Revista Internacional de Contaminación Ambiental
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MEASUREMENT AND DRIVING FACTORS OF THREE-DIMENSIONAL ECOLOGICAL FOOTPRINT IN SHENYANG CITY
Get PDFBased on the three-dimensional (3D) ecological footprint model, this paper has provided the measurements of the dynamic changes of the 3D ecological footprint of Shenyang from 2005 to 2016, and the analysis of the driving factors behind such footprint through the partial least-squares regression. Our research findings reveal that: The overall per capita 3D ecological footprint of the Shenyang City went upward from 2005 to 2016, with an average annual growth rate of 16.5%; at the meantime, the per capita ecological carrying capacity showed a year-on-year downward trend at an average annual rate of 0.79%. The analysis of partial least squares regression indicates that urban ecological construction and environmental pollution constitute the significant factors that lead to the increase of the ecological footprint year by year in Shenyang. On the contrary, the exchange and trade, the environmental governance and the structure of land use are conducive to relieving the pressure on the ecological expansion. Our analysis of the importance of variable projections demonstrates that per capita public green area and the emission indicators of the industrial waste have imposed a greater influence on the index of ecological footprint of Shenyang and are relatively consistent with the comprehensive evaluation results of the regression analysis. In the future, we shall enhance the efficiency of urban ecological construction by optimizing industrial structure, using clean energy, actively developing foreign trade and exchanges, and rationally planning urban land use.Based on the three-dimensional (3D) ecological footprint model, this paper has provided the measurements of the dynamic changes of the 3D ecological footprint of Shenyang from 2005 to 2016, and the analysis of the driving factors behind such footprint through the partial least-squares regression. Our research findings reveal that: The overall per capita 3D ecological footprint of the Shenyang City went upward from 2005 to 2016, with an average annual growth rate of 16.5%; at the meantime, the per capita ecological carrying capacity showed a year-on-year downward trend at an average annual rate of 0.79%. The analysis of partial least squares regression indicates that urban ecological construction and environmental pollution constitute the significant factors that lead to the increase of the ecological footprint year by year in Shenyang. On the contrary, the exchange and trade, the environmental governance and the structure of land use are conducive to relieving the pressure on the ecological expansion. Our analysis of the importance of variable projections demonstrates that per capita public green area and the emission indicators of the industrial waste have imposed a greater influence on the index of ecological footprint of Shenyang and are relatively consistent with the comprehensive evaluation results of the regression analysis. In the future, we shall enhance the efficiency of urban ecological construction by optimizing industrial structure, using clean energy, actively developing foreign trade and exchanges, and rationally planning urban land use
CONTENIDO DE PLOMO, CADMIO Y ARSÉNICO EN TEJIDOS BIOLÓGICOS DE LA PALOMA COMÚN (Columba livia) PRESENTES EN UN ÁREA URBANA PREVIAMENTE CONTAMINADA CON RESIDUOS MINEROS
Get PDFThe north of Chile presents numerous cases of environmental contamination by heavy metals and others chemical elements, particularly due to the inadequate handling of its waste. In the Arica city, northern Chile, in the decade of 1980, 19 000 tons of mining waste were deposited from Europe, with high contents of Pb, As and Cd. Its effects have only been evaluated in the human population, but until now it is unknown if those chemical elements were incorporated by other species that are part of the biological community of the urban radius. In this study we evaluated the presence and concentrations of Pb, As and Cd in feral pigeons (Columba livia) inhabitants of Arica, both in the urban radius and in a nearby valley (valley of Azapa). The values found are higher in relation to other birds of similar ecological characteristics. For example, regarding Pb, 1.7 μg/g were found on average in liver tissue and 10.84 μg/g in bone tissue. In relation to As, concentrations were 2.63 μg/g in liver tissue and 2.13 μg/g in bone. Finally, concentrations of Cd in liver were 11.7 μg/g and 3.43 μg/g in bones. This indicates that the common pigeons from Arica are highly contaminated by heavy metals and arsenic and could be considered an environmental bioindicator species for future environmental assessment of the city.El norte de Chile presenta numerosos casos de contaminación ambiental por metales pesados y otros químicos, particularmente debido al manejo inadecuado de desechos. En la ciudad de Arica, norte de Chile, se depositaron en la década de 1980 alrededor de 19 mil toneladas de desechos mineros provenientes de Europa, con altos contenidos de Pb, As y Cd. Sus efectos sólo han sido evaluados en la población humana, pero hasta ahora se desconoce si esos elementos químicos fueron incorporados por otras especies que son parte de la comunidad biológica del radio urbano. En este estudio evaluamos la presencia y concentración de Pb, As y Cd en palomas (Columba livia) que habitan en la ciudad de Arica, tanto en el radio urbano como en un valle aledaño (valle de Azapa). Los valores encontrados son altos en relación con otras aves de similares características ecológicas, por ejemplo respecto del Pb se encontraron en promedio 1.7 μg/g en tejido hepático y 10.84 μg/g en tejido óseo. En relación con el As, la concentración en hígado fue de 2.63 μg/g y en hueso de 2.13 μg/g; finalmentela concentración de Cd en hígado fue de 11.7 μg/g y en hueso de 3.43 μg/g. Esto indica que las palomas de la ciudad de Arica están altamente contaminadas por metales pesados y As, y podrían considerarse como una especie bioindicadora para futuras evaluaciones ambientales de la ciudad.
EVALUACIÓN DE LA TOXICIDAD DE LOS SEDIMENTOS DEL CURSO ALTO DEL RÍO LERMA, MÉXICO
Get PDFThe aim of this study was to evaluate the toxicity of sediments in the upper course of the Lerma River (UCLR), in the State of Mexico by means of Microtox® test using the basic solid phase test protocol. The surface sediment samples were collected in 23 sites distributed following the main stream flow of the river: 12 on the river and 11 on its tributaries for two sampling campaigns in a one year period. Half maximal effective concentration (EC50) in Vibrio fischeri varied in the river sediment from 139 mg/L to 3588 mg/L and for the tributaries it varied between 108 mg/L to 16436 mg/L. In general, sediments of the UCLR can be classified as extremely toxics which show the impact of anthropogenic contributions that come from urban and industrial untreated discharges.El objetivo de este estudio fue determinar la toxicidad de los sedimentos del curso alto del río Lerma (CARL), Estado de México, por medio del ensayo Microtox® con el protocolo básico en la fase sólida. Se colectaron muestras de sedimento superficial en 23 sitios distribuidos sobre el CARL: 12 sobre el cauce del río y 11 en sus tributarios, durante dos campañas de muestreo en un periodo de un año. La concentración efectiva media (EC50) en Vibrio fischeri varió para los sedimentos riverinos entre 139 mg/L y 3588 mg/L y para los de las descargas fue entre 108 mg/L y 16436 mg/L. En general los sedimentos del CARL pueden clasificarse como extremadamente tóxicos, lo cual es un indicativo del impacto de las contribuciones antrópicas de origen doméstico e industrial que recibe este importante cuerpo de agua
SOLID WASTE GENERATION IN A HOTEL EVENT SERVICE
Get PDFThe large influx of tourists worldwide as well as the expansion of tourism events increase the environmental impact caused by hotel services. The aims of this work were to characterize the solid waste generated by hotel sectors, and to compare that waste generation between different events organized in the enterprise. The data collection was performed using qualitative and quantitative characterizations, where the waste generation in each sector and the type of event organized, were registered. The results showed that most residues were found in the kitchen, bathrooms, rooms, and at the event hall, with higher values being generated in the festive events. The waste generation by these events corresponded to 48 % of the total generated in the lodging, while 8 % corresponded to the business events. The difference between the characterization of waste generated in festive events and that of business events, along with no occurrence of event at all, showed that it could be attributed to the increase in the per capita generation of categories of waste, primarily glass. The results obtained in this study are essential to the creation and/or improvement of a management plan of solid waste in lodging facilities.The large influx of tourists worldwide as well as the expansion of tourism events increase the environmental impact caused by hotel services. The aims of this work were to characterize the solid waste generated by hotel sectors, and to compare that waste generation between different events organized in the enterprise. The data collection was performed using qualitative and quantitative characterizations, where the waste generation in each sector and the type of event organized, were registered. The results showed that most residues were found in the kitchen, bathrooms, rooms, and at the event hall, with higher values being generated in the festive events. The waste generation by these events corresponded to 48 % of the total generated in the lodging, while 8 % corresponded to the business events. The difference between the characterization of waste generated in festive events and that of business events, along with no occurrence of event at all, showed that it could be attributed to the increase in the per capita generation of categories of waste, primarily glass. The results obtained in this study are essential to the creation and/or improvement of a management plan of solid waste in lodging facilities
BIOCONVERSIÓN DE DESPERDICIOS VEGETALES A BIOGÁS A PARTIR DE MICROORGANISMOS RUMINALES
Get PDFThe growing demand for food in urban areas generates an increasing amount of organic wastes, including vegetable residues. The management of these wastes can lead to greenhouse gases emissions (GHG) through its process, including collection, transportation, and accumulation in landfills. To identify the potential GHG from vegetable residues, in vitro fermentations of collected residues of lettuce (LS), cabbage (BOV), cauliflower (BOB), corn cob (HZM), and spinach (SO) leaves, as well as leftovers of cladodes from cactus pear (OF) from a food market, were compared with oat hay (AS), lucerne hay (AH) and corn silage (EZM), major components in ruminant feed using rumen fluid as the inoculum. The variables were: in vitro dry matter degradation (IVDMD), pH, kinetics of gas production and methane (CH4) concentration. Fermentation was carried out at 39 ºC for 96 h, and the gas samples to measure CH4 concentration were taken at 9, 12, 24, 34 and 48 h of incubation. The IVDMD of LS, BOV, BOB, HZM and OF was 12.8 % higher than those of the forages (AS, AH and EZM). Between 9 and 12 h of incubation, CH4 emission from BOV, BOB and HZM was 44.8 % higher than that from the three forages. Our results suggest that vegetable residues can be adequately degraded by the rumen microorganisms and, therefore, they can be used for biogas production in urban areas to decrease their accumulation in landfills.La creciente demanda de alimentos en áreas urbanas genera cada vez mayor cantidad de desperdicios orgánicos, incluyendo residuos vegetales. El manejo de estos residuos vegetales causa emisiones de gases efecto invernadero (GEI) por su recolección, transporte, y depósito en vertederos. Para identificar su potencial de GEI, en un mercado de alimentos se recolectaron residuos de hojas de lechuga (LS), de col (BOV), de coliflor (BOB), de maíz (HZM), de espinaca (SO) y de nopal (OF), se fermentaron in vitro usando líquido ruminal como inóculo y se compararon con heno de avena (AS), heno de alfalfa (AH) y ensilado de maíz (EZM), forrajes utilizados con frecuencia en la alimentación de rumiantes. Las variables fueron degradación in vitro de la materia seca (DIVMS), pH, cinética de producción de gas y concentración de metano (CH4). La fermentación se realizó durante 96 h a 39 ºC y las muestras de gas para medir la concentración de CH4 se tomaron a 9, 12, 24, 34 y 48 h de incubación. La DIVMS de LS, BOV, BOB, HZM y OF fue 12.8 % mayor a AS, AH y EZM. Entre las 9 y 12 h de incubación la emisión de CH4 a partir de BOV, BOB and HZM fue 44.8 % superior a los tres forrajes. La principal conclusión es que estos residuos vegetales son degradados adecuadamente por los microorganismos ruminales y, por lo tanto, se pueden usar para la producción de biogás en áreas urbanas para disminuir su depósito en vertederos
MODELO BIOQUÍMICAMENTE ESTRUCTURADO PARA LA ESTIMACIÓN DE LA EFICIENCIA DE UNA CELDA DE COMBUSTIBLE MICROBIANA
Get PDFA preliminary study focused on modeling microbial fuel cells through microbial yields was performed. A mathematical model to determine the quantity of charge generated over time in the anodic chamber of a microbial fuel cell, using Escherichia coli as the electrogenic organism, was designed. This model was used in order to estimate the electrical efficiency of microbial yields such as biomass, substrate, and product, and the stoichiometric coefficients of the species aforementioned. The mathematical model constructed described microbial growth using a logistical population model, giving a coefficient of determination of R2 = 0.960 between the model and the experimental data for the substrate, and R2 = 0.982 for the biomass. Using this electrical charge prediction model, future studies will focus primarily on measuring the experimental microbial yields and stoichiometric coefficients of electrogenic organisms in order to test the viability of this cell implementation.Se realizó un estudio preliminar de una celda de combustible microbiana a través de los rendimientos microbianos. Se obtuvo un modelo matemático para determinar la cantidad de cargas generadas en el tiempo en la cámara anódica de una celda de combustible microbiana, utilizando Escherichia coli como organismo electrogénico. El modelo se utilizó para estimar la eficiencia eléctrica desde el punto de vista de los rendimientos microbianos como son biomasa, sustrato y producto, y los coeficientes estequiométricos de las especies mencionadas. El modelo matemático se construyó mediante la descripción del crecimiento microbiano a través de un modelo logístico de población, el cual arrojó un coeficiente de determinación entre el modelo y los datos experimentales de R2 = 0.960 para sustrato y R2 = 0.982 para biomasa. Con este modelo de predicción de cargas eléctricas, en el futuro se procederá primero a medir experimentalmente rendimientos microbianos y coeficientes estequiométricos dado un organismo electrogénico, para estudiar así la factibilidad de implementación de dicha celda
MODELADO EN COLUMNA DE LECHO FIJO PARA LA BIOADSORCIÓN DE Cd2+ Y Pb2+ CON CÁSCARA DE CACAO
Get PDFIn this work the results of the biosorption of Pb+2 and Cd+2 with cocoa shell in fixed bed columns are presented. A hydrodynamic study was performed varying diameter and height of the column, as well as diameter and mass of biosorbent, to determine the best hydrodynamic conditions, which resulted in a flow through the column of 2.12 mL/min. Experimental data were adjusted to several models depending on the effluent volume, which describe the rupture curve for single component and two component systems. The removal percentages of Pb+2 and Cd+2 in single component systems are 91 and 90 %, respctively. In bicomponent systems (Pb+2-Cd+2) the removal percentages of lead and cadmium were 88 and 90 %, respectively. The dose-response model in bi and mono-component systems best reproduced the experimental rupture curves throughout the measured range.En este trabajo se presentan los resultados de ensayos de bioadsorción de Pb+2 y Cd+2 con cáscara de cacao en columnas de lecho fijo. Se realizó un estudio hidrodinámico en el que se variaron el diámetro y la altura de la columna, así como el diámetro y la masa del bioadsorbente, para determinar las mejores condiciones hidrodinámicas. El resultado fue un flujo de 2.12 mL/min a través de la columna. Los datos experimentales fueron ajustados a varios modelos en función del volumen del efluente, los cuales describen la curva de ruptura para sistemas mono y bicomponentes. Los porcentajes de remoción de Pb+2 y Cd+2 en sistemas monocomponentes fueron de 91 y 90 %, respectivamente. En sistemas bicomponentes (Pb+2-Cd+2) el porcentaje de remoción de plomo y cadmio fue de 88 y 90 %, respectivamente. El modelo de dosis-respuesta en sistemas bi y monocomponentes fue el que mejor reprodujo las curvas de ruptura experimentales en todo el rango medido
ANALYTICAL PERFORMANCE OF MICROWAVE ASSISTED SOLVENT EXTRACTION (MASE) FOR ROUTINE DETERMINATION OF PAHs IN POLLUTED SOILS BY GAS CHROMATOGRAPHIC-MASS SPECTROMETRY (GC-MS).
Get PDFThe extraction of polycyclic aromatic hydrocarbons (PAHs) from polluted soil samples using microwave-assisted solvent extraction (MASE) with subsequent determination by gas chromatography-mass spectrometry (GC-MS) was investigated. The optimum conditions for the extraction were established and, after cleansing the extracts, pollutants were quantified by GC-MS. The detection limits for the 16 USEPA members of the family, analysis time, precision and linear range of the analysis were also established. The proposed extraction methodology was compared with the most conventional Soxhlet extraction technique, and validated by applying MASE to a reference soil sample. Good recoveries for the majority of PAHs (when the calibrations were carried out by using internal standards), a significant shortening of the time of analysis and the volume-reduction of solvent used were observed. Therefore, the MASE sample preparation methodology is a very good alternative to the extraction of PAHs from soil samples before final determination by GC-MS.The extraction of PAHs from polluted soil samples using Microwave Assited Solvent Extraction (MASE) with subsequent determination by Gas Chromatography-Mass Spectrometry (GC-MS) was investigated. Optimum conditions for the extraction are established and after the cleansing of extracts, those pollutants were quantified by GC-MS. Detection limits for the 16 US-EPA members of the family, analysis time, precision and linear range of the analysis have been also established. The proposed extraction methodology was compared with the most conventional Soxhlet extraction technique, and validated by applying the MASE to a reference soil sample. Good recoveries for the majority of PAHs (when calibrations were carried out by using internal standards), significant shortening time of analysis and reduction of volume of solvent used were observed. Thus, the MASE sample preparation methodology constitutes a very good alternative to extraction of PAHs from soil samples before the final determination by GC-MS
SOLUBILIZACIÓN DE FUENTES INORGÁNICAS DE FÓSFORO POR MICROMICETOS AISLADOS DE LA RIZOSFERA DE PAPAYA VAR. MARADOL (Carica papaya L.) Y SU SUSCEPTIBILIDAD A HERBICIDAS CONVENCIONALES
Get PDFA high amount of phosphorus content (P) from the inorganic fertilizers that are applied in papaya var. Maradol orchards (Carica papaya) is precipitated within the soil cations (Ca2+, Mg2+, Fe3+ y Al3+), resulting in an immobilized and unavailable P for plants. An alternative to release immobilized P is the use of P-solubilizing microfungi (PSMF). However, these microorganisms are susceptible to herbicide residues in soils. The objectives of this study were to isolate PSMF from the rhizosphere of C. papaya plants (var. “Maradol”), to evaluate in semisolid and liquid fermentation their ability to solubilize both Ca3(PO4)2 and FePO4, and to determine their susceptibility to glyphosate and 2,4-D herbicides. In 15 isolates, qualitatively the SP5 isolate was the best solubilizer of Ca3(PO4)2 with a solubilization index (SI) of 5.6, while the highest SI (1.4) for FePO4 was achieved by Beauveria bassiana SP9. In liquid fermentation, Penicillium sp. SP1 (108.5 mg/L) and Penicillium hispanicum SP16 (106.5 mg/L) solubilized at 100 % the Ca3(PO4)2. In addition, P. hispanicum SP16 solubilized the highest amount of FePO4 with 39.6 mg/L. Penicillium hispanicum SP16 resulted tolerant to glyphosate with a mean lethal concentration of (LC50) of 5376.0 mg/L, a greater value than the field application rate (1836 mg/L); however, it was susceptible to 2,4-D with a LC50 of 3256.0 mg/L, which was a smaller value than the field application recommended rate (3705.0 mg/L). Carica papaya rhizosphere host PSMF with potential to develop biofertilizers, if we take into account their ability to solubilize inorganic P sources (Ca3[PO4]2 and FePO4) and their tolerance to conventional herbicides (glyphosate and 2,4-D).Gran parte del fósforo (P) contenido en los fertilizantes inorgánicos aplicados al cultivo de papaya var. Maradol (Carica papaya L.) se inmoviliza al precipitarse con algunos cationes del suelo (Ca2+, Mg2+, Fe3+ y Al3+), quedando indisponible para las plantas. Una alternativa para dejar el P nuevamente disponible es el uso hongos microscópicos solubilizadores de este elemento (HMSP). Sin embargo, estos microorganismos son susceptibles a residuos de herbicidas en los suelos. Los objetivos de este estudio fueron aislar HMSP de la rizosfera de Carica papaya, evaluar en cultivo semisólido y líquido su habilidad para solubilizar Ca3(PO4)2 y FePO4, y determinar su susceptibilidad a los herbicidas glifosato y 2,4-D. De los 15 aislamientos obtenidos, SP5 solubilizó cualitativamente mejor el Ca3(PO4)2 con un índice de solubilización (IS) de 5.6, mientras que el mayor IS (1.4) para FePO4 se observó con Beauveria bassiana SP9. En fermentación líquida, Penicillium sp. SP1 (108.5 mg/L) y Penicillium hispanicum SP16 (106.5 mg/L) solubilizaron al 100 % el Ca3(PO4)2, en tanto que P. hispanicum SP16 solubilizó la mayor cantidad de FePO4 con 39.6 mg/L. En los análisis de exposición de los HMSP a herbicidas, P. hispanicum SP16 resultó tolerante al glifosato al obtener una concentración letal media (CL50)de 5376.0 mg/L, valor mayor a la dosis aplicada en campo (1836 mg/L); sin embargo, fue susceptible al 2,4-D al obtener una CL50 de 3256.0 mg/L, valor menor a la dosis aplicada en campo (3705.0 mg/L). La rizosfera de C. papaya alberga HMSP con potencial para el desarrollo de biofertilizantes, tomando en cuenta su capacidad para solubilizar fuentes inorgánicas de P (Ca3[PO4]2 y FePO4) y tolerancia a herbicidas convencionales (glifosato y 2,4-D)
DISTRIBUCIÓN ESPACIAL DE Fe Li, Pb, Mn, V, y Zn EN SUELOS URBANOS DE MORELIA, MICHOACÁN, MÉXICO
Get PDFMorelia, Michoacán, Mexico is the most populated city in the state of Michoacán, with high vehicular traffic and little industrialization. In Morelia, the presence of potentially toxic elements (PTE) has been reported in urban soils, among which Fe, Mn, Pb and V exceeded the limits established by the Mexican and US environmental standards. For the decision making it is necessary the location of the sites of greater contamination by the elaboration of maps with the spatial distribution of the PTE. The principal aim of this work was to analyze the spatial distribution of Fe, Li, Mn, Pb, V and Zn in the urban soils of Morelia to identify the areas with the highest concentration. In total, one hundred of top soil samples were collected. The analysis of the PTE was performed by inductively coupled optical plasma spectrometry. A geostatistical analysis was performed with ordinary kriging (OK) to know the distribution of PTE and with indicator kriging to identify the areas with the highest probability of contamination.The models of the variograms of Fe, Mn, Li and Zn with OK yielded values of R2 ≥ 0.8. The areas most likely to exceed environmental norms are: the dowtown for Fe and Pb, the east by Fe and V, the southwest by Mn and the west by Fe. In the downtown and east of the city there is the greatest contamination.Morelia Michoacán, México es la ciudad más poblada del estado Michoacán, con alto tráfico vehicular y poca industrialización. En Morelia se ha reportado la presencia de elementos potencialmente tóxicos (EPT) en los suelos urbanos entre los cuales el Fe, Mn, Pb y V rebasaron los límites establecidos por las normas ambientales mexicanas y estadounidenses. Para la toma de decisiones se requiere la localización de los sitios de mayor contaminación mediante la elaboración de mapas con la distribución espacial de los EPT. El objetivo de este trabajo fue analizar la distribución espacial de Fe, Li, Mn, Pb, V y Zn en los suelos urbanos de Morelia para identificar las zonas de mayor concentración. Se colectaron cien muestras de suelo superficial. La concentración de los EPT fue medida con espectrometría de plasma acoplado inductivamente de tipo óptico. Se hizo un análisis geoestadístico con kriging ordinario (KO) para conocer la distribución de los EPT y con kriging indicador (KI) para identificar las zonas con mayor probabilidad de contaminación. Los variogramas del Fe, Mn, Li y Zn con KO mostraron valores de R2 ≥ 0.8. Las zonas con mayor probabilidad de rebasar las normas ambientales son: el centro por Fe y Pb, el este por Fe y V, el suroeste por Mn y el oeste por Fe. En el centro y este de la ciudad existe la mayor contaminación