• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 119
  • 11
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 160
  • 160
  • 95
  • 94
  • 36
  • 33
  • 31
  • 31
  • 30
  • 27
  • 27
  • 24
  • 20
  • 19
  • 19
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Caracterização de linhagens bacterianas isoladas da biodiversidade brasileira quanto à produção de biopolímeros. / Characterization of brazilian biodiversity isolated bacterial strains on the production of biopolymer.

Fernanda Matias 29 January 2009 (has links)
O lixo urbano tem sido apontado como um dos maiores poluentes ambientais. O lixo plástico chega a representar 20% do volume do lixo doméstico. Como alternativa aos plásticos petroquímicos, produtos plásticos menos agressivos ao meio ambiente e mais biodegradáveis têm sido estudados, entre eles os polihidroxialcanoatos (PHA). Os PHA são poliésteres biodegradáveis acumulados como material de reserva por inúmeras bactérias e que possuem aplicabilidade comercial bastante abrangente. Recentemente, os actinomicetos passaram a ser estudados para a produção destes polímeros. Em trabalho prévio, 53 novas linhagens de actinomicetos produtoras de biopolímeros foram isoladas de solo. Neste trabalho foi feita a seleção das bactérias quanto aos polímeros produzidos em diferentes de carbono. Das quatro linhagens selecionadas, duas foram analisadas quanto à produção de um novo polímero. Nas outras duas linhagens foram amplificados e estudados os genes sintetizadores dos polímeros. Em todas as linhagens foram feitas análises taxonômicas e cultivos em rejeitos industriais. / The urban waste has been described as one of the largest environmental pollutants. The plastic garbage can represent up to 20% of the volume of household waste. As an alternative to petrochemical plastics, plastic products less damaging to the environment and more biodegradable have been studied, among them polyhydroxyalkanoates (PHA). The PHA is a biodegradable polyester material accumulated as a reserve material by many bacteria and they have very broad commercial applicability. Recently, the actinomycetes have been studied for the production of polymers. In previous work, 53 new strains of actinomycetes producers of polymers were isolated from soil. In this work the bacterial the selection of bacteria was made concerning the polymers production on different carbon. Of the four strains selected, two were analyzed for the production of a new polymer. In the other two strains were amplified and studied the genes of polymers synthases. In all lineages were analyzed taxonomically and in cultivation on industrial waste.
62

Desenvolvimento de mudas de bromélias em resíduos orgânicos e industriais / Development of seedlings of bromeliads in organic and industrial waste

Rocha, Ariane Borges de Figueiredo 04 June 2012 (has links)
Made available in DSpace on 2016-05-02T13:55:35Z (GMT). No. of bitstreams: 1 Ariane BorgesdeFigueiredoRocha-dissertacao.pdf: 220565 bytes, checksum: c0a3d2c9d3654e8b2e547557ee3aa684 (MD5) Previous issue date: 2012-06-04 / Bromeliads are commonly used for ornamental and landscaping purposes, and there is a lack of knowledge about farming techniques and ideal substrate, leading to extractive exploitation of these species in their natural habitat. Thus, proposals for reuse of these wastes can solve problems of contamination of the environment and simultaneously serve as soil conditioner. The objective of this study was to evaluate the development of seedlings of the bromeliad Neoregelia tigrina (Ruschi) in organic and industrial waste. The treatments were: 100% solid organic waste; 100% pine bark; 100% coconut fiber; 75% coir and 25% waste; 50% coir and 50% waste; 25% coconut fiber and 75% waste; 75% pine bark and 25% waste; 50% pine bark and 50% waste; 25% pine bark and 75% residue. The statistical design was completely randomized (CRD) with three replications and three plants per plot. Statistical analyzes show significance by the Scott Knott test (p <0.05). As alternative substrates the pine bark and coconut fiber substrates stood out statistically for having low cost and easy accessibility for ornamental producers. Pure waste should not be used to produce bromeliads. Bromeliad seedlings of Neogerelia tigrina (Ruschi), when grown in substrates containing 100% pine bark, showed the best results on the number of leaves, shoot growth, fresh shoot weight, root length and root dry mass. / As bromélias são comumente utilizadas para uso paisagístico e ornamentação e há um desconhecimento de técnicas de cultivo e substrato ideal, levando à exploração extrativista dessas espécies no seu habitat natural. Com isso, propostas de reutilização desses resíduos podem resolver problemas de contaminação do meio ambiente e ao mesmo tempo servir como condicionadores de solo. Objetivou-se com este trabalho avaliar o desenvolvimento de mudas de bromélias da espécie Neoregelia tigrina (Ruschi) em resíduos orgânicos e industriais. Os tratamentos utilizados foram: 100% de resíduo orgânico sólido; 100% de casca de pinus; 100% de fibra de coco; 75% de fibra de coco e 25% resíduo; 50% fibra de coco e 50% resíduo; 25% fibra de coco e 75% resíduo; 75% de casca de pinus e 25% resíduo; 50% casca de pinus e 50% resíduo; 25% casca de pinus e 75% resíduo. O delineamento estatístico foi inteiramente casualizado (DIC), com 3 repetições e 3 plantas por parcela. As análises estatísticas apresentam significância pelo teste de Scott Knott (p< 0,05). Como substratos alternativos sobressaíram-se estatisticamente a casca de pinus e a fibra de coco, substratos que apresentam baixo custo financeiro e fácil acessibilidade pelos produtores ornamentais. Não se deve utilizar resíduo puro para produção de bromélias e as mudas de bromélias Neogerelia tigrina (Ruschi) quando desenvolvidas em substratos contendo 100% casca de pinus apresentaram os melhores resultados quanto ao número de folhas, crescimento da parte aérea, massa fresca da parte aérea, comprimento do sistema radicular e massa seca do sistema radicular.
63

Problematika produktů osobní péče ve složkách životního prostředí / Personal care products as environmental contaminants

Babuš, Ondřej January 2010 (has links)
Synthetic musk compounds were first prepared artificially in the late 19th century. They have been used to perfume cosmetics, detergents and personal care products. The attention of many researchers has been focused on it recently, due to its high penetration into the nature which is a logical consequence of its great use. The main goal of this thesis is to determine the effect of the ultrafiltration on the concentration reduction of substances mentioned above in the industrial waste waters produced by the cosmetic company. Analytes from the sample were extracted using solid phase microextraction (SPME) and on gas chromatography analysis with mass spectroscopy (GC / MS) has been performed. The whole method was optimized and evaluated. Determination of the average efficiency of the ultrafiltration was made based on data obtained before and after ultrafiltration. Such efficiency determines the suitability of use of this method for removal of synthetic musk compounds from waste waters.
64

Efeito de "dregs e grits" nos atributos de um neossolo quartzarênico e na produção volumétrica de eucalipto /

Trigueiro, Rodrigo de Menezes, 1972- January 2006 (has links)
Orientador: Iraê Amaral Guerrini / Banca: Roberto Lyra Villlas Bôas / Banca: Dirceu Maximiniano Fernandes / Banca: José Luiz Stape / Banca: Fernando Carvalho Oliveira / Resumo: Devido ao crescimento na produção de celulose e papel e o conseqüente aumento na geração de resíduos industriais, foi estabelecido o presente estudo com o objetivo de consolidar as informações referentes à aplicação de resíduos alcalinos, como o dregs e o grits, provenientes do processo de clareamento da celulose, como insumo agrícola capaz de reduzir a acidez do solo e fornecer nutrientes ao sistema solo planta em plantios homogêneos de eucalipto. Nesse sentido, foi instalado um experimento na Fazenda Cara Preta, em área pertencente à empresa Votorantim Celulose e Papel Florestal S.A., situada no Município de Luiz Antônio-SP, onde o solo foi classificado como Neossolo Quartzarênico. O experimento estabelecido em outubro de 1996, constou de um delineamento experimental em blocos casualizados com 9 tratamentos, onde foram aplicadas doses crescentes da mistura dregs+grits em combinação com diferentes doses de adubação mineral convencional em plantios do híbrido Eucalyptus grandis x Eucalyptus urophylla. Os tratamentos foram avaliados por meio do estudo dos atributos químicos, físicos e microbiológicos do solo, nas camadas superficiais e ao longo do perfil. Foram estudados também o crescimento das plantas em altura, diâmetro do caule e volume de madeira com casca, além do status nutricional das plantas pela análise química do tecido foliar. Os resultados obtidos mostraram que o uso de dregs e grits, nas doses de 4 e 8 Mg ha-1, foram capazes de reduzir a acidez do solo, aumentando a mineralização da matéria orgânica e disponibilizando o enxofre nela contido. A alta concentração cálcio elevou seu 2 teor na solução do solo, favorecendo a lixiviação de Na no perfil. Os efeitos nos atributos físicos do solo foram pequenos e não diminuíram sua permeabilidade. As maiores produtividades em volume de madeira com casca foram alcançadas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Because of an ever growing production of cellulose and paper and the consequent increase in the generation of industrial waste, this study was established in order to consolidate information regarding the application of alkaline residues, such as dregs and grits, resulting from the cellulose bleaching process, as an agricultural input capable of reducing soil acidity and providing nutrients to the soil-plant system in homogeneous eucalyptus plantations. In this respect, an experiment was installed at the Cara Preta Farm, in an area that belongs to Votorantim Celulose e Papel Florestal S.A., located in the City of Luiz Antônio-SP, where the soil has been classified as a Typic Quartzipsamment. The experiment, established in October 1996, consisted of a random block experimental design with 9 treatments, in which increasing rates of the mixture dregs+grits were applied in combination with different rates of conventional mineral fertilization in plantations of the hybrid Eucalyptus grandis x Eucalyptus urophylla. The treatments were evaluated by studying the chemical, physical, and microbiological soil 4 attributes in the soil's upper layers and through the profile. We also studied plant growth in height, stem diameter, and volume of timber with bark, in addition to the nutritional status of plants by chemically analyzing the leaf tissue. The results obtained showed that the use of dregs and grits at rates of 4 and 8 mg ha-1 were capable to reduce soil acidity, increasing organic matter mineralization and making the sulfur it contains available to plants. The high concentration of calcium increased its content in the soil solution, favoring Na leaching into the soil profile. The effects on soil physical attributes were small and did not decrease soil permeability. The highest productivities in volume of timber with bark were achieved with the application of 8.0 mg ha-1 of the dregs + grits... (Complete abstract click electronic access below) / Doutor
65

Caracterização e reaproveitamento das areias descartadas de fundição (ADF) na produção de blocos de concreto sextavado para pavimento intertravado /

Santos, Luis Fernando dos. January 2019 (has links)
Orientador: Silvio Rainho Teixeira / Banca: Jorge Luis Akasaki / Banca: Agda Eunice de Souza Albas / Resumo: O presente trabalho consistiu no reaproveitamento da mistura das areias descartadas de fundição (ADF-M) em substituição total ao agregado miúdo natural na produção de blocos de concreto sextavados para a aplicação em pavimento intertravado. Para tanto, foram realizados ensaios de caracterização química, estrutural, térmica das ADF e ADF-M. A Fluorescência de raios X constatou elevada presença de óxido de silício (SiO2), determinando o elemento predominante nas ADF e ADF-M. Na análise de microscopia eletrônica de varredura (MEV/EDS) foi identificada a presença de bentonita, pó de carvão e resinas fenólicas em volta dos grãos de óxido de silício (SiO2), interferentes nas propriedades físicas e mecânicas. De acordos com a normas brasileiras NBR 10005 e 10006, a ADF-M foi classificada como resíduo classe II A, resíduo não perigoso e não inerte. Para a análise da influência da ADF-M no concreto, foram moldados corpos de prova e blocos de concreto sextavado com substituição total da areia natural pela ADF-M. O teste de abatimento de tronco cone apresentou consistência fluida após adicionado o aditivo. No que tange as propriedades físicas e mecânicas, tanto os corpos de prova como os blocos de concreto foram observados um aumento na absorção de água e uma diminuição de resistência à compressão em relação ao traço de referência. Os valores obtidos de absorção de Água (≤6%) e resistência à compressão (≥ 35MPa) estão acima dos valores mínimos de acordo com a normas brasileiras para pav... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present work consisted of the reuse of the spent foundry sand mixture (SFS-M) instead of the natural fine aggregate in the production of hexagonal concrete blocks for an interlocked pavement application. For this, chemical, structural and thermal characterization tests of the SFS and SFS-M were performed. X-ray fluorescence verified the presence of silicon oxide (SiO2), determining the predominant element in SFS and SFS-M. Scanning electron microscopy (SEM / EDS) analysis identified bentonite, coal dust and phenolic resins around the silicon oxide (SiO2) grains, interfering with physical and mechanical properties. Deficiency with NBR 10005 and 10006 standards, an SFS-M was used as class II A waste, non-hazardous and noninert waste. For an analysis of the influence of SFS-M on concrete, specimens and hexagonal concrete blocks were molded with the total replacement of natural sand by SFS-M. The trunk taper test showed fluid consistency after the added or additive. Regarding the physical and mechanical properties, both specimens and concrete blocks were observed in an increase in water absorption and a reduction in pressure resistance in relation to the reference line. Water absorption (≤6%) and compressive strength (≥ 35MPa) levels are above the minimum values according to the Brazilian pavement standard. From an economic and environmental point of view, an SFS-M is viable for civil construction applications. / Mestre
66

Improved prediction of biogas production at Uddebo wastewater treatment plant : Substrate modelling in SIMCA

Gullman, Isak January 2021 (has links)
Anaerobic digestion is a complex process, dependent on multiple factors, which can be made more stable and efficient with the help of process models. A more stable process could reduce biogas torching, which increases the amount of renewable energy available for heat- and electricity production and vehicle fuel.  Fluctuations in the produced biogas at Uddebo WWTP in Luleå, Sweden, has been observed, where imported industrial waste was suspected to be the cause. The purpose of this master thesis was to increase the predictability of the biogas production at Uddebo WWTP by creating a process model based on historical data. The historical data consisted of quantitative data of the substrates loaded into the anaerobic digestor and biogas collected from the digestor.  The results showed that the calculated error between modelled and measured biogas production was &lt;20%, which was considered good. However, due to the demarcation of this report, many variables were ignored in the creation of the model. Further research is therefore a requirement for the model to function properly:  The error should be reduced to &lt;10%, This could be done by increasing the period and resolution toinclude and statistically secure fast and seasonal variations.  make qualitative modelling easier, i.e., prediction of the biomethane amount in the biogas.  The industrial liquid waste storage should be included in the calculation.   A more detailed analysis of all substrates is needed to make the comparison between the literature based and measured production more realistic.  Expanding the demarcation of the model to also include the environment in the digestor. This could also increase the total amount of biogas produced.
67

Evaluating the toxic effects of industrial waste from a historic landfarming site using bioassays

Van Wyk, Mia 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Landfarming is a widely used method for the disposal of contaminants in the petrochemical industry. It involves ploughing the contaminants into the top soil layer allowing biological breakdown. A historically landfarmed site was identified at a South African petrol refinery. The refinery used to dispose so-called American Petroleum Institute (API) -sludge onto a landfarming site. API-sludge consisted of a mixture of oil and water soluble contaminants originating from a process of separating refinery waste from reusable water and oil. Landfarming on this site was discontinued after excessive quantities of sludge were ploughed into the soil over time and it became obvious that effective biodegradation could not take place. An environmental assessment had to be carried out to assess to what extent the soil has recovered from the contamination and after remediation was done over time. Bioassays together with chemical analyses were executed to determine the level of pollutants in the soil and to assess the integrated effects of their bioavailable fractions. The landfarming site of the refinery was divided into two sections namely, a more contaminated north-site and less contaminated south-site. Soil samples were collected from both sites as well as from an off-site (control site). The soils were analysed physically, chemically and used in the bioassays. Two additional control soils were also used, OECD-soil and LUFA2.2 soil. Chemical analysis of the site soils showed the presence of heavy metals and high levels of diesel range organic hydrocarbons. The north-site had higher levels of contaminants compared to the south-site. Three species of soil organisms were used in standardised tests: Eisenia andrei, Enchytraeus doerjesi and Folsomia candida were exposed to the respective soils to study their survival, growth, reproduction success and avoidance behavior. Exposures to both site-soils were not acutely toxic to any organisms. F. candida had a decrease in juvenile production in both north- and south-site soils (289.42 ± 58.62 and 253.33 ± 122.94 respectively) compared to the control soil (479.89 ± 30.42). E. doerjesi showed an increase in produced juveniles exposed to north- and south-site soil (339.75 ± 76.92 and 414.00 ± 17.78 ) compared to control soil (57 ± 34.39). E. andrei had similar cocoon production when exposed to south-site soil than in off-site soil (19.00 ± 5.3 and 18.5 ± 9.7 respectively) but significantly less in north-site soil (1.25 ± 0.7). Only E. doerjesi showed avoidance of north-site soil. To determine the sensitivity of the organisms to the API-sludge, they were exposed to concentration series of API-sludge-spiked control soils. The effect concentrations were calculated as the concentration of API-sludge that will decrease the studied endpoints by 50% of the control soil (EC50). The EC50s varied for each species exposed in the different control soils showing that the toxicity of the API-sludge is to a certain extent dependent on the physical soil properties of the substrate. The reproduction of F. candida were most sensitive to the API-sludge in off-site soil (EC50 = 90 mg/kg) and the E. doerjesi the least sensitive in LUFA2.2 soil (EC50 = 36000 mg/kg). Five plant species were exposed to API-sludge-spiked potting soil and the germination success, early growth rate and biomass were studied. The plants were not as sensitive to API-sludge as the soil animals. Lettuce and grass were affected the most by API-sludge and beans were the most resilient species. With the addition of low levels API-sludge to the substrate, the growth rate of beans was stimulated. This study showed that the south-site has been successfully remediated and most soil organisms exposed to these soils were not affected by the levels of toxicants present. However, exposures to north-site soil still had negative effects on soil organisms. It is recommended that hydrocarbon contamination should be further remediated in the north-site soil before landfarming should be allowed to continue. / AFRIKAANSE OPSOMMING: Ploegverwerking is ‘n algemene remediëringsmetode vir die verwerking van afvalmateriaal in petrochemiese industrieë. Dit behels die inploeg van toksiese afvalmateriaal in die boonstegrondlaag sodat dit biologies afgebreek kan word. ‘n Voorbeeld van ‘n histories ploegverwerkte grondstuk is geidentifiseer by ‘n Suid-Afrikaanse olieraffinadery. Die raffinadery het in die verlede van die grondstuk gebruik gemaak om sogenaamde Amerikaanse Petroleum Instituut-slik (API-slik) daarin te ploeg. Die API-slik bestaan uit ‘n mengsel van olie- en wateroplosbare kontaminante afkomstig van die proses waardeur die raffinadery se afvalprodukte van hernubare water en olie geskei word. Nadat oormatige konsentrasies slik in die grond ingewerk is en bioremediasie nie meer doeltreffend kon voortgaan nie, is die ploegverwerking gestaak. ‘n Omgewingimpakstudie moes uitgevoer word om te bepaal tot watter mate die grond herstel het nadat remediasie oor tyd uitgevoer is. Toksisiteitstoetse en chemiese analises is uitgevoer om die vlakke van besoedeling sowel as die biobeskikbare fraksie daarvan in die grond te bepaal. Die ploegverwerkte area van die raffinadery is in twee verdeel naamlik, ‘n meer gekontamineerde noordelike area en ‘n minder gekontamineerde suidelike area. Grondmonsters is van die onderskeie areas asook van ‘n ongekontamineerde veld (as kontrole) naby die ploegverwerkte area versamel Die gronde is fisies- en chemies geanaliseer en toksisiteitstoetse is uitgevoer. Twee addisionele kontolegronde is ook tydens die blootstellings gebruik naamlik, OECD- en LUFA2.2-grond. Die chemiese analises van die ploegverwerkte toetsgronde het getoon dat daar steeds swaarmetale en hoë vlakke van dieselgekoppelde organiese koolwaterstowwe in die gronde teenwoordig is. Kontaminante was in hoër konsentrasies teenwoordig in die grond van die noordelike gebied as in dié van die suidelike gebied. Drie spesies van grondorganismes is gebruik tydens standaard toksisitetitstoetse. Eisenia andrei, Enchytraeus doerjesi en Folsomia candida is blootgestel aan die onderskeie toets- en kontrolegronde waarna hul oorlewing, groei, voortplantingsukses en vermydingsreaksies bestudeer is. Blootstellings aan die ploegverwerkte toetsgronde het geen akute toksisiteit vir enige van die spesies getoon nie. F. candida se juveniele produksie was laer in beide noordelike- en suidelike toetsgronde (289.42 ± 58.62 en 253.33 ± 122.94 onderskeidelik) as in die kontolegrond (479.89 ± 30.42). E. doerjesi blootstellings het ‘n toename in juveniele getalle getoon in die noordelike- en suidelike toetsgronde (339.75 ± 76.92 en 414.00 ± 17.78) in vergelyking met die ongekontamineerde kontolegrond (57 ± 34.39). Kokonproduksie by E. andrei was soorgelyk in die suidelike toetsgrond en ongekontamineerde kontrolegronde (19.00 ± 5.3 en 18.5 ± 9.7 onderskeidelik) maar beduidend minder as in noordelike toetsgrond (1.25 ± 0.7). Slegs E. doerjesi het ‘n beduidende vermydingsreaksie vir die noordelike toetsgronde getoon. Om die sensitiwiteit van die organismes aan vars API-slik te bestudeer, is hulle blootgestel aan konsentrasiereekse van API-slik in die onderskeie kontrolegronde. Die effektiewe konsentrasie (EK50) is bereken as die konsentrasie van API-slik wat die bestudeerde eindpunte met 50% sal verminder in vergelyking met die kontrolegrond Die EK50-waardes vir al die spesies het verskil na blootstelling aan die onderskeie kontrolegronde. Dus, die toksisiteit van die API-slik is tot ‘n sekere mate ook afhanklik van die fisiese grondeienskappe van die blootsellingssubstraat. Die voortplanting van F. candida was die gevoeligste eindpunt vir die blootstelling aan API-slik in kontolegrond (EK50 = 90 mg/kg) en E. doerjesi was die minste gevoelig in LUFA2.2 grond (EK50 = 36000 mg/kg). Vyf plantspesies is ook blootgestel aan API-slikgekontamineerde potgrond en die saadontkiemingssukses, vroeë groeikoers en biomassa is bestudeer. Alhoewel plante nie so sensitief was vir die API-slik soos die gronddiere nie, was blaarslaai en gras die meeste geaffekteer tydens die blootstellings. Boontjies was die ongevoeligste en met die toevoeging van lae konsentrasies API-slik (2.5% API-slik), is hul groeikoers selfs gestimuleer. Uit die studie was dit duidelik dat die suidelike deel van die grondstuk meer suksesvol as die noordelike geremidieer is en dat meeste grondorganismes wat daaraan bloot gestel is nie geaffekteer is deur die vlakke van kontaminasie wat steeds teenwoordig is in die grond nie. Die toetsgronde uit die noordelike deel het egter steeds negatiewe effekte op die grondorganismes gehad. Dit word voorgestel dat die koolwaterstof kontaminasie verder geremidieër behoort te word in die noordelike deel van die grondstuk voordat verdere ploegverwerking van die afval daar gedoen word.
68

Reaproveitamento do resíduo Terra da Shredder através da técnica de solidificação/estabilização em matrizes de cimento Portland para aplicação na construção civil / Shredder\'s soil recycling by solidification/ stabilization (S/S) technique in Portland cement matrices for application in construction

Juliana Argente Caetano 29 June 2016 (has links)
A Shredder é o equipamento para a trituração da sucata ferrosa que permite a reciclagem do aço nas siderúrgicas. A sucata é em sua maioria procedente da reciclagem de veículos de fim de vida. Por isso, esse resíduo é conhecido como ASR (Automotive Shredder Residue). A Terra da Shredder é a fração do ASR de pequena granulometria (<2mm) apresentando o aspecto de solo. Esse resíduo é tratado como rejeito e em sua totalidade destinado aos aterros industriais. O grande volume de resíduo gerado contribui para a saturação dos aterros, provoca impactos ambientais, despende um alto custo de disposição e assim exige o desenvolvimento de tecnologias para seu reaproveitamento. Este trabalho propõe utilizar a Terra da Shredder, resíduo sólido gerado na Shredder localizada em Iracemápolis-SP-BR, em peças de concreto para pavimentação através da técnica de solidificação/estabilização (S/S) em matrizes de cimento Portland. Na primeira etapa do experimento, o resíduo foi classificado como Classe IIA. A segunda etapa consistiu na produção de matrizes compostas com cimento, agregados e água, foram produzidos corpos de prova com os seguintes teores de substituição, em massa, da areia natural pelo resíduo: 5%,10%,15% e 20%. A matriz com o teor de substituição de 20% apresentou uma resistência mecânica compatível com a norma ABNT NBR 9781, por isso foram fabricadas peças de concreto com esse teor de substituição. As peças de concreto apresentaram bom desempenho mecânico, físico e, com exceção do alumínio, fenóis totais e cádmio, as outras substâncias que ultrapassaram os limites de solubilização (ferro total, fluoretos, manganês, selênio, surfactantes) foram encapsuladas pelo cimento, sendo que o cádmio também estava presente em peças de concreto para pavimentação fabricadas apenas com os materiais convencionais, sem o resíduo. Dessa forma, conclui-se que os blocos podem ser utilizados na construção civil. / The Shredder is the equipment for the processing of ferrous scrap which allows the recycling of steel. Scrap is in its majority coming from the recycling of end of life vehicles. Therefore, the residue formed in this grinding process is known as ASR (Automotive Shredder Residue). The fine fraction of the ASR has soil aspect so will be called Shredder\'s soil. This residue is treated as waste and in its entirety for the landfills. It is estimated that for each ton of metallic material separated in Shredders approximately 227 kg of waste are produced. This large volume of waste generated contributes to the saturation of landfills,causes environmental impacts, expends a high cost of disposal and thus requires the development of technologies for its reuse. This paper proposes to use the fine fraction (<2mm) of the solid waste generated in a shredder in the city of Iracemápolis-SP-BR in concrete paving blocks through the techinique of solidification/stabilization (S/S) in Portland cement matrix. The experimental research began with completion of leaching tests and solubilization for the classification of waste class IIA , substances that exceeded solubility limits were total phenols, total iron, fluoride, manganese, selenium, aluminum, cadmium and surfactants. The second stage was the production of cement matrix that is composed by cement, aggregates and water they were produced matrices with the following replacement levels of natural sand by the waste: 5%, 10%, 15% and 20%. The matrice with the 20% replacement level, showed a consistent resistance to compatible with standard ABNT NBR 9781, therefore concrete paving blocks were manufactured content this level of replacement. The blocks had good mechanical, physical and with the exception of aluminum and cadmium, other substances that exceeded solubility limits were encapsulated. Cadmium also appear in paving blocks manufactured with conventional materials, without residue. Thus, it is concluded that the concrete paving blocks can be used in construction.
69

Reaproveitamento do resíduo Terra da Shredder através da técnica de solidificação/estabilização em matrizes de cimento Portland para aplicação na construção civil / Shredder\'s soil recycling by solidification/ stabilization (S/S) technique in Portland cement matrices for application in construction

Caetano, Juliana Argente 29 June 2016 (has links)
A Shredder é o equipamento para a trituração da sucata ferrosa que permite a reciclagem do aço nas siderúrgicas. A sucata é em sua maioria procedente da reciclagem de veículos de fim de vida. Por isso, esse resíduo é conhecido como ASR (Automotive Shredder Residue). A Terra da Shredder é a fração do ASR de pequena granulometria (<2mm) apresentando o aspecto de solo. Esse resíduo é tratado como rejeito e em sua totalidade destinado aos aterros industriais. O grande volume de resíduo gerado contribui para a saturação dos aterros, provoca impactos ambientais, despende um alto custo de disposição e assim exige o desenvolvimento de tecnologias para seu reaproveitamento. Este trabalho propõe utilizar a Terra da Shredder, resíduo sólido gerado na Shredder localizada em Iracemápolis-SP-BR, em peças de concreto para pavimentação através da técnica de solidificação/estabilização (S/S) em matrizes de cimento Portland. Na primeira etapa do experimento, o resíduo foi classificado como Classe IIA. A segunda etapa consistiu na produção de matrizes compostas com cimento, agregados e água, foram produzidos corpos de prova com os seguintes teores de substituição, em massa, da areia natural pelo resíduo: 5%,10%,15% e 20%. A matriz com o teor de substituição de 20% apresentou uma resistência mecânica compatível com a norma ABNT NBR 9781, por isso foram fabricadas peças de concreto com esse teor de substituição. As peças de concreto apresentaram bom desempenho mecânico, físico e, com exceção do alumínio, fenóis totais e cádmio, as outras substâncias que ultrapassaram os limites de solubilização (ferro total, fluoretos, manganês, selênio, surfactantes) foram encapsuladas pelo cimento, sendo que o cádmio também estava presente em peças de concreto para pavimentação fabricadas apenas com os materiais convencionais, sem o resíduo. Dessa forma, conclui-se que os blocos podem ser utilizados na construção civil. / The Shredder is the equipment for the processing of ferrous scrap which allows the recycling of steel. Scrap is in its majority coming from the recycling of end of life vehicles. Therefore, the residue formed in this grinding process is known as ASR (Automotive Shredder Residue). The fine fraction of the ASR has soil aspect so will be called Shredder\'s soil. This residue is treated as waste and in its entirety for the landfills. It is estimated that for each ton of metallic material separated in Shredders approximately 227 kg of waste are produced. This large volume of waste generated contributes to the saturation of landfills,causes environmental impacts, expends a high cost of disposal and thus requires the development of technologies for its reuse. This paper proposes to use the fine fraction (<2mm) of the solid waste generated in a shredder in the city of Iracemápolis-SP-BR in concrete paving blocks through the techinique of solidification/stabilization (S/S) in Portland cement matrix. The experimental research began with completion of leaching tests and solubilization for the classification of waste class IIA , substances that exceeded solubility limits were total phenols, total iron, fluoride, manganese, selenium, aluminum, cadmium and surfactants. The second stage was the production of cement matrix that is composed by cement, aggregates and water they were produced matrices with the following replacement levels of natural sand by the waste: 5%, 10%, 15% and 20%. The matrice with the 20% replacement level, showed a consistent resistance to compatible with standard ABNT NBR 9781, therefore concrete paving blocks were manufactured content this level of replacement. The blocks had good mechanical, physical and with the exception of aluminum and cadmium, other substances that exceeded solubility limits were encapsulated. Cadmium also appear in paving blocks manufactured with conventional materials, without residue. Thus, it is concluded that the concrete paving blocks can be used in construction.
70

Investigation of causes of foaming in industrial waste water treatment and effects of substances in industrial waste water treatment

Maleka, Mamohau Julia 06 1900 (has links)
M-Tech: Chemistry (Vaal University of Technology) / ABSTRACT The research was aimed to study the causes of excessive foaming in a waste water treatment plant. Although the activated sludge process has been adopted to treat this industrial waste water , lots of problems were experienced by the inhibitory effects of toxic compounds that are found in industrial effluents and the foaming stability that was very high. Industrial waste water treatment using sludge processes was found to be more challenging than the normal municipal waste water treatment although the principle is the same; the foaming tendencies were found to be more in industrial waste water. In this study the composition of influents to the waste water treatment plant and operating parameter’s effects on foaming tendencies were examined. The foaming potential in the plant was found to be chemically related due to high contamination of compounds such as phenols, which played a major role in formation of stable foam. It was recommended that there must be pretreatment of the incoming influents to minimize their impact to waste water treatment.

Page generated in 0.1033 seconds