Revista Internacional de Contaminación Ambiental
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Urban smog in the process of industrialization - Take Xi’an, China, for example
Get PDFThis paper takes “industry development - urban smog” as the line to discuss the interaction between them, it tells us that the industry of Xi’an city has developed rapidly since the founding of the People’s Republic of China. However, the industrialization process in Xi’an is also accompanied by the appearance of smog. We found that the appearance of urban smog in Xi’an shows a certain regularity in the process of industrialization. Through analyzing the spatial distribution, historical characteristics and seasonal changes of urban smog, it reveals that the industrial production based on coal burning is an important inducement for smog in Xi’an. It calls for exploring an environmental protection road suitable for China. For example, energy structure transformation, laws improvement, promoting people’s awareness of environmental protection and industrial upgrading are all feasible ways to control urban smog. It is of practical significance to correctly handle the coordination between industrial economic development and environmental protection.This paper takes “industry development - urban smog” as the line to discuss the interaction between them, it tells us that the industry of Xi’an city has developed rapidly since the founding of the People’s Republic of China. However, the industrialization process in Xi’an is also accompanied by the appearance of smog. We found that the appearance of urban smog in Xi’an shows a certain regularity in the process of industrialization. Through analyzing the spatial distribution, historical characteristics and seasonal changes of urban smog, it reveals that the industrial production based on coal burning is an important inducement for smog in Xi’an. It calls for exploring an environmental protection road suitable for China. For example, energy structure transformation, laws improvement, promoting people’s awareness of environmental protection and industrial upgrading are all feasible ways to control urban smog. It is of practical significance to correctly handle the coordination between industrial economic development and environmental protection
Mecanismos de inhibición de la metanogénesis con lovastatina y análisis de la expresión génica
Get PDFMethanogenic archaea coexist within the rumen microbiota, converting CO2 into CH4 and using H2 as an electron donor. Methane is a potent greenhouse gas that impacts climate change and global warming. Lovastatin (Lv) is a drug used to decrease hypercholesterolemia in human beings and can be used to reduce CH4 production from ruminants. This review shows that there are several synergistic mechanisms that can directly disrupt methanogenesis. Mevalonic acid is a crucial precursor for the synthesis of methanogen’s isoprenoids. It is also a metabolite found in microorganisms of the Eukarya and Archaea domains. The β-hydroxy acid form of Lv is a competitive inhibitor of the reductase 3-hydroxy-3-methylglutaryl-coenzyme A (HMGCR), a crucial enzyme for the synthesis of isoprenoid precursors. In most reports, this is the mechanism for the inhibition of methanogenesis associated with Lv. However, alternate mechanisms for inhibition of methanogenesis have been reported, such as inhibition of cofactor F420-dependent enzymes and the increase in the concentration of acetyl-CoA synthesized from methyl-H4MPT. The expression of some essential genes in the metabolic pathway of Methanobrevibacter smithii methanogenesis has been studied under conditions of inhibition with Lv treatment. Results indicated an increased expression of the HMGCR gene, whereas the expression of NADP-oxidoreductase dependent on coenzyme F420 gene (fno) was significantly reduced.Las arqueas metanogénicas (AM) coexisten con la microbiota ruminal y utilizan H2 como donador de electrones para convertir CO2 en CH4. Este último es un potente gas atmosférico causante del efecto invernadero que tiene un impacto importante en el calentamiento global y el cambio climático. La lovastatina (Lv) es un medicamento para el tratamiento de hipercolesterolemia en humanos que también reduce la producción de CH4 en rumiantes. Esta revisión demuestra que existen diversos mecanismos sinérgicos que en conjunto afectan directamente la metanogénesis. El ácido mevalónico es el precursor clave de la síntesis de isoprenoides, los cuales constituyen la membrana de las AM. La Lv β-hidroxiácida, que es la forma activa de la molécula, es un inhibidor competitivo de la enzima reductasa 3-hidroxi-3-metilglutaril-coenzima A (HMGCR), que es clave para la producción de los precursores de isoprenoides que forman la membrana de AM. Este es el mecanismo al cual se atribuye principalmente la inhibición de la metanogénesis con Lv. Se han reportado mecanismos alternos que inciden en la inhibición de la metanogénesis, tales como la supresión de las enzimas de la metanogénesis que dependen del cofactor F420 y el aumento de la concentración de la acetil-coenzima A sintetizada a partir de metil-tetrahidrometanopterina (metil-H4MPT). Se ha estudiado la expresión de algunos genes clave en la ruta metabólica de la metanogénesis en Methanobrevibacter smithii en condiciones de inhibición con Lv. Se ha demostrado que se incrementó la expresión del gen de la HMGCR y se redujo la del gen de la NADP-oxidorreductasa dependiente de la coenzima F420 (NFOR)
Isolated bacteria from hot springs able to use hydrocarbons as carbon source
Get PDFPetroleum derivates used in energy production are gravely pollutants for the ecosystem, especially for aquatic environments and human health. This study aimed to isolate hydrocarbons-degrading bacteria from hot springs. Three strains of hydrocarbondegrading bacteria strains, belonging to the Bacillus and one of the genus Lysinibacillus were isolated. These strains tolerate temperatures from 65 to 100 ºC and were able to degrade and grow on BH medium supplemented with gasoline and diesel. Strain M2-7 shared 100 % 16S rRNA identity with Bacillus licheniformis and was the only able to degrade pyrene and benzopyrene among these isolated strains. The results indicate that B. licheniformis M2-7 could degrade a wider range of hydrocarbons and some recalcitrant hydrocarbon components, which could be particularly helpful for the treatment and bioremediation of hydrocarbon-polluted systems.Petroleum derivates used in energy production are gravely pollutants for the ecosystem, especially for aquatic environments and human health. This study aimed to isolate hydrocarbons-degrading bacteria from hot springs. Three strains of hydrocarbondegrading bacteria strains, belonging to the Bacillus and one of the genus Lysinibacillus were isolated. These strains tolerate temperatures from 65 to 100 ºC and were able to degrade and grow on BH medium supplemented with gasoline and diesel. Strain M2-7 shared 100 % 16S rRNA identity with Bacillus licheniformis and was the only able to degrade pyrene and benzopyrene among these isolated strains. The results indicate that B. licheniformis M2-7 could degrade a wider range of hydrocarbons and some recalcitrant hydrocarbon components, which could be particularly helpful for the treatment and bioremediation of hydrocarbon-polluted systems
Comparison of single and mixed plant artificial floating islands for domestic sewage treatment
Get PDFThe artificial floating island is an ecological restoration technology of water environment based on the principle of ecological hydraulics aiming at solving the problem of eutrophic water by degrading chemical oxygen demand, total nitrogen, and total phosphorus. It has good social benefits, environmental benefits, and broad application prospects. Against the backdrop of domestic wastewater treatment, the mixed plant-type artificial floating island, which include pickerel weed, Scirpus tabernaemontani, and bog rushes, was put into a test environment. Through the analysis of the adsorption and the absorption effect of various plants, the purifying effect of the mixed type of plant artificial floating island was thus determined and summarized based on the known total nitrogen, total phosphorus, and chemical oxygen demand values. According to the test results, it can be concluded that the effect of the mixed type of plant artificial floating island system in treating domestic wastewater is significant. The removal rate of total nitrogen and total phosphorus reached 55.12 % and 37.59 %, respectively, and the removal rate of chemical oxygen demand reached 47.85 %. The mixed type of plant artificial floating island can effectively dispose the nitrogen and phosphorus in the water.The artificial floating island is an ecological restoration technology of water environment based on the principle of ecological hydraulics aiming at solving the problem of eutrophic water by degrading chemical oxygen demand, total nitrogen, and total phosphorus. It has good social benefits, environmental benefits, and broad application prospects. Against the backdrop of domestic wastewater treatment, the mixed plant-type artificial floating island, which include pickerel weed, Scirpus tabernaemontani, and bog rushes, was put into a test environment. Through the analysis of the adsorption and the absorption effect of various plants, the purifying effect of the mixed type of plant artificial floating island was thus determined and summarized based on the known total nitrogen, total phosphorus, and chemical oxygen demand values. According to the test results, it can be concluded that the effect of the mixed type of plant artificial floating island system in treating domestic wastewater is significant. The removal rate of total nitrogen and total phosphorus reached 55.12 % and 37.59 %, respectively, and the removal rate of chemical oxygen demand reached 47.85 %. The mixed type of plant artificial floating island can effectively dispose the nitrogen and phosphorus in the water
Biodegradation of polycyclic aromatic hydrocarbons by Acremonium sp. activity
Get PDFChihuahua State is the largest apple producer in Mexico. To prevent apples from freezing during the winter, petroleum-based fuels are used to heat the orchards. In this research work, a microorganism isolated from inside of a fuel plastic container was identified through morphological analysis as the fungus Acremonium sp. By cultivating the fungus in potato dextrose agar medium (PDA), we were able to study the biodegradation rates of three polycyclic aromatic hydrocarbons (PAHs). The isolated microorganism was incubated at 28 ºC in M9 mineral liquid medium using phenanthrene, anthracene, and pyrene as the only carbon source at a concentration of 50 µg/mL. Degradation of PAHs was monitored using an environmentally friendly reverse phase ultra-high-performance liquid chromatography (UHPLC) system, with a C18 column, 30% water acidified at 0.1% with trifluoroacetic acid, and 70% acetonitrile as the mobile phase, 40 ºC column temperature, and UV detection at 254 nm. After 30 days of biodegradation (optimal time), the final mean concentration for individual degradation experiments were 2.51 µg/mL phenanthrene, 3.02 µg/mL anthracene and 5.53 µg/mL pyrene. Those final concentrations indicate degradation percentile of 95%, 94%, and 89%, respectively. Biodegradation experiments combining all three PAHs showed similarly high degradation percentiles of 93%, 94%, and 85% for phenanthrene, anthracene, and pyrene, respectively. The dry weight average at day 30 in the individual and combined degradation experiments was 2.34 mg/mg PAHs degraded.Chihuahua State is the largest apple producer in Mexico. To prevent apples from freezing during the winter, petroleum-based fuels are used to heat the orchards. In this research work, a microorganism isolated from inside of a fuel plastic container was identified through morphological analysis as the fungus Acremonium sp. By cultivating the fungus in potato dextrose agar medium (PDA), we were able to study the biodegradation rates of three polycyclic aromatic hydrocarbons (PAHs). The isolated microorganism was incubated at 28 ºC in M9 mineral liquid medium using phenanthrene, anthracene, and pyrene as the only carbon source at a concentration of 50 µg/mL. Degradation of PAHs was monitored using an environmentally friendly reverse phase ultra-high-performance liquid chromatography (UHPLC) system, with a C18 column, 30% water acidified at 0.1% with trifluoroacetic acid, and 70% acetonitrile as the mobile phase, 40 ºC column temperature, and UV detection at 254 nm. After 30 days of biodegradation (optimal time), the final mean concentration for individual degradation experiments were 2.51 µg/mL phenanthrene, 3.02 µg/mL anthracene and 5.53 µg/mL pyrene. Those final concentrations indicate degradation percentile of 95%, 94%, and 89%, respectively. Biodegradation experiments combining all three PAHs showed similarly high degradation percentiles of 93%, 94%, and 85% for phenanthrene, anthracene, and pyrene, respectively. The dry weight average at day 30 in the individual and combined degradation experiments was 2.34 mg/mg PAHs degraded
Spatial distribution and influencing factors of ecological efficiency in Yangtze river delta
Get PDFThis paper employs the EBM model and the Spatial Durbin Model(SDM) to describe the spatial characteristics and influencing factors of the 27 cities’ eco-efficiency in China’s Yangtze River Delta from 2003 to 2018. We find that the overall 27 cities’ eco-efficiency in China’s Yangtze River Delta fluctuates slowly, and the spatial difference of the ecological efficiency of the 27 cities in this area is obvious, showing the distribution characteristics of “East is better than west”. The findings show that PGDP, FDI, industrial structure (IND), and population density (POP) have a significant positive correlation with the eco-efficiency of this area. On the contrary, there is a significant negative correlation between greening level (GRE) and ecological efficiency, but the level of technological innovation is not significant.This paper employs the EBM model and the Spatial Durbin Model(SDM) to describe the spatial characteristics and influencing factors of the 27 cities’ eco-efficiency in China’s Yangtze River Delta from 2003 to 2018. We find that the overall 27 cities’ eco-efficiency in China’s Yangtze River Delta fluctuates slowly, and the spatial difference of the ecological efficiency of the 27 cities in this area is obvious, showing the distribution characteristics of “East is better than west”. The findings show that PGDP, FDI, industrial structure (IND), and population density (POP) have a significant positive correlation with the eco-efficiency of this area. On the contrary, there is a significant negative correlation between greening level (GRE) and ecological efficiency, but the level of technological innovation is not significant
Evaluación de riesgo ecológico por elementos potencialmente tóxicos en sedimentos costeros de un estuario tropical hipereutrófico
Get PDFThe physicochemical and biological composition of sediments has been widely used as an environmental quality indicator of aquatic ecosystems, however, the application of different quality guidelines allows for a practical estimation of ecological risks associated with the presence of potentially toxic elements (PTE) such as metals, metalloids and others. In this work the ecological risk due to Pb, Cd, Cr, Zn and Cu presence in coastal sediments from Lake Maracaibo (Venezuela) were evaluated, using a multiguidelines approach (elemental enrichment indices and evaluation of potential ecological risk). To do this, 33 surface sediment samples in 11 sampling stations in the lake coastal area were collected to determine the total PTE levels by means of atomic absorption spectrometry coupled to a graphite furnace after acid digestion in high-pressure vessels. The mean concentrations were 3.811 ± 3.161, 0.032 ± 0.090, 8.574 ± 6.429, 26.480 ± 3.762 and 2.644 ± 1.792 mg/kg dry mass for Pb, Cd, Cr, Zn and Cu, respectively. The values of applied guidelines indicated moderate to considerable ecological risks due to the Cd presence in some localities, however, the sediment quality guidelines highlighted that the occurrence probability is very low or negligible (9%), so it can be considering an environment conducive to aquatic life. The EPTs with the highest potential for ecological risk were Cd and Zn, while Cu exhibited the lowest possibilities of adverse effects. It is necessary to assess the potential ecological risk associated with EPT levels in internal sediments of the bay, the strait and the central zone of lake.La composición física, química y biológica de los sedimentos se ha usado ampliamente como indicador de calidad ambiental de los ecosistemas acuáticos, no obstante, la aplicación de directrices de calidad permite estimar de manera práctica los riesgos ecológicos asociados a la presencia de elementos potencialmente tóxicos (EPT) como metales, metaloides y otros. En este trabajo se evaluó el riesgo ecológico por Pb, Cd, Cr, Zn y Cu en sedimentos costeros del Lago de Maracaibo (Venezuela), mediante un enfoque multidirectrices (índices de enriquecimiento elemental y evaluación de riesgo ecológico potencial). Para ello, se recolectaron 33 muestras de sedimentos superficiales en 11 estaciones de muestreo de la zona costera del lago, para determinar los niveles totales de los EPT mediante espectrometría de absorción atómica con horno de grafito, previa digestión ácida en reactores de alta presión. Las concentraciones medias fueron de 3.811 ± 3.161, 0.032 ± 0.090, 8.574 ± 6.429, 26.480 ± 3.762 y 2.644 ± 1.792 mg/kg de masa seca para Pb, Cd, Cr, Zn y Cu, respectivamente. Los valores de los índices aplicados señalaron riesgos ecológicos de moderados a considerables por la presencia de Cd en algunas localidades, no obstante, las directrices de calidad de sedimento destacaron que la probabilidad de ocurrencia es muy baja o despreciable (9 %), considerándose un ambiente propicio para la vida acuática. Los EPT con mayor potencial de riesgo ecológico fueron Cd y Zn, mientras que el Cu exhibió las menores posibilidades de efectos adversos. Es necesario evaluar el riesgo ecológico potencial asociado a EPT en sedimentos internos de la bahía, el estrecho y de la zona central del lago
Caracterización estacional de los elementos traza y partículas absorbentes de luz (PAL) en la nieve del glaciar Huaytapallana (Perú)
Get PDFThis study reports for the first time the content of trace elements and light-absorbing particles (LAPs) in snow samples collected from a Peruvian glacier (Huaytapallana). The sampling campaign was carried out monthly from November 2015 to March 2019. The trace elements content was quantified by inductively coupled plasma mass spectrometry, while LAPs were analyzed using the light absorption heating method. The chemical composition dataset was assessed by descriptive statistics and t-test for assessing dry season and wet season differences. In addition, enrichment factor (EF) and hierarchical cluster analysis (HCA) were employed to identify possible emission sources. The snow, ice, and aerosol radiative (SNICAR) model was used to measure the effect of LAPs on snow albedo and radiative forcing (RF). Based on analysis of EF and HCA, it was shown that Al, Ti, Si, Co, Ce, Sr, Mn, Mg, Ba and Na have mainly natural sources; K, Ca, Fe, Cu, Pb and As have a mixture of natural and anthropogenic sources, and Zn has anthropogenic source. SNICAR model results indicated that LAPs reduced the snow albedo by up 4.5 % in the dry season with RF values as high as 33 W/m2. Therefore, we conclude that the presence of these particles substantially increases melt or sublimation rates of Peruvian glaciers.Este estudio informa por primera vez el contenido de elementos traza y partículas absorbentes de luz (PAL) en muestras de nieve colectadas de un glaciar peruano (glaciar Huaytapallana). La campaña de muestreo se realizó mensualmente desde noviembre de 2015 hasta marzo de 2019. El contenido de elementos traza se cuantificó mediante espectrometría de masa de plasma acoplado inductivamente, mientras que las PAL se analizaron utilizando un método de calentamiento por absorción de luz. El conjunto de datos de los elementos químicos se sometió a pruebas estadísticas para evaluar cambios entre las épocas seca y húmeda. Además, se emplearon análisis de agrupamiento jerárquico (AAJ), el factor de enriquecimiento (FE) y trayectorias inversas calculadas con el modelo HYSPLIT para identificar posibles fuentes de emisión. Se utilizó el modelo de transferencia radiativa SNICAR para estimar el efecto de los PAL sobre el albedo de nieve y el forzamiento radiativo (FR). De acuerdo con el análisis del FE y el AAJ, los elementos Al, Ti, Si, Co, Ce, Sr, Mn, Mg, Ba y Na están influenciados por fuentes naturales, en tanto que el K, Ca, Fe, Cu, Pb y As sugieren una mezcla de origen de fuentes naturales y antrópicas, y el Zn presenta una fuente significativamente antrópica. Por otro lado, según el modelo SNICAR, la presencia de las PAL redujo el albedo de la nieve hasta un 4.5 % en la estación seca con valores de FR de hasta 33 W/m2. Por lo tanto, concluimos que la presencia de estas partículas provenientes de fuentes antrópicas aumenta sustancialmente las tasas de fusión o sublimación de los glaciares peruanos
Dinámica del glifosato en el suelo y sus efectos en la microbiota
No full textGlyphosate, the most used herbicide worldwide, disrupts the synthesis of essential aromatic amino acids, eliminating sensitive plants. Its use has increased with the implementation of genetically modified crops that are tolerant to this herbicide and with its adoption as desiccant in some annual crops. Glyphosate, classified as probable carcinogen, has induced adverse effects to human health and has exerted selective pressure on plants resistant to this herbicide. Commercial formulations of glyphosate include molecules such as polyoxyethylenamines and heavy metals. There is no precise data on the amount of glyphosate used in Mexican agriculture, but it has been monitored in soils, rivers, seas, and the bodies of people directly or indirectly exposed to the herbicide in several countries. Glyphosate and its metabolite aminomethylphosphonic acid (AMPA) have low mobility in soils due to its high adsorption capacity. Its mobility and decomposition depend on the structure of soils, the amount and quality of the organic matter, temperature, pH, and type of clay, among other factors. Edaphic microbiota and glyphosate correlate on-to-one. Some bacterial species uses glyphosate as C and P source, metabolizing the herbicide, while, in presence of glyphosate other species change their fitness. Glyphosate alters the mycorrhization capacity of several fungi species, deregulates the expression of genes essential in processes such as amino acids’ metabolism or pathways related with detoxification. Glyphosate affects several species of worms, decreasing their ability to recycle organic matter. It is necessary to aim scientific research in agriculture to reducing the use of highly toxic and persistent agrichemicals.El glifosato, que es el herbicida más usado mundialmente, interfiere en la síntesis de aminoácidos aromáticos esenciales, eliminando las plantas sensibles. Su uso aumentó al introducirse cultivos genéticamente modificados tolerantes al herbicida, y al usarse como desecante de cultivos anuales. El glifosato, clasificado como probable cancerígeno, ha generado efectos adversos en la salud humana y ha ejercido presión de selección generando plantas resistentes al herbicida. Las formulaciones comerciales contienen moléculas como polioxietilenaminas y metales pesados. En México no hay datos sobre la cantidad de glifosato empleado en la agricultura, pero se detectó en suelo, ríos y mares, así como en personas directa o indirectamente expuestas al herbicida. El glifosato y su metabolito ácido aminometilfosfónico (AMPA) tienen baja movilidad en los suelos por su alta capacidad de adsorción; su movilización y descomposición dependen de la estructura del suelo, cantidad y calidad de la materia orgánica, temperatura, pH, y tipo de arcilla, entre otros. La relación entre la microbiota edáfica y el glifosato es biunívoca: algunas especies bacterianas lo usan como fuente de C y P, degradando al herbicida, y otras sufren alteraciones adaptativas ante la exposición al glifosato. El herbicida altera la capacidad de micorrización de los hongos arbusculares y desregula la expresión de genes implicados en procesos como el metabolismo de los aminoácidos o vías relacionadas con detoxificación. Asimismo, afecta a diversas especies de lombrices del suelo, disminuyendo su capacidad de reciclar materia orgánica. Debe promoverse la investigación orientada a la producción agrícola sin el uso de agroquímicos altamente tóxicos y persistentes