An assessment of the groundwater quality at the Olusosun landfill in Lagos, Nigeria was conducted to determine interactions between the landfill wastes and the groundwater and the potential migration of pollutants into the neighbouring communities. Groundwater samples were collected from four locations within the landfill bi-weekly for three months (March 19, 2013 to May 28, 2013), and analysed for water quality parameters and metals. The results indicated that the concentrations of some metals (Cr, Fe, Cd, Mn, and Co) and other water quality parameters in some sampling locations were slightly above the World Health Organization (WHO) and the Nigerian Standard for Drinking Water Quality (NSDWQ) standard limits. Lead was also detected in the groundwater samples, though at concentrations within the standard limits. Conclusively, the Olusosun landfill has impaired groundwater quality, thereby, posing environmental and human health concerns to the neighbouring communities of Oregun, Ketu and Ojota.

No description available.

Microbial oxidation of methane has attracted interest as an alternative process for treating landfill gas emissions. Approaches have included enhanced landfill cover layers and biocovers, passive gas drainage and biofiltration, and active gas extraction and biofiltration. Previous research has shown that microbial methane oxidation is affected by a number of factors, many of which are dependent on the environment in which the process is occurring. The aim of this research was to evaluate the behaviour and performance of a passive landfill gas drainage and biofiltration system operating in a temperate climate, and to identify and quantify the factors that determine the behaviour and performance of the system under such conditions. To achieve this a series of field trials were undertaken in Sydney, Australia, over a period of 4 years. The trials were designed to evaluate the effect of a range of factors, including landfill gas loading rate, temperature and moisture content of the biofilter media, biofilter media characteristics, and climatic conditions. The results of the field trials showed that a passive gas drainage and biofiltration system operating in a temperate climate can achieve methane oxidation efficiencies > 90% and that the behaviour and performance of a passive gas drainage and biofiltration system is primarily dependent on 3 factors: the landfill gas loading rate, which varies; the temperature of the biofilter media, which is affected by the temperature of the landfill gas being treated, the level of microbial activity occurring in the biofilter, and local climatic conditions; and the moisture conditions within of the biofilter media, which is affected by local climatic conditions and the characteristics of the biofilter media. Relationships between these factors and the performance of a passive biofilter operating in a temperate climate were developed, where able. A number of design concepts for passive landfill gas drainage and biofiltration were developed. A process for assessing the feasibility of applying the concepts and designing a passive landfill gas drainage and biofiltration system was also developed. In addition, guidelines and recommendations for the design of a passive landfill gas drainage and biofiltration system operating in temperate climate were developed.

Research Doctorate - Doctor of Philosophy (PhD) / Consolidation of clayey contaminant barriers, such as are employed as landfill liners, has been postulated as a cause of accelerated transit of contaminants and hence their earlier than expected appearance in secondary leachate. This proposition is theoretically investigated in this thesis using a novel large-deformation, one-dimensional continuum model of coupled mechanical consolidation and solute transport. The model is a generalization of existing coupled consolidation and solute transport models described in the literature. It takes into account both non-linearities in geometry as well as material constitutive relations. The latter relate the compressibility, hydraulic conductivity and effective diffusion coefficient to the deformation of the soil. In addition to providing details of the governing equations and constitutive relations, a detailed derivation of the three classical one-dimensional consolidation boundary conditions, i.e. undrained top and drained bottom, drained top and undrained bottom, drained top and bottom is also given. From the continuum model formulation, a numerical model was developed using proprietary finite element software – FEMLAB 2.3. The numerical model is verified by comparing results with those produced from other recently developed consolidation – transport models. In the course of conducting these comparisons, some results from a recent modelling investigation indicating that a twenty-fold reduction in the transit time of contaminants across a composite soil – geomembrane barrier may be possible were re-examined. This comparison reveals some apparent errors in the original analysis and indicates that the predicted large acceleration of contaminant transport induced by consolidation is probably unrealistic. The model is subsequently applied to a case study of a clay liner and geomembrane system. Results obtained are compared with those from various simplified models, including a “diffusion-only” (i.e. a rigid soil) model traditionally used in contaminant barrier design. For barriers incorporating low compressibility soils (such as well compacted clays), there is little difference between contaminant transit times predicted by the two models. However, for contaminant barriers incorporating more compressible soils, consolidation is shown to be capable of accelerating transport. These results indicate the potential importance of accounting for the effects of soil consolidation and they highlight some limitations of existing models when modelling solute transport through composite barriers utilizing soft soils. Based on these limited results, a way of taking into account soil consolidation using simplified models is suggested. In the penultimate chapter of this thesis, an extensive parametric sensitivity analysis of coupled consolidation and solute transport in composite contaminant barrier systems is presented. The analysis incorporates results of more than 3000 simulations for various combinations of barrier thickness, waste loading rate, initial void ratio, compression index, hydraulic conductivity and dispersion coefficient. Results are succinctly presented using dimensionless plots, which allow the comparison of results for a large number of parameter values, and hence, the clear identification of the most important factors affecting contaminant transport through a consolidating composite barrier system. The results demonstrate that there exists a pessimum rate of consolidation for which the contaminant transit time is minimised. In cases of extremely high barrier compressibility it is shown that an order of magnitude reduction in contaminant transit time may arise due to coupling between solute transport and consolidation. For barriers of low compressibility and porosity, such as well-engineered composite compacted clay landfill liners, it is found that the contaminant transit time is far less affected, though it may still be reduced by up to 30%. In general, the results suggest that the use of a coupled consolidation–contaminant transport model may be required for informed and conservative contamiant barrier design, especially if relatively compressible earthen components are utilised.

Thesis (M.S.)--Florida State University, 2005. / Advisor: Dr. Tarek Abichou, Florida State University, College of Engineering, Dept. of Civil and Environmental Engineering. Title and description from dissertation home page (viewed June 8, 2005). Document formatted into pages; contains ix, 62 pages. Includes bibliographical references.

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Yang Wang, Florida State University, College of Arts and Sciences, Dept. of Geological Sciences. Title and description from dissertation home page (viewed Mar. 20, 2006). Document formatted into pages; contains ix, 94 pages. Includes bibliographical references.

This dissertation centres on Montevideo’s political and moral economy of discards as experienced through the lives and labour of waste-pickers around Uruguay’s largest landfill, Felipe Cardoso. These workers are known as clasificadores [classifiers] in recognition of their role separating whatever can be recovered from the waste stream from that which cannot. Conducted from a base next to the landfill as a resident of the COVIFU housing cooperative, 12 months of continuous fieldwork and several subsequent visits consisted principally of participant observation conducted with neighbours who worked the waste stream at nearby dumps, recycling plants, and informal yards. The thesis builds on post-human discard studies by recognising the agentive role of the non-human in consecrating materials not only as waste, but also as a ‘commons’. A central idea is that Montevideo’s waste stream is comparable to the historic English commons in several key regards. These include the manner in which disputes over property status centre on use/ access rather than exchange/ ownership; the customary rights which are claimed by vulnerable subjects; and the provision of a refuge from wage labour. A central disciplinary contribution is forged by combining a renewed ethnographic interest in the commons with a historical perspective and the insights of the anthropology of infrastructure, kinship, and materiality. The commons that emerges is neither romantic nor post-capitalist but a vital, temporarily de-commodified space that thrives in the shadow of municipal infrastructure. The thesis is structured by the relationship between Montevideo’s waste commons and its attempted enclosure. Chapter two weaves ethnography of private and public sector waste managers with the history of municipal waste disposal in the city. It pinpoints technologies of containment and elimination as integral to a policy of ‘hygienic enclosure’ deemed necessary to limit waste’s capacity for hygienic and aesthetic chaos as part of attempts to grasp an ever-elusive infrastructural modernity. Chapter three moves from enclosure to the commons. It draws on ethnography conducted at the Felipe Cardoso landfill and explores waste-picker resistance to attempted hygienic enclosure before turning to historical comparison with the English commons. Chapter four narrows in on two material encounters – with melted ice-cream and plastic potatoes – that draw attention to the ways that particular materialities and affordances of what clasificadores call requeche (leftovers) prefigure both their emplacement in the waste stream and their extraction from it. Clasificador praxis is also shown to disturb the boundaries of the landfill as well as those separating subjects from objects and rural from urban commons. Chapter five returns to infrastructure, demonstrating how waste sustains relations of care while also being ‘reversed’ by the social infrastructure of clasificador kin-based labour. The final chapter draws on ethnography conducted at Montevideo’s Aries recycling plant, arguing that recent government waste policy blends clasificadores’ value-based approach to the waste-stream with a Catholic orientation towards the accompaniment of the poor. In privileging jobs for clasificadores, the state maintains a link between waste and vulnerability but encloses only a small fraction of waste-pickers in hygienic plants while dispossessing many more.

Made available in DSpace on 2014-06-11T19:26:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-06-22Bitstream added on 2014-06-13T19:33:30Z : No. of bitstreams: 1 lino_ic_me_rcla.pdf: 1827804 bytes, checksum: 91af9d464e4b7dc4de2e0458cd3df8da (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A disposição final dos resíduos sólidos urbanos esteve historicamente associada aos surtos epidêmicos que dizimaram milhares de pessoas nos centros urbanos. Contudo, apenas no século XIX iniciaram-se esforços para o desenvolvimento de métodos sanitários de disposição final. Ainda hoje, em países subdesenvolvidos predominam formas de disposição incorretas como lixões e aterros controlados, responsáveis por grande poluição ambiental e pela veiculação de doenças. Uma disposição final adequada dos resíduos sólidos urbanos se inicia com a escolha de locais favoráveis do ponto de vista ambiental. A presente pesquisa teve por objetivo comparar dois métodos de seleção de áreas para implantação de aterros sanitários: o de IG-SMA (1999), e o de Basílio (2001). Os referidos métodos foram escolhidos por terem sido desenvolvidos e aplicados em uma mesma área geográfica (região de Campinas - SP). A comparação por superposição mostrou que apesar da área geográfica ser a mesma, os resultados de ambos foram diferentes. O fato é explicado pela diferença de escalas, critérios, atributos e classes, e chegou-se à conclusão que o método de Basílio (2001) apresentou muito menos áreas favoráveis à disposição de resíduos do que IG-SMA (1999) por ser mais restritivo em seus critérios de seleção. / Historically, the incorrect waste disposal has been related to epidemics which resulted in thousand of deaths. Despite the efforts to develop sanitary disposal methods in the 19 century, even today, uncontrolled dumps are often found in undeveloped countries. These places are responsible for environment pollution and for several diseases. The process of adequate waste disposal begins with the selection of suitable landfill areas, based on environmental characteristics. The goal of this research was to compare two methods of landfill site selection: the first one developed by IG-SMA (1999), and the other by Basílio (2001). Both methods were developed and applied in the same area - region of Campinas, São Paulo State, Brazil and this fact explains the choice for them; the comparison was made by superposing maps. Despite the same geographic area, the result was very different and few areas in common were found; IG-SMA (1999) obtained more suitable areas than Basílio (2001). This has been attributed to scale, criteria and attribute differences and, as a conclusion, Basílio (2001) was considered more restrictive than IG-SMA (1999).

Orientador: José Alexandre de Jesus Perinotto / Banca: Leandro Eugenio da Silva Cerri / Banca: Ângelo José Consoni / Resumo: A disposição final dos resíduos sólidos urbanos esteve historicamente associada aos surtos epidêmicos que dizimaram milhares de pessoas nos centros urbanos. Contudo, apenas no século XIX iniciaram-se esforços para o desenvolvimento de métodos sanitários de disposição final. Ainda hoje, em países subdesenvolvidos predominam formas de disposição incorretas como "lixões" e "aterros controlados", responsáveis por grande poluição ambiental e pela veiculação de doenças. Uma disposição final adequada dos resíduos sólidos urbanos se inicia com a escolha de locais favoráveis do ponto de vista ambiental. A presente pesquisa teve por objetivo comparar dois métodos de seleção de áreas para implantação de aterros sanitários: o de IG-SMA (1999), e o de Basílio (2001). Os referidos métodos foram escolhidos por terem sido desenvolvidos e aplicados em uma mesma área geográfica (região de Campinas - SP). A comparação por superposição mostrou que apesar da área geográfica ser a mesma, os resultados de ambos foram diferentes. O fato é explicado pela diferença de escalas, critérios, atributos e classes, e chegou-se à conclusão que o método de Basílio (2001) apresentou muito menos áreas favoráveis à disposição de resíduos do que IG-SMA (1999) por ser mais restritivo em seus critérios de seleção. / Abstract: Historically, the incorrect waste disposal has been related to epidemics which resulted in thousand of deaths. Despite the efforts to develop sanitary disposal methods in the 19 century, even today, "uncontrolled dumps" are often found in undeveloped countries. These places are responsible for environment pollution and for several diseases. The process of adequate waste disposal begins with the selection of suitable landfill areas, based on environmental characteristics. The goal of this research was to compare two methods of landfill site selection: the first one developed by IG-SMA (1999), and the other by Basílio (2001). Both methods were developed and applied in the same area - region of Campinas, São Paulo State, Brazil and this fact explains the choice for them; the comparison was made by superposing maps. Despite the same geographic area, the result was very different and few areas in common were found; IG-SMA (1999) obtained more suitable areas than Basílio (2001). This has been attributed to scale, criteria and attribute differences and, as a conclusion, Basílio (2001) was considered more restrictive than IG-SMA (1999). / Mestre

Several operational and environmental conditions can result in poor biogas yield during the operation of anaerobic digesters and anaerobic bioreactor landfills. Over time, anaerobic co-digestion and leachate blending have been identified as strategies that can help address some of these challenges to improve biogas production. While co-digestion entails the co-treatment of multiple substrates, leachate blending involves combination of mature and young landfill leachate. Despite the benefits attributed to these strategies, their impact on recirculating bioreactor landfill scenarios and anaerobic digesters requires further investigation. In the first phase of this thesis, an attempt to assess biogas production improvement from organic fraction of municipal solid waste in simulated bioreactor landfills through recirculation of blended landfill leachate was conducted. Real old and new leachate blends (67%New leachate:33%Old leachate, 33%New leachate:67%Old leachate) as well as 100%New and 100%Old leachate were recirculated through six laboratory-scale bioreactors using open-loop and closed-loops modes. Compared with the control bioreactor where 100% new leachate was recirculated and operated as a closed-loop, cumulative biogas production was improved by as much as 77 to 193% when a leachate blend of 33%New:67%Old was recirculated. Furthermore, comparison of the results from open-loop and closed-loop operated bioreactors indicated that there was approximately 28 to 65% more biogas in open-loop bioreactors. The Gompertz model applied to the methane data produced a better fit (R2 > 0.99) than first order and logistic function models. Leachate blending reduced the lag phase by almost half and thus helps in alleviating the ensiling during the start-up phase. In the second phase, a biochemical methane potential (BMP) assay was conducted to investigate the synergistic effect of percentage sewage scum addition; 10%, 20% and 40% (volatile solids basis) on biogas production during mesophilic co-digestion with various organic substrates viz; organic fraction of municipal solid waste, old leachate, new leachate and a leachate blend prepared from 67%old leachate and 33%new leachate under sub-optimal condition. Results show that the net cumulative bio-methane yield was improved with increased sewage scum percentage during co-digestion because of positive synergism. Meanwhile, the addition of 40% sewage scum to the individual co-substrates improved net cumulative bio-methane yield by 28% - 67% when compared to their respective mono-substrate digestion bio-methane yield. Furthermore, reactors containing leachate blends consistently produced more biogas over other sets because of blending. Kinetic modelling applied to the bio-methane production data shows modified Gompertz equation achieved a better fit with up to an R2 value of 0.999. Finally, co-digestion substantially reduced the lag time encountered during mono-digestion. In the last phase, the biomethane potential involved in the ACo-D of sewage scum, organic fraction of municipal solid waste was investigated in this phase using either thickened waste activated sludge or leachate blend (67%old leachate and 33%new leachate) as a tertiary component. Compared to the mono-digestion of TWAS, results shows that biomethane yield was enhanced in by as much as 32 - 127% in trinary mixtures with SS and OFMSW mainly due to the effect of positive synergism. Furthermore, LB addition improved biomethane production in trinary mixtures of SS:LB: OFMSW by 38% than in corresponding trinary mixtures of TWAS. Whereas an optimal combination of 40%SS:10%TWAS:50%OFMSW and 20%SS:70%LB:10%OFMSW produced the highest biogas yield of 407mL.gVS-1 and 487mL.gVS-1 respectively. The application of the first order model showed that lower hydrolysis rates promoted methanogenesis with k = 0.04day-1 in both 20%SS:70%LB:10%OFMSW and 20%SS:50%LB:30%OFMSW. Estimations by the modified Gompertz and logistic function were conclusive methane production rate improved by as much a 60% in a trinary mixture over the production rate during mono-digestion of TWAS alone. The results of the various experiments of this thesis therefore suggest that leachate blending can be used as a strategy to improve biogas production in both bioreactor landfills and anaerobic digesters. Also, sewage scum as an energy-rich substrate can be better utilized during co-digestion with other low-energy substrates.