Revista Internacional de Contaminación Ambiental
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Ecología microbiana de minas de cobre de seis diferentes regiones geográficas
Get PDFThe main intention of this work was to compare the structure of the microbial communities in copper mines from different geographical regions to find patterns in their composition and generate new knowledge from pre-existing data. The 16S amplicons from the six copper mines were obtained from the Sequence Read Archive (SRA) of the National Center for Biotechnology Information (NCBI) website. The taxonomic assignment of the 16S amplicons was carried out through bioinformatic processing with Qiime2 and relative abundance, diversity and multivariate statistical analyses were performed using R software. Finally, PICRUSt2 was used to predict metabolic functions. The results indicate that the UK mine presents the largest number of classes. Gammaproteobacteria, Actinobacteria, and Alphaproteobacteria are the most abundant classes in all mines. All have genera that possess metabolic characteristics related to the oxidation or reduction of metals. Functional predictions suggest the presence of genes related to the reduction of heavy metals such as copper and mercury. The results obtained can enhance the understanding of the composition and functions of the bacterial communities in copper mines, allowing the future use of some metabolic characteristics of these communities.El objetivo del trabajo fue comparar la estructura de las comunidades microbianas de minas de cobre de diferentes regiones geográficas con la finalidad de encontrar patrones en la composición de las comunidades y dilucidar su potencial metabólico. Los amplicones de las minas localizadas en Brasil, Canadá, China, Portugal, Reino Unido y Bulgaria se obtuvieron del Sequence Read Archive (SRA) del sitio web del National Center for Biotechnology Information (NCBI). El estudio bioinformático para la repartición taxonómica se realizó con la plataforma Qiime2. Se determinaron la abundancia relativa, la diversidad y su correlación con parámetros físicos y químicos usando R Studio. Posteriormente, se realizó la predicción funcional con PICRUSt2. Los resultados muestran que la mina de Reino Unido es donde se presenta el mayor número de clases y la mina de Bulgaria es la menos diversa. Gammaproteobacteria, Actinobacteria y Alphaproteobacteria son las clases más abundantes en todas las minas y cuentan con géneros que poseen características metabólicas relacionadas con la oxidación o reducción de metales. Las predicciones funcionales sugieren la presencia de genes relacionados con la reducción de metales pesados como cobre y mercurio. Las minas de cobre de diferentes regiones presentan un patrón similar de clases encontradas a pesar de que existen diferencias puntuales de clases bacterianas que atribuimos a la presión de las condiciones físicas y químicas
Producción de múltiples pozos en yacimientos rectangulares naturalmente fracturados con entradas a producción a diferentes tiempos
Get PDFThis document presents, for the first time two analytical solutions to predict production profiles of multiple wells producing with different constant bottom-hole pressures starting their productions at different times in a naturally fractured rectangular reservoir with close boundaries and constant thickness. One solution is for the case of double-porosity (matrix and fractures) and another for triple-porosity (matrix, fractures, and dissolution cavities or vugs) reservoirs. The analytical solutions are inverted from the Laplace space using long-time approximations, which are validated with numerical simulation results. This paper presents results for different inter-porosity flow coefficients, matrix-fractures for 2-ϕ systems and three coefficients: matrix-fractures, matrix-vugs, and vugs-fractures for the 3-ϕ. Also, it is shown the results sensitivity to the storability ratios, for the fracture network for 2-ϕ systems, and for the fracture and vugs networks for 3-ϕ reservoirs. Lastly, a contrast between the results with a traditional single-porosity (1-ϕ) homogeneous reservoir are compared with those corresponding to 2-ϕ and 3-ϕ, showing the complexity that is captured with the proposed new models, which are more appropriate to predict the behavior of multiple wells producing from naturally fractured reservoirs with 2-ϕ and 3-ϕ. It is suggested that these analytical models are useful to make economic analysis with multiple wells considering different development schemes when the available information does not justify the use of numerical simulator.En este trabajo se presentan por primera vez dos soluciones analíticas para predecir el perfil de producción de múltiples pozos trabajando a diferentes presiones de fondo constantes, que inician su producción a diferentes tiempos en yacimientos naturalmente fracturados rectangulares con fronteras cerradas al flujo y espesor constante; una para doble porosidad (matriz y fracturas) y la segunda para yacimientos de triple porosidad (matriz, fracturas y cavidades de disolución-vúgulos), ambos con una permeabilidad. Para el caso de doble porosidad, la red de fracturas es la que conduce los fluidos hacia los pozos productores, y en el caso de triple-porosidad, la red de fracturas o la de vúgulos conduce los fluidos hacia el/los pozos. Se presentan, además, sus inversiones analíticas del espacio de Laplace al espacio real, aproximadas para tiempos grandes. Las soluciones analíticas fueron invertidas del espacio de Laplace utilizando aproximaciones a tiempos largos, las cuales fueron validadas comparando los resultados con simuladores numéricos. De la misma manera se presentan los resultados de variar los coeficientes de flujo interporoso y las relaciones de almacenamiento de fluidos, observándose comportamientos específicos para cada tipo de yacimiento. Por último, se presenta un contraste en el que se comparan los resultados de un medio poroso homogéneo (1-ϕ), con la variedad de resultados que se pueden obtener si se considera que el yacimiento es de doble porosidad (2-ϕ) o de triple porosidad (3-ϕ). Los modelos propuestos son útiles para predecir el comportamiento de múltiples pozos produciendo de yacimientos naturalmente fracturados con doble porosidad (2-ϕ) y triple porosidad (3-ϕ), así como para realizar análisis económicos de diferentes esquemas de desarrollo de campos cuando la información disponible no justifica el uso de simuladores numéricos
Inhibición in vitro de la metanogénesis ruminal de una dieta alta en grano con lovastatina
Get PDFOne of the greatest environmental impacts from livestock is caused by enteric methane emissions, a powerful greenhouse gas. In this context, some anti-methanogenic compounds have been evaluated, such as lovastatin (LOV), which is a hydroxymethylglutaryl-CoA reductase inhibitor, a key enzyme for membrane synthesis of methanogenic archaea. This could be an option to mitigate methane emissions from ruminants. However, there are few in vitro studies and there is no general agreement about the methane mitigation by LOV under these conditions. Thus, the objective of this work was to evaluate the effect of LOV on in vitro methanogenesis and fermentation characteristics in comparison with monensin (MON) and bromoethane sulfonic acid (BES). An in vitro batch incubation was carried out using a high-grain diet and bovine rumen fluid. The experimental design was completely randomized with three treatments, LOV, MON, BES, and a control with no inhibitor. The results demonstrated a favorable effect of LOV on rumen fermentation pattern in terms of methane mitigation (43.56 % inhibition) without affecting the volatile fatty acids (VFA) profile. However, the dose of LOV to obtain this result was very high compared to the doses used in the other treatments. MON was the most effective treatment based on the concentration/inhibition of methanogenesis, followed by the BES; although, both compounds were associated to changes in the VFA profile.Uno de los mayores impactos ambientales de la ganadería es la emisión de metano entérico, un potente gas de efecto invernadero. En este contexto, se han evaluado algunos compuestos antimetanogénicos tales como la lovastatina (LOV), un inhibidor de la hidroximetilglutaril-CoA reductasa, enzima clave para la síntesis de membrana en arqueas metanogénicas. Esta podría ser una opción para mitigar las emisiones de metano ruminal. Sin embargo, los experimentos in vitro son escasos y no existe un criterio general sobre la mitigación de metano con LOV en estas condiciones. Por lo tanto, el objetivo de esta investigación fue evaluar el efecto in vitro de la LOV sobre la metanogénesis y características de la fermentación ruminal, así como comparar los resultados con aquellos de la monensina (MON) y el ácido bromoetano sulfónico (BES). Se realizó una prueba in vitro en lote. Se utilizó una ración alta en grano, fluido ruminal de bovinos y tres inhibidores metanogénicos. El diseño experimental fue completamente al azar con tres tratamientos (LOV, MON, BES) y un testigo sin inhibidor. En este trabajo la LOV mostró efectos alentadores sobre la mitigación de la metanogénesis en la fermentación ruminal (43.56 %) sin afectar la producción total y perfil de AGV. Sin embargo, la dosis para obtener este resultado fue mayor en comparación con las de los otros tratamientos. La MON fue la más efectiva con relación a la concentración/inhibición de la metanogénesis, seguida del BES. Ambos tratamientos presentaron cambios en el perfil de AGV
Acid mine drainage treatment using chicken eggshell waste
Get PDFAcid mine drainage (AMD) is a source of soil and water resources pollution. Calcite is a mineral constituted of calcium carbonate (CaCO3). The AMD interaction with calcite drives their natural neutralization. Calcite is the main component of the chicken eggshell (ES). This work aimed to evaluate the use of ES waste as a material to treat raw AMD. Five treatments (T1, T2, T3, T4, and T5) were carried out with concentrations of 1, 2, 3, 4, and 5 ES g/L AMD, respectively. Each treatment was performed for 3 h at room temperature without agitation. The response variables analyzed were pH, redox potential (Eh), electrical conductivity (σ), chlorides (Cl–), alkalinity, sulfates (SO42–), nitrates (NO3–, and potentially toxic heavy metals and metalloids (PTHMM). Also, the removal efficiencies of SO42–, NO3–, and PTHMM were analyzed. Additionally, the chemical and mineralogical composition of ES and precipitates were determined. The initial pH for AMD was 2.50 and it reached a final value of 5.50, 5.60, 5.80, 5.93, and 6.12 in T1, T2, T3, T4 and, T5, respectively. Moreover, the different treatments granted alkalinity to the treated effluents, reaching a maximum value of 124 CaCO3 mg/L in T5. Finally, Al and Fe were completely removed from AMD, whereas Cu reached > 95 % removal, especially in T3, T4, and T5. Ba, Cr, and Pb showed an average removal of ~65 %. The ES concentration that showed the best results of neutralization and PTHMM removal efficiency was 5 ES g/L. The results showed that ES is a biocompatible waste material with an added value because it can be used as a sustainable material to treat raw AMD.Acid mine drainage (AMD) is a source of soil and water resources pollution. Calcite is a mineral constituted of calcium carbonate (CaCO3). The AMD interaction with calcite drives their natural neutralization. Calcite is the main component of the chicken eggshell (ES). This work aimed to evaluate the use of ES waste as a material to treat raw AMD. Five treatments (T1, T2, T3, T4, and T5) were carried out with concentrations of 1, 2, 3, 4, and 5 ES g/L AMD, respectively. Each treatment was performed for 3 h at room temperature without agitation. The response variables analyzed were pH, redox potential (Eh), electrical conductivity (σ), chlorides (Cl–), alkalinity, sulfates (SO42–), nitrates (NO3–, and potentially toxic heavy metals and metalloids (PTHMM). Also, the removal efficiencies of SO42–, NO3–, and PTHMM were analyzed. Additionally, the chemical and mineralogical composition of ES and precipitates were determined. The initial pH for AMD was 2.50 and it reached a final value of 5.50, 5.60, 5.80, 5.93, and 6.12 in T1, T2, T3, T4 and, T5, respectively. Moreover, the different treatments granted alkalinity to the treated effluents, reaching a maximum value of 124 CaCO3 mg/L in T5. Finally, Al and Fe were completely removed from AMD, whereas Cu reached > 95 % removal, especially in T3, T4, and T5. Ba, Cr, and Pb showed an average removal of ~65 %. The ES concentration that showed the best results of neutralization and PTHMM removal efficiency was 5 ES g/L. The results showed that ES is a biocompatible waste material with an added value because it can be used as a sustainable material to treat raw AMD
Transformation-based design method for the integration of green residential buildings and solar thermal collectors
Get PDFThis study investigates integrated application of solar thermal collectors (STCs), as green renewable energy, on the design of green residential buildings (GRBs). With the gradual increase of residential buildings, the use of solar thermal energy has be- come the main popularization and application mode for the integration of residential buildings and solar energy. Additionally, this study presents applicable solutions using the transformation-based design method to expand the functions of STCs through the integrated design of STCs and GRBs, thus laying a strong theoretical foundation for promoting the integrated design of solar water heaters and GRBs.This study investigates integrated application of solar thermal collectors (STCs), as green renewable energy, on the design of green residential buildings (GRBs). With the gradual increase of residential buildings, the use of solar thermal energy has be- come the main popularization and application mode for the integration of residential buildings and solar energy. Additionally, this study presents applicable solutions using the transformation-based design method to expand the functions of STCs through the integrated design of STCs and GRBs, thus laying a strong theoretical foundation for promoting the integrated design of solar water heaters and GRBs
El papel del color en la ingesta de fragmentos de microplástico por el pez cebra (Danio rerio)
Get PDFThe presence of microplastics (MPs) in the stomach contents of freshwater fish has been globally reported. However, the mechanisms underlying the consumption of MPs by aquatic biota are still unclear. In this study, the fundamental question of why wild freshwater fish ingest plastic was investigated. The intake of MPs due to confusion by fish with their natural prey, such as plankton, is a hypothesis that has gained importance lately. Therefore, the color of MPs could influence their consumption, especially in visual predators. In order to evaluate the intake of MP fragments according to the color (red, green, yellow, white, black and blue), a multiple-choice experiment was performed in the laboratory using the zebrafish (Danio rerio) as test species. The results indicated that the zebrafish preferred to ingest blue fragments, while avoiding green and white fragments when faced with an equitable supply of different-colored MPs. Although it is not yet clear how the color of the plastic is related to selectivity and consumption in freshwater fish, the visual skills of the fish could help to explain why certain colors are attractive to a particular fish species.Se ha reportado la presencia de microplásticos (MP) en el contenido estomacal de peces de agua dulce a nivel global. Sin embargo, los mecanismos subyacentes al consumo de MP por parte de los animales acuáticos aún no están claros. En este estudio se investigó la pregunta fundamental de por qué los peces silvestres de agua dulce ingieren plástico. La ingesta de MP debida a la confusión por parte de los peces con sus presas naturales, tales como el plancton, es una hipótesis que ha cobrado importancia últimamente. Por lo tanto, el color del MP podría influenciar su consumo, especialmente en depredadores visuales. Con el objetivo de evaluar la ingesta de fragmentos de MP según el color (rojo, verde, amarillo, blanco, negro y azul), se llevó a cabo un experimento de opción múltiple en el laboratorio utilizando al pez cebra (Danio rerio) como modelo de estudio. Los resultados indicaron que frente a una oferta de igual proporción de MP de distintos colores, el pez cebra prefirió consumir los fragmentos de color azul, mientras que evitó consumir los verdes y los blancos. Aunque todavía no está claro en qué forma se relaciona la coloración del plástico con la selectividad y consumo en peces de agua dulce, las habilidades visuales de los peces podrían explicar por qué ciertos colores son atractivos para una especie de pez en particular
Comparación de la actividad de butirilcolinesterasa entre habitantes de una zona rural y una urbana de Guerrero, México
Get PDFHuman exposure to cholinesterase inhibitor pesticides can vary according to the type and frequency of products used, protective measures, and organisms to be controlled at a given site. Vector-borne disease control programs are carried out mainly in urban areas, while agricultural pest control is carried out in rural areas, so exposure may be different between the people who live in one place or another. This study aimed to determine the difference in serum butyrylcholinesterase activity from a rural and an urban population. Voluntarily, 120 individuals over 18 years of age participated in the study, of which 70 (36 women and 34 men) are inhabitants of Chilpancingo de Los Bravo, and 50 (23 women and 27 men) from the town of Tilapa (Guerrero, Mexico). Through a blood sample, butyrylcholinesterase was analyzed in the participants and then compared according to locality of origin, sex, age, education, and occupation. Butyrylcholinesterase activity was decreased in Tilapa with respect to Chilpancingo (5041 vs. 5448 U/L, respectively; p = 0.291). There was no significant difference in the activity of this enzyme between both populations, however, it is essential to strengthen the research on human exposure to cholinesterase inhibitor pesticides in urban and rural areas to identify potential risks that should be addressed by health authorities and agriculture.La exposición humana a plaguicidas inhibidores de la enzima colinesterasa puede variar de acuerdo con el tipo de productos empleados, la frecuencia de uso, las medidas de protección y los organismos que se desean controlar en un sitio determinado. Las campañas de control químico de las enfermedades transmitidas por vectores se realizan principalmente en zonas urbanas, mientras que el control de plagas agrícolas se lleva a cabo en las rurales, por lo que la exposición puede ser diferente entre las personas que habitan en uno u otro sitio. El objetivo de este estudio fue determinar la diferencia en la actividad de butirilcolinesterasa en sangre entre una población rural y una urbana. De manera voluntaria, participaron en el estudio 120 individuos mayores de 18 años, de los cuales 70 (36 mujeres y 34 hombres) son habitantes de Chilpancingo de los Bravo y 50 (23 mujeres y 27 hombres) de la localidad de Tilapa (Guerrero, México). Se analizó la actividad enzimática sérica de los participantes y se comparó según la localidad de procedencia, sexo, edad, escolaridad y ocupación. La actividad de butirilcolinesterasa estuvo ligeramente disminuida en Tilapa respecto a la de Chilpancingo, con valores promedio de 5041 y 5448 U/L, respectivamente (p = 0.291). No hubo una diferencia significativa en la actividad de esta enzima entre ambas poblaciones; sin embargo, es imprescindible fortalecer la investigación sobre la exposición a plaguicidas inhibidores de la colinesterasa en zonas urbanas y rurales para identificar riesgos potenciales que deban ser atendidos por las autoridades sanitarias y agropecuarias
Oxidation of sulfonamide micropollutants by versatile peroxidase from Bjerkandera adusta
Get PDFThe oxidation of five sulfonamide antibiotics by the versatile peroxidase (VP, EC. 1.11.1.16) from Bjerkandera adusta was quantitatively assessed. The biocatalytic activity of the enzyme was studied by assaying different reaction conditions. Conversion levels were higher than 90 % for all five sulfonamide antibiotics in the model reaction system. In addition, the enzyme performance was also studied in treated wastewater effluents, where three sulfonamide antibiotics were oxidized at a higher level (greater than 85 % oxidation) and two were oxidized at a lower level (up to 50 %). The identified reaction products for two antibiotics, sulfasalazine, and sulfamethoxazole, showed higher antimicrobial activity than the parental compounds. Docking analyses exhibited that the reaction products interacted with the catalytic pocket of the dihydropteroate synthase from Escherichia coli, similar to the parental antibiotics. Though the oxidation is carried out at high velocity and conversion rates, the application of VP in the enzymatic oxidation technology of sulfonamide antibiotics must overcome the production of more toxic products.The oxidation of five sulfonamide antibiotics by the versatile peroxidase (VP, EC. 1.11.1.16) from Bjerkandera adusta was quantitatively assessed. The biocatalytic activity of the enzyme was studied by assaying different reaction conditions. Conversion levels were higher than 90 % for all five sulfonamide antibiotics in the model reaction system. In addition, the enzyme performance was also studied in treated wastewater effluents, where three sulfonamide antibiotics were oxidized at a higher level (greater than 85 % oxidation) and two were oxidized at a lower level (up to 50 %). The identified reaction products for two antibiotics, sulfasalazine, and sulfamethoxazole, showed higher antimicrobial activity than the parental compounds. Docking analyses exhibited that the reaction products interacted with the catalytic pocket of the dihydropteroate synthase from Escherichia coli, similar to the parental antibiotics. Though the oxidation is carried out at high velocity and conversion rates, the application of VP in the enzymatic oxidation technology of sulfonamide antibiotics must overcome the production of more toxic products
The performance and bearing capacity of bottom ashes filled embankment
Get PDFThe municipal solid waste incineration bottom ash (IBA) as the fill material in the geotechnical applications is a wise solution where IBA will save the bulk of earth material and can bring huge economic benefits, particularly for the embankments. In this study a series of experimental model tests of embankments filled with IBA and sand were conducted and considered two different slope ratios to investigate the performance of IBA as the fill material. During the testing, the vertical stress distribution, horizontal deformation, and vertical settlement inside of the embankment were monitored. Test results demonstrated that the IBA embankment compared with the sand embankment when slope ratios of 1:1.5 and 1:1.75, enhanced the bearing capacity by 25% and 20%, respectively, and under the same vertical pressure reduced the vertical settlement by 47% and 39.6%. When the embankment shear failure occurred, the lateral deformation inside the IBA embankment was reduced by 27.36% and 23.66%, respectively, compared with the sand embankment, under the conditions of slope ratio of 1:1.5 and 1:1.75, and the lateral deformation distribution along the height of embankment was more homogeneous. These results indicated that the use of IBA as fill material for embankments can be an economical and effective method to save the earth material.The municipal solid waste incineration bottom ash (IBA) as the fill material in the geotechnical applications is a wise solution where IBA will save the bulk of earth material and can bring huge economic benefits, particularly for the embankments. In this study a series of experimental model tests of embankments filled with IBA and sand were conducted and considered two different slope ratios to investigate the performance of IBA as the fill material. During the testing, the vertical stress distribution, horizontal deformation, and vertical settlement inside of the embankment were monitored. Test results demonstrated that the IBA embankment compared with the sand embankment when slope ratios of 1:1.5 and 1:1.75, enhanced the bearing capacity by 25% and 20%, respectively, and under the same vertical pressure reduced the vertical settlement by 47% and 39.6%. When the embankment shear failure occurred, the lateral deformation inside the IBA embankment was reduced by 27.36% and 23.66%, respectively, compared with the sand embankment, under the conditions of slope ratio of 1:1.5 and 1:1.75, and the lateral deformation distribution along the height of embankment was more homogeneous. These results indicated that the use of IBA as fill material for embankments can be an economical and effective method to save the earth material