Pulp Mill Wastewater: Characteristics and Treatment

The production of chemical pulp in recent times is 180 million tons per year; while the production of eucalyptus pulp has increased intensively, especially in the southern hemisphere. The pulp and paper industry has long been considered a large consumer of natural resources (wood and water) and one of the largest sources of pollution to the environment (air, water courses and soil). Important efforts are being made to reduce the pollutant levels and water consumption of the industry. The wastewater composition, and therefore, the efficiency of effluent treatments and characteristics of the discharges to water are strongly dependent on the applied technology and raw materials. Despite a large body of literature on softwood-based wastewater, few studies have examined the characteristics of kraft eucalyptus bleaching effluents and their behaviour in the different biological treatments. The largest secondary treatment systems today use the activated sludge process. Sixty to seventy-five per cent of all the biological effluent treatment plants within the pulp and paper industry use this kind of treatment system. This chapter reviews the current pulping technologies at mills and compares the chemical composition and biological treatment of wastewater between softwood and hardwood bleached pulps

La educación formal como instituido que media los procesos de inclusión/exclusión de las personas en situación de discapacidad

En estas sociedades occidentales modernas, deviene como “normal" y cotidiano la uniformización de los sujetos; resultando valores cada vez más preciados y exigidos la hegemonía en pensamiento, acción y sensación. En este sentido, y para el logro de tal emprendimiento, se entiende que han ido cambiando a lo largo de estos últimos tres siglos las formas de requerir tal hegemonía, no así la esencia de la misma, orientando a los seres en su individualidad y colectivamente hacia una hegemonía del deber ser. Se considera en este trabajo a la educación formal como uno de los pilares en los que se ha sostenido la formación de los sujetos sociales modernos. Será en base a las demarcaciones propias del disciplinamiento y la normalización adquirida a través de la currícula educativa que se delimiten marginalidades entre lo que se es y lo que se espera de cada sujeto.In these modern societies, becomes as "normal" and ordinary the uniformization of people, precious and required values which results of hegemony in thought, action and feeling. In this sense, it means that they have evolved over these last three centuries the forms of "require" such hegemony, not the essence itself, orienting to humans in their individuality and collectively to hegemony of the duty to be. It is considered the formal education as one of the pillars on which it has been argued the formation of modern social persons; based on discipline and normalization through educational curricula that preclude marginalities between what is and what is expected of each person.Fil: Míguez Passada, María Noel.Fil: Silva Cabrera, Cecilia

Summer 2018 GCSE, AS and A level exams : a summary of our monitoring

Uruguay has a forest resource of 1 million ha plantation of fast-growing eucalyptus and pine. Short-fiber pulp is the country second export product in value, but there is also a significant production of plywood and graded kiln-dried timber from both species, used mainly for appearance applications. However, the value chain of the wood industry is not yet fully developed, particularly for pine. This study classified different existing and potential wood products using added value as criteria, calculated at the industry level by adopting a system of inputs and outputs. Hypothetical plants to manufacture these products were technical and economically analyzed: thermally modified timber, cross laminated timber, laminated veneer lumber, pine timber, bleached Eucalyptus kraft pulp, pine bleached chemical thermo-mechanical, medium density fiberboards, oriented strand board and a power plant fueled with forest biomass. The data used for this study was obtained from the final project of undergraduate engineer students of the Faculty of Engineering, Universidad de la República, Uruguay, except for the eucalyptus pulp mill, which was proposed by the authors. The results showed that wood products obtained from logs that are the main objective of the plantation presented a higher added value than those manufactured from forest residues, thinnings or chips from the sawmilling industry. Solid wood products for appearance or structural applications are at the top of added value list, considering value added per product, unit of biomass or unit of forest land per year. The integration of the value chain of the products analyzed, linking solid wood products with panels or pulp, has the potential to boost the addition of value of the forest biomass in Uruguay

Breeding Phenology and New Host List of the Black-Headed Duck (<i>Heteronetta atricapilla</i>) In Argentina

The Black-headed Duck (Heteronetta atricapilla) is a unique interspecific brood parasite among birds where the host species provides parental care for incubation only. Despite this unique system, there are few studies on this species biology and the list of hosts remains incomplete. We present information about breeding phenology of the Blackheaded Duck and an updated list of hosts obtained from a comprehensive review of egg collections deposited in the most important natural science museums of Argentina. We include five new hosts to the list: Great Grebe (Podiceps major), Maguari Stork (Ciconia maguari), White-cheeked Pintail (Anas bahamensis), South American Stilt (Himantopus mexicanus), and Long-winged Harrier (Circus buffoni). We found that solitary nesting host species were more likely to be parasitized earlier during the breeding season than colonial nesting species. The Black-headed Duck has an extended breeding season in central Argentina (Aug–Feb) as it is able to use a variety of hosts that breed in different times during the breeding season. With this contribution, the new list rises to 23 documented hosts of the Black-headed Duck belonging to eight different waterfowl orders.Facultad de Ciencias Naturales y Muse

Ecdiesteroides II. Propiedades geométricas y electrónicas: una aproximación QSAR para determinar el potencial de actividad biológica

Se hace un análisis molecular a nivel semiempírico de los ecdiesteroides, uno de los grupos hormonales más importantes del reino animal. Actualmente, se han descrito mas de 120 compuestos naturales pertenecientes a esta familia, los cuales están involucrados en los procesos de metamorfosis, desarrollo, reproducción y activación metabólica de los procesos vitales de los invertebrados (esp. Artrópodos) y además, pueden ser antagónicos de los brasinoesteroides en plantas, donde actúan como agentes protectores contra insectos fitófagos. En esta comunicación, se describen los estudios preliminares mecanocuánticos y estructurales, de 21 ecdiesteroides naturales diferentes (a partir de la ecdisona y sus modificaciones) y la relación estructuraactividad biológica, así como los principales parámetros y descriptores que potencian la acción ecdiesteroide y las interacciones con el receptor (distancia O3-O22; O22HOMO 3; áng. 2,3,4; áng. 8,9,10; distancia C2-C3; O3 Mayor contribuyente a HOMO-3; Carga de C16) . Se detalla el proceso analítico hasta la obtención de una ecuación que describe el comportamiento de las relaciones estructura-actividad para una serie de dichos compuestos a partir de las variables determinadas a partir de cuya resolución se diferencian significativamente los grupos de moléculas con actividad biológica diferente a partir de la estructura base. Y = 15 071,3 + 66,506 (O22 HOMO 3) 10,166 (O3 HOMO-3) + 34,278 (distancia O3-O22) +172,698 3 (distancia C2-C3) 24, 306 (áng. C2,3,4) +127, 276 (áng. C8,9,10) 611,975 (qC16)

Alkali-peroxide treatment of sugar cane bagasse : Effect of chemical charges on the efficiency of xylan isolation and susceptibility of bagasse to saccharification

Sugar cane is a promising raw material for the extraction of hemicelluloses. An alkali treatment of sugar cane bagasse under proper conditions followed by a precipitation using a reasonable quantity of ethanol can be an effective method to isolate these polysaccharides. In this work, bagasse is treated to obtain two products: (a) polymeric hemicellulose and (b) an enzymatic hydrolysate from the treated bagasse after hemicellulose extraction. The effects of charges of sodium hydroxide (10, 20, 40% w/w) and hydrogen peroxide (0, 10, 20% w/w) in the alkali treatment were evaluated. A 3² experimental design was considered under control of metal ions and inert atmosphere during alkaline treatment. An acceptable proportion of xylose plus arabinose could be extracted from bagasse (up to 18.4 g/100 g of bagasse). Both the alkali and peroxide showed strong effects on the yield of the extraction, as well as on the yield of the precipitation in ethanol-water solution. Besides, the susceptibility of bagasse for cellulolytic enzymatic hydrolysis is improved. The highest hemicellulose precipitation yield was 85% which corresponded to the treatment with the highest alkali charge without peroxide. The highest yield of enzymatic hydrolysis was obtained for the highest alkali and peroxide charges.Instituto de Fisiología VegetalInstituto de Botánica "Dr. Carlos Spegazzini

Alternatives for the Management of Industrial Forest Waste: Energy, Bioethanol, and Cellulose Pulp

Modern kraft pulp mills generate solid waste of 1–2% of incoming debarked wood. Given the size of these plants, with an annual production capacity of at least 1000,000 tons, each plant generates 20,000–30,000 dry tons of waste per year. The largest current use of these residues is for combustion in biomass boilers for steam and power generation. However, the conversion of biomass into biofuels and chemicals is gaining interest due to increasing demands for energy, limited sources of fossil fuels, and growing concerns about the environmental impact of greenhouse gas emissions. This chapter shows the laboratory-scale results of the use of eucalyptus wood wastes to obtain cellulose pulp by alkali pulping reinforced with hydrogen peroxide to obtain alkaline peroxide mechanical pulp or cellulosic bioethanol. Based on the results, an industrial-scale techno-economic analysis of the processes is presented and compared with current alternatives for energy generation

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Extracción y purificación de hemicelulosas provenientes de madera de eucalipto

En el presente trabajo de Tesis se estudiaron distintas formas de extracción de hemicelulosas provenientes de eucalipto, así como diferentes métodos de purificación y concentración de las hemicelulosas extraídas y se caracterizaron las mismas. Se escogió como biomasa a utilizar la madera de eucalipto, ya que es un material que existe de forma abundante en Uruguay y que presenta perspectivas ciertas de crecimiento, mantenimiento y explotación de las hectáreas actualmente plantadas a mediano y largo plazo. Actualmente el eucalipto se utiliza para la producción de pulpa de celulosa y de tablas y chapas en aserraderos, generando un residuo que, hoy en día es quemado en calderas de biomasa para la generación de vapor y energía. Se considera que la utilización de este residuo para la producción de productos de mayor valor agregado, en el marco de una biorrefinería lignocelulósica, puede ser muy atractiva. Las hemicelulosas de eucalipto se componen mayoritariamente de O‐acetil‐4‐Ometilglucorono‐ β‐D‐xilano, normalmente denominados glucoronoxilanos o xilanos. En este trabajo se ensayaron en primera instancia diversas formas de extracción de estos xilanos de la matriz lignocelulósica. Particularmente se trabajó con pretratamientos con agua (pretratamiento hidrotérmico con agua caliente y pretratamiento por explosión a vapor) y alcalinos (pretratamiento con licor verde, con hidróxido de sodio y con hidróxido de sodio y peróxido de hidrógeno). Todos estos tratamientos se realizaron sobre residuos industriales de eucalipto, a excepción del tratamiento con licor verde, donde se analizó la pre‐extracción de hemicelulosas sobre chips, previo a su pulpeo en el marco de una planta de celulosa Kraft

Breeding phenology and new host list of the Black-headed Duck (Heteronetta atricapilla) in Argentina

The Black-headed Duck (Heteronetta atricapilla) is a unique interspecific brood parasite among birds where the host species provides parental care for incubation only. Despite this unique system, there are few studies on this species biology and the list of hosts remains incomplete. We present information about breeding phenology of the Black-headed Duck and an updated list of hosts obtained from a comprehensive review of egg collections deposited in the most important natural science museums of Argentina. We include five new hosts to the list: Great Grebe (Podiceps major), Maguari Stork (Ciconia maguari), White-cheeked Pintail (Anas bahamensis), South American Stilt (Himantopus mexicanus), and Long-winged Harrier (Circus buffoni). We found that solitary nesting host species were more likely to be parasitized earlier during the breeding season than colonial nesting species. The Black-headed Duck has an extended breeding season in central Argentina (Aug-Feb) as it is able to use a variety of hosts that breed in different times during the breeding season. With this contribution, the new list rises to 23 documented hosts of the Black-headed Duck belonging to eight different waterfowl orders.Fil: Cabrera, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; ArgentinaFil: Montalti, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Segura, Luciano Noel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin