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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.
1

Characterization and Treatability Study of the Effluent from a Fish Processing Plant

Riddle, M. J. 01 1900 (has links)
<p> The wastewater from a freshwater fish processing plant was characterized. The plant processed perch and smelt, and thus the wastewater characterized was taken from the perch and smelt processing lines and a combined perch and smelt wastewater. The plant also manufactured fish meal from the fish offal. During this process the offal is pressed to obtain stickliquor. Since this stickliquor is a potential waste product it too was characterized.</p> <p> It was concluded that the wastewater was either of medium strength with large flows or of high strength with low flows.</p> <p> Batch and continuous reactor studies were undertaken to ascertain the degradability of the combined wastewater. It was determined that a reactor with either a detention in excess of 5 days with no sludge recycle or a short detention time reactor (7.5 hours) with sludge recycle would be necessary to effect maximum removal of total BOD5.</p> <p> The effect of physical treatment, flotation, sedimentation and in-plant screening, were also examined in a preliminary manner.</p> / Thesis / Master of Engineering (MEngr)
2

Development of Risk Based Treatability and Engineering Measures for Reducing Exposure to Lead Contaminated Media in the Miami Inner City, Florida

Toomer, Tarla TaMia 06 October 2008 (has links)
A major consequence of contamination at the local level’s population as it relates to environmental health and environmental engineering is childhood lead poisoning. Environmental contamination is one of the pressing environmental concerns facing the world today. Current approaches often focus on large contaminated industrial size sites that are designated by regulatory agencies for site remediation. Prior to this study, there were no known published studies conducted at the local and smaller scale, such as neighborhoods, where often much of the contamination is present to remediate. An environmental health study of local lead-poisoning data in Liberty City, Little Haiti and eastern Little Havana in Miami-Dade County, Florida accounted for a disproportionately high number of the county’s reported childhood lead poisoning cases. An engineering system was developed and designed for a comprehensive risk management methodology that is distinctively applicable to the geographical and environmental conditions of Miami-Dade County, Florida. Furthermore, a scientific approach for interpreting environmental health concerns, while involving detailed environmental engineering control measures and methods for site remediation in contained media was developed for implementation. Test samples were obtained from residents and sites in those specific communities in Miami-Dade County, Florida (Gasana and Chamorro 2002). Currently lead does not have an Oral Assessment, Inhalation Assessment, and Oral Slope Factor; variables that are required to run a quantitative risk assessment. However, various institutional controls from federal agencies’ standards and regulation for contaminated lead in media yield adequate maximum concentration limits (MCLs). For this study an MCL of .0015 (mg/L) was used. A risk management approach concerning contaminated media involving lead demonstrates that the linkage of environmental health and environmental engineering can yield a feasible solution.
3

Technical, Economical and Social Aspects of Moving Treatability Studies for In Situ Bioremediation of Contaminated Aquifers from the Laboratory to the Field

January 2013 (has links)
abstract: This dissertation explores the use of bench-scale batch microcosms in remedial design of contaminated aquifers, presents an alternative methodology for conducting such treatability studies, and - from technical, economical, and social perspectives - examines real-world application of this new technology. In situ bioremediation (ISB) is an effective remedial approach for many contaminated groundwater sites. However, site-specific variability necessitates the performance of small-scale treatability studies prior to full-scale implementation. The most common methodology is the batch microcosm, whose potential limitations and suitable technical alternatives are explored in this thesis. In a critical literature review, I discuss how continuous-flow conditions stimulate microbial attachment and biofilm formation, and identify unique microbiological phenomena largely absent in batch bottles, yet potentially relevant to contaminant fate. Following up on this theoretical evaluation, I experimentally produce pyrosequencing data and perform beta diversity analysis to demonstrate that batch and continuous-flow (column) microcosms foster distinctly different microbial communities. Next, I introduce the In Situ Microcosm Array (ISMA), which took approximately two years to design, develop, build and iteratively improve. The ISMA can be deployed down-hole in groundwater monitoring wells of contaminated aquifers for the purpose of autonomously conducting multiple parallel continuous-flow treatability experiments. The ISMA stores all sample generated in the course of each experiment, thereby preventing the release of chemicals into the environment. Detailed results are presented from an ISMA demonstration evaluating ISB for the treatment of hexavalent chromium and trichloroethene. In a technical and economical comparison to batch microcosms, I demonstrate the ISMA is both effective in informing remedial design decisions and cost-competitive. Finally, I report on a participatory technology assessment (pTA) workshop attended by diverse stakeholders of the Phoenix 52nd Street Superfund Site evaluating the ISMA's ability for addressing a real-world problem. In addition to receiving valuable feedback on perceived ISMA limitations, I conclude from the workshop that pTA can facilitate mutual learning even among entrenched stakeholders. In summary, my doctoral research (i) pinpointed limitations of current remedial design approaches, (ii) produced a novel alternative approach, and (iii) demonstrated the technical, economical and social value of this novel remedial design tool, i.e., the In Situ Microcosm Array technology. / Dissertation/Thesis / Ph.D. Biological Design 2013
4

Estudo da aplicação do resíduo de decantador de ETA como auxiliar de floculação no tratamento de água / Study of the application of decanters waste of WTP as an aid of flocculation of water treatment

SOUZA, Leonora Milagre de 21 June 2011 (has links)
Made available in DSpace on 2014-07-29T15:01:47Z (GMT). No. of bitstreams: 1 Dissertacao _Leonora Milagre de Souza.pdf: 965865 bytes, checksum: e8839b11b69dccbdd9fd61b7554b691b (MD5) Previous issue date: 2011-06-21 / The residue generated in Water Treatment Plant (WTP) are derived from different stages of water treatment, especially the discharge of decanters. The most common practice in Brazil is the residue disposal directly into rivers, causing negative impacts to the environment. In general, the WTP have difficulties in managing the residue because the high costs of transportation and disposal, the steady increase in the consumption of chemicals, among other complicating factors. Aiming to reduce the coagulant used in the process and improving the characteristics of the residues for the outflow, this research examined the effects of biosolids application decanter of WTP in the processes of coagulation, flocculation and sedimentation of water treatment. Through laboratory tests, using Jar Test, there were three series of tests, each one using gross water with distinct turbidity. In these trials were used differents dosages of aluminum sulfate and applied to WTP samples with different concentrations of total solids suspended (TSS). After the Jar Test, the decanted water was characterized as turbidity and color, solids and coliforms were not found significant changes in their quality. For most situations, the residue application in treatment has reduced the coagulant in the range 50% to 60%. The increased turbidity of gross water allowed the application of more concentrated residue without reducing the efficiency of treatment in terms of turbidity removal. Regarding the sedimented material in the Jar Test, the decreasing of the dosage of coagulant favored the reduction of the occupied volume by the material, independent of the concentration of residue applied. The specific resistance of sedimented material was higher when compared to the situation without the application in virtually all studied situations. For water with 100 NTU and implementation of residue greater than 7.500 mg/L, and water with 210 NTU and residue less than 8.600 mg/L there was improvement in the sedimentability. The dewatering ability of the sediments by centrifugation was also improved with the application of the residue with 3.642 mg/L and 75% of the coagulant, and 7.500 mg/L using 50% of coagulant. The chemical conditioning by nonionic polyelectrolyte did not improved in the dewatering of sedimented material, but in improving water quality supernatant. Based on this study it was noticed that the application of WTP residue in water treatment was satisfactory as for the analyzed parameters, considering the dosage of coagulant used and the residue applied. / Os resíduos gerados nas Estações de Tratamento de Água (ETAs) são decorrentes das diversas etapas do tratamento da água, em especial da descarga de decantadores. A prática mais comum no Brasil de disposição desse resíduo é diretamente em corpos hídricos, podendo causar impactos negativos ao meio ambiente. Em geral, as ETAs apresentam dificuldades no gerenciamento dos resíduos devido os altos custos com transporte e disposição, o aumento constante no consumo de produtos químicos, dentre outros complicadores. Visando a redução de coagulante utilizado no processo e a melhoria das características desse resíduo para o deságue, a presente pesquisa analisou os efeitos da aplicação do resíduo de decantador de Estação de Tratamento de ETA (ETA) nos processos de coagulação, floculação e sedimentação do tratamento de água. Por meio de ensaios laboratoriais, utilizando Jar Test, foram realizadas três séries de ensaios, cada uma utilizando água bruta com turbidez distinta. Nesses ensaios foram empregadas dosagens variadas de sulfato de alumínio e aplicadas amostras de resíduo da ETA com concentrações de sólidos suspensos totais (SST) diferentes. Após a realização dos ensaios de Jar Test, a água decantada foi caracterizada quanto à turbidez, cor aparente, concentração de sólidos e coliformes, não sendo verificadas alterações significativas em sua qualidade. Para a maioria das situações, a aplicação do resíduo no tratamento possibilitou a redução de coagulante na faixa de 50% a 60%. O aumento da turbidez da água bruta permitiu a aplicação do resíduo mais concentrado, sem reduzir a eficiência do tratamento quanto a remoção de turbidez. Com relação ao material sedimentado gerado nos ensaios de Jar Test, a redução da dosagem de coagulante favoreceu a redução do volume ocupado pelo material, independente da concentração de resíduo aplicado. A resistência específica do material sedimentado foi maior se comparada à situação sem aplicação do resíduo, em praticamente todas as situações estudadas. Para a água com 100 UNT e aplicação do resíduo maior que 7.500 mg/L, e água com 210 UNT e resíduo menor que 8.600 mg/L houve melhora na sedimentabilidade. O deságue do material sedimentado por meio de centrifugação também melhorou com a aplicação dos resíduos com 3.642 mg/L e 75% de coagulante, e 7.500 mg/L utilizando 50% de coagulante. O condicionamento químico por meio de polieletrólito não iônico não auxiliou no desaguamento do material sedimentado, e sim na melhoria da qualidade da água sobrenadante. Baseado neste estudo percebeu-se que a aplicação do resíduo da ETA no tratamento de água foi satisfatória quanto aos parâmetros analisados, devendo ser levada em consideração a dosagem de coagulante empregada e a concentração do resíduo aplicado.
5

Methods and Devices for Evaluating Environmental Remediation Progress and Population Health

January 2018 (has links)
abstract: This dissertation critically evaluated methodologies and devices for assessing and protecting the health of human populations, with particular emphasis on groundwater remediation and the use of wastewater-based epidemiology (WBE) to inform population health. A meta-analysis and assessment of laboratory-scale treatability studies for removing chlorinated solvents from groundwater found that sediment microcosms operated as continuous-flow columns are preferable to batch bottles when seeking to emulate with high fidelity the complex conditions prevailing in the subsurface in contaminated aquifers (Chapter 2). Compared to monitoring at the field-scale, use of column microcosms also showed (i) improved chemical speciation, and (ii) qualitative predictability of field parameters (Chapter 3). Monitoring of glucocorticoid hormones in wastewater of a university campus showed (i) elevated stress levels particularly at the start of the semester, (ii) on weekdays relative to weekend days (p = 0.05) (161 ± 42 μg d-1 per person, 122 ± 54 μg d-1 per person; p ≤ 0.05), and (iii) a positive association between levels of stress hormones and nicotine (rs: 0.49) and caffeine (0.63) consumption in this student population (Chapter 4). Also, (i) alcohol consumption determined by WBE was in line with literature estimates for this young sub-population (11.3 ± 7.5 g d-1 per person vs. 10.1 ± 0.8 g d-1 per person), whereas caffeine and nicotine uses were below (114 ± 49 g d-1 per person, 178 ± 19 g d-1 per person; 627 ± 219 g d-1 per person, 927 ± 243 g d-1 per person). The introduction of a novel continuous in situ sampler to WBE brought noted benefits relative to traditional time-integrated sampling, including (i) a higher sample coverage (93% vs. 3%), (ii) an ability to captured short-term analyte pulses (e.g., heroin, fentanyl, norbuprenorphine, and methadone), and (iii) an overall higher mass capture for drugs of abuse like morphine, fentanyl, methamphetamine, amphetamine, and the opioid antagonist metabolite norbuprenorphine (p ≤ 0.01). Methods and devices developed in this work are poised to find applications in the remediation sector and in human health assessments. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2018

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