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Los lixiviados de rellenos sanitarios son residuos líquidos complejos, considerados un problema significativo para el medio ambiente. Las microalgas se presentan como una alternativa para el tratamiento y aprovechamiento de aguas residuales por su capacidad adaptativa, siendo una opción viable para su uso en lixiviados. Esta contribución presenta una descripción bibliométrica de las investigaciones indexadas en la base de datos SCOPUS relacionadas con microalgas y lixiviados de rellenos sanitarios. En base a esto, se identificó la relevancia del tratamiento con microalgas tanto en aguas residuales en general como en lixiviados con el fin de conocer la proporción de avance entre los dos. Se encontraron 68 artículos relacionados a microalgas y lixiviados, siendo China es el país más productivo en cuanto a número de publicaciones. Este estudio demostró que el uso de microalgas en lixiviados en un tema que aún esta en desarrollo y su enfoque está dado para el tratamiento de este residuo, siendo limitados los estudios de aprovechamiento y obtención de bioproductos.

This paper presents the implementation of a chemical treatment in a pilot well of the Colorado Field to prevent the precipitation and deposition of paraffins in the production tubing. Such treatment was previously developed in the laboratory, which proved to be effective, thus reducing the crystallization point. Was selected the Col-75 as pilot well, because he met a number of criteria needed for successful development of the project. Based on experimental design, it was determined the number of tests was performed, and the influence of chemical treatment volume and the recirculation time on the point of crystallization of the crude oil. The different treatment applications were made every eight days, taking crude samples before and after. Those samples were testing in the laboratory in order to evaluate the effectiveness of the chemical treatment. With the results it was found that the best treatment to prevent paraffin deposition inside the production tubing is having the lowest volume of treatment and recirculation time, which is economically viable compared with cleaning work of the well as corrective method. We conclude that treatment can be extended to other wells of the Colorado Field, but it is recommended to monitor and control in order to evaluate its effectiveness.

2017-397Rivers have been a major part in the development of human activities since the beginning of civilization. Globally, increased navigation in rivers and construction of oil storage infrastructure along its banks has increased the risk of spillage of these substances in freshwater bodies.Mitigation associated with such incidents impact depends largely on the formulation and implementation of adequate contingency plans. To make this possible the vulnerability assessment is a tool of primary information which integrates the identification of possible sources of hydrocarbon’s spills and the respective dispersion patterns (evaluation of susceptibility); as well as analysis of areas that could be more seriously affected by the presence of those spills (sensitivity testing). There are known methodologies and study cases for assessing vulnerability to oil spills in marine and coastal environments; however, for rivers there are not references of this type of work.This paper presents a methodological adaptation for assessing environmental vulnerability for oil spills in rivers, from the integration of known methodologies for evaluation of sensitivity and susceptibility in coastal marine and river environments. Given its standardization and wide use, the ESI (NOAA) method was selected for river sensitivity assessment. It was not considered necessary to have a standardized method for trajectory modeling and hydrocarbons spill degradation (susceptibility analysis), but it was established that in each case of study the selected tool must analyze the determinant processes as advection, adhesion to the edges, mechanical dispersion, evaporation, dissolution, and vertical mixing.Finally, an adaptation of the Index of Environmental Vulnerability to Oil (IEVO) was proposed. At the moment, the application of the methodology is being carried out in a river of Colombia, however the results still unfinished will not be part of the discussion of the work below.

A mathematical model was developed to describe the mass and energy transfer in the ethanol separation process by using vacuum membrane distillation. This mod...

This work studied the improvement of biomass and carbohydrate (glucose and xylose) lab–scale productivity in Chlorella vulgaris UTEX 1803 through the use of the carbon/nitrogen ratio. In order to do so, mixotrophic cultures were made by the modification of initial concentration of CH3COONa (5, 10 and 20 mM) and NaNO3 (0.97, 1.94 and 2.94 mM). All treatments were maintained at 23 ± 1ºC, with light/dark cycles of 12h : 12h for 5 days.It was found that in addition to the carbon/nitrogen ratio, time also influences the concentration of biomass and carbohydrates. The treatment containing 10 mM acetate: 1.94 mM nitrate, reached a concentration of 0.79 g/L of biomass, 76.9 μg/mL of xylose and 73.7 μg/mL of glucose in the fifth day. However, the treatmentcontaining 20 mM acetate: 0.97 mM nitrate produced 1.04 g/L of biomass, 78.9 μg/mL of xylose and 77.2 μg/mL of glucose in the third day, while in the same day the treatment containing 0 mM acetate: 2.94 mM nitrate, produced 0.55 g/L of biomass, 40.2 μg/mL of xylose and 31.3 μg/mL of glucose.The use of carbon/nitrogen ratios improved biomass productivity (from 0.55 to 1.04 g/L) as well as xylose (from 40.2 to 78.9 μg/mL) and glucose (from 31.3 to 77.2 μg/mL) concentration, representing an improvement of up to two times the production of both biomass and carbohydrates in only 3 days of culture.

El objetivo del presente estudio fue evaluar la viabilidad del uso de glicerina como fuente de carbono, usando algas inmovilizadas para la producción de metabolitos como carbohidratos, proteínas y lípidos. Se encontró, mediante el uso de análisis estadístico, que la acumulación de hidratos de carbono se favorece con concentraciones de glicerina de 3-5% (v/v) y 0,37 (g/L) de nitrógeno. La deposición de lípidos, se favorece con una concentración de 3% (v/v) de glicerina y 0,04 (g/L) de nitrógeno; Por otro lado, las proteínas se favorecen con mayores concentraciones de glicerina (5% v/v), y una concentración de nitrógeno similar a la utilizada para hidratos de carbono. The purpose of the present study was to evaluate the viability of glycerol as carbon source using immobilized algae coupled with a modification on nitrogen (NO3 -) and phosphate (PO4) concentration, for the production of high valuable compounds (carbohydrates, proteins and lipids). The best conditions for carbohydrate accumulation were found by statistical analysis and they were achieved within a 3-5% (v/v) glycerol and an initial concentration of nitrogen source of 0,37 (g/L). Lipid deposition was favored with a concentration of 3% (v/v) glycerol and 0.04 (g/L) nitrogen. On the other hand, proteins were favored with higher concentrations of glycerol (5% v/v) and a concentration of nitrogen similar to that used for carbohydrates

Microalgae represent a source of protein with potential applications in human and animal nutrition, since they possess a good balance of amino-acids and low content of nucleic acids in comparison with other sources of protein. However, the low productivity of cultures has prevented production at a large scale. In this work, we studied the total production of protein in Chlorella vulgaris at a laboratory scale, analyzing different pre-established parameters under the carbon/nitrogen ratio. For this, we performed mixotrophic cultures during 5 days at different concentrations of acetate (5Mm, 10Mm, 20Mm) and sodium nitrate (0,97Mm, 1,94Mm, 2,94Mm). All treatments were kept at 23 ± 1ºC, with light/dark cycles of 12h: 12h for 5 days. The highest value of protein concentration was obtained from the culture R9 with a production of 0,78±0.18 g/L, 1.7 times higher than the production of the control culture treatment. (0,46 g/L). R9 was also the culture that consumed the most nitrogen (91%). Based on these results and their analysis, we found that the total content of protein in C. vulgaris is directly proportional to the amount of acetate and nitrate present in the culture media, since the algae grown in cultures where these nutrients were limited exhibited the lowest values in terms of protein concentration Las microalgas representan una fuente de proteína con posibles aplicaciones en la nutrición humana y animal ya que poseen un buen balance de aminoácidos y bajos valores de ácidos nucleícos, en comparación con otras fuentes de proteína; sin embargo, la baja productividad de estos cultivos ha impedido implementar una producción a gran escala. En este trabajo se estudió la influencia de la relación carbono/nitrógeno en la productividad de proteínas totales presentes en Chlorella vulgarisa escala de laboratorio. Se efectuaron cultivos mixotróficos durante 5 días con diferentes concentraciones de acetato (5mM, 10mM, 20mM), y nitrato de sodio (0,97mM, 1,94mM, 2,94mM). Todos los tratamientos se realizaron a 23 ± 1ºC, con ciclos luz-oscuridad 12h: 12h. El valor más alto de concentración de proteínas se obtuvo en el medio de cultivo R9 con una productividad de 0,78±0.18 g/L, superando 1,7 veces más en producción, al cultivo control (0,46 g/L). De igual manera, fue el cultivo que consumió mayor cantidad de nitrógeno (91%). Con base en los datos obtenidos y el análisis de los mismos, se encontró que el contenido de proteínas totales en C. vulgaris es directamente proporcional a la cantidad de acetato y nitrato presentes en el medio, mientras que la respuesta de la cepa algal en cultivos con limitación de estos nutrientes, registró los valores más bajos en relación con la concentración de proteínas.

La acumulación de parafina es uno de los mayores inconvenientes en la producción, transporte y almacenamiento de crudo. La inhibición por medio del método magnético es una alternativa que mejora las propiedades reológicas del crudo tratado sin alterar sus propiedades químicas. Este estudio presenta una revisión de los trabajos hechos en campos petrolíferos a nivel nacional e internacional, donde se han aplicado distintos métodos para la inhibición de precipitación de parafinas y exaltado las ventajas del uso del método magnético: reducción de los trabajos de limpieza en los pozos tratados, bajos costos de mantenimiento, la inhibición de depósitos de parafina sin interrupción de la producción o daños a la formación utilizando únicamente la energía del yacimiento. Lo anteriormente expuesto hace del tratamiento magnético una interesante opción para reducir sustancialmente los costos del barril producido y mantener con una alta movilidad el crudo parafínico.

Las microalgas representan una fuente de proteína con posibles aplicaciones en la nutrición humana y animal ya que poseen un buen balance de aminoácidos y bajos valores de ácidos nucleícos, en comparación con otras fuentes de proteína; sin embargo, la baja productividad de estos cultivos ha impedido implementar una producción a gran escala. En este trabajo se estudió la influencia de la relación carbono/nitrógeno en la productividad de proteínas totales presentes en Chlorella vulgarisa escala de laboratorio. Se efectuaron cultivos mixotróficos durante 5 días con diferentes concentraciones de acetato (5mM, 10mM, 20mM), y nitrato de sodio (0,97mM, 1,94mM, 2,94mM). Todos los tratamientos se realizaron a 23 ± 1ºC, con ciclos luz-oscuridad 12h: 12h. El valor más alto de concentración de proteínas se obtuvo en el medio de cultivo R9 con una productividad de 0,78±0.18 g/L, superando 1,7 veces más en producción, al cultivo control (0,46 g/L). De igual manera, fue el cultivo que consumió mayor cantidad de nitrógeno (91%). Con base en los datos obtenidos y el análisis de los mismos, se encontró que el contenido de proteínas totales en C. vulgaris es directamente proporcional a la cantidad de acetato y nitrato presentes en el medio, mientras que la respuesta de la cepa algal en cultivos con limitación de estos nutrientes, registró los valores más bajos en relación con la concentración de proteínas.

Although microalgae have great potential as a raw material for biodiesel production it is necessary to increase both biomass and lipids productivity. One way to achieve this goal is the implementation of mixotrophic cultures and the regulation of carbon/nitrogen ratio. The present work aims to improve the productivity of biomass and lipids in Chlorella vulgaris UTEX 1803 using waste glycerol from biodiesel production (1, 5 and 10% v/v) and sodium acetate (5, 10 and 20 mM) as carbon sources together with modification of the initial concentration of nitrogen (1.02; 1.47 and 2.94mM de NaNO3). All experiments were performed at 23±1ºC, with light: dark cycles of 12:12 h during 5 days. In biomass production was achieved a significant increase (80% higher that autothrophic cultures without modification). The best percentages of lipids exceeded control culture up to 2.18. Lipid productivities were also found 2.83 and 3.5 times greater than control. Results show the possibility of increasing the production of biomass and lipids by applying the carbon/nitrogen ratio using as a carbon source waste glycerol of the biodiesel industry that opens up great possibilities for the re-use of this residue thus increasing the sustainability of the process in general, Also has been proved that carbon/nitrogen ratio using sodium acetate is an interesting alternative due to his low cost carbon/nitrogen ratio using sodium acetate is an interesting alternative.