Revista Internacional de Contaminación Ambiental
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Characterization of effluents from a tannery industry: a case study of Córdoba province, Argentina
No full textTannery effluents are considered to be severe pollutants around the world. The characterization of such effluents is a very important task in order to verify the compliance with legal requirements of the discharge and, if necessary, to optimize their treatment. In this study, we used the effluents from a local tannery (Córdoba, Argentina) that had implemented only a primary treatment. The effluents were periodically collected during one year to assess their physical, chemical, and microbiological characteristics, as well as their toxicity. The physical and chemical characteristics showed variations independently of the sampling time, although, in general, a high nutrient load was the most frequent finding. Moreover, parameters such as chemical oxygen demand, biochemical oxygen demand, total nitrogen, total phosphate, total phenols, Cr(VI) and settleable solids exceeded the limit set by the provincial legislation for the discharge of effluents into surface water bodies. The effluents were also characterized by a high count of bacteria, where pollutant-tolerant and some pathogenic bacteria were found. In sampling 9, Bacteroidetes, Firmicutes and Proteobacteria represented up to 93 % of the total number of sequences obtained, with Paludibacter, Tissierella Soehngenia, Proteocatella and Proteiniclasticum as the most abundant genera. In concordance with these results, all samples showed toxicity according to L. sativa and AMPHITOX bioassays. Altogether, data from this report indicate the need to optimize primary treatment of the effluents, as well as to include complementary treatments in order to reduce the negative environmental impacts of the release of this kind of runoffs.Tannery effluents are considered to be severe pollutants around the world. The characterization of such effluents is a very important task in order to verify the compliance with legal requirements of the discharge and, if necessary, to optimize their treatment. In this study, we used the effluents from a local tannery (Córdoba, Argentina) that had implemented only a primary treatment. The effluents were periodically collected during one year to assess their physical, chemical, and microbiological characteristics, as well as their toxicity. The physical and chemical characteristics showed variations independently of the sampling time, although, in general, a high nutrient load was the most frequent finding. Moreover, parameters such as chemical oxygen demand, biochemical oxygen demand, total nitrogen, total phosphate, total phenols, Cr(VI) and settleable solids exceeded the limit set by the provincial legislation for the discharge of effluents into surface water bodies. The effluents were also characterized by a high count of bacteria, where pollutant-tolerant and some pathogenic bacteria were found. In sampling 9, Bacteroidetes, Firmicutes and Proteobacteria represented up to 93 % of the total number of sequences obtained, with Paludibacter, Tissierella Soehngenia, Proteocatella and Proteiniclasticum as the most abundant genera. In concordance with these results, all samples showed toxicity according to L. sativa and AMPHITOX bioassays. Altogether, data from this report indicate the need to optimize primary treatment of the effluents, as well as to include complementary treatments in order to reduce the negative environmental impacts of the release of this kind of runoffs
A four-stage suitability evaluation framework considering restrictive factor for underground space sustainable development and the application in Jinan Pilot zone
Get PDFOne of the primary concerns for sustainable and safety development of urban underground space is to find out the key restrictive factors and the corresponding methods to avoid or modify the constraints. Aiming to provide practical decisions, a four-stage evaluation framework with fuzzy mathematics comprehensive evaluation (FMCE) method was adapted and proposed considering the restrictive factors and management programs. The four stages are 1) identifying the major indicators and restrictive factors that represent geological conditions, 2) collecting data from literature, field investigation and experts’ judgements, 3) combing the qualitative information and quantitative calculation to evaluate the suitability, 4) providing feasible suggestions with management programs that weaken the disadvantage. The four-stage framework is applied in Jinan Pilot Zone as an example. The FMCE method is conducted by employing hydrology, hydrogeology, engineering geology, mining goaf (the restrictive factor), building foundation, and developed underground space as the primary evaluation factors. Protected areas are indicated and two schemes of recharge filling and secondary landscape development are compared in terms of costs and benefits. It is suggested that the existing facilities should be used to develop the underground space with exploration and tourism projects, which might become one highlight of the Pilot Zone.One of the primary concerns for sustainable and safety development of urban underground space is to find out the key restrictive factors and the corresponding methods to avoid or modify the constraints. Aiming to provide practical decisions, a four-stage evaluation framework with fuzzy mathematics comprehensive evaluation (FMCE) method was adapted and proposed considering the restrictive factors and management programs. The four stages are 1) identifying the major indicators and restrictive factors that represent geological conditions, 2) collecting data from literature, field investigation and experts’ judgements, 3) combing the qualitative information and quantitative calculation to evaluate the suitability, 4) providing feasible suggestions with management programs that weaken the disadvantage. The four-stage framework is applied in Jinan Pilot Zone as an example. The FMCE method is conducted by employing hydrology, hydrogeology, engineering geology, mining goaf (the restrictive factor), building foundation, and developed underground space as the primary evaluation factors. Protected areas are indicated and two schemes of recharge filling and secondary landscape development are compared in terms of costs and benefits. It is suggested that the existing facilities should be used to develop the underground space with exploration and tourism projects, which might become one highlight of the Pilot Zone
Aplicación de ramnolípidos de Pseudomonas sp. Y3-B1A en la biodegradación de hidrocarburos a diferentes escalas
Get PDFThe accumulation of crude oil and its derivatives in soils is a serious environmental problem. Bioremediation is a widely studied and applied remediation technology for polluted ecosystems whose efficiency may be limited by the low solubility and toxicity of pollutants. The use of bio-surfactants stimulates the solubilization of hydrophobic molecules and increases bioavailability. In this work, the influence of rhamnolipids produced by Pseudomonas sp. Y3-B1A on the degradation of hydrocarbons at different scales was evaluated, determining also the toxicity of these molecules. In the laboratory, the degradation in a liquid medium supplemented with crude oil and incubated for 28 days was evaluated. The use of rhamnolipids increased the degradation rate of total petroleum hydrocarbons (HTP) by 61.7 % with respect to the treatment in which it was not added. In the microcosms and soil plots, the degradation of HTP, oils and grease (OG), saturated, aromatic, resins and asphaltenes compounds at 30 days was calculated. Nitrogen and phosphorus concentrations, and microbial growth were also determined. The application of rhamnolipids in the microcosms increased the degradation of HTP, saturated and aromatic compounds by more than 40 %. The increase in the degradation of HTP and aromatic compounds in soil plots was from 33 to 34 %, while for OG it reached a value of 86.5 %. The application of rhamnolipids increases the biodegradation of hydrocarbons without causing toxic effects to the ecosystem.La acumulación en suelos de petróleo crudo y sus derivados es un problema ambiental grave. La biorremediación es una tecnología de saneamiento de ecosistemas contaminados ampliamente estudiada y aplicada, cuya eficiencia puede estar limitada por la baja solubilidad y toxicidad de los contaminantes. El empleo de biotensioactivos favorece la solubilización de moléculas hidrofóbicas e incrementa la biodisponibilidad. En este trabajo se evaluó la influencia de la bioestimulación con ramnolípidos de Pseudomonas sp. Y3-B1A en la degradación de hidrocarburos a diferentes escalas, determinando a su vez la toxicidad de estas moléculas. En el laboratorio se evaluó la degradación en medio líquido suplementado con crudo e incubado por 28 días. El empleo de ramnolípidos incrementó en 61.7 % el porcentaje de degradación de hidrocarburos totales del petróleo (HTP) con relación al tratamiento sin aditivos. En los microcosmos y parcelas de suelo, se calculó la degradación de HTP, grasas y aceites (GA), compuestos saturados, aromáticos, resinas y asfaltenos a los 30 días. Además, se determinaron las concentraciones de nitrógeno y fósforo, así como el crecimiento microbiano. En los microcosmos la aplicación de ramnolípidos incrementó en más del 40 % la degradación de HTP, compuestos saturados y aromáticos. En las parcelas el incremento de la degradación de HTP y compuestos aromáticos fue de 33 a 34 %, mientras que la de GA alcanzó 86.5 %. La aplicación de ramnolípidos incrementa la biodegradación de hidrocarburos sin provocar efectos tóxicos en el ecosistema
Lake ecological evaluation and land use planning in lakeside area from the perspective of two-way interaction
Get PDFThe healthy development of the lakeside area needs a detailed assessment of lake ecology and land use, and to adopt a targeted dynamic maintenance strategy. This paper is based on the micro perspective. On the one hand, through the subdivision of land use types in lakeside area, the paper discusses the impact of non-point source (NPS) pollution from different types of land on lake ecology. On the other hand, the paper studies the impact of water environmental capacity and water ecological health assessment on lakeside area construction. From a two-way perspective, we can unify the two as a whole, and jointly promote the healthy development of the lakeside area. Studies have shown that the construction of lakeside area needs to control scale and land use types to meet the needs of water ecological protection. The 2-levels, 5-categories, and 17-subcategories of the lake ecological health assessment index can provide effective support for dynamic monitoring and optimization and adjustment of planning strategies. Lakeside area developing is a dynamic and gradual process. The paper provides a feasible method to realize lake ecological protection and urban development.The healthy development of the lakeside area needs a detailed assessment of lake ecology and land use, and to adopt a targeted dynamic maintenance strategy. This paper is based on the micro perspective. On the one hand, through the subdivision of land use types in lakeside area, the paper discusses the impact of non-point source (NPS) pollution from different types of land on lake ecology. On the other hand, the paper studies the impact of water environmental capacity and water ecological health assessment on lakeside area construction. From a two-way perspective, we can unify the two as a whole, and jointly promote the healthy development of the lakeside area. Studies have shown that the construction of lakeside area needs to control scale and land use types to meet the needs of water ecological protection. The 2-levels, 5-categories, and 17-subcategories of the lake ecological health assessment index can provide effective support for dynamic monitoring and optimization and adjustment of planning strategies. Lakeside area developing is a dynamic and gradual process. The paper provides a feasible method to realize lake ecological protection and urban development
Design of a method for water treatment technology of an indoor swimming pool based on ozone disinfection method
Get PDFAiming at the problem that most of the water treatment technology of swimming pools cannot effectively remove harmful substances, the design of a method for water treatment technology of indoor swimming pool based on ozone disinfection was proposed. Firstly, the organic composition of swimming pool water is analyzed, and the related evaluation indexes of swimming pool water are selected. Then, according to the disinfection performance of ozone disinfection, the appropriate ozone disinfection method is selected. Finally, according to the characteristics of the ozone disinfection method, the design of the water treatment cycle filtration system is completed to achieve the treatment of swimming pool water. The experimental results show that the method is superior to the conventional method by keeping urea at about 1.3 mg/L, the highest COD removal rate approaching 100%, and the lowest value only 59%. Moreover, the effect of particle reduction is obvious after the application, and the daily ozone consumption is always lower than 0.9, which fully verifies the feasibility and economic value of the method.Aiming at the problem that most of the water treatment technology of swimming pools cannot effectively remove harmful substances, the design of a method for water treatment technology of indoor swimming pool based on ozone disinfection was proposed. Firstly, the organic composition of swimming pool water is analyzed, and the related evaluation indexes of swimming pool water are selected. Then, according to the disinfection performance of ozone disinfection, the appropriate ozone disinfection method is selected. Finally, according to the characteristics of the ozone disinfection method, the design of the water treatment cycle filtration system is completed to achieve the treatment of swimming pool water. The experimental results show that the method is superior to the conventional method by keeping urea at about 1.3 mg/L, the highest COD removal rate approaching 100%, and the lowest value only 59%. Moreover, the effect of particle reduction is obvious after the application, and the daily ozone consumption is always lower than 0.9, which fully verifies the feasibility and economic value of the method
Paraoxonasa 1 y su relación con factores de riesgo en fumigadores del estado de Guerrero: estudio preliminar
Get PDFOrganophosphate pesticides (OP) are widely used for the control of pests and vector-borne diseases by state and national governments. However, these compounds can cause acute and chronic intoxication, and diverse factors play a relevant role in their toxicity. One such factor is paraoxonase 1 (PON1), a protein that hydrolyzes OP and protects the body from toxicity. The objective of this study was to assess the serum concentration of PON1 and its relationship with risk factors in a population of fumigators from the state of Guerrero, in Mexico. A cross-sectional study was conducted with 67 fumigators and a control group of 46 non-fumigators. A survey instrument was applied to capture the labor practices and pesticides used, and anthropometric and biochemical measurements were determined. Serum concentration of PON1 was quantified by enzyme-linked immunoassay (ELISA). The results show that most of the fumigators use carbamates (38 %) and OP (32 %) pesticides. The PON1 concentrations were 21.2 ng/mL in the fumigators vs. 18.7 ng/ml in the control group. We also found that body mass index, diabetes history, time in years that the worker reports carrying out the pesticide fumigation, the number of pesticides used, and the consumption of alcohol, vitamins and food supplements were risk factors associated with PON1 concentration shifts. It is necessary to consider the intrinsic and extrinsic factors of individuals when evaluating PON1 levels in populations exposed to pesticides.Los plaguicidas organofosforados (OF) son ampliamente utilizados para el control de plagas y vectores transmisores de enfermedades por gobiernos estatales y nacionales. Sin embargo, se sabe que estos compuestos pueden causar intoxicaciones agudas y crónicas, y que diversos factores desempeñan un papel relevante en su toxicidad. Uno de ellos es la paraoxonasa 1 (PON1), una proteína que hidroliza los plaguicidas OF y protege al organismo de su toxicidad. El objetivo de este estudio fue valorar la concentración sérica de PON1 y su relación con factores de riesgo que pueden modificar la concentración de la enzima en una población de fumigadores guerrerenses. Se realizó un estudio de corte transversal con 67 fumigadores y 46 en el grupo testigo. Se aplicó un instrumento para conocer sus prácticas laborales, plaguicidas utilizados y medidas antropométricas. Las concentraciones séricas de PON1 fueron cuantificadas por enzimoinmunoanálisis de adsorción (ELISA, por su sigla en inglés). Los resultados mostraron que los fumigadores utilizan principalmente carbamatos (38 %) y OF (32 %). Las concentraciones de PON1 fueron de 21.2 ng/mL en los fumigadores vs. 18.7 ng/ml en el grupo testigo. Encontramos que el índice de masa corporal, los antecedentes de diabetes, la antigüedad en la labor de fumigación, el número de plaguicidas utilizados y el consumo de alcohol, vitaminas y suplementos alimenticios son factores de riesgo asociados a los cambios en la concentración de PON1. Es necesario considerar los factores intrínsecos y extrínsecos de los individuos cuando se evalúan los niveles de PON1
Identificación de especies dominantes en un consorcio microbiano eficiente en la degradación de diésel
Get PDFThis study shows the dominant microbial species of a microbial consortium efficient in the hydrocarbon degradation, which was obtained from a sinkhole (cenote) in the Mexican Caribbean in Playa del Carmen. The microbial consortium was characterized and identified. The indices of the number of species were also analyzed. Five genera of bacteria corresponding to the consortium were identified, and it was possible to discard those that were only tolerant to hydrocarbons from those that degraded them. The 38 % of bacteria corresponded to Enterobacteriales (Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, Shigella flexneri, and Proteus mirabilis); E. coli is the only not being reported as hydrocarbonoclast but tolerant to hydrocarbons. The 23 % corresponded to Vibrionales (Vibrio cholerae pacini, Vibrio parahemolyticus, and Vibrio vulnificus). The 15 % corresponded to Lactobacillales (Enterococcus faecalis, Enterococcus faecium, and Streptococcus bovis). Lastly, Pseudomonas aeruginosa and Burkholderia cepacia represented 8 % of the total. The observed total microbial species richness (OTU) was 6 in the MacConkey agar and Endo agar media, as well as a Chao1 index of 21, both corresponding to enterobacteria. The identification of the bacteria and dominant species in the consortium carried out in this study contributes to the knowledge for establishing growth conditions to achieve a more significant degradation of polycyclic aromatic hydrocarbons.Este estudio muestra las especies microbianas dominantes que conforman un consorcio eficiente en el proceso de degradación de hidrocarburos obtenido de un cenote localizado en Playa del Carmen, en el Caribe Mexicano. Los microorganismos que conforman el consorcio se identificaron mediante diferentes pruebas bioquímicas y fenotípicas. Adicionalmente, se analizaron los índices de número de especies presentes. Se identificaron cinco géneros de bacterias y se logró discernir entre aquellas tolerantes a la presencia de hidrocarburos y las que degradan hidrocarburos aromáticos policíclicos (HAP). El 38 % de las bacterias identificadas pertenecieron a las Enterobacteriales, entre ellas: Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, Shigella flexneri y Proteus mirabilis; donde E. coli es la única bacteria no reportada como hidrocarbonoclasta, pero es tolerante a los hidrocarburos. El 23 % de las bacterias identificadas correspondió a Vibrionales: (Vibrio cholerae pacini, Vibrio parahemolyticus y Vibrio vulnificus). El 15 % correspondió a Lactobacillales (Enterococcus faecalis, Enterococcus faecium y Streptococcus bovis). Por último, Pseudomonas aeruginosa y Burkholderia cepacia representaron el 8 %. Además, se encontró una riqueza microbiana total de especies (OTU) de 6 en los medios agar MacConkey y Endo, así como un índice de Chao1 de 21; ambos correspondientes a las enterobacterias. La identificación de las bacterias y especies dominantes que constituyen al consorcio de este estudio, contribuyen y fortalecen la riqueza del conocimiento para establecer condiciones de crecimiento que permitan lograr una mayor degradación de HAP
Recuperación de nutrientes y degradación de materia orgánica de agua residual agrícola por medio de un sistema UV/H2O2 optimizado
Get PDFIn this research, nutrient recovery and organic matter removal from agricultural wastewater (AWW) were simultaneously evaluated through an advanced oxidation process (AOP). For this purpose, a 30 W/m2 UV/H2O2 system optimized regarding oxidant reagent dose and UV irradiation time was configured. The evaluated levels were 48.9, 65.3, and 84.6 Mm of hydrogen peroxide (H2O2) and 60, 90 and 120 min, respectively. Thus, through the response surface methodology (RSM) algorithm and the desirability function, it was found that it is possible to obtain efficiencies of 95 ± 5% in chemical oxygen demand (COD) removal and to generate 200 ± 11 % nitrates (NO3-N) and 100 ± 9.5 % of phosphates (PO4-P) with respect to the initial concentrations. Besides, the behavior of nitrogen and phosphorus chemical species was evaluated during the AWW treatment. The results suggest that the optimized UV/H2O2 system represents a technically feasible alternative for the efficient treatment of AWW. In fact, effluents with desirable characteristics for reuse in agriculture, such as high levels of nitrogen and phosphorus in chemical forms assimilable by crops were generated. Thus, this work contributes directly to solving problems related to water scarcity and fertilizer production.En la presente investigación se evaluaron la recuperación de nutrientes y la remoción de materia orgánica del agua residual agrícola (ARA) mediante un proceso de oxidación avanzada (POA). Para ello, se configuró un sistema UV/H2O2 de 30 W/m2 optimizado en cuanto a dosis de reactivo oxidante y tiempo de irradiación UV. Los niveles evaluados fueron 48.9, 65.3 y 84.6 mM de peróxido de hidrógeno (H2O2) y 60, 90 y 120 min, respectivamente. Así, a través del algoritmo de la metodología de superficie de respuesta (MSR) en conjunto con el de la función de deseabilidad, se encontró que es posible obtener 95 ± 5 % de remoción de la demanda química de oxígeno (DQO), así como generar 200 ± 11 % de nitratos (N-NO3) y 100 ± 9.5 % de fosfatos (P-PO4) con relación a las concentraciones iniciales. Además, se evaluó el comportamiento de las especies químicas de nitrógeno y fósforo durante el tratamiento del ARA. Los resultados sugieren que el sistema UV/H2O2 optimizado representa una alternativa técnicamente viable en el tratamiento eficiente de ARA. En efecto, se generaron efluentes con características deseables para el reúso en la agricultura, tales como altos niveles de nitrógeno y fósforo en formas químicas asimilables para los cultivos. De esta manera se contribuye directamente a solucionar problemas relacionados con la escasez de agua y la producción de fertilizantes
Estado trófico, dinámica de nutrientes y metabolismo neto de una laguna costera subtropical (Golfo de California) receptora de aguas residuales
Get PDFThe trophic state, nutrient dynamics and net metabolism of a subtropical coastal lagoon located on the east coast of the Gulf of California were evaluated. The Santa María lagoon is a receiving system for urban, shrimp farming, and agricultural wastewater. In the lagoon and adjacent sea, water samples were taken in summer and winter to gather information about temperature, salinity, dissolved oxygen, dissolved inorganic nutrients, and chlorophyll a. The trophic state was evaluated by the TRIX index, while nutrient fluxes and net ecosystem metabolism were estimated by the LOICZ biogeochemical model. The lagoon exhibited a mesotrophic state both in summer and winter. Estimations of the flushing time were 22 days in summer and 10 days in winter. The nutrient fluxes showed that the lagoon was a sink in summer (ΔNID = –0.84 mmol/m2/and y ΔFID = –0.12 mmol/m2/day) and a source in winter (ΔNID = 0.04 mmol/m2/day and ΔFID = 0.15 mmol/m2/day). In summer, the net ecosystem metabolism (NEM) was autotrophic (13 mmol C/m2/day) and the nitrogen fixation process predominated (+ 1.2 mmol/m2/ day). In winter, the NEM was heterotrophic (–16.36 mmol/m2/day) and denitrification predominated (–2.3 mmol/m2/day). It is concluded that the Santa María lagoon functions by assimilating nutrients with a predominance of autotrophic metabolism and nitrogen fixation in summer, as well as exporting nutrients with a predominance of heterotrophic metabolism and denitrification in winter. The lagoon maintains a mesotrophic state in both seasons, showing the capacity to assimilate, transform, and export nutrient loads without manifesting adverse eutrophication processes.Se evaluaron el estado trófico, la dinámica de nutrientes y el metabolismo neto de una laguna costera subtropical ubicada en la costa este del Golfo de California. La laguna Santa María es un sistema receptor de aguas residuales urbanas, camaronícolas y agrícolas. En la laguna y el mar adyacente se realizaron muestreos de agua en verano e invierno para obtener información de temperatura, salinidad, oxígeno disuelto, nutrientes inorgánicos disueltos y clorofila a. El estado trófico se estimó con el índice TRIX, mientras que los flujos de nutrientes y el metabolismo neto se estimaron con el modelo biogeoquímico LOICZ. La laguna exhibió un estado mesotrófico en verano e invierno. Las tasas de renovación del agua estimadas fueron de 22 días en verano y 10 días en invierno. Los flujos de nutrientes mostraron que la laguna fue sumidero en verano (ΔNID = –0.84 mmol/m2/día y ΔFID = –0.12 mmol/m2/día) y fuente en invierno (ΔNID = 0.04 mmol/m2/día y ΔFID = 0.15 mmol/m2/día). En verano, el metabolismo neto del ecosistema (MNE) fue autótrofo (13 mmol C/m2/día) y predominó el proceso de fijación de nitrógeno (+ 1.2 mmol/m2/día). En invierno, el MNE fue heterótrofo (–16.36 mmol/m2/día) y predominó la desnitrificación (–2.3 mmol/m2/día). Se concluye que la laguna Santa María funciona asimilando nutrientes con predominancia de metabolismo autótrofo y fijación de nitrógeno en verano, así como exportando nutrientes con predominancia de metabolismo heterótrofo y desnitrificación en invierno. La laguna mantiene un estado mesotrófico en ambas estaciones del año mostrando capacidad de asimilar, transformar y exportar las cargas de nutrientes sin manifestar procesos adversos de eutrofización
Desarrollan análisis regional sobre la gestión actual de los sedimentos en nueve países de América
Get PDFEsta nota describe los principales resultados del libro "Perspectivas de la gestión de sedimentos en nueve países de las américas", publicado recientemente por UNESCO.Esta nota describe los principales resultados del libro "Perspectivas de la gestión de sedimentos en nueve países de las américas", publicado recientemente por UNESCO