Since the United States Environmental Protection Agency (USEPA) began requiring landfills to implement a leachate collection system in 1991, the proper disposal of leachate has become a growing concern. The potential toxicity of landfill leachate will contaminate groundwater and soil if not managed properly. Research has been made in efforts to manage leachate in a cost-effective, single treatment process. Photocatalytic oxidation is an advanced oxidation process (AOP) which has shown ability to reduce toxicity of an array of leachate constituents including organics, inorganics and heavy metals. The purpose of this manuscript is to scale up the batch scale study of TiO2 photocatalytic degradation of leachate utilizing a pilot scale falling film reactor. In this research project, the use of UV/TiO2 for the removal of chemical oxygen demand (COD), ammonia, alkalinity and color will be studied in order to optimize catalyst dosage, determine pH effects and reaction kinetics and develop preliminary cost estimates. / by Frank Youngman. / Thesis (M.S.C.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Determination of the vertical and horizontal groundwater hydraulic gradient within a landfill is the first step in determining the potential of groundwater contamination from the landfill leachate. The length of a study and the frequency at which measurements are recorded can greatly affect the description of the local groundwater environment. A more comprehensive analysis can be preformed for longer periods of study and greater measurement frequency. The intent of this study was to install a continuous groundwater level monitoring system around the st. Johns Landfill for a minimum study length of one year. This would allow a more thorough study of the seasonal character and behavior of the groundwater system beneath the landfill than in previous studies. Particular interest was paid to groundwater level changes resulting from seasonal weather changes. Additional attention was paid to other forcing mechanisms which could be perturbing groundwater levels, and variations in the geochemical groundwater constituents. Included throughout this report is a literature review of various studies pertinent to the analysis of groundwater level variations. Seasonal variations in vertical groundwater hydraulic gradients were reviewed and time averaged vertical seepage rates were estimated. Areal plots of groundwater levels were used to view expected horizontal groundwater hydraulic gradients during seasonal maximum and minimum groundwater levels. A computer model was developed to study the effects temporal variations in slough water levels had on groundwater seepage rates through the perimeter dike separating the landfill from the sloughs. The modeling provided an estimate of the average horizontal leachate seepage rate into the sloughs. Comparison plots of monitoring well groundwater levels were used to analyze potential swash zones beneath the landfill and potential effects of lowered water levels in Bybee Lake. Spectral analysis techniques were imployed to determine the dominant frequencies observed in the groundwater levels, allowing determination of the type of forcing mechanism driving the fluctuations. Geochemical groundwater constituents were statistically analyzed to determine the significance of observed trends in the data: areal plots of chloride concentrations and electrical conductivity were made to view constituent distributions within the underlying aquifers. Estimated vertical and horizontal groundwater seepage rates into the local waters showed that horizontal leachate seepage is insignificant compared to vertical leachate seepage. Groundwater level comparison plots indicated no significant swashing beneath the landfill occurred. The statistical studies on groundwater forcing mechanisms indicated that either the slough or the Columbia River water levels could be perturbing groundwater levels. Trend analyses on the geochemical groundwater constituents indicated significant, positive trends in chloride concentrations, and undeterminable trends in electrical conductivity.

Landfill leachate treatment in South Africa is still in its early stages; research has been conducted but primarily at pilot scale level. Current legislation in South Africa does not prohibit the discharge of landfill leachate into the sewer line, despite the high risk of methane explosions and corrosion of the sewer pipes. Thus, to date, the off site channelling of landfill leachate into the sewer lines for further dilution in municipal wastewater treatment plants is the most common practice. Due to the development of stricter environmental regulations, the design of sustainable landfills is leading to the 'treatment at source' concept. Increasing public pressure is also forcing new landfills to be situated in remote areas where there is no avaliable sewer line to discharge into and 'treatment at source' will be required. Due to these developments, coupled with the lack of full scale leachate treatment experience in South Africa, Durban Solid Waste (The waste service unit of the Durban metropolitan), in an attempt to develop the knowledge and practical experience required for leachate treatment, undertook a research project to investigate the use of nitrification/denitrification pilot scale sequencing batch reactors (SBR) to treat leachate from the Bisasar Road and Mariannhill Landfills. The successful completion of the trials proved that the full removal of nitrogen compounds could be easily achieved, under South African climatic conditions, in a single sludge SBR system. The system was found to be simple to operate and required low maintenance. However, the final effluent required further treatment before it could meet the general discharge standards into natural watercourses. Being South Africa, a 'low gross income' country, it became necessary to consider an appropriate, cost effective and technically feasible 'polishing' treatment system. It was decided that a pilot scale treatment trial, using vegetated submerged bed constructed wetlands, be undertaken to assess the applicability and feasibility of such a passive system for the 'polishing' of the effluent from the pilot scale sequencing batch reactors. The wetland systems were found to be affected by many interrelating climatic factors. The trials concluded that the wetlands could not achieve the required discharge standards, in terms of concentration. However, it also showed that the effluent organics posed no oxygen demand or toxic threat to a receiving environment. The trials showed the ability of the wetlands to behave as mass removal systems, which could achieve the required mass removal efficiency in terms of mass output per day. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.

Co-disposal with refuse in a controlled landfill is the cheapest option for the disposal of hazardous waste and, if carefully controlled, can be an effective treatment option. In this present study a high-strength phenolic wastewater and activated sewage sludge were co-disposed with refuse. The effectiveness of phenol catabolism at two organic loading rates (500mgt1 and 1000mgtl) was assessed in the presence of various co-disposal strategies. Leachate recycle at the lower phenol organic loading rate was found to facilitate the greatest rate of phenol catabolism. Despite the effective removal of phenol, however, leachate recycle promoted the production of high concentrations of ammoniacal-N and hydrogen sulphide. At the higher phenol organic loading rate, recirculation was ineffective in reducing the residual phenol concentration due to inhibition of the phenol-catabolisers. Microcosms operated with single elution and batch co-disposal strategies at both phenol organic loading rates resulted in serious detrimental effects on the refuse fermentation and subsequent leachate quality. A high-strength leachate obtained from a closed co-disposal site was characterised to determine its chemical composition and was assessed for its susceptibility to biological treatment. If carefully controlled, co-disposal sites should produce leachates which differ little in quality to those produced by municipal waste sites. The exceptionally high specific conductivity of the leachate used in this present study was, however, uncharacteristic of a leachate from a municipal waste site. The leachate required dilution to 25 % (v/v) before responding to aerobic biological treatment due to the presence of bactericidal/bacteriostatic components. Anaerobic treatment was ineffective even at a final dilution of 10% (v/v) of the original due to the inhibition of methanogenesis caused indirectly by the high concentration of sulphate in the leachate. Following phosphate addition, aerobic biological treatment effected a significant reduction in the chemical oxygen demand (COD) but did not reduce the ammoniacal-N concentration. Scaling and precipitation occurred following addition of the phosphate, and although these did not affect the biological process they can cause operational problems in full-scale leachate treatment plants. Ion exchange, with soil, and lime treatment, were, therefore, considered for their ability to reduce the inorganic content of the leachate prior to biological treatment. However, these particular pretreatments were unsuitable due to their ineffectiveness to reduce calcium, the main inorganic element involved in scaling, to an acceptable concentration. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.

The objective of this research was to determine if mature landfill leachate could be treated to a level so that it was safe to discharge to the environment. The treatment method was an Advanced Oxidation Process. The process utilized Titanium Dioxide and UV. Three different reactor types were used, falling film, flow through and falling film + Electron Magnetic Oxygen Hydrogen (EMOH). To improve removal pre-treatment with titanium dioxide settling were conducted in conjunction with treatment in a reactor. The best removal was obtained with pre-treatment with titanium dioxide settling, followed by the falling film + EMOH reactor. In 8 hours, removal was 63% for COD, 53% for ammonia, 73% for alkalinity and 98% for calcium hardness. The kinetics found in this experiment show that full treatment times for safe discharge vary between contaminates. For complete removal of all tested contaminates to safe discharge regulations requires 185 hour of treatment. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

Most waste generated in South Africa is sent to landfills for disposal, and although it is confined in specific areas, it can potentially affect both above and below ground water resources, impacting environmental and public health. This is particularly relevant in a country where water supplies are limited and groundwater resources are prone to pollution. The primary objective of this study was to assess the performance of an upflow packed-bed bioreactor purposedesigned for the treatment of leachates produced by landfills in the Durban Metropolitan Area (DMA). The effect of parameters such as the nature of the biofilm support matrix, aeration rate and recycle rate on the efficacy of the system were investigated. Another major aim of the project was to develop a low maintenance technology that could, nonetheless, bioremediate leachate effectively at minimum cost. This aspect of process design is a crucial factor in areas where there is a shortage of both funds and skilled labour. The glass 132 l packed-bed upflow bioreactor was evaluated by measuring its efficiency in terms of chemical oxygen demand (COD) and biological oxygen demand (BOD) reduction and ammonia removal. The bioreactor could be configured as a batch-type system, which was useful for comparing operating conditions; or as a continuous cascade system, which was used to assess its overall performance. Different biofilm support matrices viz. various grades of pine bark, plastic bioballs and ceramic noodles were evaluated in 22 l batch-type reactors. Leachates from five landfill sites were remediated during the course of the study, and only the leachate from Shongweni landfill, which had a remarkably low BOD:COD ratio (0.05), was intractable and could not be successfully treated; even in flask trials designed to test strategies such as augmentation of microflora and biostimulation. The other leachates investigated were from the Umlazi, Marianhill, Bisarsar Road (all general sites) and Bul-Bul Drive (a semi-hazardous site) landfills, all of which were remediated to some degree. Originally, leachate from the Umlazi landfill site was used, but it became unavailable when the site closed enforcing the use of other leachates for the remainder of the investigation. Leachates from Marianhill, Bisarsar Road and Bul-Bul Drive were treated simultaneously in duplicate operating the six-chambered bioreactor in the batchtype configuration. The highest COD removal efficiency (49 %) was obtained in the chambers treating the Bul-Bul Drive leachate, which was therefore used for further investigations. This leachate had the highest BOD:COD ratio and was therefore expected to be the most suited to biological remediation. The bioreactor performed best when plastic bioballs were used as biofilm support matrix with a relatively low level of aeration, although the uncomposted form of pine bark was used initially as the support matrix because it is inexpensive and readily available in South Africa. However, although satisfactory COD reduction (30 – 61 %) and ammonia removal (87 – 98 %) was achieved when the Umlazi leachate was treated, the possibility of compounds leaching out of the bark and affecting the quality of the treated leachate was a concern. Also, pine bark would be prone to mechanical degradation in a full scale operation. Of the other solid support matrices tested using the Bul-Bul leachate, COD removal efficiencies were superior with plastic bioballs (60 %) than with pine bark chips (29 %). The former therefore became the preferred biofilm support matrix. Aeration level did influence bioremediation of the Umlazi landfill leachate since those chambers aerated with an aquarium pump (0.05 – 0.1 litres air/litre leachate/min; 60 % COD removal) performed better than those aerated with a blower (0.6 -0.7 litres air/litre leachate/min; 42 % COD removal) and those that remained unaerated (44 % COD removal). Recycle rate did not significantly affect bioremediation, but the performance of the system was higher when operated in batch mode (up to 60 % influent COD removal), rather than in continuous flow-through (cascade) mode when only 37 % of the influent COD in the Bul-Bul leachate was removed. Under the latter conditions, most of the reduction occurred in the first four chambers and very little biodegradation occurred in the final two chambers. The cascade-mode will require some refinement to enhance the COD removal efficiencies achieved. However, it did eliminate 89 % of the BOD present in the raw leachate, producing a treated effluent with a consistent BOD:COD ratio of 0.05. The COD removal efficiencies achieved covered a wide range from a minimum of 23 % with Marianhill leachate to a maximum of 63 % with leachate from Bul-Bul Drive. These results are comparable with many of those reported by other authors treating landfill leachate. Up to 98 % of the ammonia was removed when the Umlazi leachate was treated. However, ammonia removal from the other leachates tested was erratic. Although the treated leachate from this system could not be released into the environment without further remediation, the reduction in concentration of pollutants would allow its return to the local water supply via a wastewater treatment plant. This was achieved without temperature and pH regulation or addition of extraneous nutrient sources. A cost-effective, low maintenance technology such as this one would be a useful tool for the treatment of effluents such as landfill leachate in countries like South Africa where although water conservation is urgently required, resources for highly sophisticated effluent remediation are often not readily available. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

CAPES / A produção de resíduos sólidos urbanos (RSU) aumenta a cada dia em razão da associação de uma série de fatores, tais como crescimento da população, aumento do poder aquisitivo, facilidade de acesso aos bens de consumo, etc. Em consequência, o gerenciamento e a disposição final tornaram-se um grande problema a ser encarado onde, atualmente, um dos principais meios de destinação final dos RSU é o aterro sanitário. Otimizar sua vida útil devido à ausência de terrenos adequados para este fim, principalmente em grandes centros urbanos, e exigências mais rígidas de órgãos controladores e reguladores, tornou-se um dos principais focos dos gestores tanto municipais quanto estaduais. Uma das formas de melhorar o aproveitamento das áreas de disposição de RSU é o aumento da altura do aterro, porém, se não for realizado de forma correta pode ocasionar danos significativos para o meio ambiente e para a sociedade. A presença de materiais com propriedades semelhantes às fibras existentes na massa de resíduos sólidos, como plásticos e têxteis, promovem um acréscimo na resistência ao cisalhamento da massa de RSU depositada em aterros, porém, esses materiais vão sofrendo decomposição e alterando suas propriedades e, consequentemente, podendo ocasionar mudanças na resistência ao cisalhamento ao longo do tempo. Desta forma, o presente trabalho tem por objetivo avaliar a influência do lixiviado na resistência à força de tração do plástico mole e como objetivos específicos avaliar a influência largura, distância entre as distância entre as ancoragens e taxa de carregamento, nas trações resultantes; verificar se há variação do pH, demanda química de oxigênio (DQO), alcalinidade, ácidos voláteis, nitrogênio amoniacal e fósforo total presentes no lixiviado, ao longo do tempo e avaliar a estrutura e componentes do plástico mole com e sem imersão no lixiviado. Foram utilizadas sacolas plásticas de supermercado, cortadas em tiras de 0,5 e 1,0 cm de largura, estas ficaram em contato com o lixiviado coletado em um aterro sanitário da região metropolitana de Curitiba-PR, e em seguida foram submetidas aos ensaios de força de tração, a cada quinze dias, variando a distância entre as ancoragens (0 cm, 7 cm e 21 cm) e a taxa de carregamento de ensaio (1 mm.min-1 e 4 mm.min-1). O estudo permitiu verificar que os ensaios realizados com largura de 1 cm resultaram em força de tração superior àquelas realizadas com largura de 0,5 cm. A distância entre as ancoragens e taxa de carregamento de ensaio interferem significativamente nos valores de força de tração obtidos, sendo que ensaios realizados com taxa de carregamento de 4 mm.min-1 resultaram em força de tração superior. Quando se leva em consideração o tempo de contato, não foi possível chegar a uma conclusão definitiva, pois o tempo de contato foi relativamente pequeno. Com a análise de microscopia eletrônica de varredura (MEV) e espectroscopia de energia dispersiva (EDS) foi possível verificar que há deposição de sólidos nas tiras plásticas após imersão no lixiviado e que há deposição de diferentes componentes químicos nas tiras plásticas como o alumínio, por exemplo. / The production of municipal solid waste (MSW) increases every day because of the association of a number of factors such as population growth, increased purchasing power, facility of access to consumer goods, etc. Consequently, the management and disposal have become a major problem to be faced where currently one of the main means of disposal of MSW is the landfill. Optimize its useful life due to ausence of suitable land for this purpose, especially in large urban centers, exigencies stricter controllers and regulators; it has become a major focus of both municipal and state managers. One way to improve the use of MSW disposal sites is increasing embankment height, but if not done properly can cause significant damage to the environment and society. The presence of materials with similar properties to existing fibers in the mass of solid waste such as plastics and textiles, promote an increase in mass of the shear strength of MSW landfill, but these materials are undergoing decomposition and changing its properties, consequently, may cause changes in shear strength over time. Thus, this study aims to evaluate the influence of the leachate on the tensile strength of the soft plastic and specific objectives to assess the width, distance between anchors and speed the resulting pulls, check for variation of pH, chemical oxygen demand (COD), alkalinity, volatile fatty acids, ammonia, nitrogen and total phosphorus present in the leachate over time and to assess the structure and the soft plastic components with and without immersion in the leachate. Plastics grocery bags, cut into 0.5 to 1.0 cm wide strips were used. These were in contact with leachate collected in a landfill in the metropolitan region of Curitiba-PR, and then were sub- jected to tensile tests, every fifteen days, varying the distance between the anchors (0 cm, 7cm and 21 cm ) and the test speed (1 mm.min-1 and 4 mm.min-1) .The study showed that the tests performed with a width of 1 cm resulted in those made with superior traction width of 0.5 cm. The distance between the anchors and speed of test interfere significantly in tensile values, and tests performed at a speed of 4 mm.min-1 resulted in superior traction. When taking into account the contact time was not possible to reach a definitive conclusion as contact time was relatively low. With the analysis of scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS) were unable to verify that there is deposition of solids in the plastic strips and that there are different chemical components present in the solid aluminum, for example.

CAPES / A produção de resíduos sólidos urbanos (RSU) aumenta a cada dia em razão da associação de uma série de fatores, tais como crescimento da população, aumento do poder aquisitivo, facilidade de acesso aos bens de consumo, etc. Em consequência, o gerenciamento e a disposição final tornaram-se um grande problema a ser encarado onde, atualmente, um dos principais meios de destinação final dos RSU é o aterro sanitário. Otimizar sua vida útil devido à ausência de terrenos adequados para este fim, principalmente em grandes centros urbanos, e exigências mais rígidas de órgãos controladores e reguladores, tornou-se um dos principais focos dos gestores tanto municipais quanto estaduais. Uma das formas de melhorar o aproveitamento das áreas de disposição de RSU é o aumento da altura do aterro, porém, se não for realizado de forma correta pode ocasionar danos significativos para o meio ambiente e para a sociedade. A presença de materiais com propriedades semelhantes às fibras existentes na massa de resíduos sólidos, como plásticos e têxteis, promovem um acréscimo na resistência ao cisalhamento da massa de RSU depositada em aterros, porém, esses materiais vão sofrendo decomposição e alterando suas propriedades e, consequentemente, podendo ocasionar mudanças na resistência ao cisalhamento ao longo do tempo. Desta forma, o presente trabalho tem por objetivo avaliar a influência do lixiviado na resistência à força de tração do plástico mole e como objetivos específicos avaliar a influência largura, distância entre as distância entre as ancoragens e taxa de carregamento, nas trações resultantes; verificar se há variação do pH, demanda química de oxigênio (DQO), alcalinidade, ácidos voláteis, nitrogênio amoniacal e fósforo total presentes no lixiviado, ao longo do tempo e avaliar a estrutura e componentes do plástico mole com e sem imersão no lixiviado. Foram utilizadas sacolas plásticas de supermercado, cortadas em tiras de 0,5 e 1,0 cm de largura, estas ficaram em contato com o lixiviado coletado em um aterro sanitário da região metropolitana de Curitiba-PR, e em seguida foram submetidas aos ensaios de força de tração, a cada quinze dias, variando a distância entre as ancoragens (0 cm, 7 cm e 21 cm) e a taxa de carregamento de ensaio (1 mm.min-1 e 4 mm.min-1). O estudo permitiu verificar que os ensaios realizados com largura de 1 cm resultaram em força de tração superior àquelas realizadas com largura de 0,5 cm. A distância entre as ancoragens e taxa de carregamento de ensaio interferem significativamente nos valores de força de tração obtidos, sendo que ensaios realizados com taxa de carregamento de 4 mm.min-1 resultaram em força de tração superior. Quando se leva em consideração o tempo de contato, não foi possível chegar a uma conclusão definitiva, pois o tempo de contato foi relativamente pequeno. Com a análise de microscopia eletrônica de varredura (MEV) e espectroscopia de energia dispersiva (EDS) foi possível verificar que há deposição de sólidos nas tiras plásticas após imersão no lixiviado e que há deposição de diferentes componentes químicos nas tiras plásticas como o alumínio, por exemplo. / The production of municipal solid waste (MSW) increases every day because of the association of a number of factors such as population growth, increased purchasing power, facility of access to consumer goods, etc. Consequently, the management and disposal have become a major problem to be faced where currently one of the main means of disposal of MSW is the landfill. Optimize its useful life due to ausence of suitable land for this purpose, especially in large urban centers, exigencies stricter controllers and regulators; it has become a major focus of both municipal and state managers. One way to improve the use of MSW disposal sites is increasing embankment height, but if not done properly can cause significant damage to the environment and society. The presence of materials with similar properties to existing fibers in the mass of solid waste such as plastics and textiles, promote an increase in mass of the shear strength of MSW landfill, but these materials are undergoing decomposition and changing its properties, consequently, may cause changes in shear strength over time. Thus, this study aims to evaluate the influence of the leachate on the tensile strength of the soft plastic and specific objectives to assess the width, distance between anchors and speed the resulting pulls, check for variation of pH, chemical oxygen demand (COD), alkalinity, volatile fatty acids, ammonia, nitrogen and total phosphorus present in the leachate over time and to assess the structure and the soft plastic components with and without immersion in the leachate. Plastics grocery bags, cut into 0.5 to 1.0 cm wide strips were used. These were in contact with leachate collected in a landfill in the metropolitan region of Curitiba-PR, and then were sub- jected to tensile tests, every fifteen days, varying the distance between the anchors (0 cm, 7cm and 21 cm ) and the test speed (1 mm.min-1 and 4 mm.min-1) .The study showed that the tests performed with a width of 1 cm resulted in those made with superior traction width of 0.5 cm. The distance between the anchors and speed of test interfere significantly in tensile values, and tests performed at a speed of 4 mm.min-1 resulted in superior traction. When taking into account the contact time was not possible to reach a definitive conclusion as contact time was relatively low. With the analysis of scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS) were unable to verify that there is deposition of solids in the plastic strips and that there are different chemical components present in the solid aluminum, for example.