published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Dissertation submitted in compliance with the requirements for the Master's Degree in Technology: Biotechnology, Technikon Natal, 2001. / Landfills play an important role in the removal of waste from the surroundings. There is a limit to the types of waste that can be recycled and the landfill becomes the final method of waste disposal. Because waste constitutes a wide variety of materials, the microbial consortia that develop within a landfill will be equally varied, depending on the type of waste deposited, the temperature of the landfill and moisture content of the waste. The metabolism of these microbial consortia can result in products that are either harmful or beneficial. In order to increase the pool of knowledge on landfill microbiology, it is important to study the various consortia that inhabit the landfill to determine the various microbial interactions that occur and subsequently to manipulate these interactions to enhance the benefits of a landfill site and reduce the harmful effects. In this research, an attempt was made to isolate anaerobic cellulolytic bacteria from a landfill site. Six waste samples, varying in age were obtained over a period of two years. Samples were excavated from a maximum depth of 4m. Samples are processed in anaerobic, phosphate buffer and cultivated in various pre-reduced anaerobic media and incubated under anaerobic conditions. Samples were also collected from other potential anaerobic sites namely, anaerobic sludge, decomposing bagasse, compost, manure, rumen and pond sediment. Results of degradation of the cellulose source (Whatman No. 1 filter paper) indicated that it was possible to cultivate cellulose-degrading microorganisms from the landfill. Zones of clearing around colonies, which would be indicative of cellulose degradation on solid media, were not obtained. Samples from the anaerobic sludge, compost and rumen showed degradation of cellulose in liquid media but not on solid media. It is concluded that the solid media used was unsuitable for the cultivation of anaerobic, cellulolytic bacteria or that the anaerobic conditions employed were not adequate to initiate the growth of the anaerobic cellulolytic bacteria. / M

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements of the degree of Master of Science in Geology Johannesburg, 1998 / This study determines the potential of prerncting pollution to ground water by sanitary landfills. The tracing capabilities of both stable and radioactive environmental isotopes are also evaluated. Four landfills were selected, the Linbro Park and Waterval sites in Johannesburg, and the Bloemfontein northern and southern landfill sites. The sites all differ in geological environment, size. age and physiographic setting. [Abbreviated Abstract. Open document to view full version] / MT2017

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Um dos desafios na elaboração de projetos de aterros sanitários é o equacionamento do destino/tratamento dos líquidos percolados em função das elevadas concentrações de poluentes, associadas a grandes variações, e seu abrandamento natural ao longo do tempo. Nesse sentido, o trabalho avalia, a partir da montagem de unidade piloto, a viabilidade do lançamento dos líquidos percolados gerados no aterro de sanitário, localizado no município de Piracicaba-SP, na Estação de Tratamento de Esgoto que dispõe de sistema australiano de lagoas. A unidade foi montada na própria estação e operada durante 18 meses, sendo avaliado o comportamento da eficiência para vazões crescentes de líquidos percolados. No trabalho foi investigado também a adequação dos métodos Suíço, Racional e do Balanço Hídrico na previsão da taxa de geração de líquidos percolados, a partir da comparação das estimativas obtidas pela aplicação dos métodos com a observada na prática. De maneira geral, pode-se dizer que é viável o lançamento de chorume em estações de tratamento de esgoto, sem prejuízo na eficiência do sistema. Com relação às estimativas das vazões de chorume pela aplicação dos métodos, os erros variaram desde menos 22% até mais 20% da vazão obtida na prática. / One of the challenges in the project of sanitary landfills is the solution of the destination/treatment of leachates due to the high concentration of pollutants, which is also associated to large variations and a natural reduction with time. This work evaluates, based on a pilot unit, the feasibility of the treatment of leachates, produced in sanitary landfills, in a wastewater treatment plant that uses a system of stabilization lagoons. The pilot unit was mounted in the wastewater treatment site and operated for 18 months, in which the performance was monitored for crescent flowrates of leachates. It was also investigated the prediction of leachate flowrates by different methods (Swiss, Rational and Hydric Balance) based on the comparison of predicted leachate generation rates with observed data. In general, it is possible to perform the treatment of leachates in wastewater treatment plants because there was no reduction of efficiency. Related to the prediction of leachate volumes, the errors of the tested methods range from -22% to + 20% of the observed flowrates.

Sempre houve uma preocupação com relação a disposição final do lixo, tanto nas grandes como nas pequenas cidades. Este trabalho consiste em analisar áreas para uma disposição adequada de aterros sanitários no Município de São Carlos. O Município de São Carlos, localizado no Estado de São Paulo, apresenta uma área de 1.151 km2 e conta com uma população de aproximadamente 180.000 habitantes. Está assentado sobre as Formações geológicas: Pirambóia, Botucatu, Serra Geral, Itaqueri, que são recobertas por materiais inconsolidados retrabalhados; o Botucatu constitui um grande manancial de águas de subsuperfície. Algumas áreas devem ser protegidas, visto que constituem zonas de recarga de aqüíferos. A metodologia Leite (1995) foi usada neste trabalho para a escolha dos atributos e análise dos resultados. Os principais atributos considerados foram: bacias hidrográficas, declividade, poços profundos, precipitação pluviométrica, substrato rochoso, mineralogia, espessura de materiais inconsolidados, landforms, distâncias do centro urbano, existência de outros aterros; esses atributos foram associados às informações geotécnicas analisadas em laboratório. Estas informações, permitiram avaliar as áreas mais favoráveis para a disposição de resíduos e a produção da Carta de Zoneamento em escala 1:50.000. / The final disposal of waste has always been a matter of trouble in big or small urban centers. This work presents the results acquired during the application of engineering geological mapping techniques in the evaluation of favorable areas for the development of waste sanitary landfills in São Carlos region. São Carlos region is located in the center State of São Paulo, Brazil, has an area of 1,151 km2 and a population 180,000. It\'s geology is characterized by the Pirambóia, Botucatu, Serra Geral and Itaqueri formations, which are covered by residual and reworked unconsolidated materiais; Botucatu represent large aquifer. The methodology from LEITE (1995) was used in this work, both for choosing the attributes or analyzing the results. The main considered attributes were the drainage basins, slope dips, rainfall, underlying rocks, thickness of unconsolidated materials, landforms, distance from the urban center and the occurrence of other landfills; these attributes were associated to laboratorial test informations. These informations, as a whole, led to an evaluation of the most favorable areas for waste disposal and the elaboration of a 1:50,000 scale zoning chart.

Thesis submitted in fulfilment of the requirements for the degree of Master of Technology: Chemistry in the Faculty of Applied Sciences at the Cape Peninsula University of Technology, 2012 / Batch experiments were conducted to assess the removal of Ni(II) from aqueous solutions and landfill leachates using low cost adsorbents eggplant peel (EGP), sweet potato peel (SWP) and banana peel (BNP). Preliminary studies were carried out to optimize biosorbent mass, pH, Ni(II) concentration, temperature and contact time for Ni(II) removal. The optimized conditions were then applied to landfill leachates using the selected low cost adsorbents. Ni(II) removal efficiency for each biosorbent was investigated for each parameter. Results indicated that biosorbents masses, pH, initial concentration as well as solution temperature were important factors influencing Ni(II) removal from aqueous solutions. Percentage Ni(II) removal was 66±0.30, 38±3.97 and 33±1.20 using EGP, SWP and BNP, respectively. Ni(II) removal efficiency increased significantly (P ≤ 0.05) with increasing biosorbent mass, pH and Ni(II) initial concentration while it decreased significantly (P ≤ 0.05) with increasing temperature. Although Ni(II) removal efficiency varied significantly with time and the biosorbents no significant (P 0.05) difference was observed between the time interval whether the experiment was conducted in batch or semi batch mode. Results of FTIR studies indicated that several binding and chelating functional groups such as carboxyl, carbonyl and hydroxyl groups on the biomaterials surfaces could be responsible for Ni(II) biosorption. The optimum biosorbent mass for EGP and SWP was 0.4 g and for BNP was 0.05 g. The values for initial concentration, pH, temperature and contact time were 100 mg/L, 5, 22oC and 2 hours, respectively. Ni(II) removal efficiencies using EGP, SWP and BNP were 66, 38 and 33%, respectively. Taking into account the result and optimum condition obtained on Ni(II) removal efficiency from aqueous solution using EGP, SWP and BNP, the Ni(II) removal efficiency using these biosorbents from landfill leachate was investigated. It was found to be significantly (P ≤ 0.05) lower than what was found from aqueous solution.

Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable. One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have been shown to be stable and numerically robust for advection-dominated transport in heterogeneous velocity fields. However, the existing finite analytic methods for solute transport in multiple dimensions have the following disadvantages. First, the method is computationally inefficient when applied to heterogeneous media due to the complexity of the formulation. Second, the evaluation of finite analytic coefficients is when the Peclet number is large. Third, the method introduces significant numerical diffusion due to inadequate temporal approximation when applied to transient problems. This thesis develops improved finite analytic methods for two-dimensional steady as well as unsteady solute transports in steady velocity fields. For steady transport, the new method exploits the advantages of the existing finite analytic and finite difference methods. The analytically difficult diffusion terms are approximated by finite difference and numerically difficult advection and reaction terms are treated analytically in a local element in deriving the numerical schemes. The new finite analytic method is extended to unsteady transport through application of Laplace transformation. Laplace transformation converts the transient equation to a steady-state expression that can be solved with the steady version of the improved finite analytic method. Numerical inversion of the transformed variables is used to recover solute concentration in the physical space-time domain. The effectiveness and accuracy of the new finite analytic method is demonstrated through stringent test examples of two dimensional steady-state transport in highly variable velocity fields. The results clearly demonstrated that the improved finite analytic methods are efficient, robust and accurate.

The potential for leachate movement out of a sanitary landfill was evaluated and simulated by a computer program model. Landfill operations and geohydrological conditions in the area were investigated in order to develop a conceptual model of the system and to obtain numerical data for the development of the simulation.The landfill is operated in a 20 to 27 foot thick clay till which overlies a 10 foot thick, continuous sand and gravel aquifer. Monitor wells located around the site indicate minimal changes in groundwater quality to this date. This is attributed to the slow movement of leachate through the confining layer which would take at least 5 to 10 years.Numerical parameters not readily determined were varied in 16 simulations. This procedure allowed analysis of the different plumes developed as well as observation of the program’s sensitivity to such changes. In simulations of five years from the time leachate would enter the aquifer, leachate plumes were developed which extended a mile and one half down the hydrologic gradient from the landfill. Varying the parameters led to fairly consistant conclusions regarding the effects of the landfill.Ball State UniversityMuncie, IN 47306