Tratamiento de residuos de agave de la industria tequilera mediante procesos de oxidación avanzada con ozono para elaborar pasta de papel

119 páginas. Maestría en Ciencias e Ingeniería Ambientales.En el proceso de fabricación del tequila se obtiene un residuo proveniente del proceso de cocimiento y molienda de las cabezas de Agave tequilana Weber variedad azul. Este residuo, conocido como bagazo de agave, es producido a razón de entre 55 y 60 kilogramos por litro de tequila elaborado y su disposición final se realiza en tiraderos. En el año 2015 la producción total de tequila fue de 248.3 millones de litros, por lo tanto, se estima que se generaron entre 10.17 y 11.09 millones de toneladas de bagazo. En este estudio se investigó la posibilidad de transformar dicho material de desecho en pasta de papel mediante un tratamiento de oxidación avanzada con ozono. En la parte experimental, a fin de conocer el proceso convencional de cocción con sosa en autoclave y comparar resultados con ozono, se elaboraron manualmente hojas de papel con el bagazo de agave mediante este método. Con el proceso de ozonización se llevaron a cabo pruebas preliminares para evaluar la remoción de lignina. En la etapa principal de la experimentación con ozono se determinó el pH al cual se obtiene la máxima reducción de lignina, efectuando ozonizaciones al bagazo de agave a diferentes valores de pH (2.5 a 12), manteniendo constante las demás variables, asimismo se analizó el contenido de celulosa y hemicelulosa en cada experimento. Con el pH ya definido se efectuó una ozonización incrementando el tiempo de reacción. La máxima reducción de lignina que se logró con el ozono fue del 38.67 %, en una de las pruebas preliminares. También se realizó una prueba de tratamiento del bagazo con sosa al 25 % a ebullición con reflujo, así como una prueba de ozonización con NaOH al 6 %. Se tomaron imágenes del bagazo con microscopio estereoscópico, microscopio óptico y microscopio electrónico de barrido, en donde no se observó ninguna diferencia significativa entre el bagazo original y el bagazo ozonado, en contraste, en el bagazo tratado únicamente con sosa se apreció la liberación de las fibras. Como conclusión general, el proceso de ozonización permite disminuir el contenido de lignina en el bagazo de agave, pero no se llega a ablandar lo suficiente para poder separar las fibras individuales para obtener la pasta de papel en un proceso de refinación en una pila holandesa y, de esta manera, estar en posibilidades de elaborar hojas de papel.Tequila manufacturing process gets a residue from heads of Agave tequilana Weber blue variety cooking and milling process. This residue, known as agave bagasse, is produced at a rate of between 55 and 60 kilograms per liter of tequila produced and final disposal is carried out in landfills. In 2015 tequila total production was 248.3 million litres, therefore, it is estimated that they were generated between 10.17 and 11.09 million tons of bagasse. In this study investigated the possibility of transforming such waste material in pulp through an advanced oxidation treatment with ozone. In experimental part, in order to know the cooking conventional process with soda in autoclave and compare results with ozone, were made manually paper sheets with agave bagasse through this method. With ozonization process preliminary tests were conducted to evaluate lignin removal. On experimentation main stage with ozone it was determined the pH which gives the maximum lignin reduction, making agave bagasse ozonizations at different pH values (2.5 to 12), keeping the rest variables constant, also it was analysed each experiment cellulose and hemicellulose content. With the defined pH was made an ozonization by increasing reaction time. The maximum lignin reduction which was achieved with ozone was 38.67 %, in one of the preliminary tests. A bagasse treatment test with 25 % soda boiling with reflux and a ozonization test with 6 % NaOH were performed too. Bagasse images with stereoscopic microscope, optical microscope and scanning electronic microscope were taken, where not observed any significant difference between original baggase and ozonated baggase, on the other hand, in baggase treated only with soda showed fibers release. As a general conclusion, ozonization process allows to reduce lignin content of agave bagasse, but did not get softened enough to can separate individual fibers to obtain pulp in a hollander beater refining process, in this way, be able to produce paper sheets.Consejo Nacional de Ciencia y Tecnología (México)

Movilidad en transporte privado y emisión de CO2: patrones geoespaciales e implicancias en el ordenamiento territorial para el Área Metropolitana de Santiago, Chile

Transportation ranks as the second sector with the highest contribution of carbon dioxide (CO2) emissions in the world for the year 2012. This phenomenon is exacerbated by physical expansion, urban fragmentation, and inequality in cities, with the Metropolitan Area of Santiago (AMS) serving as a notable example. Therefore, the objective of this study is to determine the geospatial patterns of CO2 emissions resulting from intercommunal mobility in private transportation within the AMS. To begin, the emissions of CO2 from mobility were quantified, resulting in a total of 2,838,199 tonnes per year. Subsequently, the geospatial emission patterns were identified using three indicators. These indicators substantiate the existence of a significant concentration of private mobility due to the unequal distribution of services in a specific sector of the AMS. This reinforces the geospatial pattern of population mobility towards the northeastern region of the city. The discussion and promotion of planning initiatives within the AMS emphasize the need for a comprehensive approach to land use planning. This approach aims to foster a more sustainable city, enhance the quality of life, and promote greater equality of opportunities for all residents.El transporte es el segundo sector que más dióxido de carbono (CO2) emite a nivel mundial, según datos del año 2012. Este fenómeno se ve potenciado por la expansión física de las ciudades, la fragmentación urbana y la desigualdad en su estructura. Un caso destacado es el Área Metropolitana de Santiago (AMS). En este contexto, el objetivo de esta investigación es determinar los patrones geoespaciales de emisión de CO2 causados por la movilidad intercomunal en transporte privado en el AMS. En primer lugar, se cuantificaron las emisiones de CO2 generadas por la movilidad, y se obtuvo un resultado de 2.838.199 toneladas por año. A continuación, se analizaron los patrones geoespaciales de emisión utilizando tres indicadores. Estos confirman la alta concentración de la movilidad privada en un sector específico del AMS, debido a la desigual distribución de servicios. Esto refuerza el patrón geoespacial de movilidad de la población hacia el cono nororiente de la ciudad. Se discute y se promueve la necesidad de planificar el AMS con una perspectiva integral de ordenamiento territorial, con el objetivo de lograr una ciudad más sustentable, mejorar la calidad de vida y fomentar una mayor igualdad de oportunidades para todos los habitantes

Deslignificación del bagazo de agave mediante procesos de ozonización

Se investigó la deslignificación del bagazo de agave mediante un tratamiento con ozono. Se llevaron a cabo pruebas preliminares para evaluar la remoción de lignina. Se determinó el pH al cual se obtiene la máxima reducción de lignina, efectuando ozonizaciones a diferentes valores de pH (2.5 a 12), manteniendo constante las demás variables. Se analizó el contenido de celulosa y hemicelulosa en cada experimento. Con el pH ya definido se efectuó una ozonización incrementando el tiempo de reacción. La máxima reducción de lignina que se logró con el ozono fue del 38.67%, en una de las pruebas preliminares. El proceso de ozonización permite disminuir el contenido de lignina en el bagazo de agave, para una posible aplicación posterior, ya sea en la obtención de pulpa para papel, blanqueo de pulpa o producción de bioetanol.Agave bagasse deslignification through a treatment with ozone was investigated. Preliminary tests were conducted to evaluate lignin removal. It was determined the pH which gives the maximum lignin reduction, making ozonizations at different pH values (2.5 to 12), keeping the rest variables constant. It was analysed each experiment cellulose and hemicellulose content. With the defined pH was made an ozonization by increasing reaction time. The maximum lignin reduction which was achieved with ozone was 38.67%, in one of the preliminary tests. Ozonization process allows to reduce lignin content of agave bagasse, for a possible further application, whether in obtaining pulp for paper, pulp bleaching or bioethanol production

Obtención de estireno a partir de residuos de poliestireno expandido mediante pirolisis catalítica

En este trabajo se estudió un proceso de pirolisis catalítica que permite transformar los residuos de poliestireno expandido a su monómero de estireno, con la finalidad de ser reutilizado en la industria del poliestireno para la fabricación de nuevos productos y, de esta manera, efectuar su reciclaje. El poliestireno, a diferencia de otros polímeros, tiene un gran potencial para producir su monómero a través de un proceso de pirolisis y es posible aumentar su rendimiento utilizando un catalizador adecuado. Debido a la baja densidad del poliestireno expandido (0.012 g/mL) es necesario reducir su volumen, disolviéndolo en un solvente apropiado. Los criterios para seleccionar el solvente fueron: buena solubilidad del poliestireno, no estar clasificado como tóxico, tener bajo costo y disponibilidad en el mercado. Se realizaron pruebas con diferentes catalizadores básicos para determinar cuál es el que proporciona el mejor rendimiento. Se determinó la cinética de la reacción de pirolisis del poliestireno expandido.In this work it was studied a catalytic pyrolysis process that allows to transform waste expanded polystyrene to its styrene monomer, in order to be reused in the polystyrene industry for the manufacture of new products and, in this way, to carry out its recycling. Polystyrene, unlike other polymers, has great potential to produce its monomer through a pyrolysis process and it is possible to increase its yield using a suitable catalyst. Due to the low density of expanded polystyrene (0.012 g/mL) it is necessary to reduce its volume, dissolving it into an appropriate solvent. The criteria for selecting the solvent were: polystyrene good solubility, not being classified as toxic, having low cost and availability in the market. Tests were performed with different basic catalysts to determine which one provides the best yield. The kinetics of expanded polystyrene pyrolysis reaction were determined

Promoting FAIRness in marine data at Centro Nacional Instituto Español de Oceanografía

The Spanish Institute of Oceanography is responsible, among other aspects, for scientifc and technical advice for the Government’s fsheries policy as well as for the protection and sustainability of the marine environment. In this task, it generates a large amount of oceanographic data characterized by its spatial dispersion during acquisition as well as by its diferent typology. The purpose of both the National Oceanographic Data Center and the GIS team is to safeguard data and to disclose what data exists and where, how and when it has been acquired and, in addition, to provide access to that data through the collaboration with diferent international data infrastructures like EMODnet or SeaDataNet. To this end, the data and metadata are subjected to quality control and formatted for integration into a national Spatial Data Infrastructure (SDI). This SDI has a GeoNetwork catalogue with ~ 1750 oceanographic campaigns, together with (meta)data and services that are continuously being revised and incorporated. All this with the ultimate goal of making the data increasingly FAIR.Peer Reviewe

Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes.

8 páginas, 4 tablas, 8 figuras.The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and managementFinancial support from the Spanish Ministry of the Environment (MMA, project 05/99) and the Junta de Andalucía (research group 4086)enabled us to carry out the present work.Peer reviewe

Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes.

8 páginas, 4 tablas, 8 figuras.The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and managementFinancial support from the Spanish Ministry of the Environment (MMA, project 05/99) and the Junta de Andalucía (research group 4086)enabled us to carry out the present work.Peer reviewe

Pancreatic metastases from renal cell carcinoma. Postoperative outcome after surgical treatment in a Spanish multicenter study (PANMEKID)

Background: Renal Cell Carcinoma (RCC) occasionally spreads to the pancreas. The purpose of our study is to evaluate the short and long-term results of a multicenter series in order to determine the effect of surgical treatment on the prognosis of these patients. Methods: Multicenter retrospective study of patients undergoing surgery for RCC pancreatic metastases, from January 2010 to May 2020. Variables related to the primary tumor, demographics, clinical characteristics of metastasis, location in the pancreas, type of pancreatic resection performed and data on short and long-term evolution after pancreatic resection were collected. Results: The study included 116 patients. The mean time between nephrectomy and pancreatic metastases' resection was 87.35 months (ICR: 1.51-332.55). Distal pancreatectomy was the most performed technique employed (50 %). Postoperative morbidity was observed in 60.9 % of cases (Clavien-Dindo greater than IIIa in 14 %). The median follow-up time was 43 months (13-78). Overall survival (OS) rates at 1, 3, and 5 years were 96 %, 88 %, and 83 %, respectively. The disease-free survival (DFS) rate at 1, 3, and 5 years was 73 %, 49 %, and 35 %, respectively. Significant prognostic factors of relapse were a disease free interval of less than 10 years (2.05 [1.13-3.72], p 0.02) and a history of previous extrapancreatic metastasis (2.44 [1.22-4.86], p 0.01). Conclusions: Pancreatic resection if metastatic RCC is found in the pancreas is warranted to achieve higher overall survival and disease-free survival, even if extrapancreatic metastases were previously removed. The existence of intrapancreatic multifocal compromise does not always warrant the performance of a total pancreatectomy in order to improve survival. (C) 2021 The Authors. Published by Elsevier Ltd

Repeated pancreatic resection for pancreatic metastases from renal cell Carcinoma: A Spanish multicenter study (PANMEKID)

Background and objectives: Recurrent isolated pancreatic metastasis from Renal Cell Carcinoma (RCC) after pancreatic resection is rare. The purpose of our study is to describe a series of cases of relapse of pancreatic metastasis from renal cancer in the pancreatic remnant and its surgical treatment with a repeated pancreatic resection, and to analyse the results of both overall and disease -free survival. Methods: Multicenter retrospective study of patients undergoing pancreatic resection for RCC pancreatic metastases, from January 2010 to May 2020. Patients were grouped into two groups depending on whether they received a single pancreatic resection (SPS) or iterative pancreatic resection. Data on short and long-term outcome after pancreatic resection were collected. Results: The study included 131 pancreatic resections performed in 116 patients. Thus, iterative pancreatic surgery (IPS) was performed in 15 patients. The mean length of time between the first pancreatic surgery and the second was 48.9 months (95 % CI: 22.2-56.9). There were no differences in the rate of postoperative complications. The DFS rates at 1, 3 and 5 years were 86 %, 78 % and 78 % vs 75 %, 50 % and 37 % in the IPS and SPS group respectively (p = 0.179). OS rates at 1, 3, 5 and 7 years were 100 %, 100 %, 100 % and 75 % in the IPS group vs 95 %, 85 %, 80 % and 68 % in the SPS group (p = 0.895). Conclusion: Repeated pancreatic resection in case of relapse of pancreatic metastasis of RCC in the pancreatic remnant is justified, since it achieves OS results similar to those obtained after the first resection

Resultados de una encuesta sobre el soporte nutricional perioperatorio en la cirugía pancreática y biliar en España

Introduction: a survey on peri-operative nutritional support in pancreatic and biliary surgery among Spanish hospitals in 2007 showed that few surgical groups followed the 2006 ESPEN guidelines. Ten years later we sent a questionnaire to check the current situation. Methods: a questionnaire with 21 items sent to 38 centers, related to fasting time before and after surgery, nutritional screening use and type, time and type of peri-operative nutritional support, and number of procedures. Results: thirty-four institutions responded. The median number of pancreatic resections (head/total) was 29.5 (95% CI: 23.0-35; range, 5-68) (total, 1002); of surgeries for biliary malignancies (non-pancreatic), 9.8 (95% CI: 7.3-12.4; range, 2-30); and of main biliary resections for benign conditions, 10.4 (95% CI: 7.6-13.3; range, 2-33). Before surgery, only 41.2% of the sites used nutritional support (&lt; 50% used any nutritional screening procedure). The mean duration of preoperative fasting for solid foods was 9.3 h (range, 6-24 h); it was 6.6 h for liquids (range, 2-12). Following pancreatic surgery, 29.4% tried to use early oral feeding, but 88.2% of the surveyed teams used some nutritional support; 26.5% of respondents used TPN in 100% of cases. Different percentages of TPN and EN were used in the other centers. In malignant biliary surgery, 22.6% used TPN always, and EN in 19.3% of cases. Conclusions: TPN is the commonest nutrition approach after pancreatic head surgery. Only 29.4% of the units used early oral feeding, and 32.3% used EN; 22.6% used TPN regularly after surgery for malignant biliary tumours. The 2006 ESPEN guideline recommendations are not regularly followed 12 years after their publication in our country.Introducción: realizamos una encuesta sobre soporte nutricional perioperatorio en cirugía pancreática y biliar en hospitales españoles en 2007, que mostró que pocos grupos quirúrgicos seguían las guías de ESPEN 2006. Diez años después enviamos un cuestionario para comprobar la situación actual. Métodos: treinta y ocho centros recibieron un cuestionario con 21 preguntas sobre tiempo de ayunas antes y después de la cirugía, cribado nutricional, duración y tipo de soporte nutricional perioperatorio, y número de procedimientos. Resultados: respondieron 34 grupos. La mediana de pancreatectomías (cabeza/total) fue de 29,5 (IC 95 %: 23,0-35; rango, 5-68) (total, 1002), la de cirugías biliares malignas de 9,8 (IC 95 %: 7,3-12,4; rango, 2-30) y la de resecciones biliares por patología benigna de 10,4 (IC 95 %: 7,6-13,3; rango, 2-33). Solo el 41,2 % de los grupos utilizaban soporte nutricional antes de la cirugía (< 50 % habian efectuado un cribado nutricional). El tiempo medio de ayuno preoperatorio para sólidos fue de 9,3 h (rango, 6-24 h), y de 6,6 h para líquidos (rango, 2-12). Tras la pancreatectomía, el 29,4 % habían intentado administrar una dieta oral precoz, pero el 88,2 % de los grupos usaron algún tipo de soporte nutricional y el 26,5 % usaron NP en el 100 % de los casos. Los demás grupos usaron diferentes porcentajes de NP y NE en sus casos. En la cirugía biliar maligna, el 22,6 % utilizaron NP siempre y NE en el 19,3 % de los casos. Conclusiones: la NP es el soporte nutricional más utilizado tras la cirugía de cabeza pancreática. Solo el 29,4 % de las unidades usan nutrición oral precoz y el 32,3 % emplean la NE tras este tipo de cirugía. El 22,6 % de las instituciones usan NP habitualmente tras la cirugía de tumores biliares malignos. Las guías ESPEN 2006 no se siguen de forma habitual en nuestro país tras más de 10 años desde su publicación