Non-isothermal kinetic for lyophilized leachate from sanitary landfill and composting usine

Leachate samples from a sanitary landfill of Araraquara city and composting usine of Vila Leopoldina, São Paulo, Brazil were lyophilized to remove the water content. TG/DTG curves at different heating rates were recorded. The second step of the thermal decomposition of leachate from the Araraquara landfill (CB1), from the composting usine from Vila Leopoldina (CB2) from the organic phase extracted (FO) and aqueous phase (FA) were all kinetically evaluated using the non-isothermal method.By Flynn-Wall isoconversional method the following values were obtained: E=234 +/- 3.65 kJ mol(-1) and logA=29.7 +/- 0.58 min(-1) for CB1; E=129 +/- 1.66 kJ mol(-1) and logA=11.8 +/- 0.10 min(-1) for CB2; E=51.6 +/- 1.35 kJ mol(-1) and logA=6.09 +/- 0.09 min(-1) for FO and E=76.91 +/- 6.33 kJ mol(-1) and logA=8.88 +/- 0.7 min(-1) for FA with 95% confidence level. Applying the procedures of Malek and Koga, SB kinetic model (Sestak-Berggren) is the most appropriate to describe the decomposition of CB1, CB2, FO and FA.

Evaluation of remote sensing for the detection of landfill gas and leachate in an urban environment

The technique of remote sensing provides a unique view of the earth's surface and considerable areas can be surveyed in a short amount of time. The aim of this project was to evaluate whether remote sensing, particularly using the Airborne Thematic Mapper (ATM) with its wide spectral range, was capable of monitoring landfill sites within an urban environment with the aid of image processing and Geographical Information Systems (GIS) methods. The regions under study were in the West Midlands conurbation and consisted of a large area in what is locally known as the Black Country containing heavy industry intermingled with residential areas, and a large single active landfill in north Birmingham. When waste is collected in large volumes it decays and gives off pollutants. These pollutants, landfill gas and leachate (a liquid effluent), are known to be injurious to vegetation and can cause stress and death. Vegetation under stress can exhibit a physiological change, detectable by the remote sensing systems used. The chemical and biological reactions that create the pollutants are exothermic and the gas and leachate, if they leave the waste, can be warmer than their surroundings. Thermal imagery from the ATM (daylight and dawn) and thermal video were obtained and used to find thermal anomalies on the area under study. The results showed that vegetation stress is not a reliable indicator of landfill gas migration, as sites within an urban environment have a cover too complex for the effects to be identified. Gas emissions from two sites were successfully detected by all the thermal imagery with the thermal ATM being the best. Although the results were somewhat disappointing, recent technical advancements in the remote sensing systems used in this project would allow geo-registration of ATM imagery taken on different occasions and the elimination of the effects of solar insolation.

Influence of Spatial Variation of Hydraulic Conductivity of Municipal Solid Waste on Performance of Bioreactor Landfill

The current study analyzes the leachate distribution in the Orchard Hills Landfill, Davis Junction, Illinois, using a two-phase flow model to assess the influence of variability in hydraulic conductivity on the effectiveness of the existing leachate recirculation system and its operations through reliability analysis. Numerical modeling, using finite-difference code, is performed with due consideration to the spatial variation of hydraulic conductivity of the municipal solid waste (MSW). The inhomogeneous and anisotropic waste condition is assumed because it is a more realistic representation of the MSW. For the reliability analysis, the landfill is divided into 10 MSW layers with different mean values of vertical and horizontal hydraulic conductivities (decreasing from top to bottom), and the parametric study is performed by taking the coefficients of variation (COVs) as 50, 100, 150, and 200%. Monte Carlo simulations are performed to obtain statistical information (mean and COV) of output parameters of the (1) wetted area of the MSW, (2) maximum induced pore pressure, and (3) leachate outflow. The results of the reliability analysis are used to determine the influence of hydraulic conductivity on the effectiveness of the leachate recirculation and are discussed in the light of a deterministic approach. The study is useful in understanding the efficiency of the leachate recirculation system. (C) 2013 American Society of Civil Engineers.

Avaliação da eficiência de wetland construído como unidade de polimento de efluente de tratamento secundário de lixiviado por lodos ativados

Uma das dificuldades a ser enfrentada na implantação de aterros sanitários é o tratamento adequado do lixiviado gerado e seu lançamento no meio ambiente dentro dos padrões estabelecidos pela legislação. O potencial poluidor do lixiviado está ligado principalmente aos altos valores de carga orgânica que promove a redução do oxigênio disponível (utilizado na degradação da matéria orgânica) em cursos dágua, prejudicando a fauna e a flora nesses meios. O objetivo do presente trabalho foi avaliar o sistema de tratamento por wetland construído como unidade de polimento do efluente secundário de uma estação de tratamento de lixiviado de aterro de resíduos sólidos urbanos na Região Metropolitana do Rio de Janeiro. Além dos parâmetros coletivos específicos e não específicos, também foram empregados o fracionamento pelo processo de separação por membranas e ensaios de toxicidade aguda. Os resultados mostram que o wetland tem uma ação positiva como unidade de polimento refletida na redução dos parâmetros turbidez (84%), DQO (19%), amônia (30%) e sólidos totais (3%) reduzindo, assim, os impactos ambientais do lançamento do lixiviado. Contudo, a qualidade do efluente final encontra-se acima dos parâmetros de referência de controle ambiental e mostra a necessidade de um efluente secundário de melhor qualidade. Os resultados mostraram também que altos valores de DQO inerte tanto no afluente (85% em média) quanto no efluente (93,5% em média) do wetland indicam que esses lixiviados apresentam natureza refratária confirmada pelos baixos valores de biodegradabilidade no afluente (20,5% em média) e no efluente (5% em média) do wetland. O fracionamento com membranas mostrou que o afluente e o efluente do wetland possuem maiores contribuições de moléculas na fração >1 kDa. Os ensaios de toxicidade com Aliivibrio fischeri mostraram que o afluente e o efluente do wetland possuem toxicidade aguda, sendo a mesma menor na faixa com moléculas menores.

Seismic performance of geomembrane placed on a slope in a MSW landfill cell -A centrifuge study

Geomembranes are one of the most commonly used geosynthetics in landfill liner systems. They retain the leachate produced by the waste and prevent leakage. Geomembranes may experience harsh environmental conditions such as extreme temperatures or earthquake loading. Earthquake loading can be an extreme loading case for landfills located in seismic regions. This study, based on dynamic centrifuge testing, investigates the effects of simulated earthquake loading on the tension experienced bythe geomembrane on a landfill slope. The landfill modeled in the dynamic centrifuge test was a municipal solid waste (MSW) landfill cell with a single geomembrane-clay liner system (45° side slope and 10 m slope length). The paper shows that moderate earthquake loading (base acceleration between 0.1g to 0.2g) can result in transient increases of around 20% in geomembrane tension, with permanent tension increases of around 5%.

Assessment of estrogenic activity of leachate from automobile tires with two in vitro bioassays

In this study, a combination of enzyme-linked receptor assay (ELRA) and yeast estrogen screen (YES) assay was firstly applied to determine whether automobile tires immersed in fresh water can leach chemicals, which display estrogenic activity. We optimized ELRA substituting the chromogene substrate by a luminescent one, and found that luminescent ELBA was more sensitive to 17 beta-estradiol (17 beta-E2) with a detection limit of 0.016 mu g/l, compared to 0.088 mu g/l in the chromogene version. In ELRA, all tire leachates obviously showed estrogenic activity, which was increased with duration of immersion. Moreover, the leachate from hackled tires showed more potent estrogenicity than that from the whole ones. In comparison to ELRA, no detectable estrogenic activity was found in all tire leachates with YES assay. The results from YES assay further evidenced that antiestrogenic compounds can be leached from tires. As tire leachates contain estrogenic compounds, they could be important pollution sources, potentially harmful to wildlife and human health. Thus, use of shredded tires as road fill or in landfill sites should arouse our attention.

Carbon Isotopic Fractionation of CFCs during Abiotic and Biotic Degradation

Carbon stable isotope ((13)C) fractionation in chlorofluorocarbon (CFC) compounds arising from abiotic (chemical) degradation using zero-valent iron (ZVI) and biotic (landfill gas attenuation) processes is investigated. Batch tests (at 25 °C) for CFC-113 and CFC-11 using ZVI show quantitative degradation of CFC-113 to HCFC-123a and CFC-1113 following pseudo-first-order kinetics corresponding to a half-life (t(1/2)) of 20.5 h, and a ZVI surface-area normalized rate constant (k(SA)) of -(9.8 ± 0.5) × 10(-5) L m(-2) h(-1). CFC-11 degraded to trace HCFC-21 and HCFC-31 following pseudo-first-order kinetics corresponding to t(1/2) = 17.3 h and k(SA) = -(1.2 ± 0.5) × 10(-4) L m(-2) h(-1). Significant kinetic isotope effects of e(‰) = -5.0 ± 0.3 (CFC-113) and -17.8 ± 4.8 (CFC-11) were observed. Compound-specific carbon isotope analyses also have been used here to characterize source signatures of CFC gases (HCFC-22, CFC-12, HFC-134a, HCFC-142b, CFC-114, CFC-11, CFC-113) for urban (UAA), rural/remote (RAA), and landfill (LAA) ambient air samples, as well as in situ surface flux chamber (FLUX; NO FLUX) and landfill gas (LFG) samples at the Dargan Road site, Northern Ireland. The latter values reflect biotic degradation and isotopic fractionation in LFG production, and local atmospheric impact of landfill emissions through the cover. Isotopic fractionations of ?(13)C ~ -13‰ (HCFC-22), ?(13)C ~ -35‰ (CFC-12) and ?(13)C ~ -15‰ (CFC-11) were observed for LFG in comparison to characteristic solvent source signatures, with the magnitude of the isotopic effect for CFC-11 apparently similar to the kinetic isotope effect for (abiotic) ZVI degradation.

Treatment of mature urban landfill leachates by anammox process

This thesis results from the collaborative projects between the LEQUIA-UdG group and Cespa (a company in charge of several landfill sites in Spain). The aim of the work was the development of a suitable alternative treatment for nitrogen removal from mature landfill leachates. The thesis presents the application of the anammox (anaerobic ammonium oxidation process) process to treat ammonium rich leachates as the second step of the PANAMMOX® process. The work deals with preliminary studies about the characteristics of the anammox process in a SBR, with special focus on the response of the biomass to nitrite exposure. The application of the anammox process with leachate was first studied in a lab-scale reactor, to test the effect of the leachate matrix on anammox biomass and its progressive adaptation. Finally, a start-up strategy is developed and applied for the successful start-up of a 400L anammox SBR in less than 6 months.

Decomposição de resíduos sólidos domiciliares e variações na resistividade e cargabilidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of mechanical and thermal properties after chemical degradation of PVC and HDPE geomembranes

Chemical compatibility between geomembranes and site-specific waste liquids should be assessed since the waste liquids are highly complex mixtures. This paper presents some considerations about the chemical compatibility of geomembranes and some results of mechanical tests in HDPE and PVC geomembranes that were exposed to leachate and chemical residue (niobium). PVC and HDPE geomembranes of two thicknesses were tested: 1.0, 2.0 mm (PVC) and 0.8, 2.5 mm (HDPE). The results obtained show that after exposure the PVC geomembranes (1.0, 2.0 mm) were more rigid and stiffer than fresh samples. The HDPE geomembranes, on the other hand, when exposed to leachate and niobium residue presented increases in deformation. Melt flow index (MFI) tests were also carried out to verify the oxidation. © 2013 ejge.

Geofísica aplicada no monitoramento de área de disposição de resíduos sólidos domiciliares

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Utilização de parâmetros qualitativos dos resíduos aterrados como referência no processo de seleção de valores empregados em modelos matemáticos para a estimativa de geração de metano

The study of mathematical modeling assists in evaluation of the capacity of production and measurement of generation time of biogas in landfills, enabling the implantation of projects of energy generation from methane. Thus, the work aims, by simulating scenarios of potential methane generation in the landfill in Rio Claro, the use of field data from methane flow and waste grounded parameters as references for selecting values of k e L0 used to estimate methane generation model in LandGEM. As a result it was found that compared the characteristics adopted in the four scenarios recommended by the USEPA literature with those found in the landfill of Rio Claro (high amount of organic matter in the waste landed and daily practice of leachate recirculation), the scenario that apparently better represent the rate of methane generation is the scenario 01, with k = 0.7 and L0 = 96. Now, the adjustment of parameters in relation to the data field of methane flow, the value of L0 which best fits the methane generation from the landfill in Rio Claro is 150, while for k the line behavior that best represents the reality are values between 0.7 and 0.3. Regarding the parameters of the waste grounded, between the suggested values of k, 0,3 is most consistent with the intermediate level of biological degradation of the residue grounded, while L0 due to the biodegradability of the waste, a new value between 120 and 150 may be more appropriate for the study

Comparative analysis between biogas flow in landfill and electrical resistivity tomography in Rio Claro city, Brazil

The biogas originated from anaerobic degradation of organic matter in landfills consists basically in CH4, CO2, and H2O. The landfills represent an important depository of organic matter with high energetic potential in Brazil, although with inexpressive use in the present. The estimation of production of the productive rate of biogas represents one of the major difficulties of technical order to the planning of capture system for rational consumption of this resource. The applied geophysics consists in a set of methods and techniques with wide use in environmental and hydrogeological studies. The DC resistivity method is largely applied in environmental diagnosis of the contamination in soil and groundwater, due to the contrast of electrical properties frequent between contaminated areas and the natural environment. This paper aims to evaluate eventual relationships between biogas flows quantified in drains located in the landfill, with characteristic patterns of electrical resistivity in depth. The drain of higher flow (117 m3 /h) in depth was characterized for values between 8000 Ω⋅m and 100.000 Ω⋅m, in contrast with values below 2000 Ω⋅m, which characterize in subsurface the drain with less flow (37 m3 /h), besides intermediary flow and electrical resistivity values, attributed to the predominance of areas with accumulation or generation of biogas.

Bath Landfill : Decatur, Illinois.

"32571"--Colophon.

Bath, Inc. Landfill : Macon County, Illinois.

The 17-acre landfill southwest of Decatur on the south bank of the Sangamon River was permitted in 1974 as a demolition debris landfill. It originated as an open dump in 1918. The site had a history of not complying with the state landfill rules in the 1980s. The landfill also exceeded its permitted waste disposal limits, by the time that the operations stopped in 1991. The owner failed to comply with an August 1994 court order requiring proper cover to be installed and maintained. Visible leachate seeps (leachate is water that has traveled through the landfill and contacts waste material) and exposed refuse were observed along the bank of the Sangamon River. ... This landfill was one of the 33 landfills in Illinois identified by the Illinois EPA in 1998 as most in need of immediate repairs. The state legislature responded by passing legislation that allocated $50 million over five years to address these 33 sites. These 33 landfills are being managed through the Abandoned Landfill Program.