A maioria dos processos de fabricação de um produto geram resíduos. Quando não se dispõem de uma tecnologia para o seu reaproveitamento, certamente este material será depositado na natureza e poderá ocasionar inúmeros problemas ambientais. Este trabalho trata da reutilização dos resíduos de concreto como agregado, para dosagens de concreto estrutural. Na maioria das vezes, os agregados provenientes de resíduos são considerados materiais de baixa qualidade, isso ocorre pelo desconhecimento de suas propriedades e da tecnologia para seu emprego. Fazendo uma pesquisa bibliográfica, teórica e experimental, o objetivo deste estudo foi de uma maneira informativa, contribuir para o entendimento do material, caracterizando algumas propriedades do agregado e do concreto reciclado. / Most of making process of a product produces residue. When there isn\'t a technology to use it again, certainly this material will be deposited in nature and it can bring about countless environmental problems. This work presents the reuse of concrete residues as aggregate, for dosage of structural concrete. Most of times, the aggregates provenient from the residues are considered low quality materials, it occurs due to the lack of knowledge of its properties and technology for its use. Doing a bibliographical, theorical and experimental research, the objective of this study was, on an informative way, to contribute for understanding of the material, characterizing some properties of aggregate and the recycled concrete.

Neste trabalho, buscou-se verificar a possibilidade de, com a utilização do processo eletrolítico, se obter dióxido de manganês a partir da reciclagem de pilhas e baterias exauridas, visto a grande demanda por produtos que utilizam esse mineral. Utilizou-se, para tanto, uma solução eletrolítica que continha os íons metálicos: Ca (270mg/L), Ni (3000 mg/L), Co (630 mg/L), Mn(115300 mg/L), Ti (400 mg/L) e Pb (20 mg/L) em meio de ácido sulfúrico, sintetizada, seguindo-se dados de pesquisa anterior. A produção do dióxido de manganês eletrolítico (DME) foi realizada galvanostaticamente, com a utilização de uma fonte estabilizada que monitorava o potencial do eletrodo de trabalho. Utilizaram-se, preliminarmente, um eletrodo de trabalho de chumbo e dois contra-eletrodos de grafite, à temperatura de 98 ºC (±2ºC) e densidade de corrente de 1,69 A.dm-2. Após a verificação preliminar da possibilidade de obtenção do DME, repetiu-se sistematicamente o processo, aplicando-se variações de densidade de corrente (0,61 A.dm-2 a 1,93 A.dm-2) e de pH (0,00 a 1,20). O material obtido com essas variações foi analisado através dos processos de espectrometria de fluorescência de raios-X, difração de raios-X, área superficial específica pelo método BET e microscopia eletrônica de varredura (MEV). Os melhores resultados quanto a eficiência de corrente, pureza e área superficial se obtiveram com densidade de corrente entre 1,02 A.dm-2 e 1,39 A.dm-2 e com pH 0,50. Em todos os experimentos, como comprova a análise de difração de raios-X, foi constatada a obtenção da variedade alotrópica -MnO2, uma das formas viáveis para utilização na fabricação de pilhas. Os resultados apontam para a viabilidade desse processo de reciclagem como alternativa diante da escassez de fontes naturais de MnO2 com características compatíveis com a aplicação em questão e como forma de diminuição da poluição ambiental causada pelo descarte de pilhas e baterias. / Considering the growing demand for products containing manganese in its composition, this work seeks to verify the possibility of using depleted batteries as a source of manganese applying the electrolytic process. It was used an electrolyte solution containing the metal ions: Ca (270mg / L), Ni (3000 mg / L), Co (630 mg / L), Mn (115300 mg / L), Ti (400 mg / L) and Pb (20 mg / L) in concentrated sulfuric acid, following data from previous research. The production of electrolytic manganese dioxide (EMD) was performed through galvanization using a stabilized source that monitored the potential of the working electrode. It was preliminary used an electrode of lead and two counter electrodes of graphite at a temperature of 98ºC (± 2ºC) and current density of 1.69A.dm-2. After preliminary verifying the possibility of obtaining electrolytic manganese dioxide (EMD), the process was systematically repeated, applying different current density (0.61A.dm-2 to 2.51A.dm-2) and pH (0.00 to 1.20). The material obtained at these variations was analyzed through the process of X-ray fluorescence spectrometry, X-ray diffraction, specific surface area (BET) and scanning electron microscopy (SEM). The best values referring to current efficiency, level of purity and specific surface area were obtained with the current density ranging between 1.02 A.dm-2 and 1.39 A.dm-2, and pH 0.50. In any of the tested electrolysis conditions the -MnO2 structure was obtained as evidenced by the diffraction of X-rays analysis. The results indicate the feasibility of this recycling process as an alternative before shortage of natural sources of MnO2 and as a means of reducing environmental pollution caused by the disposal of batteries.

"A ¡°mixed cathodes¡± LIB recycling process was first proposed and developed in the CR3 center at Worcester Polytechnic Institute. This process can efficiently and economically recover all the valuable metal elements in LIB waste. In the end of the recovery process, lithium, nickel, manganese, and cobalt ions will be recovered in the leaching solution. The objective of this work is to utilize the leaching solution to synthesis NixMnyCoz(OH)2 precursors and their corresponding LiNixMnyCozO2 cathode materials. The synthesized cathode materials can be used to build new LIBs, allowing the overall process to be a ¡°closed loop¡±. "

Waste plastic treatment was a global issue currently. A sustainable recycling process was required to recovery the monomer units from the polymer, thus avoiding environmental impacts due to disposal and enhancing the economic benefit from the recovered products. Pyrolysis was one of the promising process and previous MQP group has studied the pyrolysis with molten salts. In this work, a standardized and optimized pyrolysis reaction process of polystyrene was developed, based on the previous work on molten salt pyrolysis 5. The literature of pyrolysis mechanism and catalytic effects were reviewed as a guide process design. The orientation of the reactor was standardized to be consistent with literature record of preceding work. The positioning of the flow tube for the carrier gas and thermocouple were standardized in locations to provide mixing process of the reactant, the removal of products, and the accurate measurement of reaction temperature. The product collection system was also investigated and optimized to maximize collection efficiency while avoiding excessively low temperatures. The experiment results with standardized reaction configuration showed an improved styrene yield, 65%, compared with a previous yield of 44%. Then with the standardized reaction configuration, the catalytic effects of molten salt were studied at 400℃ pyrolysis temperature. Quantitative analysis indicated that the molten salt improved the styrene selectivity of the monomer compared to the dimer. Analysis of product composition and mass balance indicated formation of heavy non-GC detectable species in the liquid products. Gas phase secondary reaction during pyrolysis, and re-polymerization inside the liquid products, were discussed to explain the different styrene yield and the existence of heavy species. Based on the current results, recommendations for the pyrolysis temperature, initial reactants loading, and condenser temperature and analysis strategies were provided for further study of the molten salt pyrolysis of polystyrene.

In the metalworking industry lubricants are used for   production. For production of seamless stainless steel pipes Sandvik   Materials Technology uses chlorinated pilgering oil, a lubricant produced   from paraffin and chlorine. Today these lubricants are disposed by   incineration when the lubricant is too contaminated so production drops, and   the lubricant is replaced by new lubricant. RecondOil found a solution to clean   these oils instead of disposing them. To assess the environmental impact for   the process of cleaning a screening Life Cycle Assessment (LCA) was   conducted. The functional unit used is the amount of chlorinated pilgering   oil used per year, and impact categories were chosen to be Global Warming   Potential (GWP) and Acidification Potential (AP). The study was conducted for   the impact from cradle to grave. The outcome of the LCA showed that the main   impact for GWP comes from the disposal phase for the conventional process,   which is incineration. For the cleaning and reusing process major impacts   where found to be from the transportation of raw materials, half-fabricates,   products and waste. It was found that only transportation had a major impact   on AP. The results show that for both GWP and AP the recycling process has   lower potential emissions than the conventional method, but further research   on for example electricity and chlorine production is needed to compose a   better comparison of the two processes from a life cycle perspective. / <p>2018-06-08</p>

Digitized by Kansas Correctional Industries

: It is problematic from an environmental point of view when consumers have damaged or worn out textiles and need to dispose of them (Domina and Koch, 2002). Domina and Koch (2002) explain that unwanted consumer textiles that are not suited for donation to charity organizations, are simply thrown into the trash. Textiles are nearly 100 percent recyclable and according to Hawley (2006), nothing in the textile and apparel industry consequently should be wasted. It will be a major positive impact on the environment if we can reduce the amounts of textile waste through recycling. In addition, recycling will reduce the emissions arising from new manufacturing by making use of existing resources (Naturvårdsverket, 2013). Recycling signifies any recovery operation by which waste materials are re-processed into products, materials or substances (Tojo., et al. 2012). It is an ecosystem-inspired design approach where all waste from one component of the system becomes food for another (Fletcher, 2008). There is currently no large scale recycling of textiles in Sweden, nor is there any major export for recycling of Swedish textiles (Palm, 2011). But Swedish producers and retailers have started to consider the value of re- establishing a recycling plant within the country (Tojo et al., 2012). The future market of the textile industry faces an inevitable challenge. It is important to find materials that could replace the large amount of cotton used today and find solutions on how to produce synthetic fiber without increasing the yield of oil (Sandow, 2012). In addition, Consequently, there might be a greater demand for recycled textile fibers in the future. However, the issue of the implementation of a textile recycling system in Sweden is complex with many aspects to take into account. The aim for this report was to explore the areas of research in textile recycling, and by dint of seven experts, determine whether or not Sweden should implement a textile recycling system, and how that should be done. The essential factors for implementing a textile recycling system in Sweden was concluded to be: environmentally sustainable growth, better technology and chemistry, consumer responsibility, producer responsibility, supply of textiles for recycling, demand for recycled fibers, facilitating the voluntary organizations (optimizing reuse), pricing and profitability, sustainable and economical logistics, supporting policies, sustainable products that are easy to recycle, global collaborations. It was concluded that Sweden should implement a textile recycling system. The initial phase of the system (within ten years) should be to establish collecting arrangement for textiles in all conditions. The discarded textiles should be sorted in Sweden and exported for recycling. If the textile industry will shift to having a near-sourcing strategy and if synthetic cellulose fibers will revive the Swedish textile industry, Sweden could benefit from having a complete recycling system within 20 years. / Program: Applied Textile Management

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Bibliography: leaves 95-96. / by Cordelia Mae Price. / M.S.

Le polylactide (PLA) est un polymère à la fois biodégradable et biosourcé focalisant l'attention des chercheurs pour le remplacement des plastiques conventionnels. A la température ambiante, le PLA est fragile et nécessite d’être modifié par plastification physique afin d’augmenter sa ductilité, mais dans le même temps sa rigidité chute fortement. Une alternative à cette plastification physique est la plastification par extrusion réactive. L’extrusion réactive du PLA avec l’acrylate de poly(éthylène glycol) (acrylPEG) donne lieu à un PLA plastifié nommé pPLA. Cette thèse a pour objectifs l’identification de la structure du pPLA et l’étude de son évolution lors de transformations thermomécaniques d’étirage et de recyclage. La structure du pPLA a été analysée par une approche multi-échelles et multidisciplinaire. L’acrylPEG polymérisant et formant des inclusions, est partiellement greffé au PLA et partiellement libre. De plus, les réactions conduisent à une légère réticulation de la matrice. La présence de plastifiant conduit à un bon équilibre entre rigidité et ductilité. Les mécanismes de déformation du pPLA sous étirage ont montré que les mécanismes d’orientation moléculaire sont prépondérants par à l’endommagement, qui lui prédomine dans le PLA. L’analyse du recyclage thermomécanique du pPLA a mis en évidence une dégradation du matériau dépendant du type de procédé utilisé. L’utilisation de la compression à chaud est le procédé le plus défavorable, conduisant à une dégradation plus importante du pPLA par rapport au PLA. Ces travaux ont permis de développer des méthodologies de caractérisation permettant une meilleure identification structurale des biopolymères / Polylactide (PLA), a biodegradable and bio-based polymer, raised researchers’ attention to replace conventional plastics. At room temperature, PLA is brittle and requires physical plasticization that increases its ductility but at the same time drastically decreases its stiffness. As an alternative, plasticization by reactive extrusion was recently developed. The reactive extrusion of PLA with acrylated poly(ethylene glycol) (acrylPEG) as plasticizer yields a plasticized PLA named pPLA. This thesis aims at identifying the structure of this pPLA and studying its evolution engendered by thermomechanical transformations as drawing and recycling. First, pPLA’s structural features are analyzed by a multi-scale and multi-disciplinary approach. pPLA is characterized by partially grafted and partially free inclusions of the polymerized plasticizer and a slightly crosslinked PLA matrix. These plasticizer inclusions lead to a material with a good stiffness-ductility balance. Second, the deformation mechanisms of pPLA upon drawing indicate that chain orientation mechanisms are predominant compared to damage, the latter dominating deformation in PLA. Third, the thermomechanical recycling of pPLA shows that degradation is dependent on the type of processing step. Compression-molding is detrimental to pPLA inducing after recycling a higher degradation compared to PLA. This thesis releases new characterization methodologies enabling a better identification of biopolymer structural features

With millions of people involved in collecting and treating recyclable products, waste recycling provides a critical entry point to an investigation of the spaces and dynamics of the Chinese economy. Based on sixteen months of in-depth ethnographic research, this thesis, 'Invisible spaces: variegated geographies of waste in China', describes and analyses waste and its boundaries, as well as the actors that deal with it at different scales within the country. The work examines how waste circulates, how it is regulated, and how it is represented in China. It presents stories of the people and places that configure the waste industry, and situates its analysis at the intersection of three different strands of literature: i) variegated capitalism; ii) informal economy; and iii) geographies of waste. The research contends that the 'afterlives' of goods are a productive prism which can be used to understand the variegated mode of capitalism in contemporary China and thus investigates the following question: to what extent do the different cultural, social, political, economic, and material dimensions of waste reveal the heterogeneous characteristics of Chinese capitalism? Central to my analysis is the concept of invisibility. I conceive invisibility as a socio- political process that brings about an uneven access to resources and labour for subaltern groups, as well as a relational concept encompassing the three complementary and dialectical dimensions of absolute, relative, and relational space. Invisibility is not only a metaphor to define the agency of informal workers, but also an allegory to describe the marginalisation of their activities and spaces. It is an asset and a curse, a condition and a strategy. These multiple dimensions make invisibility a productive device bringing to light the geographies of different accumulation regimes and everyday practices, as well as a potent tool to analyse the alternative representations of waste, value, labour, and development at play in contemporary China. With this in mind, the thesis engages with a number of important debates in geography. In particular, the five empirical chapters engage with literature on global production networks, labour geography, primitive accumulation, geographies of waste, and urban political ecology. While drawing these literatures into conversation with the variegated capitalism framework, the work suggests that the invisibility of waste activities is a powerful tool to analyse the nature and the mechanisms of the variegated modes of production in contemporary China.