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  • 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.
221

THE IMPLICATIONS OF BEHAVIORAL ASPECTS ON THE PRODUCTION AND DISCARD OF HOUSEHOLD HAZARDOUS WASTES.

Wilson, Douglas Calvin. January 1985 (has links)
No description available.
222

Stabilisation of waste in shallow test cells : focus on biogas.

Chetty, Nevendra Krishniah. January 2006 (has links)
Present day society generates large volumes of waste that present an environmental hazard when disposed of in landfills. As our population grows, so does the volume of waste generated and hence the threat to our environment. One method of reducing harmful emissions in landfills is the mechanical-biological pretreatment of waste prior to landfilling. The purpose of this dissertation is to investigate the degree of stabilization of waste in shallow landfills (simulated by test cells) with particular focus on biogas production and quality. Municipal waste was composted in aerobic, open windrows for periods of eight and sixteen weeks. Five test cells, designed and operated according to the PAF model (Pretreatment, Aeration and Flushing) were constructed at the Bisasar Road landfill site. These cells were used to simulate large scale municipal landfill sites. They were filled with fresh and pretreated waste and were used to monitor the dynamics of prolonged aeration and degradation of waste over a period of six months. The cells were monitored on a weekly basis while being aerated. Two flushing events were conducted at the beginning of the passive aeration. Gas emissions were also monitored by recording the methane, carbon dioxide and oxygen volumes per volume of air in probes strategically placed in each cell. These results were then analysed to assess the effect of mechanical-biological pretreatment of municipal solid waste on the emission quality of sanitary landfills and the appropriateness of prolonging the aeration in shallow landfills, as often used in sub-tropical countries. It was found that the design of the test cells was appropriate for the landfilling and stabilization of waste that was aerobically treated. After six months in the test cells, analysis of the waste from each cell showed that the waste was completely degraded. The PAF model, when applied to shallow landfills, is very effective in stabilising waste and would be appropriate for a sub-tropical climate. Waste that is pretreated, placed in shallow landfills, initially flushed and then aerated over a six month period was fully stabilized. The requirement for such treatment would be relatively small amounts of waste, a wet climate and the availability of open space for shallow landfills. This method, therefore, would be very appropriate in a South African context. The major problem with this method may be the generation of large quantities of leachate which will have to be treated and disposed of in an environmentally safe manner. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2006.
223

Sustainable management of tannery hair waste through composting

Onyuka, Arthur January 2010 (has links)
Bovine hair, resulting from the unhairing of hides and skins, forms a major component of tannery solid wastes that is often disposed to landfill. However, following increasing environmental legislation restricting the disposal of commercial and industrial organic wastes to landfill, alternative treatment of tannery solid hair waste is necessary. The overall aim of this research was to develop conditions favourable for the decomposition of bovine hair waste in a composting environment. In this study, chemical pretreatments of bovine hair were carried out to enhance susceptibility to enzymatic digestion. Pretreatment using a combination of potassium thioglycolate and sodium hydroxide enhanced enzymatic digestibility of hair. Comparative solubilisation of black, brown and white hair samples with sodium sulfide showed that, the percentage soluble nitrogen, from white hair was 73% (w/w) as compared to 28% (w/w) and 24% (w/w) of black and brown hair, respectively; indicating that white hair was more vulnerable to solubilisation. Although chemical pretreatment was effective, it was considered non-compatible with the composting process. Consequently, enzymatic and microbial degradation were considered suitable alternatives. The results of the preliminary biochemical studies indicated that, the breakdown of the hair structure was enhanced when treated with a combined protease solution containing proteinase K and trypsin enzymes as compared with individual enzymes. Enzymatic and microbial degradation of hair was observed to be preferential, starting with the least resistant components, in this sequence: (1) cell membrane, (2) endocuticle, (3) medulla, and (4) cytoplasmic material and fibrillar components of the cortex. The cuticle was most resistant to degradation. Synergistic action of microbial-expressed enzymes was observed to be the fundamental mechanism for the enhanced hair degradation. Composting of bovine hair, mixed with dry leaves, soil, and wood chips/sawdust was performed in a rotary drum under controlled conditions. Optimum conditions, in order to sustain thermophilic microbial flora, were found to be (1) a moisture content of 55-+2% RH, (2) pH 7-8, (3) temperature of 49-+ C, and (4) a carbon to nitrogen ratio of 35:1. Structural changes in hair, assessed during composting using scanning electron microscopy (SEM), indicated that degradation occurred under these conditions. Microscopy results further indicated that the addition of an inoculant, containing a microbial crude enzyme, expressed by the bacteria of Bacillus species, improved the biodegradation of hair during the controlled composting process. The compost stability evaluated by monitoring the humification parameters and carbon to nitrogen ratio, indicated that the final product reached the following values: degree of humification (73 - 78%), humification ratio (26 - 32%), humification index (0.29 - 0.35), and a carbon to nitrogen ratio (25 - 29). The high level of humification of the end-product indicated reasonable stability, suggesting the product from the composted bovine hair may be suitable, suggesting the product from the composted bovine hair may be suitable for agronomical purposes. The use of composting as alternative technology for the treatment of tannery solid bovine hair waste, as a value added product, has been demonstrated.
224

Phytostabilization of multi-metal contaminated mine waste materials: long-term monitoring of influence of soil amendments on soil properties, plants, and biota and the avoidance response of earthworms

Gudichuttu, Vindhya January 1900 (has links)
Master of Science / Department of Agronomy / Ganga M. Hettiarachchi / Mine waste materials from the Tri-State mining region in Kansas, Missouri, and Oklahoma pose environmental hazards. The area is contaminated with trace elements, such as Pb, Zn and Cd, which are transported to surrounding areas through water, wind erosion, and runoff. Phytostabilization or establishing healthy vegetative cover could be used to reduce or control these contaminated materials from further spreading with wind and water. However, further research is needed to monitor the long-term sustainability and assess if high applications of compost amendments could help to facilitate soil reclamation. The overall focus of this thesis was to monitor long-term effects of compost or lime additions at two different rates, with or without other soil amendments, on soil properties, plants, and soil biota. We used the earthworm avoidance test as a screening tool for testing effects of soil amendments on ecotoxicity. In the first field study, pelletized manure compost additions of 448 Mg ha⁻¹ significantly decreased the bioavailable Pb, Zn, and Cd while increasing plant nutrients, vegetative cover, and plant biomass as compared to the contaminated control and the low addition of compost (224 Mg ha⁻¹) over 2.5 years. Plant tissue metal concentrations with compost addition did not show any phytotoxicity in this study. Lime additions did not show any significant effect on any of the measurements. Results from the first study suggest that one time addition of large quantities of compost at 224 to 448 Mg ha⁻¹ can support establishing and maintaining healthy vegetative cover at least for a 2.5 year period. In the second field study, long-term monitoring of the effectiveness of the amendments was studied. Compost was applied at two different rates (45 or 269 Mg ha⁻¹) in 2006. Various chemical properties, microbial activities, and vegetative growth or plant biomass were measured approximately for 4.5 years to evaluate long-term changes in soil quality and sustainability of phytostabilization efforts, when combined or assisted with soil amendments to improve the quality of trace element-contaminated mine waste materials. Plants grown with compost additions of 269 Mg ha⁻¹ showed higher nutrients, biomass, and enzyme activities as compared to plants grown on the contaminated control and with the low addition of compost (45 Mg ha⁻¹) over 4.5 years. Decrease in plant biomass and enzyme activities seen in the high compost treatments by the end of the study period suggested that long-term sustainability of these efforts may require repeated addition of soil amendments every 4 to 5 years. Additionally, a laboratory study was conducted to assess the long-term effects of treatments used in the second field study on ecotoxicity using the avoidance behavior responses of the earthworm Eisenia fetida. There was no mortality of earthworms after a 48 h exposure period of any of these treated and untreated mine waste materials. Avoidance was clear for the contaminated control and the low compost treatment (45 Mg ha⁻¹). Moreover, the contaminated control did show habitat limitation (< 20% of earthworms was found in test soil). Current research studies provide evidence that, high rates of compost applications can be used to stabilize and reduce the bioavailability of trace elements in mine waste materials.
225

Population exposure to cyanide vapour from gold mine tailings dams

22 June 2011 (has links)
M.Sc. / Atmospheric emissions of dust and chemicals from gold mine tailings are ongoing environmental management issues on the Witwatersrand, where residential areas have developed in proximity to dumps. Residual amounts of cyanide, used as a chemical in the gold extraction process, are deposited with the mineral tailings. This study deals with the evaluation of population exposure to cyanide vapour emitted from gold mine tailings dams, an issue of environmental impact and public health concern. The first part of this study deals with the determination of the emission factors of cyanide vapour from three selected gold mine tailings dams: one under reclamation; one no longer operational; and one fully operational as a slimes deposition site. These three sites are located in the Boksburg area of the Ekurhuleni Metropolitan Municipality. Twelve samples were collected in all: six from the Cason (2628AAL91) mine dump (under reclamation in 2006); four from the ERPM tailings complex [comprising the dormant deposits 4/L/47, 4/L/48, 4/L/49 and 4/L/50, which are north of the N17 national highway; and the 2628ACL1 deposit, which is south of the N17]; and two from the Rooikraal (active) deposition site. All samples were collected in the year 2006. In the second part of the study, the obtained emission factors were used in an Industrial Source Complex dispersion model to measure the degree of population exposure to cyanide vapour for communities that are in proximity to the operational gold mine tailings dams in the Johannesburg Metropolitan Municipality. In the third part, a health risk assessment was carried out for communities in proximity to the selected gold mine tailings dams. The study revealed the average flux (± std. dev.) of Cason to be (4.7 ± 0.8) x 10-7 g m-2 s-1, the average flux of ERPM (3.9 ± 0.6) x 10-7 g m-2 s-1, the average flux of Rooikraal (1.7 ± 0.2) x 10-5 g m-2 s-1. The concentrations of cyanide vapour emitted from the older tailings deposits (sand) that are under reclamation and the dormant slimes dams are very low (and pose little health risk to occupants of adjacent land). However, HCN emission factors from operational tailings dams, which are receiving continuous depositions, are 3 to 80 times higher than the emission factors from dormant mine tailings. Ambient cyanide concentrations near the active tailings deposits may sometimes exceed selected international health standards. The average hourly, daily and annual dispersion model calculations for the Nasrec tailings deposition sites in Johannesburg revealed that 117 938, 18 722 and 8 130 people respectively were exposed to hydrogen cyanide concentrations that were above international (Ontario, Canada) standards. This raises environmental concerns that require institution of cyanide monitoring and setting of emission limits applicable to South African legal and environmental circumstances. These conclusions are based on a small number of emission factor determinations and hence these findings should be regarded as provisional. Further testing and verification are required for emission factors from a larger number of dormant, reworked and active tailings dams.
226

Estudo do sistema de gerenciamento integrado de resíduos de construção e demolição do município de São Carlos - SP / Study of the integrated management of construction and demolition wastes from São Carlos - SP

Córdoba, Rodrigo Eduardo 21 May 2010 (has links)
Com a intensificação da geração de resíduos sólidos urbanos, as autoridades, pesquisadores e sociedade têm voltado seus esforços para enfrentar as dificuldades de manejo e disposição final adequada desses resíduos. Neste sentido, é coerente afirmar que os resíduos de construção e demolição (RCD) fazem parte dessa problemática, pois geralmente representam a maioria dos resíduos sólidos gerados no meio urbano. A ausência de políticas públicas em relação à gestão e gerenciamento desses resíduos tem provocado diversos impactos como, por exemplo, o surgimento de vários depósitos clandestinos nas áreas mais afastadas do perímetro urbano e gastos por parte da administração pública com modelos de gestão corretiva. Entretanto, esse modelo corretivo tem se demonstrado obsoleto e ineficaz para minimizar os impactos negativos gerados pela deposição irregular de RCD. Diante desses fatos, foi criada a Resolução CONAMA nº 307/2002, que instituiu que os municípios devem prover políticas públicas voltadas a evitar o descarte dos RCD em locais irregulares e que contemplem a minimização dos impactos causados ao meio ambiente e saúde humana. Assim, com intuito de contribuir nesta área de conhecimento a presente pesquisa teve por finalidade estudar a situação do sistema de gerenciamento integrado de RCD do município de São Carlos-SP, após a regulamentação da Resolução CONAMA nº 307/2002. Para tanto, foi realizado um levantamento da situação atual do gerenciamento dos RCD no município, por meio de quatro etapas de estudo - contextualização dos indicadores básicos locais; caracterização quantitativa; caracterização qualitativa e por fim análise das áreas de descarte clandestino e áreas de implantação de pontos de captação para pequenos volumes de RCD. Com base nos resultados obtidos neste estudo, foi possível verificar que o município de São Carlos possui um Plano Integrado de Gerenciamento de RCD, em consonância com a Resolução CONAMA nº 307/2002. Porém pode-se constatar que o respectivo município não possui implantada uma rede de captação que contemple os pequenos volumes, assim este sofre com o aumento de áreas de descarte clandestino, as quais causam diversos impactos ao meio ambiente e saúde pública local. Entretanto, medidas adotadas neste novo sistema também demonstraram fatores positivos como a redução de descartes em aterros e geração de emprego e renda. Por fim, esta pesquisa implementou uma metodologia de caracterização dos RCD por análise de imagens, a qual se demonstrou eficiente na caracterização de amostras que apresentavam peças com grandes volumes como, por exemplo, vigas, pilares e placas de concreto. / With the increased generation of urban solid wastes, the authorities, researchers and society have turned their efforts to tackle the difficulties of handling and final disposal of such wastes. In this sense, it is consistent to say that the construction and demolition wastes (C&D) are part of this problem, because they generally represent the majority of solid waste generated in urban areas. The absence of public politics regarding the management of such waste have caused many impacts, for example, illegal discharges dumping sites in areas furthest from the urban perimeter and spending by the government with corrective models. However, this corrective model has proven obsolete and ineffective to minimize the negative impacts caused by the irregular disposal of C&D wastes. Given these facts, the resolution nº 307/2002 of the National Environmental Council (CONAMA) for the C&D wastes was created, which established that municipalities must provide public politics that aim at preventing the disposal of C&D wastes at irregular areas and reduce impacts to the environment and human health. Therefore, to contribute to this area of knowledge this research studied the situation of the integrated management system of C&D wastes from São Carlos-SP, after the implementation of resolution nº 307. For this, a survey was done of the current situation of management of C&D wastes in the city through four stages - local contextualization of basic indicators, quantitative characterization, qualitative characterization and finally analysis of areas of irregular discharge and areas of implantation of points for small volumes of C&D wastes. Based on the results of this study, we observed that the municipality of São Carlos has an Integrated Waste Management of C&D wastes, according to resolution nº 307. However, it was found that the municipality has not established a system of small volumes, so it suffers with increasing areas of irregular disposal, which causes many impacts to the environment and local public health. However, measures taken in this new system also demonstrated positive factors such as the reduction of discards in landfills and the generation of employment and income. Finally, this study implemented a methodology to characterize the C&D by image analysis, which has demonstrated effectiveness in the characterization of samples with high volume parts such as beams, pillars and slabs of concrete.
227

Estudo da remoção de Sr2+ de soluções aquosas utilizando fibras de coco bruta e ativada com peróxido de hidrogênio em meio básico / Study of removal of Sr2+ from aqueous solution using raw coconut fibers and treated with hydrogen peroxide in basic condition

Fonseca, Heverton Cardan Oda 25 November 2015 (has links)
Neste trabalho é apresentado o potencial de remoção de íons estrôncio de soluções aquosas pelas fibras de coco na forma bruta e na forma ativada com peróxido de hidrogênio, 1% e 4%, em meio básico. Os experimentos de biossorção foram realizados em batelada com 2 mg.L-1 de solução de Sr(NO3)2 e foram estudadas as influências dos seguintes parâmetros: tempo de contato, pH e a eficiência de biossorção das fibras ativadas em comparação com a fibra de coco bruta (FCB). A caracterização das fibras antes e após o tratamento, e a presença de Sr2+ nas fibras foram realizadas por microscopia de varredura eletrônica com detector de espectroscopia de energia dispersiva, espectroscopia de difração de raios X, espectroscopia de infravermelho e por análise térmica. Dentre as fibras estudadas, a fibra de coco ativada com 1% H2O2 (FCA 1) apresentou a maior capacidade de biossorção: 3,6 mg.g-1, nas seguintes condições: 5 mg de biomassa em pH 6, após 90 minutos de tempo de contato à temperatura ambiente. A fibra de coco ativada com 4% H2O2 (FCA 2) levou a uma maior degradação dos constituintes da fibra e consequentemente a uma menor remoção de íons de Sr2+.Para os estudos de modelos de isotermas de biossorção de Sr2+, tanto a FCB quanto a FCA 1 ajustaram-se melhor ao modelo de Langmuir e à cinética de pseudo-segunda ordem. Os parâmetros termodinâmicos energia livre de Gibbs (&Delta;G) e coeficiente de distribuição (KD) foram -0,90 kJ.mol-1 e 265,3L.Kg-1 para a FCB e de -7,2 kJ.mol-1 e 824,3 L.Kg-1 para a FCA1. Esses resultados demonstraram que a FCA 1 possui uma boa eficiência para remover íons de Sr2+de resíduos químicos aquosos e é uma boa alternativa no tratamento de rejeitos radioativos líquidos contendo íons 90Sr. / This work presents the potential of strontium ions removal from aqueous solutions using coconut fiber in raw and treated form with hydrogen peroxide, 1% and 4%, in alkaline conditions. The biosorption experiments were performed in batch mode with 2 mg.L-1 solution of Sr(NO3)2 and the influence of the following parameters were studied: contact time and pH. It was also evaluate the biosorption efficiency of the treated coconut fibers in comparison with the raw coconut fiber (RCF). The fibers characterizations before and after treatment and the presence of the Sr2+ in the fibers were performed by scanning electron microscopy with a detector energy dispersive spectroscopy, diffraction of x-ray spectroscopy, infrared spectroscopy and thermal analysis. Among the studied fibers, the treated coconut fiber with 1% of H2O2 (TCF 1) showed the major biosorption capacity of 3.6 mg.g-1 in the following conditions: 5 mg of biomass at pH 6, 90 minutes of contact time at room temperature. Treated coconut fiber with 4% H2O2 (TCF 2) showed the lowest Sr2+ ions removal due to degradation of the fibers constituents. For studies of biosorption isotherms, both raw and treated coconut fiber (TCF 1) were fitted better to Langmuir model and the kinetics reaction was of pseudo-second order. The thermodynamic parameters Gibbs free energy (&Delta;G) and distribution coefficient (KD) were -0.90 kJ.mol-1 and 265.3 L.Kg-1 for RCF and of -7,2 kJ.mol-1 and 824.3L.Kg-1 for TCF 1. These results demonstrated that the TCF 1 has good efficiency for removing Sr2+ ions in the aqueous chemical waste and is a good alternative in treatment of liquid radioactive wastes containing 90Sr.
228

Estudo laboratorial acerca da possibilidade de aproveitamento da cinza pesada de termelétrica em bases e sub-bases de pavimentos flexíveis / Laboratory study concerning the possible utilization of the bottom ash from thermal power station in the bases and sub-bases of pavements

Leandro, Rodrigo Pires 17 October 2005 (has links)
A cinza pesada é um sub-produto gerado do processo da queima do carvão mineral pulverizado nas caldeiras das termelétricas para a produção de vapor aquecido que atuará na geração de energia elétrica. Não há um destino adequado para esse tipo de cinza, sendo que o volume gerado diariamente é depositado em bacias de sedimentação, causando, dessa forma, problemas ambientais. Principalmente nos Estados Unidos, muitas pesquisas têm evidenciado o sucesso do emprego deste resíduo na construção de rodovias. Contudo, no Brasil as pesquisas sobre cinza pesada estão mais voltadas para a área de edificações. Deste modo, a proposta da pesquisa foi investigar os efeitos da cinza pesada quando incorporada a solos, através de ensaios laboratoriais, visando o aproveitamento deste resíduo na construção de bases e sub-bases de pavimentos. Também foi avaliado o efeito da adição de cal às misturas solo-cinza. Os ensaios utilizados na etapa experimental foram os de mini-CBR, resistência à compressão simples e resistência à tração por compressão diametral. Complementarmente, realizaram-se ensaios de CBR e de resistência à compressão simples na condição imersa. Os resultados mostraram que as adições de cinza pesada aos solos não melhoram as propriedades mecânicas das misturas compactadas. Entretanto, a adição de 3% de cal às misturas de solo-cinza proporciona a melhora significativa no comportamento mecânico das misturas, oferecendo uma solução para aproveitamento da cinza pesada na construção rodoviária. / Bottom ash is a by-product from the burning of mineral coal. It is utilized as fuel in thermal power stations in order to produce electrical energy. The bottom ashes are deposited in the lagoons and are harmful to the environment. In the United States, several researches have indicated successful uses of this waste in the construction of roadways. However, in Brazil the researches have been accomplished to use the bottom ashes in the civil construction. Thus, the purpose of the present research was to investigate the results of the bottom ash additions to soil in order to utilization in bases and sub-bases of pavements. Afterward, the effects of lime additions to soil-bottom ash mixtures were evaluates. The tests employded were mini-CBR, unconfined compressive strength and indirect tensile strength. California bearing ratio and immersion unconfined compressive strength were accomplish such supplementary tests. The results indicated that bottom ash additions to soils does not improve the mechanical properties of the compacted mixtures. However, the addition of the 3% of the lime to soil-bottom ash mixtures provided better mechanical performance, offering a feasible solution for the use of this waste in road construction.
229

Resíduos de mineração e metalurgia: efeitos poluidores em sedimentos e em espécie biomonitora - Rio Ribeira de Iguape - SP / Residues of mining and metallurgy: pollutant effect in sediments and biomonitor organism - River Ribeira de Iguape

Guimarães, Valeria 10 May 2007 (has links)
Por aproximadamente 40 anos, o Rio Ribeira de Iguape recebeu resíduos da mineração: rejeitos das plantas de concentração mineral (enriquecidos em Cu, Cr, Pb, Ag e Zn) e escórias de uma unidade de metalurgia (enriquecidas em Cu, Zn, Cr, Fe, Pb e As), produzidos e descartados pela empresa Plumbum S/A, localizada em Adrianópolis (Paraná). Para verificar a contribuição destes resíduos na contaminação deste rio, como também identificar a possibilidade de depuração natural ou não no mesmo, definiu-se a necessidade de avaliar três compartimentos: resíduos, sedimentos e organismo biomonitor. Nas amostras de resíduos foram realizadas caracterizações físicas e químicas, nos sedimentos foram realizadas análises químicas, granulométricas e algumas amostras investigadas por MEV/EDS e no biomonitor (molusco Asiático da espécie Corbicula fluminea) foram realizadas análises químicas dos tecidos e das carapaças. Estas análises indicaram a existência de elevados teores de Pb nos resíduos da mineração, os quais ultrapassaram os valores deste metal estabelecidos na norma NBR 10.005 da ABNT. Nesta comparação, os rejeitos do concentrado da Mina do Rocha ultrapassaram em 32 vezes, os da Plumbum em 41 vezes e as escórias em 34 vezes, os limites estabelecidos por tal norma, sendo assim classificados como pertencentes à Classe I ? perigosos. Destes resíduos o mais problemático atualmente é o rejeito da Plumbum, por apresentar granulometria fina, pH mais baixo, apresentar maior teor de Pb no teste de lixiviação, além de estar depositado muito próximo de uma das margens do Rio Ribeira de Iguape. A interação destes resíduos com o sistema aquático foi verificada a partir da detecção de Pb, Zn, Cu nos sedimentos. Os sedimentos depositados em bancos de areia e os estuarinos exibiram maiores teores para Pb (média de 135,00 mg/kg para os depósitos em bancos de areia e 124,00 mg/kg para os estuarinos) e Zn (média de 112,62 mg/kg para os depositados em bancos de areia e de 133,00 mg/kg para os estuarinos). Em todos os tipos de sedimentos foi constatado que o local de coleta que exibiu teores mais elevados para os metais de estudo foi em Iporanga, secundariamente na Ilha do Caranguejo na região do Mar Pequeno, a sul de Iguape. Nos sedimentos em suspensão, as análises em MEV/EDS exibiram a presença de grãos de escória, indicando que estes ainda hoje, estão interagindo com este ambiente e sendo transportados. Esta comprovação, só foi possível, de fato, a partir das análises de tecidos e de carapaças da espécie Corbicula fluminea, os quais demonstraram estar havendo interação dos metais pesados provenientes dos resíduos com a biota deste sistema aquático. Nos tecidos deste biomonitor foram detectados em média 23,99 ?g/g de Cu, 144,21 ?g/g de Zn, 0,71 ?g/g de Cd, 2,41 ?g/g de Pb e 7,11 ?g/g de Cr. Destes metais, o mais preocupante é o Pb, ele apresenta concentrações mais elevadas que os relatados em outros estudos para este mesmo bivalve e também, ultrapassa o valor de referência da ANVISA (2,00 ?g/g) para a concentração deste metal pesado em peixes e produtos de pesca para consumo. Além dos tecidos, as carapaças deste biomonitor, também estão concentrado estes metais pesados. De modo geral, concluiu-se que o Rio Ribeira não está sofrendo processos naturais de depuração e que ainda hoje representa um problema ambiental, pois os metais estão migrando ao longo do curso da drenagem e neste processo sendo biodisponibilizados, o que pode vir a gerar transferência e acumulação na cadeia trófica. / For approximately 40 years, Ribeira de Iguape River received mining wastes (enriched in Cu, Cr, Pb, Ag and Zn) and metallurgical slags (enriched in Cu, Zn, Cr, Fe, Pb and As), produced and discharged by Plumbum S/A, a company located in Adrianópolis (Paraná). In order to verify the contribution of these residues in the river contamination and natural purification the compartments of mining residues, sediments and bioindicator organisms were evaluated. Physical and chemical characterizations were realized in the residues samples; while chemical analyses, grain size evaluation and MEV/EDS were carried out in sediments. Asiatic clam (Corbicula fluminea) was taken as a bioindicator, through chemical analyses of its tissues and shells. The results showed high Pb levels, being classified as Class 1 ? dangerous - by ABNT, norm NBR 10,005, once the limited levels were exceeded by Rocha wastes (32x), Plumbum wastes (41x) and slags (34x). The Plumbum waste is currently the most problematic, as it is made of fine grain, lower pH, higher Pb level detected in the extraction test and is deposited very close to the draining site. The interactions of these residues with the aquatic system was verified through Pb, Zn, Cu detection in the sediments. Pb and Zn levels were, respectively, 135.00 mg/kg and 112.62 mg/kg in the sand banks deposits, and 124.00 mg/kg and 133.00 mg/kg in the estuaries deposits, with prominent metal levels in Iporanga and, secondary, in Crab Island, region of the Small Sea, south of Iguape. MEV/EDS analyses carried out in suspended sediments showed the presence of slags grains, suggesting that still nowadays they are transported and interact with the environment, once they have been detected in tissues and shells samples of Corbicula fluminea. In the tissues of this bioindicator, there were detected average levels of 23.99 ?g/g of Cu, 144.21 ?g/g of Zn, 0.71 ?g/g of Cd, 7.11 ?g/g of Cr and 2.41 ?g/g of Pb; making evident that this last value is strongly high and over the ANVISA reference (2.00 ?g/g) for fish and other consumption products. The results suggest that natural processes of Ribeira de Iguape River are not sufficient for its purification, keeping metals\' transport and bioavailability, which can accumulate in the trophic chain, representing a serious environmental problem.
230

Biogas Production from Organic Waste, Meat and FOG by Anaerobic Digestion and Ultimate Sludge Digestibility

Unknown Date (has links)
The anaerobic biodegradability of food waste (FW), meat waste and FOG (fats, oils and greases) with municipal primary sewage sludge was assessed using a laboratory scale anaerobic digester and by ultimate sludge digestibility, at mesophilic conditions by varying the inoculum to feedstock ratio (1:2-1:10) and solids retention time (SRT). Preliminary analysis assessed the anaerobic digestion of food waste and meat at a biogas production over 30 days at 1000 mL and 1400 mL, respectively. The maximum methane yield was 0.18 m3/kg VS and 0.50 m3/kg VS for 1:10 in meat and FOG, respectively in 28 days with 56-61% volatile solids of destruction and first order methane generation rate of 0.15 d-1 for both meat and FOG. The optimal ratio for meat and FOG was determined to be beyond highest ratio tested (1:10), and longer SRT should be considered to investigate the impact of feedstock on methane yield. Preliminary modeling suggests that for one 1.74 MG digester, diverting just 0.6% of the food waste generated in one-third of Palm Beach County could produce enough methane to power 130-360 homes for one full month. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

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