Revista Internacional de Contaminación Ambiental
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Determinación histórica de índices de calidad del agua en observatorios participativos en el norte de México
Get PDFThe Water Quality Indices (WQI) are tools that help to communicate the status of quality to a non-specialized audience, they are based on the existing regulations of the region. The objective of this project was to determine the WQI in five Participatory Observatories (PO) located in the north of Mexico, in addition to generating maps and charts that present information in a concrete and clear way on water quality and risk areas. Using data from the Comisión Nacional del Agua, the water quality was evaluated with the León and Canadian Council of Ministers of the Environment indices, as well as the microbiological quality based on fecal coliform reports. PO sites are classified, in terms of microbiological quality, from “excellent” to “heavily contaminated”. Under the permissible limits by the official Mexican standards for water for human consumption and agricultural irrigation, a relative scale was applied with a score of 0 to 100, for the indices determined in the POs. The results indicate, through the maps developed in the study, the presence of three microbiologically contaminated sites. Regarding the quality required for human consumption, the Canadian index classifies the quality of the water as “poor” in all the sites studied, while the León index classifies it on the scale of “contaminated” to “slightly contaminated”. Both indices indicate the imperative need for treatment before being used for human consumption.Los índices de calidad del agua (ICA) son herramientas para comunicar la calidad del agua a una audiencia no especializada, basándose en los datos del monitoreo de los cuerpos de agua. El objetivo de este proyecto fue determinar el ICA en cinco observatorios participativos (OP) ubicados en el norte de México, además de generar mapas y cuadros que presenten la información de forma concreta y clara sobre la calidad del agua y zonas de riesgo. Utilizando los datos de la Comisión Nacional del Agua se determinó la calidad de agua con los índices de León y del Consejo Canadiense de Ministros de Medio Ambiente, así como la calidad microbiológica con base en los reportes de coliformes fecales. Se clasificaron los sitios de los OP, en cuanto a la calidad microbiológica, de “excelente” a “fuertemente contaminada”. De acuerdo con los límites permisibles por las normas oficiales mexicanas para agua de consumo humano y riego agrícola, se aplicó una escala relativa con un puntaje de 0 a 100, para los índices determinados en los OP. Los resultados indican a través de los mapas desarrollados en el estudio, la presencia de tres sitios fuertemente contaminados microbiológicamente. En lo referente a la calidad requerida para consumo humano, el índice canadiense califica la calidad del agua como “pobre” en todos los sitios estudiados, mientras que el índice de León la clasifica en la escala de “contaminada” a “levemente contaminada”. Ambos índices indican la necesidad imperiosa de un tratamiento antes de ser destinada al uso de consumo humano
Calidad agronómica de las aguas residuales en los distritos de riego Tula y Alfajayucan
Get PDFWastewater provides nutrients for crops and increases the volume of water available for irrigation, but it represents risks such as salinization and sodification of soils, toxicity to plants, and risks to human health. With the objective of identifying the risks of salinization and sodification of soils in the irrigation districts Tula and Alfajayucan, the physical and chemical characterization of 70 water samples taken from canals, rivers, dams, and springs was carried out. The analysis of the parameters pH and electrical conductivity (EC) was carried out, and the concentration of the next ions was determined: Ca2+, Mg2+, Na+, K+, CO32–, HCO3–, Cl–, SO42–, B and PO43–. Only 5.7 % of the sampled sites have good agronomic water quality, according to the EC; Na+, HCO3– and Cl– predominate in all the sampled sites, which give rise to the formation of NaHCO3 and NaCl salts, which are toxic to most crops; there is a risk of infiltration reduction in 65.7 % of the sampled sites; in 87.1 % of the sites, boron is found in concentrations that can be toxic to crops, and in 48.6 % the concentration of 2 mg/L of orthophosphates is exceeded. With the parameters evaluated, it is concluded that the agronomic quality of the water used in Tula and Alfajayucan irrigation districts is deficient, due to the high risks of salinization and sodification of the soil, as well as toxicity to crops.Las aguas residuales aportan nutrientes para los cultivos y aumentan el volumen de agua disponible para el riego, pero representan contingencias como la salinización y sodificación de los suelos, toxicidad en las plantas y riesgos para la salud humana. Con el objetivo de identificar los riesgos de salinización y sodificación de los suelos en los distritos de riego Tula y Alfajayucan, se realizó la caracterización física y química de 70 muestras de agua tomadas en canales, ríos, presas y manantiales. Se realizó el análisis de los parámetros pH y conductividad eléctrica (CE), y se determinó la concentración de los iones Ca2+, Mg2+, Na+, K+, CO32–, HCO3–, Cl–, SO42–, B y PO43–. Solo el 5.7 % de los sitios muestreados tiene buena calidad agronómica, de acuerdo con la CE; en todos los sitios muestreados predominan los iones Na+, HCO3– y Cl–, que dan lugar a la formación de las sales NaHCO3 y NaCl, que son tóxicas para la mayoría de los cultivos; existe riesgo de reducción en la infiltración del agua en el suelo en el 65.7 % de los sitios muestreados; en el 87.1 % de los sitios, el boro se encuentra en concentraciones que pueden ser tóxicas para los cultivos, y en el 48.6 % se supera la concentración de 2 mg/L de ortofosfatos. Con los parámetros evaluados, se concluye que la calidad agronómica de las aguas utilizadas en los distritos de riego Tula y Alfajayucan es deficiente, por los riesgos altos de salinización y sodificación del suelo, así como de toxicidad para los cultivos
The environmental quality inspection model of the construction of sea crossing bridges with based on the evolutionary game theory
Get PDFIn order to reduce the impact of sea crossing bridge construction on the environment, it is necessary to adopt the method of multi-party supervision to detect the environmental quality in the construction process. Therefore, this paper constructs an environmental quality inspection model of cross-bridge construction based on evolutionary game theory. The model includes the physical means detection model between the government, the public, and construction enterprises and the tripartite evolutionary game supervision model. A reasonable test method is chosen according to the actual situation, game monitoring on the environmental quality of bridge construction is conducted, and the monitoring points are carefully arranged. Finally, the government needs to improve the basic system of pollution management, put forward effective supervision strategies, strengthen supervision measures, establish a pollution evaluation system, and punish enterprises that do not actively control pollution. The construction environmental quality of the sea crossing bridge is obtained through the actual detection, and the supervision improvement strategy is analyzed through the game model.In order to reduce the impact of sea crossing bridge construction on the environment, it is necessary to adopt the method of multi-party supervision to detect the environmental quality in the construction process. Therefore, this paper constructs an environmental quality inspection model of cross-bridge construction based on evolutionary game theory. The model includes the physical means detection model between the government, the public, and construction enterprises and the tripartite evolutionary game supervision model. A reasonable test method is chosen according to the actual situation, game monitoring on the environmental quality of bridge construction is conducted, and the monitoring points are carefully arranged. Finally, the government needs to improve the basic system of pollution management, put forward effective supervision strategies, strengthen supervision measures, establish a pollution evaluation system, and punish enterprises that do not actively control pollution. The construction environmental quality of the sea crossing bridge is obtained through the actual detection, and the supervision improvement strategy is analyzed through the game model
Cloning and analysis of the sequences of the super-selenium-rich plant Cardamine hupingshanensis
Get PDFWe employed a pair of universal primers for PCR amplification of Cardamine hupingshanensis leaf DNA collected from the soil of a unique selenium-rich deposit in Yutangba, Enshi, China. Then the PCR products were sequenced to obtain the 852-bp DNA sequences containing internal transcribed spacers (ITS). The ITS DNA sequences of different Cardamine species were aligned and spliced to obtain a “reference” sequence. Next, the base differences were compared between the ITS sequences of different Cardamine species and the “reference” sequence. Our results showed that Cardamine hupingshanensis had the greatest differences (17) compared with the “reference” sequence, much more than those between the ITS sequences of other Cardamine species and the “reference” sequence and 3.2 times higher than the average. It is speculated that some Cardamine species growing in selenium-rich regions of Enshi for a long time produce genetic variations that can adapt to high selenium soil stress and develop a super selenium enrichment capacity, thus evolving the new species Cardamine hupingshanensis. Therefore, we proposed the hypothesis of accelerated evolution of Cardamine hupingshanensis under high selenium soil stress.We employed a pair of universal primers for PCR amplification of Cardamine hupingshanensis leaf DNA collected from the soil of a unique selenium-rich deposit in Yutangba, Enshi, China. Then the PCR products were sequenced to obtain the 852-bp DNA sequences containing internal transcribed spacers (ITS). The ITS DNA sequences of different Cardamine species were aligned and spliced to obtain a “reference” sequence. Next, the base differences were compared between the ITS sequences of different Cardamine species and the “reference” sequence. Our results showed that Cardamine hupingshanensis had the greatest differences (17) compared with the “reference” sequence, much more than those between the ITS sequences of other Cardamine species and the “reference” sequence and 3.2 times higher than the average. It is speculated that some Cardamine species growing in selenium-rich regions of Enshi for a long time produce genetic variations that can adapt to high selenium soil stress and develop a super selenium enrichment capacity, thus evolving the new species Cardamine hupingshanensis. Therefore, we proposed the hypothesis of accelerated evolution of Cardamine hupingshanensis under high selenium soil stress
Cáscara de cacahuate como material adsorbente para la remoción de iones de cobre y fluoruros
Get PDFLike many other pollutants that alter the quality of water bodies, copper and fluoride represent a risk to ecosystems and people’s health. To solve this problem, various adsorbent materials are used as an economical and efficient alternative in processes that seek to remove these elements from contaminated water. The process will also be environmentally friendly if the adsorbent materials are biodegradable, as with peanut shells. This project’s main objective is to apply peanut shells as an adsorbent material in copper removal processes and its subsequent reuse in fluoride removal. For this, the peanut shell is first used for copper removal, and the material with adsorbed copper is dried and used again for fluoride removal. Through mathematical models, it was determined that the adsorption was carried out by a combination of physical and chemical processes in both cases. According to the Langmuir model, the removal capacity was 31.1 mg/g for Cu2+, while for the removal of F–, it was 1.6 mg/g. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) characterize the peanut shell before and after the adsorption processes.Como muchos otros contaminantes que alteran la calidad de los cuerpos de agua, el cobre y el flúor, representan un riesgo para los ecosistemas y la salud de las personas. Para mitigar este problema diversos materiales adsorbentes se utilizan como una alternativa económica y eficiente en procesos que buscan remover estos elementos de aguas contaminadas. Si los materiales adsorbentes son biodegradables, como es el caso de la cáscara de cacahuate, el proceso será también amigable con el ambiente. El objetivo principal del presente proyecto es la aplicación de la cáscara de cacahuate como material adsorbente en procesos de remoción de cobre y su posterior reúso en la remoción de fluoruros. Para ello, la cáscara de cacahuate se utiliza primero para la remoción de cobre, el material con el cobre adsorbido se seca y se utiliza nuevamente para la remoción de fluoruros. Por medio de modelos matemáticos se determinó que la adsorción se llevó a cabo por una combinación de procesos físicos y químicos, en ambos casos. La capacidad de remoción, de acuerdo con el modelo de Langmuir, fue de 31.1 mg/g para el Cu2+ mientras que para la remoción de F– fue de 1.6 mg/g. La cáscara de cacahuate se caracterizó por medio de microscopía electrónica de barrido (MEB) y espectroscopía de fotoelectrones de rayos X (XPS) antes y después de los procesos de adsorción
First approach to microplastics occurrence in sandy beaches in the province of Islay (Arequipa), southern Peru
Get PDFPlastic pollution in marine and coastal environments has been widely recognized as a growing environmental concern. Plastic particles generated mainly by the degradation of larger plastic debris have been called microplastics (< 5 mm), which are being widely studied in all regions of the world. In South America there has been a constant increase of the research on this topic mainly on the Pacific coast. Specifically, in Peru, the number of publications has also increased, but the northern and southern zones are not well studied. Due to the importance of determining the presence of these contaminants, especially in coastal regions, which are considered as repository environments for these plastics, it is necessary to establish baselines of their current situation. This research aimed to determine and characterize the presence of microplastic particles (< 5 mm) on five sandy beaches in the province of Islay in southern Peru and to consider the possible effect of the Tambo River mouth on the transport and deposition of microplastics on two adjacent beaches. Three sampling stations were determined for each selected beach, consisting of three to two quadrants (1 m2) sampled at 5 cm depth. The results confirm the presence of microplastics. A total of 304 particles were found, with an average density between 1 to 4 part/m2. The areas with the highest concentration of microplastic particles and frequency of occurrence were the beaches adjacent to the river estuary where the most frequent types of particles were fragments and fibers, followed by foams and films, but no pellets.Plastic pollution in marine and coastal environments has been widely recognized as a growing environmental concern. Plastic particles generated mainly by the degradation of larger plastic debris have been called microplastics (< 5 mm), which are being widely studied in all regions of the world. In South America there has been a constant increase of the research on this topic mainly on the Pacific coast. Specifically, in Peru, the number of publications has also increased, but the northern and southern zones are not well studied. Due to the importance of determining the presence of these contaminants, especially in coastal regions, which are considered as repository environments for these plastics, it is necessary to establish baselines of their current situation. This research aimed to determine and characterize the presence of microplastic particles (< 5 mm) on five sandy beaches in the province of Islay in southern Peru and to consider the possible effect of the Tambo River mouth on the transport and deposition of microplastics on two adjacent beaches. Three sampling stations were determined for each selected beach, consisting of three to two quadrants (1 m2) sampled at 5 cm depth. The results confirm the presence of microplastics. A total of 304 particles were found, with an average density between 1 to 4 part/m2. The areas with the highest concentration of microplastic particles and frequency of occurrence were the beaches adjacent to the river estuary where the most frequent types of particles were fragments and fibers, followed by foams and films, but no pellets
Elaboración de carbón activado a partir de endocarpio de coco para la remoción de anaranjado de metilo en fase acuosa
No full textThis work shows the generation of activated carbon from coconut shells, using chemical activation with potassium hydroxide under an inert atmosphere. Kinetic adsorption studies were performed for four initial concentrations and equilibrium batch studies in a four-concentration range. For both studies, methyl orange solutions at 40, 80, 200, and 400 mg/L were used. The pseudo-second order model showed the best fit to describe the adsorption process for all the initial concentrations studied. From this result, graphs were plotted to determine the percentage of removal as a function of the amount of adsorbent and the contact time. The intramolecular diffusion model showed that it was not the only mechanism restricting the rate of adsorption. The linear Langmuir equation showed a good fit and calculated the maximum adsorption on the monolayer as 147.013 mg/g.En este trabajo se muestra el proceso de generación de carbón activado a partir de endocarpio de coco, utilizando hidróxido de potasio, en el procedimiento de activación química y en una atmósfera inerte. Se llevaron a cabo estudios de cinética de adsorción para cuatro concentraciones iniciales y estudios de equilibrio por carga en un rango de cuatro concentraciones, con soluciones de anaranjado de metilo a 40, 80, 200 y 400 mg/L para ambos estudios. Se determinó que el modelo cinético de pseudosegundo orden es el que mejor describió el proceso de adsorción en el tiempo para todas las concentraciones iniciales estudiadas. A partir de ese resultado se construyeron los gráficos respectivos para determinar el porcentaje de remoción en función de la cantidad de adsorbente y el tiempo empleado. El modelo de difusión intraparticular arrojó que éste no era el único que determinaba la velocidad del proceso. La expresión lineal de la isoterma de Langmuir muestra un buen ajuste de los datos, dando como resultado una capacidad máxima de adsorción de 147.01 mg/g
Tourism sustainability, Official Mexican Standards and the fulfillment of the human right to a healthy environment: Hydrocarbons, plastics, and bioremediation
Get PDFThe negative effects of tourism have led to urban, environmental, and social deterioration in various Mexican tourist destinations. Biotechnology can provide some technical alternatives for hydrocarbon and plastic pollution with promising results of bioremediation. However, the scientific approach apparently is insufficient due to the magnitude of environmental concerns regarding these materials. In this work, remediation and prevention are studied. Therefore, Official Mexican Standards that directly address environmental problems, particularly those generated by hydrocarbons and microplastics, are necessary.The negative effects of tourism have led to urban, environmental, and social deterioration in various Mexican tourist destinations. Biotechnology can provide some technical alternatives for hydrocarbon and plastic pollution with promising results of bioremediation. However, the scientific approach apparently is insufficient due to the magnitude of environmental concerns regarding these materials. In this work, remediation and prevention are studied. Therefore, Official Mexican Standards that directly address environmental problems, particularly those generated by hydrocarbons and microplastics, are necessary
Desarrollo de un método analítico para la determinación de las especies Cr(III) y Cr(VI) en medio acuoso
Get PDFChromium is present in nature mainly as Cr(III) and Cr(VI) species. Cr(III) is known as an essential trace element, whereas Cr(VI) presents acute toxicity. A chromatographic method (HPLC-ionic) was developed for the determination of both chromium species in contaminated aqueous medium during their treatment by phytoremediation. For this, the previous formation of the anionic complex [Cr(III)-EDTA]– was required. The ionic strength of the mobile phase was evaluated in isocratic mode, while the flow velocity and gradient time were evaluated in gradient mode. Cr(VI) showed a strong interaction with the stationary phase and the determination with 9.0 mM Na2CO3/3.0 mM NaHCO3 of greater ionic strength was adequate, whilst for Cr(III) determination was performed with 2.8 mM Na2CO3/3.4 mM NaHCO3. The use of a concentration gradient allowed for the separation and quantification of both species simultaneously with the appropriate conditions: mobile phase A: 2.8 mM Na2CO32-/3.4 mM NaHCO3 with the gradual introduction of B: 9.0 mM Na2CO3/3.0 mM NaHCO3, t = 0.5 min, flow rate of 1.5 mL/min, and sample volume of 50 μL. The use of HPLC-ionic represents an efficient, fast alternative with less environmental impact than conventional techniques with the remarkable advantage of the simultaneous determination of these species.El cromo está presente en la naturaleza principalmente como las especies Cr(III) y Cr(VI). El Cr(III) se conoce como oligoelemento esencial, mientras que el Cr(VI) presenta toxicidad aguda. Se desarrolló un método cromatográfico (HPLC-iónico) para la determinación de ambas especies de cromo en medio acuoso contaminado durante su tratamiento por fitorremediación. Para esto se requirió la formación previa delcomplejo aniónico [Cr(III)-EDTA]–. Se evaluó en modo isocrático la fuerza iónica de la fase móvil y en modo gradiente la velocidad de flujo y el tiempo de gradiente. El Cr(VI) presentó una fuerte interacción con la fase estacionaria, siendo adecuada la determinación con 9.0 mM Na2CO3/3.0 mM NaHCO3, de mayor fuerza iónica. Para Cr(III) la determinación fue con 2.8 mM Na2CO3/3.4 mM NaHCO3. Mediante el uso del gradiente de concentración se logró separar y cuantificar simultáneamente ambas especies en las siguientes condiciones: fase móvil A: 2.8 mM Na2CO3/3.4 mM NaHCO3 con introducción gradual de B: 9.0 mM Na2CO3/3.0 mM NaHCO3, a t = 0.5 min, velocidad de flujo de 1.5 mL/min y volumen de muestra de 50 μL. El uso de HPLC-iónico representa una alternativa eficiente, rápida y con menor impacto ambiental que las técnicas convencionales con la notable ventaja de la determinación simultánea de estas especies