Revista Internacional de Contaminación Ambiental
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Huella ambiental de la producción de biodiésel utilizando Jatropha curcas mexicana cultivada en suelos marginales
Get PDFThe objective of this study was to assess environmental footprint associated with biodiesel production using a Mexican ecotype of Jatropha curcas as raw material, which has a seed production potential of 1021 kg/ha even when being cultivated in marginal land with minimal water resources and biofertilization. Life-cycle assessment methodology was used to assess the environmental footprint through 18 midpoint impact categories through Hierarchical ReCiPe method 2016. The production system is comprised of the following stage: (i) obtaining raw material, (ii) oil extraction, and (iii) biodiesel production. Among the most relevant results, this system showed 27.56 kg CO2 eq/GJ biodiesel of potential emissions in global warming and 0.527 GJ fossil energy/GJ biodiesel in energy consumption. Due to fact that minimal resources were invested in Jatropha curcas cultivation stage, the oil extraction stage showed the greatest impacts in 14 of 18 impact categories evaluated, mainly due to the electricity consumption used in the fruit skin and seed shells separation process, which had 80 % of contribution. The Mexican ecotype of Jatropha curcas is promising as a raw material for biodiesel production because the production system evaluated in this study showed reductions in the environmental impacts compared to a system that uses Jatropha curcas under irrigation and fertilization cultivation. El objetivo de este estudio fue evaluar la huella ambiental que genera el proceso de producción de biodiésel utilizando un ecotipo mexicano de Jatropha curcas como materia prima. Este ecotipo tiene un potencial de producción de semillas de hasta 1021 kg/ha en suelos con baja humedad y bajo nivel nutricional. La evaluación de la huella ambiental se determinó a través de un análisis de ciclo de vida de 18 categorías de impacto de punto intermedio con el método ReCiPe Jerárquico 2016. El sistema de producción analizado está constituido por las etapas: (i) obtención de materia prima, (ii) extracción de aceite y (iii) producción de biodiésel. Entre los resultados más relevantes, este sistema presentó emisiones potenciales en calentamiento global de 27.56 kg CO2 eq/GJ de biodiésel y un consumo de energía de 0.527 GJ de energía fósil/GJ de biodiésel. Debido a que en la etapa de cultivo de Jatropha curcas se invierten recursos mínimos, la etapa de extracción de aceite fue la que presentó los mayores impactos potenciales en 14 de 18 categorías evaluadas, principalmente debido al consumo de electricidad utilizado en el proceso de la separación de las cáscaras de frutos y semillas de Jatropha curcas; dicho proceso tuvo una participación de 80 % de las contribuciones. El ecotipo mexicano de Jatropha curcas cultivado en suelos marginales es prometedor como materia prima para la producciЧn de biodiésel. El sistema de producción presentó reducciones en los impactos ambientales potenciales comparado con un sistema que utiliza un cultivo de Jatropha curcas con riego y fertilizantes
Índices de contaminación bacteriana en la ostra Crassostrea cf. corteziensis procedente de Portovelo, estuario Río Chone, Manabí, Ecuador
Get PDFThe Portovelo oyster (Crassostrea cf. corteziensis) from the Chone River estuary, Manabí province, Ecuador, is an item of artisanal exploitation and commercial sale for consumption (particularly raw), without knowing its microbial load. During one year, the microbiological quality (aerobic mesophilic, total coliforms, Vibrio spp., Escherichia coli and Salmonella) of the bivalve was evaluated monthly, as well as the environmental parameters (temperature, salinity, dissolved solids and pH) in the waters of the bank. The annual averages obtained in oyster meat for mesophilic aerobes were 4.76 × 105 CFU/g, total coliforms 1.15 × 103 CFU/g, and vibrios 0.61 × 104 CFU/g. Apart from this, there was the presence of Escherichia coli in the first months of 2019 with values up to 7.70 x 102 CFU/g, and the presence of Salmonella in 25% of the samples in the months of March, April and June 2019. Many of the values exceed international regulations and reflect a high risk to public health when consuming this mollusk without having previously undergone a purification or process that reduces the bacterial load. The results show a high variability of values during the year, which produces significant differences between months. Aerobic mesophiles and Vibrio spp. show the existence of a strong positive association with temperature, while coliforms (including Echericha coli) exhibit a negative association with salinity and dissolved solids, which suggests a relationship with the rainy season, with greater discharge and dragging of pollutants.La ostra de Portovelo (Crassostrea cf. corteziensis) del estuario del río Chone, provincia de Manabí, Ecuador, supone un rubro de explotación artesanal y venta comercial para el consumo (particularmente cruda) sin conocerse su carga microbiana. Durante un año se evaluó mensualmente la calidad microbiológica (mesofílicos aerobios, coliformes totales, Vibrio spp., Escherichia coli y Salmonella) del bivalvo, así como los parámetros ambientales (temperatura, salinidad, sólidos disueltos y pH) en las aguas del banco. Los promedios anuales obtenidos en la carne de la ostra para los aerobios mesófilos fueron de 4.76 × 105 UFC/g, coliformes totales de 1.15 × 103 UFC/g y vibrios de 0.61 × 104 UFC/g. Aparte de ello existió presencia de Escherichia coli en los primeros meses del 2019 con valores hasta 7.70 x 102 UFC/g, y la presencia de Salmonella en el 25 % de las muestras los meses de marzo, abril y junio del 2019. Muchos de los valores sobrepasan las normativas internacionales y reflejan un alto riesgo para la salud pública al consumir este molusco sin haber sido previamente sometido a una depuración o procesado que disminuya la carga bacteriana. Los resultados muestran una alta variabilidad de valores durante el año, la cual produce diferencias significativas entre meses. Los mesofílicos aerobios y Vibrio spp. muestran la existencia de una fuerte asociación positiva con la temperatura, en tanto que los coliformes (incluyendo Echericha coli) exhiben asociación negativa con la salinidad y los sólidos disueltos, lo cual sugiere una relación con el periodo de lluvias, con mayor descarga y arrastre de contaminantes
Effective sediment depth for phosphorus release in a monomictic eutrophic lake
Get PDFSediments play an important role in phosphorus (P) dynamics in eutrophic lakes. P concentrations are higher in surface sediments compared to deeper layers, representing a pool of P that can be released into the water column. Effective sediment depth for P release is different among lakes and little is known about this depth. Through experimental evaluation of P release in sediment cores, characterization of sediment porosity and distribution of P fractions in the sediment profile from a monomictic eutrophic lake, we determined which sediment layers produce release of P. The release of P in sediment layers of different depths varied between 0.89 and 2.07 mg P/m2×d with the highest P flow found in the sediment layer of 0-15 cm. The porosity of the sediment strata varied between 68 and 80%, with higher porosity in the surface sediment and decreasing porosity with depth of the sediment profile. We found that P bound to Fe/Mn (BD-P), Al/Fe oxides (NaOH-SRP), and organic matter (NaOH-NRP) were higher in the layer of 0-15 cm than in deeper layers. Sediment porosity, P release, total P and concentrations of the different P species in the sediment profile declined with sediment depth, stabilizing at the depth of 15 cm in the sediment profile. Therefore, we conclude that the effective sediment depth for release of P in this monomictic eutrophic lake is found up to 15 cm.Sediments play an important role in phosphorus (P) dynamics in eutrophic lakes. P concentrations are higher in surface sediments compared to deeper layers, representing a pool of P that can be released into the water column. Effective sediment depth for P release is different among lakes and little is known about this depth. Through experimental evaluation of P release in sediment cores, characterization of sediment porosity and distribution of P fractions in the sediment profile from a monomictic eutrophic lake, we determined which sediment layers produce release of P. The release of P in sediment layers of different depths varied between 0.89 and 2.07 mg P/m2×d with the highest P flow found in the sediment layer of 0-15 cm. The porosity of the sediment strata varied between 68 and 80%, with higher porosity in the surface sediment and decreasing porosity with depth of the sediment profile. We found that P bound to Fe/Mn (BD-P), Al/Fe oxides (NaOH-SRP), and organic matter (NaOH-NRP) were higher in the layer of 0-15 cm than in deeper layers. Sediment porosity, P release, total P and concentrations of the different P species in the sediment profile declined with sediment depth, stabilizing at the depth of 15 cm in the sediment profile. Therefore, we conclude that the effective sediment depth for release of P in this monomictic eutrophic lake is found up to 15 cm
El polvo urbano de las vialidades de la Ciudad de México: un análisis espacialmente lineal de los elementos potencialmente tóxicos, propiedades magnéticas y tamaño de partículas
Get PDFUrban dust is a reservoir of potentially toxic elements and particles of various sizes that represent a risk to human health, hence the importance of determining its characteristics. The objectives of this study were the identification of the sites of greatest contamination by potentially toxic elements, magnetic material and particle size in urban dust, as well as evaluating the influence that different types of public transport have on urban dust. Six primary roads were selected, based on constant vehicular traffic during the day, an average travel speed of 30 km/h, and circulation of a single type of public transport. The urban dust sample was taken in an area of 1 m2 on the asphalt strip. Potentially toxic elements, magnetic properties and particle size were analyzed. The urban dust of the roads of Mexico City had variable concentrations of Cr, Cu, Pb, V, Zn, PM10, PM2.5 and magnetic material. The elements with highest concentration in urban dust were Zn and Pb. The content of PM10 and PM2.5 in urban dust was 10 to 30 % of the total weight of the sample. The areas with the greatest accumulation are located at road crossings, roads near the airport and the industrial park.El polvo urbano es un reservorio de elementos potencialmente tóxicos y de partículas de diversos tamaños que representan un riesgo para la salud humana, por lo cual es importante determinar sus características. Los objetivos de este estudio fueron: identificar los sitios de mayor contaminación por elementos potencialmente tóxicos, material magnético y tamaño de partícula del polvo urbano, así como evaluar la influencia de los diferentes tipos de transporte público en el polvo urbano. Seis vialidades primarias fueron seleccionadas con base en el tránsito vehicular constante durante el día, velocidad de desplazamiento promedio de 30 km/h y circulación de un solo tipo de transporte público. La muestra de polvo urbano se tomó en un área de un 1 m2 sobre la cinta asfáltica. Se determinaron tanto el contenido de elementos potencialmente tóxicos como las propiedades magnéticas y el tamaño de partícula. El polvo urbano de las vialidades de Ciudad de México tuvo concentraciones variables de Cr, Cu, Pb, V, Zn, PM10, PM2.5 y material magnético. Los elementos de mayor concentración en el polvo urbano fueron: Zn y Pb. El contenido de partículas PM10 y PM2.5 en el polvo urbano fue de 10 a 30 % del peso total de la muestra. Las áreas de mayor acumulación se ubican en cruces viales, vialidades cercanas al aeropuerto y el parque industrial
Research on evolutionary game of the transformation of green technological innovation in manufacturing industries under environmental regulation
Get PDFAs the product of the combination of the concept of sustainable development and the transformation of traditional manufacturing industries, green technological innovation will be affected by various factors, such as the willingness of subject of innovation, environmental regulation and so on. How to research the evolution law of the transformation of green technological innovation in manufacturing industries from the perspective of concept-behavior dual logic coupling is the focus of academia. This composition breaks through the traditional limitation of only studying green technological innovation from the perspective of behavior logic, and brings the conceptual logic of the subject into the perspective of research. It designs the mechanism of the transformation of green technological innovation in manufacturing industries driven by internal and external factors, constructs a three-party evolutionary game model of manufacturing-government-consumer, and mobilizes Matlab software to simulate. Thus, the effects of environmental regulations with different intensities on the transformation of green technology innovation in manufacturing industries are revealed, to provide a theoretical basis for environmental regulations to guide it.As the product of the combination of the concept of sustainable development and the transformation of traditional manufacturing industries, green technological innovation will be affected by various factors, such as the willingness of subject of innovation, environmental regulation and so on. How to research the evolution law of the transformation of green technological innovation in manufacturing industries from the perspective of concept-behavior dual logic coupling is the focus of academia. This composition breaks through the traditional limitation of only studying green technological innovation from the perspective of behavior logic, and brings the conceptual logic of the subject into the perspective of research. It designs the mechanism of the transformation of green technological innovation in manufacturing industries driven by internal and external factors, constructs a three-party evolutionary game model of manufacturing-government-consumer, and mobilizes Matlab software to simulate. Thus, the effects of environmental regulations with different intensities on the transformation of green technology innovation in manufacturing industries are revealed, to provide a theoretical basis for environmental regulations to guide it
Retención de contaminantes aromáticos líquidos mediante hidrotalcitas, óxidos mixtos derivados e hidrotalcitas reconstruidas
No full textAnionic clays or hydrotalcites are multifunctional materials that can improve processes such as adsorption of contaminants. Among these, aromatic organic compounds represent an environmental problem, since they are dispersed in wastewater usually generated by the petrochemical industry. This work presents the synthesis of hydrotalcites and mixed oxides derived from hydrotalcites, used in the adsorption of organic pollutants of the BTEX-phenol present in aqueous media. The results were compared with those of the reconstructed hydrotalcites in presence of BTEX-phenol. It was found that the adsorptive properties depend on the chemical composition and the structural properties of the materials. Although the initial hydrotalcites and the derived mixed oxides were efficient adsorbents, the regenerated hydrotalcites were much more active.Las arcillas aniónicas o hidrotalcitas son materiales multifuncionales que permiten optimizar procesos como la adsorción de contaminantes, entre los cuales los compuestos orgánicos aromáticos representan un grave problema ambiental, ya que se encuentran dispersos en aguas residuales generadas normalmente por la industria petroquímica. En este trabajo se presenta la síntesis de hidrotalcitas y de óxidos mixtos derivados de éstas, empleados en la adsorción de contaminantes orgánicos de tipo BTEX-fenol presentes en medio acuoso. Los resultados se compararon con los de las hidrotalcitas reconstruidas en presencia de BTEX-fenol. Se encontró que las propiedades adsorptivas dependen fundamentalmente de la composición química de los materiales y de la estructura. Si bien las hidrotalcitas iniciales y los óxidos mixtos resultaron ser adsorbentes eficientes, las hidrotalcitas reestructuradas fueron mucho más activas
Evaluación de la contaminación por As, Ni, Cu, Pb, Zn y Cr en sedimentos de la zona marino-costera asociada a la terminal marítima de Nuevitas, Cuba
Get PDFIn studies of contamination by trace elements in aquatic environments, sediments constitute a key line, since by acting as traps for numerous compounds they behave as secondary sources of contamination in the marine environment, thus affecting the ecological and biogeochemical balance of the ecosystem. Due to the existing lack of knowledge about the concentration levels of pollution indicator elements in the sediments of the marine-coastal zone associated with the Nuevitas maritime terminal (Cuba), the objective of this research was to evaluate the contamination by As, Ni, Cu, Pb, Zn and Cr in sediments from that area by determining the total content, comparing it direcly to reference concentrations established in international sediment quality guidelines, and using enrichment indices. The sediments were collected during May 2016 in six stations with influence of the maritime terminal, and digested according to the EPA 3052 method. Atomic emission spectroscopy with an inductively coupled plasma source was used as a detection technique. The evaluation of the total content in sediments showed that the order of abundance of the analyzed elements was Cr > Zn > Ni > Pb > Cu > As. Concentrations that exceed the corresponding probable effect level (PEL) for most of the studied elements were detected In the sediments of stations E1, E3 and E5. Cr and Ni showed higher levels than those causing moderate biological effects (ERM). Through the enrichment factors it was verified that Ni levels in the sediments are due to natural causes and that there is a moderately severe or severe Cr enrichment in the sediments of stations E1, E3, E6 and E5, evidencing the anthropic character of such contamination.En los estudios de contaminación por elementos traza en los ambientes acuáticos los sedimentos constituyen un renglón clave ya que actúan como trampas para numerosos compuestos, afectando así el equilibrio ecológico y biogeoquímico del ecosistema. Debido al desconocimiento existente sobre los niveles de concentración de elementos indicadores de contaminación en los sedimentos de la zona marino-costera asociada a la terminal marítima de Nuevitas (Cuba), el objetivo de la presente investigación fue evaluar la contaminación por As, Ni, Cu, Pb, Zn y Cr en sedimentos de esa zona mediante la determinación de los contenidos totales, su comparación directa con concentraciones de referencia establecidas en guías internacionales de calidad de sedimentos y el empleo de índices de enriquecimiento. Los sedimentos fueron colectados, durante el mes de mayo de 2016, en seis estaciones donde existe influencia de la terminal marítima, y digeridos según el método EPA 3052. Se empleó como técnica de detección la espectroscopia de emisión atómica con fuente de plasma acoplado inductivamente. La evaluación del contenido total en los sedimentos mostró que el orden de abundancia de los elementos analizados fue: Cr > Zn > Ni > Pb > Cu > As. En los sedimentos de las estaciones E1, E3 y E5 se detectaron concentraciones que sobrepasan los tenores de efecto probable (PEL) correspondientes para la mayoría de los elementos estudiados, destacándose el Cr y el Ni por superar los niveles causantes de efectos biológicos moderados (ERM). Se comprobó, mediante los factores de enriquecimiento, que los niveles de Ni en los sedimentos se deben a causas naturales y que existe un enriquecimiento moderadamente severo o severo de Cr en los sedimentos de las estaciones E1, E3, E6 y E5, evidenciando el carácter antrópico de dicha contaminación
Detección UV-VIS de marcadores de diferenciación sexual en extractos hidroetanólicos de Vallisneria americana
Get PDFThe sexuality of submerged dioecious macrophytes acquires importance to strengthen research on environmental stress and repopulation of aquatic ecosystems. The objective of this work was to determine biomarkers that allow the sexual identification of Vallisneria americana by spectrophotometry analysis of the hydroethanolic extracts of its leaves or roots. Within the water column of the male and female vegetation, the parameters of pH, temperature, dissolved oxygen, conductivity, dissolved solids, and redox potential were measured in situ. For each reproductive morphotype, the number of leaves and the length of the predominant leaf and main root in each plant were analyzed. Spectral scanning of the extracts in the range of 340 to 750 nm was used both to compare the dominant wavelengths of the metabolites present and to quantify chlorophylls (a and b), carotenoids, and monomeric anthocyanins. The chlorophyll quotient was also obtained. The biomarkers of sexuality of this submerged macrophyte can be related to the content of the four pigments in the leaves that were invariably high in males, whereas the physics and chemistry of water and the vegetative morphology of each sex were almost similar. A possible microalgal influence is described by the inverse relationship of chlorophylls in roots and the finding of phycobilins in male leaves. The results offer the potential for ecological and biotechnological applications of V. americana aimed at the repopulation of wetlands affected by abiotic and biotic factors.La sexualidad de las macrófitas dioicas sumergidas adquiere importancia para fortalecer investigaciones sobre estrés ambiental y repoblación de ecosistemas acuáticos. El objetivo de este trabajo fue determinar biomarcadores que permitan la identificación sexual de Vallisneria americana mediante el análisis por espectrofotometría de los extractos hidroetanólicos de sus hojas o raíces. Dentro de la columna de agua de la vegetación femenina y masculina se midieron in situ los parámetros de pH, temperatura, oxígeno disuelto, conductividad, sólidos disueltos y potencial redox. Por cada morfotipo reproductivo se analizaron el número de hojas y la longitud de la hoja predominante y raíz principal en cada planta. El escaneado espectral de los extractos en el rango de 340 a 750 nm se usó tanto para comparar las longitudes de onda dominantes de los metabolitos presentes como para cuantificar clorofilas (a y b), carotenoides y antocianinas monoméricas. También se obtuvo el cociente de clorofilas. Los biomarcadores de sexualidad de esta macrófita sumergida se pueden relacionar por el contenido de los cuatro pigmentos en las hojas que fueron invariablemente altos en masculinos, mientras que las características físicas y químicas del agua y la morfología vegetativa de cada sexo fueron casi similares. Una posible influencia microalgal es descrita por la relación inversa de clorofilas en raíces y el hallazgo de ficobilinas en hojas masculinas. Los resultados ofrecen un potencial para las aplicaciones ecológicas y biotecnológicas de V. americana orientadas a la repoblación de humedales afectados por factores abióticos y bióticos