Revista Internacional de Contaminación Ambiental
Not a member yet
1371 research outputs found
Sort by
In vitro and In vivo biocontrol of leaf spot disease caused by Curvularia lunata in maize landrace by Bacillus licheniformis M2-7
Get PDFurvularia lunata (Wakker) Boedijn is a phytopathogen that causes leaf spot disease in maize (Zea mays L.), a cereal crop of great economic importance. However, the use of biocontrol agents such as Bacillus species offers an effective and sustainable alternative to reduce the severity of leaf spot disease. Therefore, our study sought to evaluate the applicability of Bacillus licheniformis M2-7 as a potential biocontrol agent against Curvularia lunata in maize landrace plants both in vitro and in vivo. The in vitro experiments demonstrated that strain M2-7 inhibited mycelial growth and conidial germination by 73.75 and 78.66%, respectively. In the in vivo tests, 1 × 103 and 1 × 106 CFU concentrations of strain M2-7 significantly reduced disease severity compared to the control. Our findings suggested that Bacillus licheniformis M2-7 could be used on a commercial scale as an effective biocontrol agent against leaf spot disease in maize.Curvularia lunata (Wakker) Boedijn is a phytopathogen that causes leaf spot disease in maize (Zea mays L.), a cereal crop of great economic importance. However, the use of biocontrol agents such as Bacillus species offers an effective and sustainable alternative to reduce the severity of leaf spot disease. Therefore, our study sought to evaluate the applicability of Bacillus licheniformis M2-7 as a potential biocontrol agent against Curvularia lunata in maize landrace plants both in vitro and in vivo. The in vitro experiments demonstrated that strain M2-7 inhibited mycelial growth and conidial germination by 73.75 and 78.66%, respectively. In the in vivo tests, 1 × 103 and 1 × 106 CFU concentrations of strain M2-7 significantly reduced disease severity compared to the control. Our findings suggested that Bacillus licheniformis M2-7 could be used on a commercial scale as an effective biocontrol agent against leaf spot disease in maize
Evaluación de la remoción de la materia orgánica de efluente de camal aplicando procesos Fenton y foto-Fenton
Get PDFSlaughtering animals in a slaughterhouse requires large consumption of water and, consequently, generates wastewater with a high organic load, the disposal of which represents an environmental problem. For this reason, in the present investigation, the efficiency of the Fenton and photo-Fenton processes in the removal of organic matter from the effluent of the municipal slaughterhouse of Cusco, Peru, was evaluated using statistical techniques. Previously, the effluent’s characteristics and the sampling point’s diagnosis were evaluated, monitored, and analyzed. The methodology and sampling procedures established by Peruvian regulations were used for the effluent sampling. The initial and final concentration of the biochemical oxygen demand (BOD5) was determined in each experiment. The box-Behnken design was used for the distribution matrix of the 30 experiments with their respective levels, corresponding to the following parameters: FeSO4•7H2O, H2O2, and pH. The tests were carried out in a jar test, with a stirring speed of 150 rpm and a reaction time of 1 h. In the case of the photo-Fenton process, a photoreactor with a 13 W lamp (UV-C 254 nm) was installed using the same stirring speed and reaction time. The results achieved in the research, with respect to the Fenton process, indicate a BOD5 decrease of 93.96 % compared to the Photo-Fenton process, which reached 94.63 %.Las actividades de sacrificio de animales en un camal (matadero) requieren de gran consumo de agua; en consecuencia, generan aguas residuales con alta carga orgánica, cuya disposición representa un problema ambiental. Por esta razón, en la presente investigación se evaluó, mediante técnicas estadísticas, la eficiencia de los procesos Fenton y foto-Fenton para la remoción de materia orgánica del efluente del Camal Municipal de Cusco-Perú. Previamente se realizó la evaluación, el seguimiento y el análisis de las características del efluente y el diagnóstico del punto de muestreo. Para el muestreo del efluente se utilizaron la metodología y los procedimientos de toma de muestra establecidos por la normativa peruana. En cada uno de los experimentos realizados se determinaron las concentraciones inicial y final de la demanda bioquímica de oxígeno (DBO5). Se utilizó el diseño de caja Behnken para la matriz de distribución de los 30 experimentos con sus respectivos niveles, correspondiente a los parámetros FeSO4•7H2O, H2O2 y pH. Los ensayos se realizaron en una prueba de jarras, con velocidad de agitación de 150 rpm y tiempo de reacción de 1 h. En el caso del proceso foto-Fenton, se instaló un foto-reactor con una lámpara 13 W (UV-C 254 nm), empleando la misma velocidad de agitación y tiempo de reacción. Respecto del proceso Fenton, los resultados alcanzados en la investigación indican un decaimiento de la DBO5 del 93.96 %, en comparación con el proceso foto-Fenton, que alcanzó un 94.63 %
Atmospheric particulate matter deposition in herbaceous species on a university campus in Colombia
Get PDFAtmospheric particulate matter (PM) is one of the most harmful atmospheric pollutants with implications for human health. Plants have been used as an alternative for the removal of atmospheric PM in urban environments. The removal of PM depends on different plant morphological traits, including trichomes and epicuticles evaluated on trees. However, leaf traits for herbaceous plants commonly used in urban gardens have not been fully explored. This study used filtering to quantify the PM deposition and to describe leaf morphological traits throughout optical devices on 20 leaves from six herbaceous species –Calathea rufibarba, Calathea zebrina, Heliconia psittacorum, Heliconia rostrata, Philodendron sp. and Dieffenbachia sp. Our results suggest that structures such as trichomes –C. rufibarba– and epicuticle –H. psittacorum– play a role in PM deposition. On the other hand, large leaf size did not influence the deposition of PM per leaf unit area. Therefore, for improving city air quality, our study suggests selecting species with epidermal traits independent of leaf area. This is the first study focusing on ornamental herbaceous species ability for PM deposition in urban environments in Medellín, Colombia.Atmospheric particulate matter (PM) is one of the most harmful atmospheric pollutants with implications for human health. Plants have been used as an alternative for the removal of atmospheric PM in urban environments. The removal of PM depends on different plant morphological traits, including trichomes and epicuticles evaluated on trees. However, leaf traits for herbaceous plants commonly used in urban gardens have not been fully explored. This study used filtering to quantify the PM deposition and to describe leaf morphological traits throughout optical devices on 20 leaves from six herbaceous species –Calathea rufibarba, Calathea zebrina, Heliconia psittacorum, Heliconia rostrata, Philodendron sp. and Dieffenbachia sp. Our results suggest that structures such as trichomes –C. rufibarba– and epicuticle –H. psittacorum– play a role in PM deposition. On the other hand, large leaf size did not influence the deposition of PM per leaf unit area. Therefore, for improving city air quality, our study suggests selecting species with epidermal traits independent of leaf area. This is the first study focusing on ornamental herbaceous species ability for PM deposition in urban environments in Medellín, Colombia
Criterios mínimos del ambiente construido saludable
Get PDFThis article proposes to establish minimum criteria for the development of a healthy built environment based on direct categories essential in human health, considering the definition of health by the World Health Organization, which implies physical, mental well-being. and social of the inhabitants. The methodology uses a systematic review of various authors and institutions related to healthy buildings and meta-analysis to investigate the search for categories in information sources and evaluate their dispersion, along with the frequency analysis of direct factors that imply a risk in health within the built environment. The result comprehensively establishes seven direct categories: indoor air quality, hygrothermal range, acoustic range, humidity, lighting range, electromagnetic fields, security and accessibility. The objective is that these categories can be evaluated and disseminated in an accessible manner in countries with economies of low and medium level of consumption, such as the countries of Latin American and Caribbean, in order to strengthen their regulatory framework that regulates construction processes to improve health by promoting the development of well-being skills in inhabitants.El presente artículo propone establecer criterios mínimos para el desarrollo de un ambiente construido saludable a partir de categorías directas indispensables en la salud humana, considerando la definición de salud de la Organización Mundial de la Salud, que implica el bienestar físico, mental y social de los habitantes. La metodología utiliza la revisión sistemática de diversos autores e instituciones relacionadas con el edificio saludable y el metaanálisis para investigar la búsqueda de las categorías en fuentes de información y evaluar su dispersión, junto con el análisis de frecuencia de los factores directos que implican un riesgo a la salud dentro del ambiente construido. El resultado establece de manera integral siete categorías directas: calidad del aire interior, rango higrotérmico, rango acústico, humedad, rango lumínico, campos electromagnéticos, seguridad y accesibilidad. El objetivo es que dichas categorías puedan ser evaluadas y difundidas de manera accesible en países de economías de bajo y medio nivel de consumo, como los países de Latinoamérica y el Caribe, con el fin de fortalecer su marco normativo que regule los procesos de la construcción para mejorar la salud, promoviendo el desarrollo de habilidades del bienestar en los habitantes.
Design of remote acquisition system for ecological water demand information of an estuarine wetland
Get PDFIn order to improve data coverage and data collection efficiency, the design method for a remote collection system of ecological water demand information of an estuarine wetland is proposed. The hardware design of the remote information acquisition system is realized through the overall structure design, the Unified Modeling Language (UML), system outline design, system logic design, and system module division. The information is acquired by polling, and the acquisition frequency is adjusted according to the actual situation and user needs. In the system software design, the Scale-invariant feature transform algorithm (SIFT) is used to extract the image features of the estuarine wetland, and a support vector machine is used to cluster the collected information according to the image features to realize the remote acquisition of water demand information of the estuarine wetland. The experimental results show that the maximum data coverage of the proposed method is 95%, and the data acquisition time is less than 0.2 h, indicating that the proposed method has high information acquisition efficiency and high data coverage
Riesgo a la salud de la población por inhalación de PM2.5 en la República Mexicana
Get PDFMexico is not exempt from the growing global concern about the increase in air pollution and its harmful effects on health. Therefore, this study aims to determine the health risk index for PM2.5 inhalation present in Mexico’s atmosphere. To this end, the number of atmospheric monitoring networks in the country (36) was reviewed, and how many of them had available data on PM2.5 (9), as well as meteorological data (wind direction and speed, temperature) during the period 2016-2019. Data tables were produced for each monitoring network, and the spatial behavior and meteorological variables of PM2.5 were determined. The health risk index was calculated, and it was determined that the sites with the highest risk index for PM2.5 inhalation in Mexico were, first, San Cristóbal in the State of Mexico and second, Xalostoc in Mexico City.México no está exento de la creciente preocupación mundial por el incremento de la contaminación atmosférica y sus efectos nocivos para la salud, por lo que el objetivo del presente trabajo es determinar el índice de riesgo a la salud por inhalación de partículas suspendidas menores a 2.5 μm (PM2.5) presentes en la atmósfera de la República Mexicana. Para ello, se revisó la cantidad de redes de monitoreo atmosférico que existen en la república (36) y cuántas de ellas contaban con datos disponibles sobre PM2.5 (9), así como con datos meteorológicos (dirección y velocidad del viento, temperatura) durante el periodo 2016-2019. Se elaboraron cuadros de datos para cada una de las redes de los estados de la república y con ellas se determinó el comportamiento espacial de las PM2.5 y de las variables meteorológicas. Se calculó el índice de riesgo a la salud y se determinó que los sitios con mayor índice de riesgo por inhalación de PM2.5 fueron, en primer lugar, San Cristóbal en el Estado de México, y en segundo lugar Xalostoc en la Ciudad de México
Guía para la identificación y clasificación de peligros químicos en los centros de trabajo
Get PDFThe use of chemical substances in the workplace carries an inherent risk that is seldom easily recognized, which is why this work aims to offer a guide for understanding the Globally Harmonized System (GHS) and its application in the workplace. For practical purposes, the guide is divided into four stages. Stage I consists on the description and interpretation of the elements of the GHS. In stage II, the identification of the hazards that represent the chemical substances is carried out, in the next stage the hazard description is recorded and, in the fourth and final stage, the substances are classified based on their chemical compatibility and the risks they represent. Finally, some important considerations for the handling and storage of hazardous chemicals in the workplace are addressed.El uso de sustancias químicas en los centros de trabajo conlleva un riesgo inherente que pocas veces se reconoce con facilidad, es por ello que en el presente trabajo se pretende ofrecer una guía para el entendimiento del Sistema Globalmente Armonizado (SGA) y su aplicación en el reconocimiento y clasificación de riesgos químicos en los centros de trabajo. Con fines prácticos, la guía se divide en cuatro etapas. La etapa I, consiste en la descripción e interpretación de los elementos del SGA. En la etapa II se realiza la identificación de los peligros que representan las sustancias químicas, en la siguiente etapa se hace el registro de la descripción de peligro. Por último, en la cuarta y última etapa se clasifican las sustancias con base en la compatibilidad química y los riesgos que representan. Finalmente, se abordan algunas consideraciones importantes para el manejo y almacenamiento de las sustancias químicas peligrosas en los centros de trabajo
Concentración de azufre bioacumulado en líquenes corticícolas del género Parmotrema en áreas verdes urbanas de Asunción, Paraguay
Get PDFConsidering the limited information available on the impact of air quality on sensitive organisms, its use as an alternative tool for measuring pollutants in Paraguay, and the population growth with projections for the coming years, the present study aimed to determine the bioaccumulated sulfur concentrations in corticolous lichens of the genus Parmotrema in green areas in the city of Asunción, the capital of Paraguay. The sampled sites were distributed into six groups and one control group (National Park), and the number of trees present at each site was also considered, establishing five ranges. The lichens from the control group showed a significantly lower mean concentration than the other groups. Group B, with high vehicular traffic, presented a higher mean sulfur concentration compared to the other groups. Furthermore, it was observed that in sites with a greater number of trees, the mean sulfur concentration on lichen thalli decreases. The results obtained in the city of Asunción indicate different levels of pollution, which suggests the need to carry out additional investigations to determine the precise source of contamination and to assess the potential effects on human health and the natural environment.Considerando la escasa información disponible sobre el impacto de la calidad del aire en organismos sensibles, su uso como herramienta alternativa de medición de contaminantes en Paraguay y el crecimiento poblacional con las proyecciones para los próximos años, se planteó en el presente estudio determinar las concentraciones de azufre bioacumuladas en líquenes corticícolas del género Parmotrema en áreas verdes en la ciudad de Asunción, capital de Paraguay. Los sitios muestreados fueron distribuidos en seis grupos y un testigo (Parque Nacional), además se consideró la cantidad de árboles presentes en cada sitio estableciendo cinco rangos. Los líquenes del grupo testigo presentaron una concentración media significativamente menor que la de los demás grupos. El grupo B, de alta concurrencia vehicular, presentó una concentración media de azufre más elevada comparada con los demás grupos. Además, se observó que en los sitios con gran número de árboles la concentración media de azufre disminuye en los talos liquénicos. Los resultados obtenidos en la ciudad de Asunción indican diferentes niveles de contaminación, lo cual sugiere la necesidad de llevar a cabo investigaciones adicionales para determinar la fuente precisa de contaminación y evaluar los posibles efectos en la salud humana y el entorno natural
Marcadores relacionados a las emisiones de la industria cerámica
No full textThe ceramic industry generates atmospheric emissions containing fluorine, particulate matter, organic compounds, and raw material residues deposited on the ground. This research aimed to identify air and soil quality parameters that can be used as emissions tracers. Parameters such as wind speed and direction; air quality parameters such as particulate material PM10 and PM2.5, fluorine content in PM2.5 and metals in PM10; soil quality parameters such as the content of anions and metals, and mineralogical contents, were analyzed. The results showed that the concentration of fluorine in PM2.5 in the air of the urban area is between < 5 and 279 µg/m3, which could cause damage to vegetation; the PM2.5/PM10 ratio reaches values between 62.2 and 95.8 %, indicating that the presence of particulate matter is due to firing processes; the sodium concentration in PM10 reaches values between 32.80 and 50.31 µg/m3 coming from the plagioclases. The concentration of metal and anions, and the percentage of plagioclase in the soil were higher in the most influence area. It was concluded that the parameters fluorine in PM2.5, sodium in PM10, and PM2.5/PM10 ratio in the air are emissions tracers from the firing processes. Furthermore, the increase in the concentration of metals, anions, and the percentage of plagioclase in the soil are tracers of deposition of particulate matter or raw materials residues.La industria cerámica genera emisiones que contienen flúor, partículas atmosféricas, compuestos orgánicos y residuos de materia prima que se precipitan al suelo. El objetivo de esta investigación fue identificar los parámetros de calidad de aire y suelo que sirvan como marcadores de las emisiones. Para ello se evaluaron los parámetros de velocidad y dirección del viento; la presencia de partículas atmosféricas PM10 y PM2.5; el contenido de flúor en PM2.5 y metales en PM10 como parámetros de calidad de aire; el contenido de aniones, metales y análisis mineralógico como indicadores de calidad de suelo. Se determinó que la concentración de flúor en PM2.5 se encuentra entre < 5 y 279 mg/m3, lo que puede ocasionar daños a la vegetación; se estableció que la relación PM2.5/PM10 alcanzó valores de 62.2 a 95.8 %, medición que indica la presencia de partículas atmosféricas debida a los procesos de cocción, y que la concentración de Na en PM10 alcanzó valores de 32.80 a 50.31 mg/m3 provenientes de las plagioclasas. Se puede agregar que la concentración de metales y aniones, así como el porcentaje de plagioclasas en suelo, fueron superiores en la zona de mayor influencia. Se concluye que la presencia de flúor en PM2.5 y Na en PM10, así como la relación PM2.5/PM10 en el aire son marcadores de las emisiones del proceso de cocción, y que el incremento de la concentración de metales y aniones, y el porcentaje de plagioclasas en suelo son marcadores del depósito de partículas atmosféricas o residuos de materias primas
Evaluation of manganese bioleaching and silver extraction in mining tailings by native bacteria using a flooded system
Get PDFDuring the silver extraction process in mining, the generated residues (called tailings) still contain approximately 100-140 g/ton of silver due to the presence of refractory materials that trap this metal and prevent its solubilization by conventional methods. These residues can be treated by biohydrometallurgical processes allowing, together with the cyanidation process, an increase in the efficiency of silver extraction by eliminating refractory materials such as manganese, which is present as pyrolusite (MnO2, 3.78 %). Pyrolusite can change from manganese (IV) to manganese (II) when solubilized by bioleaching. This research analyzed the effects of bioleaching using native bacteria on the concentration of silver extraction from the removal of manganese in mining tailings. The native bacteria ITDBC2, ITDBC5, and ITDBC6 were identified as Leptospirillum ferriphilum by amplification of the 16S gene corroborated by bioinformatic analysis. The experimentation was carried out using a flooded bioleaching system (9.43 L) to resemble the industrial geometry with the following variables: concentration of ferrous ions (2, 7, and 14 g/L), pH (2, 4, and 6) and agitation time at 100 rpm (2, 4 and 6 min/day). The experimentation lasted 18 days. The removal of manganese and silver extraction was 71.84 and 55.53 %, respectively. The scaled-up of the evaluated bioprocess could reduce energy consumption and process larger amounts of pulp than the reported at the laboratory scale.During the silver extraction process in mining, the generated residues (called tailings) still contain approximately 100-140 g/ton of silver due to the presence of refractory materials that trap this metal and prevent its solubilization by conventional methods. These residues can be treated by biohydrometallurgical processes allowing, together with the cyanidation process, an increase in the efficiency of silver extraction by eliminating refractory materials such as manganese, which is present as pyrolusite (MnO2, 3.78 %). Pyrolusite can change from manganese (IV) to manganese (II) when solubilized by bioleaching. This research analyzed the effects of bioleaching using native bacteria on the concentration of silver extraction from the removal of manganese in mining tailings. The native bacteria ITDBC2, ITDBC5, and ITDBC6 were identified as Leptospirillum ferriphilum by amplification of the 16S gene corroborated by bioinformatic analysis. The experimentation was carried out using a flooded bioleaching system (9.43 L) to resemble the industrial geometry with the following variables: concentration of ferrous ions (2, 7, and 14 g/L), pH (2, 4, and 6) and agitation time at 100 rpm (2, 4 and 6 min/day). The experimentation lasted 18 days. The removal of manganese and silver extraction was 71.84 and 55.53 %, respectively. The scaled-up of the evaluated bioprocess could reduce energy consumption and process larger amounts of pulp than the reported at the laboratory scale