Utilització de no teixits de fibres vegetals per al seu ús com a reforç de materials cimentosos.

Since ancient times it has been used different construction materials. Cement has always been the material used in construction, and even years these were used for cement used on roofs of industrial buildings and elements of sanitation (drains). But the relationship of asbestos material used in this cancer are appearing with regulations banning the use of this material, making it virtually nonexistent around 2000. Thus, this material was replaced in those covered by steel plates, and the drains for plastics. Currently, almost the only company in Europe that manufactures this material are they trying to redo cement again, but with both natural and synthetic fibers, although much remains to be done The main problems of these fiber cement plant fibers are degraded cellulose fiber content due to Ca (OH) 2 cement; and loss of fiber-matrix adhesion for the volume variations experienced by fibers due to changes in humidity. Therefore, this study will evaluate two treatments for solving the above problems. Pozzolans use substances to reduce lime hydroxide (Ca (OH) 2); and applying different treatments to the fibers, as cornification and ironing, ... plasma treatment to enhance the volumetric stability thereof. So the fiber-matrix adhesion is measured on the basis of the two above mentioned treatments. To accomplish this, there have been seven matrices with different concentrations of cement and pozzolanic materials to carry them further study bending and compression, to choose the matrix with more reduction hydroxide lime, and also with more resistance. Furthermore, regarding the treatment of fibers, we have differentiated to 5 treatments, whether iron, autoclave, both two or argon plasma. Furthermore, regarding the treatment of fibers, we have differentiated to 5 treatments, whether iron, autoclave, both two or argon plasmaDes de l'antiguitat s'ha utilitzat diferents materials per a la construcció. El ciment sempre ha estat el material més utilitzat en la construcció, i fins els anys aquests era utilitzar per obtenir fibrociment utilitzat en cobertes de naus industrials i elements de sanejament (desguassos). Però la relació de l'amiant utilitzat en aquest material amb el càncer, van apareixen normatives amb la prohibició de l'ús d'aquest material, fent-lo pràcticament inexistent al voltant de l'any 2.000. Així, aquest material va ser substituït en les cobertes per xapes d'acer, i en els desguassos per materials plàstics. Actualment, quasi la única empresa a Europa que fabrica aquest material, està intentant tornar a fer fibrociment de nou, però amb fibres tant naturals com sintètiques, tot i que encara queda mol camí per fer. Els principals problemes d'aquests fibrociments amb fibres vegetals són: una degradació de la cel·lulosa de la fibra degut al contingut de Ca(OH)2 del ciment; i una pèrdua d'adherència matriu-fibra per les variacions de volum que experimenten les fibres a causa dels canvis d'humitat. Per tant, en aquest treball valorarem dos tipus de tractaments per tal de solucionar els problemes anterior. Utilitzarem substancies putzolanes per tal de reduir l'hidròxid de calç (Ca(OH)2); i una aplicació de diferents tractaments a les fibres, com la cornificació i planxat, tractaments amb plasma... per tal de millorar l'estabilitat volumètrica d'aquestes. Així es valorarà l'adherència fibra-matriu a partir dels dos tractaments anomenats anteriorment. Per dur a terme aquests, s'han realitzat 7 matrius amb diferents concentracions de ciment i materials putzolànics per tal de dur-les a un estudi posterior de flexió i compressió, per escollir la matriu amb més reducció d'hidròxid de calç, i també amb més resistència. D'altre banda, en quant els tractament de les fibres, hem diferenciat fins a 5 tractaments, ja siguin planxa, autoclau, ambos dues o amb plasma d'argó.Desde la antigüedad se ha utilizado diferentes materiales para la construcción. El cemento siempre ha sido el material más utilizado en la construcción, y hasta los años estos era utilizar para obtener fibrocemento utilizado en cubiertas de naves industriales y elementos de saneamiento (desagües). Pero la relación del amianto utilizado en este material con el cáncer, van apareciendo normativas con la prohibición del uso de este material, haciéndolo prácticamente inexistente alrededor del año 2000. Así, este material fue sustituido en las cubiertas por chapas de acero, y en los desagües para materiales plásticos. Actualmente, casi la única empresa en Europa que fabrica este material, está intentando volver a hacer fibrocemento de nuevo, pero con fibras tanto naturales como sintéticas, aunque todavía queda mucho camino por hacer Los principales problemas de estos fibrocementos con fibras vegetales son: una degradación de la celulosa de la fibra debido al contenido de Ca (OH) 2 del cemento; y una pérdida de adherencia matriz-fibra para las variaciones de volumen que experimentan las fibras debido a los cambios de humedad. Por tanto, en este trabajo valoraremos dos tipos de tratamientos para solucionar los problemas anterior. Utilizaremos sustancias puzolanas para reducir el hidróxido de cal (Ca (OH) 2); y una aplicación de diferentes tratamientos a las fibras, como la cornificación y planchado, tratamientos con plasma ... para mejorar la estabilidad volumétrica de éstas. Así se valorará la adherencia fibra-matriz a partir de los dos tratamientos mencionados anteriormente. Para llevar a cabo estos, se han realizado 7 matrices con diferentes concentraciones de cemento y materiales puzolánicos para llevarlas a un estudio posterior de flexión y compresión, para escoger la matriz con más reducción de hidróxido de cal, y también con más resistencia. Por otro lado, en cuanto los tratamiento de las fibras, hemos diferenciado hasta 5 tratamientos, ya sean plancha, autoclave, ambos dos o con plasma de argón. Por otro lado, en cuanto los tratamiento de las fibras, hemos diferenciado hasta 5 tratamientos, ya sean plancha, autoclave, ambos dos o con plasma de argón

Estudio de la viabilidad técnico-económica y ambiental de la gestión de fangos EDAR por adición de CaO para su valorización en la industria cementera

Urban wastewater treatment plants produce a variety of residuals during their operation, the typology of which are in function of the design of the treatment process. The problem aborded in the present thesis refers to the sludge produced as a result of the treatment. After the banning of disposal to continental and/or marine waters, established at the EU through Directive 91/271 CEE and then in Spain trough Royal Decree [RD 11/95] those sludges should be object, essentially after treatment, of controlled using or disposition. Previously to the using or disposition a previous treatment can be required, that could be organic (essentially composting with other amendments), drying or other physic-chemical treatment, between those last alkaline stabilization. Alkaline stabilization can accomplish on a single step reduction or elimination of pathogen vectors, smell elimination and a reduction in the putrefaction potential. Its base is the alteration of the physic-chemical characteristics of the environment of the sludge by addition of alkaline material. One of the processes of inertization, object of the analysis proposed in the present thesis, is the treatment realized trough addition of calcium oxide. Essentially it is a physic-chemical treatment trough which it is possible to obtain a dry product with the addition of calcium oxide (quicklime) to the urban wastewater sludge. The result of the chemical reactions and water evaporation is oriented to obtain a dry product (10% humidity) as powder and with a reduction of mass in relation to the original wastewater sludge of about 40%. The realized work have been developed over the basis of the analysis of the technical, economical and environmental feasibility of the proposed alternative, using though normalized methodology on each of the different concrete aspects that are developed. A very important part of the experimental work which validates the technology under study has been developed at pilot plant level. Additionally, the proposed management alternative of the sludge includes using the inertized sludge as a secondary raw material in Portland cement clínker production, having been developed a industrial pilot test to validate the theoretical hypothesis been established. The thesis has been developed in the core of task 6b of Project Sostaqua in program CENIT, promoted by the Centro para el Desarrollo Tecnológico e Industrial (CDTI). This had as an objective the creation of new knowledge to contribute to the development of a sustainable water life cycle. Being the sludge part of that cycle, task 6b has intended demonstrate the feasibility of the treatment with addition of alkaline agents, in this case with addition of calcium oxide. Over the basis of the obtained results it has been considered that the proposed process constitutes a feasible alternative to the management of the urban wastewater sludge. Considering that this management it is a difficult task to abroad, due to the technical difficulties implied, it should be convenient to diversify the alternatives in order to have backup treatment capacity in order to avoid the final disposition to landfill

Economic impacts of alternative water policy scenarios in the Spanish production system: an input-output analysis

The objective of this paper is to analyse the economic impacts of alternative water policies implemented in the Spanish production system. The methodology uses two versions of the input-output price model: a competitive formulation and a mark-up formulation. The input-output framework evaluates the impact of water policy measures on production prices, consumption prices, intermediate water demand and private welfare. Our results show that a tax on the water used by sectors considerably reduces the intermediate water demand, and increases the production and consumption prices. On the other hand, according to Jevons' paradox, an improvement in technical efficiency, which leads to a reduction in the water requirements of all sectors and an increase in water production, increases the amount of water consumed. The combination of a tax on water and improved technical efficiency takes the pressure off prices and significantly reduces intermediate water demand. JEL Classification: C67 ; D57 ; Q25. Keywords: Production prices; Consumption prices; Water uses; Water policy; Water taxation.Preus, Consum (Economia), Aigua-Utilització, Aigua-Polítiques de gestió, Aigua-Impostos,