). Whereas an increase in Glu was observed at a higher concentration of AsT-U (β = 0.22, IC from 0.09 to 0.35, R2 = 0.09, p < 0.05). These results suggest that As exposure increases atherogenesis risk in Molinos, Jauja, Peru. La exposición a arsénico (As) a través del agua de consumo es una problemática mundial que afecta a varias áreas geográficas. Sin embargo, la información relacionada con su exposición y sus efectos en Perú es limitada. Con el objetivo de estimar la relación entre la exposición a As y los factores de riesgo de aterogénesis en residentes de Jauja, Perú (3390 msnm), se realizó un estudio transversal en residentes de Apata (n = 31) y Molinos (n = 81) que consumían agua con concentraciones de As entre 5 y 47 µg/L, respectivamente. Se evaluaron las concentraciones de As en agua y orina por espectrofotometría de absorción atómica con generación de hidruros, además del perfil lipídico, la actividad arilesterasa de la paraoxonasa 1 (PON-ARE), la presión arterial y los niveles de glucosa en ayunas (Glu). En el estudio participaron 112 adultos de 18 a 81 años de edad. La mediana de las concentraciones de As total en orina (AsT-U) fue de 4.4 y 28.5 µg/L para Apata y Molinos, respectivamente. Según el análisis de regresión lineal múltiple por pasos, la disminución de la actividad PON-ARE y las concentraciones de colesterol no HDL estuvieron relacionadas con mayor concentración de AsT-U (Apata: β = –0.26, IC de –0.93 a –0.17, R2 = 0.07, p < 0.001; Molinos: β = –0.38, IC de –0.797 a –0.295, R2 = 0.15, p < 0.001). Por otra parte, se observó un aumento de Glu a mayor concentración de AsT-U (β = 0.22, IC de 0.09 a 0.35, R2 = 0.09, p < 0.05). Los resultados sugieren que la exposición a As puede aumentar el riesgo de aterogénesis en la población de Molinos Jauja, Perú
Transient storage and nitrogen retention in headwater stream of a suburban watershed in Beijing, China
Get PDFTransient storage refers to a vital process affecting nutrient retention dynamics. To explore how streambed topography, discharge, and nutrient ambient concentration impact the transient storage and nitrogen retention of the headwater stream, tracer experiments were performed in five reaches of the Yanqi watershed. The one-dimensional transport with inflow and storage model (OTIS) was employed to simulate the solute injection. Transient storage potential was evaluated by transient storage metrics. Moreover, the material balance method was adopted to obtain the amount of nitrogen retention in the respective reach, and the nutrient spiraling metrics were determined to assess the nitrogen retention potential. As revealed from this study, improving transient storage under low flow conditions effectively facilitated nitrogen retention (except for the case of low-head weirs reach), while the erosion of high discharge destroyed the transient storage zone, thereby reducing the nitrogen retention potential. Ecological restoration in the Yanqi watershed could rescue nitrogen retention potential to a natural state under low flow, whereas limitations were identified in nitrogen retention potential under high flow and high ambient concentration.Transient storage refers to a vital process affecting nutrient retention dynamics. To explore how streambed topography, discharge, and nutrient ambient concentration impact the transient storage and nitrogen retention of the headwater stream, tracer experiments were performed in five reaches of the Yanqi watershed. The one-dimensional transport with inflow and storage model (OTIS) was employed to simulate the solute injection. Transient storage potential was evaluated by transient storage metrics. Moreover, the material balance method was adopted to obtain the amount of nitrogen retention in the respective reach, and the nutrient spiraling metrics were determined to assess the nitrogen retention potential. As revealed from this study, improving transient storage under low flow conditions effectively facilitated nitrogen retention (except for the case of low-head weirs reach), while the erosion of high discharge destroyed the transient storage zone, thereby reducing the nitrogen retention potential. Ecological restoration in the Yanqi watershed could rescue nitrogen retention potential to a natural state under low flow, whereas limitations were identified in nitrogen retention potential under high flow and high ambient concentration
Mechanical properties of concrete after acid rain corrosion based on particle discrete element
Get PDFTo predict the durability of concrete structure and ensure the safety of life and property, a method to analyze the mechanical properties of concrete corroded by acid rain based on particle discrete element is presented. Eight test specimens of prestressed concrete beams were designed, and then test specimens of concrete beams with different corrosion rates were obtained by simulation of acid rain corrosion. The impact splitting load test was carried out based on the particle discrete element, and then the meso-mechanics model of concrete particle discrete element was built. Experiment results show that the stress process of the test concrete beam after acid rain corrosion includes three stages: uncracking, crack increasing with load, crushing and spalling. After the acid rain corrosion, the splitting tensile strength of TYL-b (the upper tensile reinforcement) beam is the highest, and the splitting tensile strength of TYL-d (the lower compression reinforcement) beam is the lowest. The corrosion rate of acid rain is inversely proportional to the splitting tensile strength of concrete. The splitting tensile strength of concrete after acid rain corrosion obtained by the proposed method is consistent with the actual value. Therefore, the proposed method has high accuracy and high practical value.To predict the durability of concrete structure and ensure the safety of life and property, a method to analyze the mechanical properties of concrete corroded by acid rain based on particle discrete element is presented. Eight test specimens of prestressed concrete beams were designed, and then test specimens of concrete beams with different corrosion rates were obtained by simulation of acid rain corrosion. The impact splitting load test was carried out based on the particle discrete element, and then the meso-mechanics model of concrete particle discrete element was built. Experiment results show that the stress process of the test concrete beam after acid rain corrosion includes three stages: uncracking, crack increasing with load, crushing and spalling. After the acid rain corrosion, the splitting tensile strength of TYL-b (the upper tensile reinforcement) beam is the highest, and the splitting tensile strength of TYL-d (the lower compression reinforcement) beam is the lowest. The corrosion rate of acid rain is inversely proportional to the splitting tensile strength of concrete. The splitting tensile strength of concrete after acid rain corrosion obtained by the proposed method is consistent with the actual value. Therefore, the proposed method has high accuracy and high practical value
Evaluación del peligro de contaminación del agua subterránea en áreas agrícolas
Get PDFThis work evaluates the groundwater contamination hazard associated with the use of pesticides, considering their properties, the soil where they are applied and the aquifer to which they can potentially leach. The study area considered was the Quequén Grande River basin where the only water supply is the Pampeano aquifer and agriculture is the dominant activity. The contamination hazard was obtained by combining the aquifer vulnerability (DRASTIC index) and the potential pollutant load (AFT index) working whit ARCGIS software. The sectors with the least vulnerability were in the upper zone of the watershed and those with the greatest vulnerability in the lower zone. Five pesticides were classified with a category higher than “unlikely leaching”, obtaining the highest potential pollutant loads in the upper sector. Two hazard maps were obtained. In both, the least hazard areas are located in the northeast, where the water table is deeper, and the percentage of organic matter is higher. The areas of greatest hazard are in the west and southeast due to the shallow water level, lower content of organic matter, and low thickness of the A horizon. These maps obtained can then be used in groundwater management: if the contaminant load is low, the use of the maps obtained according to the AFT index is considered sufficient. On the contrary, in those cases where the load is greater, the use of hazard maps should be considered.El objetivo del presente trabajo consistió en evaluar el peligro de contaminación del agua subterránea asociado al uso de plaguicidas, considerando sus propiedades, las del suelo donde son aplicados y las del acuífero al cual potencialmente pueden lixiviar. La zona de estudio considerada fue la cuenca del río Quequén Grande donde la única provisión de agua es el acuífero Pampeano y la agricultura la actividad dominante. Se trabajó en entorno ARCGIS y el peligro de contaminación se obtuvo por la combinación de la vulnerabilidad del acuífero (índice DRASTIC) y la carga contaminante potencial (índice AFT). El mapa de vulnerabilidad mostró que los sectores menos vulnerables se ubican en la zona alta de la cuenca y los de mayor en la zona baja. Cinco plaguicidas fueron clasificados con una categoría superior a “poco probable lixiviación”, con las mayores cargas contaminantes en el sector alto. Se obtuvieron dos mapas de peligro, con las zonas de menor peligro en la zona NE, debido al nivel freático más profundo y mayor porcentaje de materia orgánica. Las zonas de mayor peligro se ubican en el sector O y SE, debido a menores contenidos de materia orgánica, bajos espesores del horizonte A y un nivel freático más somero. Estos mapas obtenidos pueden ser utilizados entonces en la gestión del hídrico subterráneo: si la carga contaminante es baja, se considera suficiente el uso de los mapas obtenidos según el índice AFT. Por el contrario, en aquellos casos que la carga sea mayor, se debe contemplar el uso de los mapas de peligrosidad