Revista Internacional de Contaminación Ambiental
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Memorias 1er Congreso Internacional de Ingeniería Ambiental (CIAMB): Perspectivas para la Sustentabilidad
No full textActividad enzimática ligninolítica de dos poblaciones de Ganoderma spp. en interacción con Trichoderma spp.
Get PDFThe objectives of the present study were to evaluate the ligninolytic enzymatic activity (LEA = laccase, manganese peroxidase [MnP] and lipase peroxidase [LiP]) of two Ganoderma spp. populations (ruderal and urban), determine the type of fungal interaction of each population in co-cultures with Trichoderma spp. strains, and quantify the LEA in the interactions. Seven ruderal and seven urban strains were isolated, their daily growth rate (DGR) and LEA were determined and compared. With three strains from each population with the best DGR, co-cultures with three Trichoderma spp. strains were established (T85, T98 and T99). Ruderal strains produce more MnP and LiP activities, but have lower DGR compared to urban strains. Laccase activity was the same in both populations. The most common interaction between Ganoderma spp. and Trichoderma spp. was the inhibition at contact. Ruderal strains of Ganoderma spp. (4R and 9R) when grown in monoculture did not show MnP activity; however, when they interact with Trichoderma spp., MnP was present (between 150 to 3000%) and increased LiP (between 13 to 51%) activities. In urban strains of Ganoderma spp. laccase (between 8 to 183%), MnP (between 24 to 144%) and LiP (between 5 to 6268%) activities increased in interactions with Trichoderma spp. The LEA in each population was variable, the most common interaction between Ganoderma spp. and Trichoderma spp. was block at contact with significant increases in LEA.Los objetivos del presente estudio fueron evaluar la actividad enzimática ligninolítica (AEL = lacasa, manganeso peroxidasa [MnP]) y lipasa peroxidasa [LiP]) de dos poblaciones de Ganoderma spp. (ruderal y urbana), determinar el tipo de interacción fúngica de cada población en cocultivos con cepas de Trichoderma spp. y cuantificar la AEL en las interacciones. Se aislaron siete cepas ruderales y siete urbanas, se determinó y comparó su tasa de crecimiento diario (TCD) y su AEL. Con tres cepas de cada población con mejor TCD, se establecieron cocultivos con tres cepas de Trichoderma spp. (T85, T98 y T99). Las cepas ruderales presentaron más actividad MnP y LiP, pero menor TCD en comparación con las cepas urbanas. La actividad de la lacasa fue igual en ambas poblaciones. La interacción más común entre Ganoderma spp. y Trichoderma spp. fue la inhibición al contacto. Las cepas ruderales de Ganoderma spp. (4R y 9R) cuando crecen en monocultivo no presentaron actividad MnP; sin embargo, cuando interactúan con Trichoderma, la MnP se presentó (entre 150 a 3000 %) e incrementó la LiP (entre 13 al 51 %). En cepas urbanas de Ganoderma spp. la actividad lacasa (entre 8 a 183 %), MnP (entre 24 a 144 %) y LiP (entre 5 a 6268 %) aumentó en las interacciones con Trichoderma. La AEL en cada población fue variable, la interacción más común entre Ganoderma spp. y Trichoderma spp. fue el bloqueo al contacto con incrementos significativos en la AEL
Evaluation of China’s provincial eco-efficiency with the explainable boosting machine (EBM) model and Tobit regression
Get PDFThe explainable boosting machine (EBM) model measures China’s provincial eco-efficiency, and the Tobit regression model reveals internal driving factors to provide consultation for promoting China’s green development based on the panel data of 30 provinces from 2000 to 2018. The findings of this article are as follows: provincial-level regional ecological efficiency is low, growth is slow, regional differentiation is significant, and development still has a trend of incoordination and multi-polarization. From the perspective of global autocorrelation, the Moran index is significantly positive, and the province eco-efficiency of the first grade presents a positive spatial correlation and has the characteristics of spatial agglomeration. The regression analysis results show that the economic level, the FDI, the level of technological innovation, and the level of human capital are the main influencing factors of eco-efficiency, and there are spatial differences. Relevant suggestions are based on the status and influencing factors of the unbalanced development heterogeneity of provincial eco-efficiency in China
Analysis of the potential of the electroactive biofilm growth in a microbial fuel cell type H (Fabricio Espejel and Reyna García, Editors)
No full textMicrobial fuel cells (MFC) constitute an attractive alternative as an environmental remediation technology since they can generate electrical current using organic waste as a substrate. Since the performance of MFCs depends on the characteristics of the biofilm on the anode surface, it is important to assess the genetic information of the microorganisms that grow on the electrode. For this purpose, a sewage sludge sample was obtained from a wastewater treatment plant and used to inoculate a type H MFC. Electrochemical characterization, on one hand, indicates that while the biofilm has a typical electrochemical performance reflected by the generated voltage (near 0.4 V) and by the electroactivity observed in cyclic voltammetry experiments, and on the other hand, the metagenomic analysis shows that the most abundant genera are Pseudomonacea, Nitrosomonas, Hyphomonas, and Opitutus. The study also indicates that the biofilm’s electroactive microorganisms can metabolize amino acids, lipids, and carbohydrates and possess genetic tools for ionic transport and energy production. Regarding the electron acceptor/donator capabilities, several oxidases, reductases, and complexes were identified, mainly terminal cytochrome C oxidase and respiratory complex I, which could be associated with the exoelectrogenic capacity of the microorganisms. Finally, the metagenomic information indicates that the biofilm can synthesize rhamnose, sialic acid, and alginate molecules, which could possibly be associated with the formation and consolidation of the microbial biofilm.Microbial fuel cells (MFC) constitute an attractive alternative as an environmental remediation technology since they can generate electrical current using organic waste as a substrate. Since the performance of MFCs depends on the characteristics of the biofilm on the anode surface, it is important to assess the genetic information of the microorganisms that grow on the electrode. For this purpose, a sewage sludge sample was obtained from a wastewater treatment plant and used to inoculate a type H MFC. Electrochemical characterization, on one hand, indicates that while the biofilm has a typical electrochemical performance reflected by the generated voltage (near 0.4 V) and by the electroactivity observed in cyclic voltammetry experiments, and on the other hand, the metagenomic analysis shows that the most abundant genera are Pseudomonacea, Nitrosomonas, Hyphomonas, and Opitutus. The study also indicates that the biofilm’s electroactive microorganisms can metabolize amino acids, lipids, and carbohydrates and possess genetic tools for ionic transport and energy production. Regarding the electron acceptor/donator capabilities, several oxidases, reductases, and complexes were identified, mainly terminal cytochrome C oxidase and respiratory complex I, which could be associated with the exoelectrogenic capacity of the microorganisms. Finally, the metagenomic information indicates that the biofilm can synthesize rhamnose, sialic acid, and alginate molecules, which could possibly be associated with the formation and consolidation of the microbial biofilm
Variación en profundidad de las propiedades de un suelo de textura arenosa enmendado superficialmente con estiércol o biosólidos
Get PDFThe uncontrolled accumulation of livestock or urban waste may threaten the environment. Although the use of manure or biosolids as an organic amendment improves soil physical, chemical, and biological properties, it may introduce certain trace elements (ET) into soils. Due to the fact that some soil properties may be modified in depth with the application of waste of biological origin, the objective of this work was to study the vertical variation of pH, electrical conductivity, and organic and inorganic carbon content dissolved in a disturbed soil of sandy texture superficially amended with cow manure, biosolids and biosolids plus ash. Soil columns were used. The three amendments originated a significant increase in pH and EC in the superficial layer (0-1.7 cm) compared to control. The concentration of dissolved organic carbon (COD) was significantly higher (22-72%) in the upper layer of the amended soil columns compared to control. Manure treatments presented a significantly higher COD concentration in all layers compared to biosolids or biosolids plus ash treatments, suggesting that manure’s organic matter presented a higher degree of mineralization than the corresponding to the other two amendmentsLa acumulación incontrolada de residuos de origen pecuario o urbano es una problemática que puede provocar problemas en el ambiente. Si bien la utilización de estiércol o biosólidos como enmienda orgánica mejora las propiedades físicas, químicas y biológicas de los suelos, puede introducir ciertos elementos traza (ET) a los suelos. Debido a que algunas propiedades edáficas pueden modificarse en profundidad con la aplicación de residuos de origen biológico, el objetivo de este trabajo fue estudiar la variación vertical del pH, la conductividad eléctrica (CE) y el contenido de carbono orgánico e inorgánico disuelto en un suelo de textura arenosa enmendado superficialmente con estiércol vacuno, biosólidos y biosólidos más cenizas. Se utilizaron columnas de suelo disturbado y se observó que las tres enmiendas generaron un incremento significativo de pH y CE con respecto al testigo en el estrato superficial (0-1.7 cm). La concentración de carbono orgánico disuelto (COD) fue significativamente más elevada (22-72%) en el estrato superior en las columnas de suelo enmendadas con respecto al testigo. A su vez, los tratamientos con estiércol presentaron una concentración de COD significativamente más elevada en todos los estratos comparado con los tratamientos con biosólidos o biosólidos más cenizas, sugiriendo que la materia orgánica del estiércol presentó un mayor grado de mineralización que la correspondiente a las otras dos enmienda
Tagetes erecta y Azotobacter vinelandii inmovilizadas para la biorremediación de diésel en suelos agrícolas
Get PDFThe growing energy demand for oil and its derivatives has caused a high incidence of environmental events that negatively affect agroecosystems, so the study of biotechnological tools allows the reduction in agrochemicals, and the decontamination of the soil has been increasing. This research aimed to bioremediate agricultural soil contaminated with diesel using phytoremediation treatments with Tagetes erecta and bioaugmentation with free and immobilized Azotobacter vinelandii under greenhouse conditions. The bioremediation test lasted 50 days; subsequently, the heterotrophic microbial populations in colony-forming units (CFU/g) were quantified by serial dilution, plate count, and the residual concentration of hydrocarbons (mg/kg) by gravimetry. Finally, a genotoxicity and cytotoxicity assay using Allium sativum cells was performed. Bioremediation showed significant removal in all treatments with T. erecta, achieving removal percentages between 31.92 and 55.96 %. On the other hand, the association of T. erecta and free A. vinelandii presented the highest increase in total heterotrophic microorganisms with 3.83 × 1010 UFC/g in soil (p = 0.00). Similarly, the morphological parameters of Tagetes erecta were evaluated using the Dickson Quality Index, revealing an optimal value for treatments with plants without alginate beads (p = 0.02). However, a cytotoxic and genotoxic effect was observed in all treatments (Mitotic index ≤ 50 %, χ2 ≥ 3.84, respectively), pointing out the importance of toxicity studies in bioremediation tests.La creciente demanda energética del petróleo y sus derivados ha ocasionado una alta incidencia de eventos ambientales que afectan negativamente los agroecosistemas, por lo que el estudio de herramientas biotecnológicas que permitan la descontaminación promete ser una alternativa sostenible. El objetivo de esta investigación fue evaluar la biorremediación de suelos agrícolas contaminados con diésel utilizando tratamientos de fitorremediación con Tagetes erecta y bioaumentación con Azotobacter vinelandii (libre e inmovilizada) en condiciones de invernadero. El ensayo de biorremediación tuvo una duración de 50 días. Las variables de respuesta fueron: bacterias totales heterótrofas en unidades formadoras de colonias (UFC/g), variables morfológicas de las plantas e hidrocarburos totales del petróleo (mg/kg). La toxicidad de los suelos biorremediados se evaluó por ensayos de genotoxicidad y citotoxicidad utilizando células de Allium sativum. La biorremediación mostró remoción significativa en todos los tratamientos con T. erecta, logrando porcentajes de remoción de 31.92 a 55.96 %. Por otra parte, la asociación de T. erecta y A. vinelandii libre presentó el mayor incremento de microorganismos heterótrofos totales con 3.83 × 1010 UFC/g de suelo (p = 0.00). En los parámetros morfológicos de Tagetes erecta el índice de calidad de Dickson, mostró un valor óptimo para los tratamientos con plantas (p = 0.02). No obstante, se observó efecto citotóxico y genotóxico en todos los tratamientos (índice mitótico ≤ 50 %, χ2 ≥ 3.84, respectivamente)
Mineralization of microalgal carbon and nitrogen in sodic soils
Get PDFSodic soils pose a challenge for the agricultural production due to their lack of nutrients, poor structure, low organic matter content, and susceptibility to erosion (water and wind). Their recovery is carried out by soil washing and applying calcium salts, which are sometimes unprofitable processes. A low-cost and environmentally friendly alternative to remedy adverse soil conditions is bioremediation using microorganisms or organic amendments. For this reason, this study intended to evaluate the effects of the addition of dry microalgal biomass on sodic soils and suggest its use as an organic amendment. The effect of the microalgal biomass was studied through the mineralization dynamics of carbon and nitrogen sources in short-term experiments. All experiments were performed at laboratory scale. Microalgal biomass was obtained from a consortium grown in dairy wastewater and subsequently dried and pulverized. Four different treatments of dry microalgal biomass were applied to 50 g of sodic soil, and high microbial activity was observed in the soil (obtaining a production of 240 mg C-CO2/kg dry soil), along with the production of nitrates (presenting values 33.8-1.45 mg N-NO3+/kg dry soil) via the release of ammonia (obtaining 5.46 mg N-NH3+/kg dry soil), and mineralization of organic N into ammonium (producing 1071.92 mg N-NH4+/kg dry soil). The microalgal biomass as an organic amendment showed to be prone to mineralization and release of carbon and nitrogen sources, improving the microbial activity in a soil with sodicity problems.Sodic soils pose a challenge for the agricultural production due to their lack of nutrients, poor structure, low organic matter content, and susceptibility to erosion (water and wind). Their recovery is carried out by soil washing and applying calcium salts, which are sometimes unprofitable processes. A low-cost and environmentally friendly alternative to remedy adverse soil conditions is bioremediation using microorganisms or organic amendments. For this reason, this study intended to evaluate the effects of the addition of dry microalgal biomass on sodic soils and suggest its use as an organic amendment. The effect of the microalgal biomass was studied through the mineralization dynamics of carbon and nitrogen sources in short-term experiments. All experiments were performed at laboratory scale. Microalgal biomass was obtained from a consortium grown in dairy wastewater and subsequently dried and pulverized. Four different treatments of dry microalgal biomass were applied to 50 g of sodic soil, and high microbial activity was observed in the soil (obtaining a production of 240 mg C-CO2/kg dry soil), along with the production of nitrates (presenting values 33.8-1.45 mg N-NO3+/kg dry soil) via the release of ammonia (obtaining 5.46 mg N-NH3+/kg dry soil), and mineralization of organic N into ammonium (producing 1071.92 mg N-NH4+/kg dry soil). The microalgal biomass as an organic amendment showed to be prone to mineralization and release of carbon and nitrogen sources, improving the microbial activity in a soil with sodicity problems
Síntesis de carbones activados con semillas de chirimoya y su aplicación en la adsorción de colorantes textiles
Get PDFThis work describes the preparation of five activated carbons from a vegetable waste: custard apple seeds (Annona cherimola). All carbons were chemically activated with phosphoric acid. Three of them were calcinated at 673 K (CarChiQ, CarChiQE, and CarChiQC) and the other two (CarChiQE600 and CarChiQC600) at 873 K for three hours. The carbons were characterized by nitrogen adsorption, methylene blue number, bulk density, scanning electron microscopy, and infrared spectroscopy. In addition, the point of zero charge indicated the acid character of the carbons. To establish the contact time between the solutions of dye and the carbons, the adsorption kinetics of methylene blue dye was followed. The adsorption kinetics for all the carbons fit the pseudo second order model. The adsorption of aqueous solutions containing anionic and cationic dyes with an initial concentration of 300 mg/dm3 was studied. It was found that, using CarChiQ, basic dyes were adsorbed in percentages ranging between 82 and 99.9 %; with CarChiQE, between 65 and 92 %; and using CarChiQC, CarChiQE600, and CarChiQC600, the adsorption almost reached 100 %. The acid dye was adsorbed in a smaller proportion, but in CarChiQE600 and CarChiQC600, its adsorption was total. A wastewater containing textile dyes was treated, and its quality was improved after the adsorption treatment. The chemical oxygen demand was reduced up to 76 % and its color until 98 %.En este trabajo se describe la preparación de cinco carbones activados a partir de un residuo vegetal, la semilla de chirimoya (Annona cherimola). Todos los carbones fueron activados químicamente con H3PO4, tres de ellos se calcinaron a 673 K (CarChiQ, CarChiQC y CarChiQE) y los otros dos a 873 K (CarChiQC600 y CarChiQE600) por tres horas. Los carbones fueron caracterizados por adsorción de nitrógeno, número de azul de metileno, densidad aparente, microscopía electrónica de barrido y espectroscopía infrarroja. Además, se determinó el punto de carga cero que indicó el carácter ácido de todos los carbones. Se siguió la cinética de adsorción con el colorante azul de metileno, lo que permitió establecer el tiempo de contacto entre las soluciones de colorante y los carbones. La cinética de adsorción para los carbones se ajustó al modelo de pseudo segundo orden. Se estudió la adsorción de soluciones acuosas de colorantes textiles de tipo ácido y básico con una concentración inicial de 300 mg/dm3. Los colorantes básicos se adsorbieron en CarChiQ entre 82 y 99.9 %, en CarChiQE entre 65 y 92 % y en CarChiQC, CarChiQC600 y CarChiQE600 prácticamente se adsorbieron 100 %. El colorante ácido se adsorbió en menor proporción sobre los carbones, con excepción de CarChiQC600 y CarChiQE600 con adsorción total. Se trató un agua residual conteniendo colorantes textiles, la calidad de ésta mejoró después del tratamiento de adsorción, reduciéndose la demanda química de oxígeno hasta 76 % y el color hasta 98 %
Identificación y evaluación de riesgos ambientales en un astillero: enfoque en fuentes de riesgo y sustancias potencialmente peligrosas
Get PDFAccording to the UNE 150008:2008 standard, the use of environmental risk analysis is proposed to improve the environmental performance of a shipyard and prevent pollution. The methodology used includes identifying risk sources, potentially hazardous substances, and cause-and-effect scenarios. The resulting evaluation is used to quantify and classify the risks associated with shipyard activities, allowing for prioritization of efforts and the establishment of environmental objectives.Se propone el uso del análisis de riesgos ambientales acorde con la norma UNE 150008:2008 para mejorar el desempeño ambiental de un astillero y prevenir la contaminación. La metodología empleada incluye la identificación de fuentes de riesgo, sustancias potencialmente peligrosas y escenarios de causas y consecuencias. La evaluación resultante se utiliza para cuantificar y clasificar los riesgos asociados a las actividades del astillero, lo que permite priorizar los esfuerzos y establecer objetivos ambientales
Producción de briquetas a partir de residuos biomásicos
Get PDFInnovating in the use of renewable energy is a challenge facing the world, given the depletion of fossil resources and climate change. Biomass is a versatile key bioenergy, being used in simple combustion processes, up to complex pyrolysis processes such as torrefaction, where products such as methane (CH4), syngas and torrefacted biomass are obtained, the latter with characteristics that facilitate its use as fuel. In this study, biomass residues of pine sawdust (ADP) and blueberry pruning (PDA) were used, through torrefaction processes to obtain torrefacted biomass (BT) as the main product to make briquettes. This work is based on an experimental design of 3 factors and 2 levels, which are: torrefaction temperature at 280 and 310 ºC, catalyst or without catalyst in the produced gas, and the type of biomass: ADP and PDA, applying an analysis of variance to verify the importance of the factors. With BT, briquettes were made in mixtures of BT-ADP and BT-PDA, using water as a binder, characterizing them through their humidity, proximals, and calorific value. The results showed that BT presents yields around 55-70%, with a maximum conversion when ADP is used at 280 ºC, without catalyst. The CH4 as a secondary product has a yield of 0.38%, obtained with ADP at 310 ºC, with catalyst. briquettes synthesis was possible in the mixtures of 60% BT–40% ADP, with 40% by weight of water and 60% BT–40% PDA, with 55% by weight of water.La innovación en el aprovechamiento de energías renovables es un reto mundial, dado el agotamiento de recursos fósiles y el cambio climático. La biomasa es un bioenergético clave y versátil, utilizándose desde procesos simples de combustión hasta en procesos complejos como la torrefacción, de la cual se obtienen principalmente metano (CH4), syngas y biomasa torrefactada, esta última con características que facilitan su uso como combustible. En este estudio se aprovechan residuos biomásicos de aserrín de pino (ADP) y poda de arándano (PDA), mediante procesos de torrefacción para obtener biomasa torrefactada (BT) para elaborar gránulos. Para ello se realizó un diseño experimental de tres factores y dos niveles: temperatura en la torrefacción (280 y 310 ºC), catalizador (con catalizador y sin catalizador en el gas producido), y tipo de biomasa (ADP y PDA), aplicando un análisis de varianza para verificar la importancia de los factores. Con la BT se elaboraron briquetas en mezclas de BT-ADP y BT-PDA, utilizando como aglutinante agua, caracterizándolos a través del poder calorífico, humedad y proximales. Los resultados muestran que la BT presenta rendimientos alrededor del 55-70 %, con una conversión máxima cuando se utiliza ADP a 280 ºC, sin catalizador. El CH4 como producto secundario tiene rendimientos de 0.38 %, obtenido con ADP a 310 ºC, con catalizador. La formación de gránulos se posibilitó en las mezclas de 60 % BT-40 % ADP, con 40 % en peso de agua y 60 % BT–40 % PDA, con agua al 55 % en peso.
Los resultados muestran que la BT presenta rendimientos alrededor del 55-70 %, con una conversión máxima cuando se utiliza ADP a 280ºC, sin catalizador. El CH4 como producto secundario tiene rendimientos de 0.38 %, obtenido con ADP a 310ºC, con catalizador. La peletización se posibilitó en las mezclas de 60 % BT-40 % ADP, con 40 % en peso de agua y 60 % BT–40 % PDA, con agua al 55% en peso