A presença de elevados teores de elementos metálicos nos resíduos industriais desperta o interesse no seu reaproveitamento. O setor coureiro-calçadista, por exemplo, importante no estado do Rio Grande do Sul, produz resíduos perigosos provenientes da etapa de curtimento do couro ao cromo. A possibilidade de utilização deste importante metal contido no resíduo se tornou realidade a partir da introdução, em nível piloto, de uma unidade de incineração. A cinza dos resíduos é utilizada, neste trabalho, como matéria-prima para a produção de uma liga ferro-cromo do tipo alto carbono (FeCrAC) – que tem amplo emprego na produção de aço-inoxidável; outros resíduos industriais do Estado também são utilizados neste processo extrativo. A cinza – denominada CIAC neste trabalho –, matéria-prima principal e fonte de cromo, contém ~50% Cr2O3. Outros resíduos empregados como insumos foram: finos de carvão vegetal da produção de carvão para a preparação de alimentos, sílica proveniente de operações de polimento de peças de ágata, carepa de produtos siderúrgicos e casca de ovos. O cálculo da carga foi realizado com a ajuda da termodinâmica computacional, pela simulação do processo de redução carbotérmica na temperatura de 1600 °C e pressão de 1 atm. A simulação utilizou algumas metas como diretrizes: i) obtenção de uma escória com a menor temperatura sólidus possível; (ii) obtenção de uma escória de baixa viscosidade; e, (iii) obtenção de teores apropriados de Cr e C na liga. Devido ao alto teor de P da CIAC, um procedimento experimental para a redução deste elemento foi estabelecido tendo por base (i) o uso de reagentes baratos e (ii) a sinergia que decorre da conjunção destes reagentes. Para a produção da liga ferro-cromo, seis tipos de experimentos foram realizados variando-se a composição da carga (fontes do cromo e ferro) e dois lotes diferentes da cinza. Os teores de Cr e C nas ligas FeCr obtidas nos experimentos variaram entre: 50 - 60 % Cr e 7 - 10% C, demonstrando a possibilidade de reutilização do cromo contido nas cinzas, para produção da liga FeCr. / The presence of high levels of metals in industrial waste arouses interest in its reuse. The leather-footwear industry, for example, important in the state of Rio Grande do Sul, produces hazardous Cr-containing waste from the leather tanning stage. The possibility for reuse of this important metal contained in the residue became a reality with the introduction, in a pilot project, of an incineration plant. The ash waste is used in this work as a raw material for the production of high carbon ferro-chrome type (FeCrAC) - which has wide use in the production of stainless steel; other industrial waste are also used in this extraction process. Ash - called CIAC thereafter - the main raw material and source of chromium, contains ~ 50% Cr2O3. Other residues employed as inputs were: coal fines from coal production plant for food preparation, silica from polishing operations from pieces of agate mill, scale from steel products and egg shell. The reactor load calculation was carried out with the help of computational thermodynamics, the simulation being of the carbothermic reduction process at a temperature of 1600 °C and 1 atm pressure. The simulation used as targets some guidelines: i) production of a slag with a lower solidus temperature as possible, (ii) or a low viscosity slag, and (iii) to provide suitable amounts of C and Cr in the alloy. Due to the high P content of CIAC, an experimental procedure for the reduction of this element was established based on (i) the use of inexpensive reagents, and (ii) the synergy arising from the combination of these reagents. For the production of ferro-chromium six types of experiments were performed varying the charge composition (sources of Cr and Fe) and two different lots of ash. The Cr and C contents in FeCr alloy in the experiments varied between 50 - 60% Cr and 7 - 10% C, demonstrating the possibility for reuse of Cr contained in the ashes for the production of FeCr alloy.

A presença de elevados teores de elementos metálicos nos resíduos industriais desperta o interesse no seu reaproveitamento. O setor coureiro-calçadista, por exemplo, importante no estado do Rio Grande do Sul, produz resíduos perigosos provenientes da etapa de curtimento do couro ao cromo. A possibilidade de utilização deste importante metal contido no resíduo se tornou realidade a partir da introdução, em nível piloto, de uma unidade de incineração. A cinza dos resíduos é utilizada, neste trabalho, como matéria-prima para a produção de uma liga ferro-cromo do tipo alto carbono (FeCrAC) – que tem amplo emprego na produção de aço-inoxidável; outros resíduos industriais do Estado também são utilizados neste processo extrativo. A cinza – denominada CIAC neste trabalho –, matéria-prima principal e fonte de cromo, contém ~50% Cr2O3. Outros resíduos empregados como insumos foram: finos de carvão vegetal da produção de carvão para a preparação de alimentos, sílica proveniente de operações de polimento de peças de ágata, carepa de produtos siderúrgicos e casca de ovos. O cálculo da carga foi realizado com a ajuda da termodinâmica computacional, pela simulação do processo de redução carbotérmica na temperatura de 1600 °C e pressão de 1 atm. A simulação utilizou algumas metas como diretrizes: i) obtenção de uma escória com a menor temperatura sólidus possível; (ii) obtenção de uma escória de baixa viscosidade; e, (iii) obtenção de teores apropriados de Cr e C na liga. Devido ao alto teor de P da CIAC, um procedimento experimental para a redução deste elemento foi estabelecido tendo por base (i) o uso de reagentes baratos e (ii) a sinergia que decorre da conjunção destes reagentes. Para a produção da liga ferro-cromo, seis tipos de experimentos foram realizados variando-se a composição da carga (fontes do cromo e ferro) e dois lotes diferentes da cinza. Os teores de Cr e C nas ligas FeCr obtidas nos experimentos variaram entre: 50 - 60 % Cr e 7 - 10% C, demonstrando a possibilidade de reutilização do cromo contido nas cinzas, para produção da liga FeCr. / The presence of high levels of metals in industrial waste arouses interest in its reuse. The leather-footwear industry, for example, important in the state of Rio Grande do Sul, produces hazardous Cr-containing waste from the leather tanning stage. The possibility for reuse of this important metal contained in the residue became a reality with the introduction, in a pilot project, of an incineration plant. The ash waste is used in this work as a raw material for the production of high carbon ferro-chrome type (FeCrAC) - which has wide use in the production of stainless steel; other industrial waste are also used in this extraction process. Ash - called CIAC thereafter - the main raw material and source of chromium, contains ~ 50% Cr2O3. Other residues employed as inputs were: coal fines from coal production plant for food preparation, silica from polishing operations from pieces of agate mill, scale from steel products and egg shell. The reactor load calculation was carried out with the help of computational thermodynamics, the simulation being of the carbothermic reduction process at a temperature of 1600 °C and 1 atm pressure. The simulation used as targets some guidelines: i) production of a slag with a lower solidus temperature as possible, (ii) or a low viscosity slag, and (iii) to provide suitable amounts of C and Cr in the alloy. Due to the high P content of CIAC, an experimental procedure for the reduction of this element was established based on (i) the use of inexpensive reagents, and (ii) the synergy arising from the combination of these reagents. For the production of ferro-chromium six types of experiments were performed varying the charge composition (sources of Cr and Fe) and two different lots of ash. The Cr and C contents in FeCr alloy in the experiments varied between 50 - 60% Cr and 7 - 10% C, demonstrating the possibility for reuse of Cr contained in the ashes for the production of FeCr alloy.

Den här kandidatavhandlingen undersöker fördelarna och begränsningarna med Internetbaserade operativsystem i molnet, så kallade Internet OS, och hur IT-företag ser på ämnet. Internet OS är operativsystem som placerar sina resurser och processorkraft ute på Internet, ofta med hjälp av olika molnettjänster. Det finns problem och utmaningar med Internet OS. Dessa problem kan vara ett hinder för företag att överge de traditionella operativsystemen, som exempelvis Windows, och övergå till Internet OS. Det saknas undersökningar om IT-företag vill eller kan flytta sin verksamhet till molnet. Vi vill ge en tydligare bild och bidra med ny kunskap om företags syn på Internet OS. Arbetet har genomförts med en litteraturstudie som har fokuserats på vad den akademiska världen vet om Internet OS med fokus på Chrome OS. Litteraturstudie går in på fördelar och nackdelar, samt framtida visioner. Resultatet har därefter jämförts med intervjuer där erfarna praktiker verksamma i Sverige ger sin syn på Internet OS. Litteraturstudien gav resultatet att Internet OS kan göra det enklare att uppdatera och installera program. Det kan bli smidigare att samarbeta och att dela data med andra användare. Datorn kan bli snabbare, säkrare och användaren slipper installera olika pluginer. En artikel menar även att företag kan spara pengar med Internet OS. Nackdelen blir främst beroendet av Internetåtkomst. Det finns en osäkerhet kring den personliga integriteten, samt vem som äger data som placeras och skapas i molnettjänster. Indikationerna från intervjuerna är att branschen är orolig för säkerheten och kontrollen av data när molnetlösningar används. De ser risker med att företag förlorar pengar om Internetåtkomst saknas och att företaget blir beroende av molnetleverantörer. De intervjuade tror att Internet OS kan konkurrera mot de traditionella operativsystemen när det gäller privatbruk, men har svårt att se att företag kan använda Internet OS primärt.

Made available in DSpace on 2016-01-26T18:56:28Z (GMT). No. of bitstreams: 1 Daniele Mozzini Silva.pdf: 353385 bytes, checksum: 9acd9685652be97497a877a473ae1f95 (MD5) Previous issue date: 2012-12-18 / The use of tannery sludge in agriculture represents an alternative disposal of this waste sustainably This study aims to evaluate the use of tannery sludge as a component of commercial substrate, to produce seedlings for reforestation of four native species (Angico red and white, and mutamba mastic) and an exotic (eucalyptus). In this study the incorporation of five doses (5, 10, 15, 20 and 25%) Slurry commercial tannery in a substrate used for the growth of different plant species suitable for reforestation. The experiment was conducted in greenhouse seedling growth. After seeding in substrate packaged in tubes, according to each treatment, was accompanied on plant development, for 120 days, with periodic assessments of height and final evaluation of biomass (roots and shoots) in plants, as was also the levels of macro and micronutrients and accumulation of chromium in the leaf tissue. Of the five forest species assessed three (mastic, mutamba and eucalyptus) responded positively to the addition of up to 25% of tannery sludge in commercial substrate for seedling production. There were significant adjustments by the regression analysis for the absorption of phosphorus, boron and manganese from the incorporation of the residue in most species evaluated. Occurred phyto-extraction of chromium substrate with significant linear fit in three forest species evaluated. / A utilização do lodo de curtume na agricultura representa uma das alternativas de disposição deste resíduo de forma sustentável Este trabalho tem como objetivo avaliar o emprego do lodo de curtume como componente de substrato comercial, para produção de mudas de reflorestamento de quatro espécies florestais nativas (Angico vermelho e branco, mutamba e aroeira) e uma exótica (eucalipto). Neste estudo foi avaliada a incorporação de cinco doses (5, 10, 15, 20 e 25%) de lodo curtume em substrato comercial utilizado para o crescimento de diferentes espécies de plantas apropriadas para reflorestamentos. O experimento foi conduzido em estufas de crescimento de mudas. Após a semeadura em substrato acondicionado em tubetes, de acordo com cada tratamento, foi acompanhado o desenvolvimento das mudas, durante 120 dias, com avaliações periódicas de altura e avaliação final de produção de biomassa (raiz e parte aérea) nas plantas, como também foram avaliados os teores de macro e micronutrientes e o acúmulo de cromo no tecido foliar. Das cinco espécies florestais avaliadas, três (aroeira, mutamba e eucalipto) responderam positivamente a adição de até 25% de lodo de curtume no substrato comercial para produção de mudas. Ocorreram ajustes significativos pela analise de regressão para absorção de fósforo, boro e manganês, proveniente da incorporação do resíduo, na maioria das espécies avaliadas. Ocorreu fito-extração de cromo do substrato com ajuste linear significativo em três espécies florestais avaliadas.

Made available in DSpace on 2016-07-18T17:51:11Z (GMT). No. of bitstreams: 1 Daniele Mozzini Silva.pdf: 353385 bytes, checksum: 9acd9685652be97497a877a473ae1f95 (MD5) Previous issue date: 2012-12-18 / The use of tannery sludge in agriculture represents an alternative disposal of this waste sustainably This study aims to evaluate the use of tannery sludge as a component of commercial substrate, to produce seedlings for reforestation of four native species (Angico red and white, and mutamba mastic) and an exotic (eucalyptus). In this study the incorporation of five doses (5, 10, 15, 20 and 25%) Slurry commercial tannery in a substrate used for the growth of different plant species suitable for reforestation. The experiment was conducted in greenhouse seedling growth. After seeding in substrate packaged in tubes, according to each treatment, was accompanied on plant development, for 120 days, with periodic assessments of height and final evaluation of biomass (roots and shoots) in plants, as was also the levels of macro and micronutrients and accumulation of chromium in the leaf tissue. Of the five forest species assessed three (mastic, mutamba and eucalyptus) responded positively to the addition of up to 25% of tannery sludge in commercial substrate for seedling production. There were significant adjustments by the regression analysis for the absorption of phosphorus, boron and manganese from the incorporation of the residue in most species evaluated. Occurred phyto-extraction of chromium substrate with significant linear fit in three forest species evaluated. / A utilização do lodo de curtume na agricultura representa uma das alternativas de disposição deste resíduo de forma sustentável Este trabalho tem como objetivo avaliar o emprego do lodo de curtume como componente de substrato comercial, para produção de mudas de reflorestamento de quatro espécies florestais nativas (Angico vermelho e branco, mutamba e aroeira) e uma exótica (eucalipto). Neste estudo foi avaliada a incorporação de cinco doses (5, 10, 15, 20 e 25%) de lodo curtume em substrato comercial utilizado para o crescimento de diferentes espécies de plantas apropriadas para reflorestamentos. O experimento foi conduzido em estufas de crescimento de mudas. Após a semeadura em substrato acondicionado em tubetes, de acordo com cada tratamento, foi acompanhado o desenvolvimento das mudas, durante 120 dias, com avaliações periódicas de altura e avaliação final de produção de biomassa (raiz e parte aérea) nas plantas, como também foram avaliados os teores de macro e micronutrientes e o acúmulo de cromo no tecido foliar. Das cinco espécies florestais avaliadas, três (aroeira, mutamba e eucalipto) responderam positivamente a adição de até 25% de lodo de curtume no substrato comercial para produção de mudas. Ocorreram ajustes significativos pela analise de regressão para absorção de fósforo, boro e manganês, proveniente da incorporação do resíduo, na maioria das espécies avaliadas. Ocorreu fito-extração de cromo do substrato com ajuste linear significativo em três espécies florestais avaliadas.

Desgaste é um dos três principais problemas industriais comumente encontrados, que levam à substituição de componentes e equipamentos em engenharia. A possibilidade de se recuperar esses componentes, ou prepará-Ios para suportar melhor as condições de trabalho, é constantemente estudada e novas técnicas são propostas, sempre no sentido de aumentar a vida útil e reduzir custos operacionais. Esta é a razão para o aumento da importância dos sistemas de revestimentos. O cromo duro eletrolftico tem sido muito utilizado para conferir resistência ao desgaste elou à corrosão, porém as características do processo de deposição eletrolítica do mesmo, com a presença do cromo hexavalente, altamente cancerígeno, têm resultado numa limitação crescente ao seu uso. Devido a isso se tomou necessário o desenvolvimento de novos revestimentos alternativos menos agressivos. Os substitutos mais promissores são os \"cermets\" depositados pelo processo HVOF, que foram produzidos no presente trabalho e comparados com o cromo duro eletrolítico quanto à resistência ao desgaste. Os revestimentos obtidos foram caracterizados por meio de ensaios micrográficos óticos, eletrônicos, raios-x, densidade e ensaios de desgaste dos seguintes tipos: roda de borracha e areia a seco, ensaio abrasivo para carbonetos e micro-abrasivo. O revestimento Cr3 Cr2-NiCr apresentou desempenho geral inferior ao do cromo duro. Entretanto no caso do desgaste micro-abrasivo, onde o mecanismo de desgaste apresentado no mesmo foi misto adesivo-abrasivo, ao contrário dos demais que tiveram características abrasivas, sua resistência ao desgaste foi superior a dos demais. O revestimento constituído de WC-CoCr apresentou o melhor desempenho entre todos os avaliados, o que o indica como um candidato altamente promissor à substituição do cromo / Wear is one of the three main industrial problems, that causes the substitution of components and equipments in engineering. The possibility to recover those components or to prepare them to better support the work conditions is constantly studied and new techniques are proposed, a/ways seeking to increase the life span and to reduce operational eosts. This is the reason why the coating systems are important. The hard ehrome coatings has been traditionally used to improve wear resistance and/or eorrosion resistance. However the eharacteristics of the electroplated deposition proeess, with the presence of the hexavalente ehrome, highly cancerous, result in a growing limitation to its use. Due to that it beeome necessary the development of new less aggressive alternative eoatings. The most promising substitutes are the \"cermets\" deposited by the HVOF process that were produced in the present work and compared with electroplated hard ehrome coatings for wear resistance. The obtained coatings were characterized through optical and electronic mierographics analysis , x-ray, density and submitted to the following types of wear tests: Dry Sand I rubber wheel, Wear test for cemented carbides and mieroabrasive wear test. The coating Cr3Cr2-NiCr presented smaller general performance in comparison with the hard ehrome. However, in the case of the miero-abrasive wear, where the wear mechanism presented was mixed adhesive-abrasive, unlike the others that had only abrasive eharacteristics, the resistance to the wear was superior. The WC-CoCr coating presented the best performance overall, what indicates it as a candidate to the hard ehrome substitution

Content: It is acknowledged that conventional chrome tanning in leather processing discharges significant amounts of chromium, dissolved solids and chlorides. The recycling technology is one of the effective solutions to reduce the environmental impact of chrome tanning waste water at source. In this work, a novel closed recycling technology of chrome tanning wastewater was applied in the tanning process of the goat skins at a pilot scale level. The properties of chrome tanning liquors obtained by the recycling technology and the resultant crust were analyzed. The results show that this close recycling process works well. The contents of Cr2O3, total organic carbon, ammonia nitrogen and chloride ion in the waste water tend to accumulate with the increase of recycling times, and finally reach a balance after 5 times of recycling. The obtained leather sample is full, soft and having a shrinkage temperature comparable to that of conventional chrome tanned leather. SEM images indicate that the resulting leather samples by this recycling technology show fine and clean grain and well-dispersed fibrils. TG and DSC results show that the thermal stability of wet blue leathers tanned by the circular process are similar to those tanned by conventional chrome tanning process. Compared with conventional chrome tanning technology, water, salt and chrome tanning agent are saved in this process, and the zero emission of chrome tanning wastewater is realized. The cleaner production technology exhibits promising application prospect for its economic and environmental benefits. Take-Away: 1. A novel closed recycling technology of chrome tanning wastewater was applied in the tanning process of the goat skins at a pilot scale level. 2. The chrome tanning liquors obtained by the recycling technology and the resultant crust were analyzed. 3. Water, Sodium chloride and chrome tanning agent are saved by the closed recycling technology, and the zero emission of chrome tanning wastewater is realized.

Content: In leather making processes, the thermal and non-thermal effect of microwave, especially non-thermal effect, strengthen the combination between collagen and chemicals. Although tanning under microwave makes the leather have better thermal stability, the tanning process and leather properties have not been studied in detail. For illustrating the influence of microwave on chrome tanning process, pickled skin was tanned for 6h as penetration procedure and then basified for another 4h as fixation procedure. The tanning under microwave heating (MW) was experimental sample and under water bath heating was control. UVVis, ICP-OES and pH meter were used to measure the changes of tanning effluent during tanning, and Shrinkage temperature meter, DSC, TG, FT-IR, SEM, XRD and XPS were applied to determine the differences between MW and WB in aspect of leather property and structure. The results indicated microwave accelerated chrome tanning agent penetration and had better promotion effect on chromium complex hydrolysis and olation. The leather tanned with microwave assisting had special effect on improve tanning effect which led better thermal stability and resistance of leather, but the collagen structure, including triple helix structure, stayed as WB and the combination mechanism between collagen and chromium was also same with conventional. In sum, microwave had positive effect on accelerating tanning rate and resulting in better leather without any negative effect on leather structure. Therefore, microwave would be a potential for achieving clean and sustainable chrome tanning by making tanning much faster and more efficiency. Take-Away: Microwave promotes chrome tanning agent penetration and combination Microwave has positive effect on tanning effect further as the leather tanned by microwave assisting has higher thermal stability. Although microwave promotes chrome tanning process, the collagen structure and tanning mechanism remained as normal.

Content: Pre-treatments are widely used during tanning processes as to improve the performance of the main tannage. Synchrotron small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) were used to study four common types of pre-treatments, viz. monodentate complexing agent (sodium formate, SF), chelating agent (disodium phthalate, DSP), covalent cross-linker (glutaraldehyde, GA) and nanoclay (sodium montmorillonite, MMT) about their effects on chromium-collagen cross-linking reaction during tanning. Based on the results, the performance of chromium-collagen cross-linking with and without pre-treatments was presented considering five aspects: cross-linking, the level of hydration, hydrothermal stability, uniformity through leather cross-section and the uptake of chrome. Comparing to the original ThruBlu chrome tanning, at the same chrome offers, leather pre-treated using SF, DSP and MMT showed improved hydrothermal stability, uniformity and the level of hydration, while GA showed decreased hydration. All of the pre-treatments reduce surface fixation by decreasing the reactivity of chromium with collagen. Changes in the reaction performance can influence the properties of the leather products as well as the efficiency of the leather manufacturing processes. Insights into the structural changes of collagen during tanning with varied reaction conditions can guide the design of novel, benign tanning processes to reduce environmental impact. Take-Away: 1. Uniformity of the hydrothermal stability through leather cross-section were improved by all of the studied pre-treatments. 2. Reactivity of chromium to cross-link with collagen was reduced as a result of the complexing, covalent cross-linking, or preferential adsorption. 3. Complexing agents and nanoclay pre-treatments tend to retain collagen bound water, while covalent cross-linker causing decrease in the level of hydration of collagen.

Content: Sustainable tannery effluent treatment system in achieving required discharge standards including Total Dissolved Solids (TDS) is one of the major challenges faced by the World Leather Industry. Conventional treatment system reduces Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Suspended Solids (SS), heavy metals etc. and not the TDS and salinity. To achieve the TDS level, the tanneries in South India were forced to adopt Zero Liquid Discharge (ZLD) system by incorporating Reverse Osmosis (RO) system and Multiple Effect Evaporator (MEE). Though recovery of water is beneficial to certain extend in adopting ZLD system, the major challenges are high energy consumption, huge operation & maintenance cost and no safe disposal method for large quantity of mixed/contaminated salt generated from MEE. In view of the challenges faced in adoption of ZLD system, sustainable major technological developments have been made to control more than 50% of TDS in the effluent by adopting cleaner tanning process, segregation of saline streams, treatment and recovery of chromium and salt for reuse by the member units. The balance composited waste stream with low TDS is further treated and taken for mixing/dilution with treated domestic sewage to achieve all discharge standards including TDS. This development is being implemented in many tannery clusters in India such as Pallavaram in South India and Jajmau, Unnao, Banthar, etc. in North India. The Common Effluent Treatment Plants (CETPs) are being upgraded with financial support from Govt. of India and respective State Governments. Take-Away: Improved Chrome Recovery System for Reuse, Recovery of Salt from Saline Stream and Reuse, Sustainable TDS Management