ABSTRACT
Landfills are considered the main option for dumping of municipal solid waste (MSW) all over the world, but these landfills are mostly non-engineered. The decomposition of solid waste in the landfill and rainwater penetration into the decomposing waste produces leachate that contains dissolved organic and inorganic compounds, heavy metals, suspended particles, and hazardous substances. Leachate migration in the environment may pose serious health risks to organisms exposed. Hence, the present study explored the cytotoxic potential of landfill leachate collected in different seasons from the Okhla landfill site, Delhi, India. Cytotoxicity of leachate samples was evaluatedby cell apoptosis and ultrastructural observation based on Transmission Electron Microscopy (TEM) of the cells of root tips of vicia faba seedlings treated with the leachates collected in summer, winter and monsoon in a time and dose dependent manner. Leachate collected in all the three seasons induced apoptosis in cells of root tips of vicia faba that increased in a time and dose dependent manner when compared to control. The apoptosis was highest in the samples treated with leachate collected in the summer season, followed by winter and monsoon. It was further confirmed with TEM images that there was induction of apoptotic-like morphological changes in the root cells treated with landfill leachate when compared with the control. The present study indicates that municipal solid waste leachate is very toxic and it should be treated before disposing it to the environment.
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The present study was carried out to characterize leachate from waste dumping site and its impact on surrounding surface water quality at Rajbandh in Khulna. For this purpose, surface water samples (10) and leachate samples (5) were taken from the site during two season the monsoon season and post monsoon respectively. The samples were taken during the daytime from 9 a.m. to 1 p.m because at midday the temperature rises and the physico-chemical parameters of the water are modified. Some physico-chemical parameters such as pH, Electrical conductivity (EC), Total dissolved Solids (TDS), Dissolve Oxygen (DO), Chloride (Cl-), Magnesium (Mg2+), Calcium (Ca2+), Sodium (Na+), Potassium (K+), Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Iron (Fe2+), Phosphate (PO43-), Sulfate (SO42-), Nitrate (NO32-) were analyzed in the laboratory in accordance with standard laboratory procedure. As well as some heavy metals such as Cadmium, Chromium, Lead, Manganese, Iron and Zinc were also analyzed in the laboratory. It is observed that, the physicochemical characteristics of surface water and leachate samples vary among the parameters in two seasons throughout the study period. The concentration of TDS and EC were found to be high in leachate compare to surface water samples that might be caused due to the existence of high-level various anions and soluble salts with other inorganic components. In monsoon the TDS values ranged from 3227 � 2357 for leachate and 737 � 498 for surface water samples whereas in post-monsoon the variation followed by 4640 � 1790 and 803 � 232 for surface water and leachate respectively. In case of EC for leachate it varied from 3630 � 1397 and 4900 � 1734 for monsoon and post-monsoon seasons correspondingly but varied from 1473 � 498 in monsoon and 1627 � 473 in post-monsoon for surface water samples. The high concentration of BOD (3.91 � 1.54 in monsoon and 6.25 � 3.27 in post- monsoon) and COD (117.80 � 58.31 in monsoon and 229.39 � 166.55 in post-monsoon) value were found in surface water samples compared to leachate samples. In case of Cr for leachate it varied from 0.081 � 0.029 and 0.070 � 0.026 for monsoon and post-monsoon seasons correspondingly. As well as the concentration of Cd (0.023� 0.006 in monsoon and 0.087�068 in post monsoon) and Pb (0.35�109 in monsoon and 0.025�013 in post monsoon) varied greatly during both season. The concentration of heavy metals such as Pb, Zn, Cr and Mn in surface water samples was also greater than 0.001mg/l. Further for leachate COD was very strongly correlated with TDS and cadmium. Magnesium was significantly correlated with potassium. For surface water sample TDS was significantly correlated with EC and pH. Chloride was significantly correlated with Cd and pb was correlated with calcium. This study recommended that the authority should take proper steps for the management of waste as well as give emphasis on the leachate collection.
ABSTRACT
ABSTRACT Biomethane can readily replace fossil fuels including natural gas, which has similar physical and chemical properties. In Brazil, municipal solid waste is predominantly disposed of in landfills. Landfill gas is mostly employed for electricity generation, but still at low levels when compared to the existing potential. Production of biomethane from landfill gas may be an alternative to exploit the existing potential, but Brazil's pipeline network is rather limited and concentrated along the country's coast. In this context, the research sought to identify the locational viability of using landfill gas to produce biomethane and injecting it into pipelines, considering the available potential and its proximity to Brazil's existing pipeline network. The QGis software was used to integrate the information. Territorial arrangements with a biomethane production capacity of more than 15,000 Nm3 day−1 and located up to 50 km from the pipeline network were considered feasible. The research estimated a potential production equivalent to 3,407,027 Nm3 day−1 of biomethane from landfills in Brazil. This potential corresponds to 6% of country's natural gas consumption in 2019 and is almost 32 times greater than current production of biomethane from all substrates used with this purpose in that year. The results indicate the suitability of using geographic information systems to identify regions that can benefit from the production of biomethane from landfill gas using the existing natural gas pipelines as an alternative to the electricity generation and provides relevant subsidies to the formulation of more efficient public policies in both the sanitation and energy sectors.
RESUMO O biometano pode substituir facilmente os combustíveis fósseis, incluindo o gás natural, que possui propriedades físicas e químicas similares. No Brasil, os resíduos sólidos urbanos são descartados predominantemente em aterros sanitários. O gás dos aterros sanitários é empregado principalmente na geração de eletricidade, mas ainda em níveis baixos quando comparado ao potencial existente. A produção de biometano a partir do gás de aterro pode ser uma alternativa para explorar o potencial existente, mas a rede de gasodutos do Brasil é bastante limitada e concentrada ao longo da costa do país. Nesse contexto, esta pesquisa buscou identificar a viabilidade locacional do uso de gás de aterro sanitário para produzir biometano e injetá-lo em dutos, considerando o potencial disponível e sua proximidade com a rede de dutos existente no Brasil. O software QGis foi utilizado para integrar as informações. Foram considerados viáveis arranjos territoriais com uma capacidade de produção de biometano maior que 15.000 Nm3 dia−1 e localizados a até 50 km da rede de gasodutos. A pesquisa estimou uma produção potencial equivalente a 3.407.027 Nm3 dia−1 de biometano a partir de aterros sanitários no Brasil. Esse potencial corresponde a 6% do consumo de gás natural do país em 2019 e é quase 32 vezes maior que a produção de biometano de todos os substratos utilizados com essa finalidade naquele ano. Os resultados indicam a adequação do uso de sistemas de informação geográfica para identificar regiões que podem se beneficiar da produção de biometano a partir de gás de aterro sanitário, utilizando os gasodutos de gás natural existentes como alternativa à geração de eletricidade e fornece subsídios relevantes para a formulação de políticas públicas mais eficientes, tanto no setor de saneamento quanto no de energia.
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RESUMO A região hidrográfica da Bacia da Baía de Guanabara integra 17 municípios do estado do Rio de Janeiro, entre os quais estão os maiores geradores de resíduos sólidos: São Gonçalo, Belford Roxo, Nova Iguaçu, Rio de Janeiro e Duque de Caxias. O lixiviado, efluente altamente tóxico, quando descartado de maneira inadequada, pode provocar diversos impactos negativos nos corpos hídricos. Este trabalho apresenta, por meio de uma abordagem qualitativa e quantitativa, as áreas de destinação final de resíduos sólidos e os principais corpos hídricos vulneráveis e potencialmente receptores de lixiviado da região hidrográfica da Bacia da Baía de Guanabara. Realizou-se uma pesquisa em documentação legal das centrais de tratamento de resíduos, aterros controlados e vazadouros, relatórios das visitas técnicas do Grupo de trabalho Chorume, informações do ICMS Ecológico 2019-2020 — ano de referência 2018 — e demais documentos institucionais pertinentes ao objeto da pesquisa. Observou-se que, impulsionados pela Política Nacional de Resíduos Sólidos, pelo Imposto sobre Circulação de Mercadorias e Serviços Ecológico e por programas do Governo do Estado, como o Pacto pelo Saneamento (Rio + Limpo e Lixão Zero), os municípios da região hidrográfica da Bacia da Baía de Guanabara, em sua maioria, encerraram seus lixões nos últimos 10 anos. Não obstante, grande parte dos aterros sanitários construídos não dispõe de estações de tratamento de lixiviado que atendam à vazão gerada e os aterros controlados e lixões, ativos e desativados, seguem produzindo lixiviado e descartando nos corpos hídricos da Baía de Guanabara.
ABSTRACT The hydrographic region of the Guanabara Bay basin includes 17 municipalities in the state of Rio de Janeiro and among them are the largest solid waste generators in the state: São Gonçalo, Belford Roxo, Nova Iguaçu, Rio de Janeiro, and Duque de Caxias. Leachate, a highly toxic effluent, can cause several negative impacts on water bodies when improperly disposed of. This study, through a qualitative and quantitative approach, maps the areas used for the final disposal of solid waste within the hydrographic region of the Guanabara Bay basin and vulnerable water bodies which are potential receivers of leachate. Research was carried out analyzing legal documentation for sanitary and controlled landfills and dumps, reports of technical visits of the Leachate Work Group, data from the 2018 Ecological Imposto sobre Circulação de Mercadorias e Serviços (reduced state tax incentives) and other institutional documents related to the research object. It was observed that most of the municipalities in the hydrographic region of the Guanabara Bay basin closed their landfills within the last 10 years, driven by the National Solid Waste Policy, Ecological Imposto sobre Circulação de Mercadorias e Serviços and state government programs, such as the Pact for Sanitation (Rio + Clean and Zero Dump). Nevertheless, most of these closed sites do not have leachate treatment stations that meet the flow rate and thus continue producing leachate and discarding it into the water bodies of Guanabara Bay.
ABSTRACT
Landfill is one of the important sources of carbon tetrachloride (CT) pollution, and it is important to understand the degradation mechanism of CT in landfill cover for better control. In this study, a simulated landfill cover system was set up, and the biotransformation mechanism of CT and the associated micro-ecology were investigated. The results showed that three stable functional zones along the depth, i.e., aerobic zone (0-15 cm), anoxic zone (15-45 cm) and anaerobic zone (> 45 cm), were generated because of long-term biological oxidation in landfill cover. There were significant differences in redox condition and microbial community structure in each zone, which provided microbial resources and favorable conditions for CT degradation. The results of biodegradation indicated that dechlorination of CT produced chloroform (CF), dichloromethane (DCM) and Cl- in anaerobic and anoxic zones. The highest concentration of dechlorination products occurred at 30 cm, which were degraded rapidly in aerobic zone. In addition, CT degradation rate was 13.2-103.6 μg/(m2·d), which decreased with the increase of landfill gas flux. The analysis of diversity sequencing revealed that Mesorhizobium, Thiobacillus and Intrasporangium were potential CT-degraders in aerobic, anaerobic and anoxic zone, respectively. Moreover, six species of dechlorination bacteria and eighteen species of methanotrophs were also responsible for anaerobic transformation of CT and aerobic degradation of CF and DCM, respectively. Interestingly, anaerobic dechlorination and aerobic transformation occurred simultaneously in the anoxic zone in landfill cover. Furthermore, analysis of degradation mechanism suggested that generation of stable anaerobic-anoxic-aerobic zone by regulation was very important for the harmless removal of full halogenated hydrocarbon in vadose zone, and the increase of anoxic zone scale enhanced their removal. These results provide theoretical guidance for the removal of chlorinated pollutants in landfills.
Subject(s)
Bacteria/metabolism , Biodegradation, Environmental , Carbon Tetrachloride/metabolism , Methane/metabolism , Waste Disposal FacilitiesABSTRACT
RESUMO Os aterros sanitários são obras construídas para o confinamento seguro dos resíduos sólidos e, entre seus elementos de projeto, destaca-se a camada de impermeabilização da cobertura final, frequentemente construída com solo argiloso, que deve, entre outras funções, minimizar ao máximo a infiltração de águas pluviais para o interior do aterro e o fluxo de gases com o meio ambiente. As características físicas, químicas e mineralógicas dos materiais dessa camada devem ser analisadas para a avaliar seu potencial de utilização. O presente trabalho teve como objetivo avaliar o desempenho de argilas expansivas, sujeitas à variação de umidade, como material impermeabilizante de cobertura de aterros sanitários, sendo caracterizadas duas amostras por meio de ensaios geotécnicos. As características foram compatíveis com os requisitos exigidos nas normas consultadas. A parte superior de uma camada de argila compactada foi reproduzida com uma das amostras em um modelo experimental, sujeita à secagem, com observação da formação de trincas e medições do teor de umidade ao longo do tempo e profundidade. A formação de trincas na superfície se iniciou para teores de umidade acima do limite de plasticidade. A aplicação de uma carga hidráulica na superfície após a etapa de secagem resultou em um fechamento das trincas em razão da expansão da argila, indicando eficiência na restrição de entrada de águas pluviais. No entanto, o uso de material expansivo para esse fim deve ser investigado quanto ao seu desempenho em campo, tanto na fase de construção, durante a compactação, quanto de operação, quando estará sujeito às variações climáticas.
ABSTRACT Solid waste landfills are works built to contain solid urban waste, being the most used final disposal method in Brazil. One of the most important components of the project is the final cover, the low hydraulic conductivity layer, with clayey materials, which has the function of minimizing the infiltration of rainwater into the landfill and the entry and exit of gases. The physical, chemical and mineralogical characteristics of clayey materials must be analyzed for potential use as a cover layer. The present work aimed to evaluate the use of clays, with expansive characteristics, subject to water content variations, as cover material in landfills, being characterized two clay samples through geotechnical tests. The characterization indicated samples with characteristics compatible with the requirements demanded by the consulted standards. One of them was used in a laboratory model and reproduced the upper part of a layer of compacted clay, subject to drying on the surface, with observation of the formation of cracks, and with measurements of the water content over time and depth. Cracks on the clay surface occurred during the drying process, starting for water contents above the limit of plasticity of the clay. The application of a hydraulic head on the surface, after the drying step, resulted in cracks closure, due to the expansion of the clay, indicating efficiency in the restriction of rainwater entry. However, the use of expansive material for this purpose should be investigated regarding its performance in the field, both in the construction phase, during compaction, and in operation, subject to climatic variations.
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ABSTRACT Improper design and management of the cover layer of a sanitary landfill has been proven to produce harmful environmental impacts on the environment. One alternative at hand is to develop scenarios based on simulation of physical and computational models to represent the expected field water balance of a landfill coverage layer. This paper investigates the design of a sanitary landfill final cover in the municipality of Seropédica, which is located at the state of Rio de Janeiro - Brazil. More specifically, the compact soil coverage, which is widely used for landfill final cover of municipal solid waste, is evaluated in contrast to vegetation cover by grass, vegetation cover by brachiaria and capillary barrier. To accomplish such task, hydrometeorological forcing conditions, namely daily rainfall and temperature, were retrieved from the Anchieta weather station, which is situated nearby the study area. The Hydrus 1D and 2/3 D computational codes were employed to develop a set of scenarios to follow the contamination plume evolution within the landfill along the time frame of 20 years with some degree of reliability. It should be noted that the performed evaluation indicates the possibility to control the leachate release and consequently to avoid contaminating the environment, notably to prevent soil and water resources pollution. Vegetation cover by grass and brachiaria showed important control mechanisms with respect to the movement of the contaminant plume. In addition, it should be noticed that the best results for the landfill final cover were achieved for the capillary barrier, while poor performance results were obtained for the commonly employed compact soil.
RESUMO O projeto e a gestão inadequados da camada de cobertura de um aterro sanitário produzem impactos ambientais prejudiciais ao meio ambiente. Uma alternativa disponível é desenvolver cenários baseados na simulação de modelos físicos e computacionais para representar o balanço hídrico que se espera que ocorra em uma camada de cobertura do aterro por meio de um experimento de campo. O presente trabalho investiga o projeto de cobertura final de um aterro sanitário no município de Seropédica, localizado no estado do Rio de Janeiro - Brasil. Mais especificamente, a cobertura compacta do solo, que é amplamente utilizada para a cobertura final de aterro de resíduos sólidos urbanos, é avaliada em contraste com a cobertura vegetal por gramíneas, cobertura vegetal por braquiária e barreira capilar. Para realização dessa tarefa, forçantes hidrometeorológicas, nomeadamente precipitação e temperatura na escala diária, foram obtidas da estação meteorológica de Anchieta, situada nas proximidades da área de estudo. Os códigos computacionais Hydrus 1D e 2/3 D foram empregados para desenvolver um conjunto de cenários para acompanhar a evolução da pluma de contaminação no interior do aterro ao longo do período de 20 anos com algum grau de confiabilidade. Ressalta-se que a avaliação realizada indica a possibilidade de controlar a liberação de chorume e, consequentemente, de evitar a contaminação do meio ambiente, notadamente para prevenir a poluição do solo e dos recursos hídricos. A cobertura vegetal por gramíneas e braquiárias apresentou importantes mecanismos de controle com relação ao movimento da pluma contaminante. Além disso, deve-se notar que os melhores resultados para a cobertura final do aterro foram alcançados para a barreira capilar, enquanto que os resultados de baixo desempenho foram obtidos para o solo compacto comumente empregado.
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The study assessed the Clinicopathological changes of Wistar rats exposed to municipal landfill gaseous particulate emissions. Four groups of Wistar rats were exposed to the different sites of landfill emission with use of filters for filtering landfill gaseous emission while the control group was not exposed. Performance of the animals was evaluated weekly, blood and lung, liver, kidney and heart tissues were taken for haematological and histopatholgical examinations. At the end of six weeks exposure, the peak weight was recorded as 108.96±0.45 of Group B as compared to 126.352±0.88 of the Control Group, as well as the decrease in the body weight of Group A-D compared to the Control Group. There was leucocytosis, lymphocytosis and neutrophilia in the rats that were exposed to landfill emission. There were pulmonary, hepatic, and renal lesions while the heart was spared. Changes were observed on the use of filters for filtering landfill gaseous emission. The 3M 6001 CN Gas Mask Carnister Cartridge which filters 50% of landfill emission together with black polythene nylon restricting external air into the filtered cage was not sufficient to reduce the effect of landfill gaseous emission at the end of the exposure period. The screening with PM2.5 material which filters 100% of PM2.5 emission was only able to screen PM2.5 emission but could not screen other landfill gaseous emission. This indicates that landfill gaseous emission is capable of inducing respiratory problems and tissue damage on dumpsite workers if there is sufficient and continuous exposure to landfill gaseous emissions. To prevent the hazard that may arose from dumpsite activities; gas nose mask respirator is recommended for an individual who works as scavengers and landfill workers before entering the dumpsite environment..
Subject(s)
Humans , Ventilators, Mechanical , Waste Disposal Facilities , Risk Assessment , Clinical AlarmsABSTRACT
RESUMO O Aterro Controlado do Jóquei Clube (ACJC), localizado no Distrito Federal, operou como área de disposição final inadequada de resíduos sólidos desde 1960 até o início de 2018. O principal objetivo desta pesquisa consistiu em avaliar o potencial de contaminação desse aterro, em razão da produção de chorume e biogás. Inicialmente, foram identificadas as áreas mais suscetíveis à contaminação nas sub-bacias hidrográficas do Bananal e do Riacho Fundo, onde o aterro está situado, por meio da produção de um mapa de vulnerabilidade natural à contaminação dos aquíferos. Para tanto, utilizou-se a metodologia DRASTIC, que consiste em uma combinação linear ponderada de sete parâmetros hidrogeológicos, com o auxílio da ferramenta de análise multicritério AHP (Análise Hierárquica de Processos) e de algoritmos de álgebra de mapas implementados em ambiente de Sistema de Informação Geográfica (SIG). Esse mapa evidenciou que o ACJC está localizado em áreas de moderada a elevada vulnerabilidade natural à contaminação. Simulou-se também o balanço hídrico no aterro por meio do modelo Hydrologic Evaluation of Landfill Performance (HELP), o qual possibilitou a identificação de áreas com maior potencial de contaminação em razão do maior volume de chorume produzido. Por fim, realizou-se uma análise da temperatura de cobertura do solo na região do aterro, por meio de imagens sazonais do sensor orbital TM/Landsat entre os anos de 1986 e 2016, as quais evidenciaram aumento gradual da temperatura, servindo de possível indicador da distribuição subsuperficial de biogás presente no aterro.
ABSTRACT The Jockey Club Landfill is a solid waste disposal site located at Brazil's Federal District, which operated inadequately from 1960 until the beginning of 2018. The main objective of this paper was to assess the contamination potential of the Jockey Club Landfill due to leachate and biogas production. Initially, the most susceptible areas to contamination were identified within the two hydrographic sub-basins of Bananal and Riacho Fundo, where the landfill is located, by producing a map of the aquifer's natural vulnerability to contamination. This map was produced based on the DRASTIC methodology, which consists in a weighted linear combination of seven important hydrogeological parameters, with support of the multicriteria Analytic Hierarchy Process (AHP) and map algebra tools implemented in a Geographic Information System (GIS) environment. This map evidenced that Jockey Club Landfill is located in areas of moderate to high natural vulnerability to contamination. The water balance throughout the landfill profile was also simulated using the Hydrologic Evaluation of Landfill Performance model (HELP), whose results evidenced that the contamination potential is higher in some portions of the landfill due to greater volumes of leachate produced. Lastly, an analysis of ground cover temperature in the landfill region was undertaken, using TM/Landsat seasonal images between the years 1986 to 2016, which indicated a gradual increase in ground temperature, evidencing a possible occurrence of subsurface biogas distribution in the landfill.
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RESUMO A contaminação do solo tem sido motivo de muita preocupação em diversas regiões do mundo. A geração desenfreada de resíduos sólidos e sua disposição inadequada têm agravado o risco de contaminação dos solos. O presente artigo teve por objetivos o tratamento e a refuncionalização do solo contaminado por lixiviado do aterro sanitário urbano do município de Altinho (PE). A descontaminação foi realizada por meio dos processos Fenton e foto-Fenton com luz negra e luz solar, sendo avaliado o percentual de conversão de carbono orgânico total. Após o tratamento com o foto-Fenton solar, o solo apresentou-se bastante ácido, com pequenas concentrações de íons inorgânicos, elevada saturação por alumínio e baixo grau de saturação por bases, revelando-se um solo infértil. Para a refuncionalização do solo foi adicionado lodo de esgoto nas proporções de 10, 30 e 50% em relação à massa do solo pós-tratado e validado pelo plantio da espécie Coriandrum sativum L. Os melhores resultados para o crescimento da raiz, comprimento total da planta, quantidade de folhas e massa das plantas foram obtidos para o tratamento com inserção de 30% de lodo de esgoto. Esse tratamento apresentou percentual de inibição de raízes de 13,2%, não representando risco de toxicidade para a espécie Lactuca sativa L. Também foi observado o aumento da capacidade de troca de cátions, do índice de saturação por bases e dos níveis de nitrogênio e fósforo, além da redução da saturação por alumínio, revelando melhoria nas condições agronômicas do solo.
ABSTRACT Soil contamination has been a major concern in many regions of the world. Rampant generation of solid waste and its inadequate disposal has aggravated the risk of soil contamination. The objective of this article was to treat and refunctionalize soil contaminated by leachate from the landfill of Altinho, Pernambuco. Soil decontamination was carried out using the Fenton and photo-Fenton processes with black light and sunlight, evaluating the percentage of total organic carbon conversion. After the treatment with the photo-Fenton solar, the soil was very acidic, with small concentrations of inorganic ions, high saturation by aluminum and low degree of base saturation, revealing an infertile soil. For soil refunctioning, sewage sludge was added in the proportions of 10, 30 and 50% in relation to the post-treated soil mass and validated by planting Coriandrum Sativum L., obtaining better results for root growth, total length of plant, amount of leaves and mass of plants for the treatment with 30% sewage sludge insertion. This treatment had a percentage of root inhibition of 13.2% and did not present a risk of toxicity to the Lactuca Sativa L. species. It was also possible to observe an increase in the cation exchange capacity, base saturation index, nitrogen and phosphorus levels, in addition to the reduction in aluminum saturation, showing an improvement in the agronomic conditions of the soil.
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This paper presents potential impact on health of emission from landfill site on Uyo village road, Uyo local government area of Akwa Ibom State, Nigeria. Three sampling points were assessed for particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), hydrogen sulphide H2S, ammonia (NH3), total volatile organic carbon (TVOC) and hydrogen cyanide (HCN) using highly sensitive digital portable meters. The data obtained were expressed in terms of an air quality index. Air quality index indicates that the ambient air can be described as unhealthy for sensitive groups for NO2, unhealthy for SO2 and PM2.5 and moderate for CO, respectively. H2S, NH3, TVOC, HCN, PM10 were not indicated in USEPA air quality standards. It recommended that stringent and proper landfill emissions management together with appropriate burning of wastes should be considered in the study area to ease the risks associated with these pollutants on public health.
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Studies have reported deleterious effect of landfill leachate and their surrounding water sources around the world. None has been reported on the Port Harcourt (Eliozu) landfill. This therefore necessitates this study that evaluated the hepatotoxiceffects of Port Harcourt (Eliozu) landfill in wistar rats. 25 wistar rats were grouped into five of five rats each. Group 1 served as the control and received 1ml of commercial non-carbonated bottled water; Group 2 served as negative control and received 1ml of water obtained from borehole about 1km from the landfill; while Groups 3,4 and 5 received 1ml of 10% of leachate concentration, 1ml of 50% of leachate concentration and 1ml of 100% of leachate concentration respectivelyonce daily for90 days. After the treatment period, the rats were sacrificed and 5ml of blood was collected via cardiac puncture. The blood samples were prepared and used for the determination of serum concentrations of liver enzymes. The rats were also dissected and the liver harvested for histochemical analysis using the periodic acidSchiff stain. Result showedthe serum concentrations liver enzymes significantly increased in the rats exposed to the leachate and water from a nearby borehole. Also histochemistry examination showed a marked distortion of the hepatic cells and cirrhotic changein the test groups compared to control. This study therefore concludes that exposure to Port Harcourt Eliozu landfill leachate (PELL) may cause significant hepatotoxicity in rats
ABSTRACT
RESUMO A necessidade crescente de alternativas para o tratamento e a disposição de lixiviados de aterros sanitários é uma realidade no Brasil, principalmente com os avanços estabelecidos pela Política Nacional de Resíduos Sólidos a partir de 2010 e consequentes metas de substituição de lixões por aterros sanitários. Uma alternativa empregada, devido à facilidade de implantação, é o cotratamento com esgoto sanitário, por meio do recebimento do lixiviado em estações de tratamento de esgoto (ETE). Este estudo avaliou a aplicabilidade do Activated Sludge Model No. 1 (ASM1) para lagoas aeradas promovendo o cotratamento de esgoto e lixiviado. Os cenários simulados consistiram em proporções crescentes de adição de lixiviado ao sistema - que variaram de 0 a 10% - e, para cada um deles, foi avaliado o desenvolvimento de biomassa heterotrófica e autotrófica, o consumo de demanda química de oxigênio (DQO) em diferentes frações, a nitrificação, o consumo de oxigênio e a alcalinidade. Os resultados das simulações geradas indicaram que o modelo foi otimista em relação ao período de partida do sistema e à adaptação das comunidades microbianas consideradas frente aos cenários progressivamente agressivos oferecidos pela maior presença de lixiviado. Porém, representou adequadamente o prejuízo à qualidade do efluente devido à matéria orgânica recalcitrante e aos problemas relacionados à manutenção da nitrificação, frente ao aumento da capacidade de aeração e da demanda de alcalinidade. O ASM1 teve boa aplicabilidade, portanto, como ferramenta para avaliar qualitativamente o comportamento de ETE ao receber lixiviado para cotratamento e corroborar os riscos associados a essa alternativa, necessitando, porém, de modificações e detalhamentos adicionais para otimização de sistemas reais.
ABSTRACT The growing necessity for alternative landfill leachate treatment and disposal is a reality in Brazil, mainly when the advancements of the National Policy on Solid Wastes (2010) established goals for replacing dumping grounds with landfills. Due to its simplicity, a usual alternative is to perform co-treatment of municipal sewage and landfill leachate in wastewater treatment plants (WWTPs). This study assessed the applicability of the Activated Sludge Model No 1 (ASM1) to aerated lagoons promoting sewage and leachate co-treating. The simulated scenarios consisted of increasing proportions of leachate addition to the system, ranging from 0 to 10%, and for each of them the development of heterotrophic and autotrophic biomass, COD consumption in different fractions, nitrification, oxygen consumption and alkalinity were evaluated. The simulation results showed that the model was optimistic regarding the treatment system startup and microbial communities adaptation when exposed to increasingly aggressive conditions due to leachate addition. However, it correctly represented the detrimental effects on effluent quality due to recalcitrant organic matter and the issues with maintaining proper nitrification regarding aeration capacity and alkalinity demands. ASM1 has good applicability, therefore, as a tool to qualitatively assess the behavior of WWTP when receiving leachate for co-treatment and corroborates the risks associated with this alternative, however, requiring further modifications and details to optimize real systems.
ABSTRACT
RESUMO Encerrar vazadouros, implantar e operar aterros sanitários são importantes passos para consolidar um sistema de gestão de resíduos sólidos urbanos (RSU) eficiente e sustentável. No estado do Rio de Janeiro, desde 2007, existem avanços significativos nesse processo. Entretanto, é fundamental transcender as terminologias que distinguem os locais de disposição final e avaliar a real qualidade da prestação desse serviço público. Não resta dúvida que encerrar vazadouros deve ser prioridade dos estados e municípios, todavia, não se deve distanciar o olhar da avaliação constante do desempenho ambiental dessas atividades e, consequentemente, de suas qualidades operacionais. Baseado nesse princípio, o estado do Rio de Janeiro, por meio do Instituto Estadual do Ambiente (INEA), desenvolveu, em 2013, uma metodologia para a obtenção do Índice de Qualidade de Destinação Final de Resíduos (IQDR). O principal objetivo deste artigo é avaliar o resultado da aplicação do IQDR do Rio de Janeiro em 19 aterros sanitários e em sete aterros controlados do Estado entre os anos de 2013 e 2015. Essa análise possibilitou criticar as estratégias propostas pelas políticas públicas de gestão de resíduos vigentes no estado, bem como a sua eficácia. Constatou-se que os aterros de Seropédica, Campos e São Gonçalo apresentaram os melhores desempenhos no período avaliado, tendo sido considerados adequados. Juntos, esses aterros receberam mais de 10 milhões de toneladas de RSU no período, 58% da quantidade coletada no estado. Os aterros de Miguel Pereira, Barra do Piraí e Piraí apresentaram o pior desempenho - foram considerados inadequados - , tendo recebido cerca de 47 mil toneladas de RSU no período, menos de 1% do montante coletado no estado.
ABSTRACT Shutting down dumpsites, implanting and operating landfills are important steps to consolidate an efficient and sustainable urban solid waste management system. In the state of Rio de Janeiro, since 2007, there have been significant advances in this process. However, it is fundamental to transcend the terminology that distinguishes the final disposal sites and to evaluate the real quality of the provision of this public service. There is no doubt that shutting down dumpsites should be a priority for states and municipalities, however, this thought should not distance oneself from the constant evaluation of the environmental performance of these activities and, consequently, the operational quality of the landfills. Based on this principle, the state of Rio de Janeiro, through the State Environmental Institute (INEA), developed in 2013 a methodology for obtaining the Final Destination of Waste Quality Index. The main objective of this article is to evaluate the results of the application of Rio de Janeiro's Final Destination of Waste Quality Index, in the years of 2013, 2014, and 2015. This analysis made it possible to criticize the strategies proposed by the public policies for waste management in the state, as well as their effectiveness. It was verified that the landfills of Seropédica, Campos, and São Gonçalo presented the best performances and were considered adequate. Together, these landfills received more than ten million tons in the period, about 58% of the urban solid waste collected in the state. The Miguel Pereira, Barra do Piraí, and Piraí landfills presented the worst performance, considered inadequate, receiving about 47,000 tons in the period, less than 1% of the MSW collected in the state.
ABSTRACT
BACKGROUND: The determination of kinetic parameters and the development of mathematical models are of great interest to predict the growth of microalgae, the consumption of substrate and the design of photobioreactors focused on CO2 capture. However, most of the models in the literature have been developed for CO2 concentrations below 10%. RESULTS: A nonaxenic microalgal consortium was isolated from landfill leachate in order to study its kinetic behavior using a dynamic model. The model considered the CO2 mass transfer from the gas phase to the liquid phase and the effect of light intensity, assimilated nitrogen concentration, ammonium concentration and nitrate concentration. The proposed mathematical model was adjusted with 13 kinetic parameters and validated with a good fit obtained between experimental and simulated data. CONCLUSIONS: Good results were obtained, demonstrating the robustness of the proposed model. The assumption in the model of DIC inhibition in the ammonium and nitrate uptakes was correct, so this aspect should be considered when evaluating the kinetics with microalgae with high inlet CO2 concentrations.
Subject(s)
Carbon Dioxide/analysis , Microalgae/radiation effects , Microalgae/physiology , Kinetics , Weirs , Photons , Microalgae/isolation & purification , Microalgae/growth & development , Photobioreactors , Wastewater , Models, Biological , Nitrates , NitrogenABSTRACT
RESUMO Neste trabalho, são apresentados os resultados do desempenho de dois sistemas de tratamento combinado de lixiviado de aterros sanitários e lodos de fossas. Na escala de laboratório, empregou-se um geobag de pequenas dimensões e um filtro biológico de percolação a jusante dele. Na escala real, investigou-se o desempenho de uma unidade de tratamento constituída de geobag seguido de lagoas de estabilização e wetland. Em ambos os estudos, empregou-se relação volumétrica de 4:1 (lodo de fossa:lixiviado) e adicionou-se floculante à mistura antes de sua alimentação no geobag. As remoções obtidas na unidade de campo foram superiores às alcançadas em laboratório para os parâmetros carbono orgânico dissolvido (COD) e sólidos em suspensão totais, cujas remoções foram superiores a 50 e a 95%, respectivamente. A remoção de nitrogênio amoniacal, entretanto, foi maior na instalação de bancada (68%). O desempenho desses sistemas de tratamento com relação à toxicidade para os organismos-teste Aliivibriofischeri, Daphniasimillis e Daniorerio também foi investigado.
ABSTRACT This paper presents the performance results of two combined landfill leachate and sewage sludge treatment systems. In the laboratory scale, a small geobag was followed by a trickling filter. In the real scale, the performance of a geobag treatment unit followed by stabilization and wetland lagoons was investigated. In both studies, a 4:1 volumetric ratio (pit sludge: leachate) was employed and flocculant was added to the mixture prior to feeding in the geobag. The field unit removals were higher than those obtained in the laboratory for the following parameters: dissolved organic carbon and suspended solids, whose removals were greater than 50 and 95%, respectively. Ammonium nitrogen was removed at higher percentages in the lab-scale unit (68%). The performance of both treatment units regarding toxicity to Aliivibriofischeri, Daphnia simillis and Danio rerio organisms was also investigated.
ABSTRACT
RESUMO Neste trabalho, foi realizado o tratamento do lixiviado de um aterro urbano por meio de uma combinação dos processos de coagulação/floculação e adsorção. O lixiviado empregado foi coletado no aterro de resíduos sólidos urbanos da Muribeca (PE) e coagulado com cal. O objetivo foi avaliar o uso do pó de ostra como adsorvente. Os experimentos de adsorção foram realizados em batelada, utilizando as melhores condições para a ativação e para o processo por intermédio de dois planejamentos experimentais. Em seguida, foram realizados os estudos cinéticos e de equilíbrio e uma avaliação de cada etapa do processo. O tempo de equilíbrio foi de 40 min. As isotermas de adsorção seguiram o modelo de Langmuir e a capacidade máxima de adsorção foi de 45,45 Hazen.L.g-1. A combinação dos processos de tratamento em questão foi bastante eficiente, obtendo reduções de aproximadamente 95% da demanda bioquímica de oxigênio (DBO), 40% da demanda química de oxigênio (DQO) e 70% da cor do lixiviado.
ABSTRACT In this work the leachate treatment of an urban landfill was carried out through a combination of coagulation/flocculation and adsorption processes. The leachate employed was collected in the municipal solid waste landfill of Muribeca-PE and coagulated with lime. The objective was to evaluate the use of oyster powder as adsorbent. The adsorption experiments were performed in batch using the best conditions for activation and process through two experimental designs. Then, the kinetic and equilibrium studies were carried out as well as an evaluation of each stage of the process. The equilibrium time was 40 min. Adsorption isotherms followed the Langmuir model and the maximum adsorption capacity was 45.45 Hazen.L.g-1. The combination of the treatment processes in question was very efficient, achieving a reduction of approximately 95% DBO, 40% COD, 70% of the leachate color.
ABSTRACT
ABSTRACT A set of experiments were carried out in order to establish and evaluate the potential of activated carbon, produced from coffee waste in adsorption process, in the depuration of landfill leachate. Different reagents were studied in the activation of carbon: HCl, HCl + H2O2, H3PO4, H3PO4 + H2O2, all with an impregnation rate of 1:1. The activated carbon that showed the best global results was activated with H3PO4, obtaining a 51.0, 32.8, 66.0, 81.0 and 97.1% elimination of chemical oxygen demand, ammonia, total chlorine, bromine and copper, respectively. This activated carbon has a total pore area of 4.85 m2/g and a median pore diameter of 65.32 micrometers. When different loads of this carbon were placed in a stirrer system in contact with landfill leachate, with the aim of evaluating the effect of the adsorption load and contact time, the concentration of ammonia decreased from the beginning of the adsorption process to the end of it, and the removal of ammonia increased with the increase in the adsorbent load. However, the trend of the amount adsorbed per unit mass decreased with increased dosage. The model Freundlich equilibrium isotherm fits experimental data adequately, giving R2 values of 0.95, 1/n of 0.5183, and a K value of 7.08*10-5 L/g, being favourable for adsorption process.
RESUMO Foi realizada uma série de experimentos para estabelecer e avaliar o potencial de carvão ativado produzido de resíduos de café por meio de um processo de adsorção na depuração do lixiviado de aterro sanitário. Foram estudados diferentes reagentes para a ativação do carvão: HCl, HCl + H2O2, H3PO4, H3PO4 + H2O2, todos com taxa de impregnação de 1:1. O carvão que apresentou os melhores resultados foi ativado com H3PO4, obtendo uma eliminação de 51,0; 32,8; 66,0; 81,0; e 97,1% de demanda química de oxigênio e concentração de amônia, cloro total, bromo e cobre, respetivamente. O referido carvão ativado tem uma área total de poro de 4,85 m2/g e diâmetro médio de poro de 65,32 micrômetros. Com o objetivo de avaliar o efeito da carga de adsorção e do tempo de contato, foram colocadas diferentes cargas desse carvão em um sistema de agitação em contato com o lixiviado de aterro sanitário. Observou-se que a concentração de amônia diminuiu e que sua remoção foi maior à medida que a carga adsorvente aumentava. No entanto, a quantidade adsorvida por unidade de massa diminuiu com o aumento da dosagem. Os dados experimentais adequaram-se corretamente ao modelo de isoterma de Freundlich, obtendo-se valores de R2 de 0,95, 1/n de 0,5183, e um valor de K de 7,08*10-5 L/g, considerados favoráveis para o processo de adsorção.
ABSTRACT
BACKGROUND: The amount of municipal solid waste (MSW) gradually increased along with the rapid development of modern cities. A large amount of landfill leachate are generated with excessive chemical oxygen demand (COD), which create a great deal of pressure on the environment-friendly treatment process. Anaerobic digestion is an ideal technique to solve the above problem. RESULTS: A thermophilic granular sludge was successfully adapted for anaerobic digestion of MSW leachate (from an aging large-scale landfill) for methane production. The COD degradation efficiency improved by 81.8%, while the methane production rate reached 117.3 mL CH4/(g VS d), which was 2.34-fold more than the control condition. The bacterial and archaeal communities involved in the process were revealed by 16S rRNA gene high-throughput pyrosequencing. The richness of the bacterial community decreased in the process of thermophilic granular sludge, while the archaeal community structure presented a reverse phenomenon. The bacterial genus, Methanosaeta was the most abundant during the mesophilic process, while Methanobacterium, Methanoculleus, Methanosaeta and Methanosarcina were more evenly distributed. The more balanced community distribution between hydrogenotrophic and acetotrophic methanogens implied a closer interaction between the microbes, which further contributed to higher methane productivity. The detailed relationship between the key functional communities and anaerobic digestion performances were demonstrated via the multivariate canonical correspondence analysis. Conclusions: With the assistance of adaptive thermophilic granular sludge, microbial community structure was more evenly distributed, while both of COD degradation rate and methane production was improved during anaerobic digestion of MSW landfill leachate.
Subject(s)
Bacteria, Anaerobic/metabolism , Solid Waste , Anaerobic Digestion , Sludge Treatment , Methane/metabolism , Sewage/microbiology , Bacteria, Anaerobic/isolation & purification , Water Pollutants, Chemical , Polymerase Chain Reaction , Urban Area , Biofuels , Biological Oxygen Demand Analysis , Hot Temperature , AnaerobiosisABSTRACT
RESUMO Este artigo versa sobre a análise da compressibilidade dos resíduos sólidos urbanos (RSUs) do antigo vazadouro da Marambaia, localizado no município de Nova Iguaçu, Rio de Janeiro, que operou como um lixão durante o período de 1987 a 2003, quando foi encerrado e remediado. O estudo foi levado a cabo por meio de dados de monitoramento de recalque superficial, obtidos por meio de marcos superficiais de 2008 a 2015. As medidas de recalques foram analisadas à luz dos seguintes modelos de compressibilidade: Sowers, Meruelo, Ling et al. e Oweis. Os resultados do monitoramento apresentaram valores de recalques entre 79 e 204 mm, representando deformações na faixa de 0,16 a 0,41% em relação à altura inicial do maciço. Os modelos Sowers, Meruelo e Ling et al apresentaram valores de recalques relativamente próximos, evidenciando que, embora diferentes conceitualmente, podem ser usados para prever recalques em longo prazo com boa aproximação. O modelo de Oweis é o mais elaborado dos modelos analisados e o que apresentou valores mais elevados de recalques.
ABSTRACT This paper deals with the analysis of the compressibility of the old Marambaia dumping grounds' MSW, located at Nova Iguaçu City (Rio de Janeiro) that was used as a waste dump from 1987 until 2003, when it was closed and remediated. The study was carried out based on superficial settlement monitoring data of reference points between 2008 and 2015. These data were analyzed considering the following compressibility models: Sowers, Meruelo, Ling et al. and Oweis. The results of the monitoring showed settlement values between 79 and 204 mm representing deformations in the range of 0.16 to 0.41% with regards to the of the landfill's initial height. The models of Sowers, Merueloand Ling et al. render settlement values that are relatively close; revealing that, although being different in conception, both can be used to predict long-term settlements with a good approximation. The model of Oweis is the most elaborated of all models analyzed and predicted the greatest values for settlement.