Contamination assessment of soil and groundwater of a deactivated dumpsite in Brazil.

The final disposal of solid waste in dumpsites can result in the migration of leachate components through the soil, contaminating it as well as the groundwater. The purpose of this manuscript was to analyze the contamination of a dumpsite along with three unlined leachate ponds that operated for approximately 25 years. Soil, surface water from three leachate lagoons, and groundwater samples were collected. Chemical analyses such as chloride, ammonia nitrogen, and total organic carbon were performed. The present work also aimed at elaborating the local flow pattern map and the assessment of subsoil. The results showed local subsoil mostly clayey, also occurring a region of sandy predominance, and great variation of rocky outcrops depth. The groundwater flow occurs from the waste towards one of the leachate lagoons. The leachate lagoon located closer to deposited area presented the highest concentration of all contaminants measured. Groundwater and soil showed low ammonia nitrogen with a maximum value of 2 mg.L-1. Elevated chloride levels were detected in all matrices studied. In soil depth, the concentration varied ​​between 17 and 1270 mg.L-1 and in groundwater between 843 and 3,252 mg.L-1. Results suggest the migration of leachate components through the local soil. The concentration of total organic carbon measured in soil was of 10-982 mg.L-1, suggesting its natural presence.

O uso de indicadores de desempenho na avaliação da qualidade operacional dos aterros sanitários do estado do Rio de Janeiro no triênio 2013-2015 / The use of performance indicators in the evaluation of the operational quality of the Rio de Janeiro state sanitary landfill in the 2013-2015 triennium

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.

Aplicação de solução semianalítica para modelagem de ensaios de sorção e difusão pura com lixiviado / Application of semi-analytical solution for modeling sorption and pure diffusion assays with leachate

RESUMO A implementação da Política Nacional de Resíduos Sólidos (Lei nº 12.305, de 2 de agosto de 2010) foi um marco para a disposição final e o tratamento de resíduos sólidos no país. A contaminação decorrente da negligência na disposição dos resíduos sólidos urbanos atinge sistemas naturais vitais para a existência humana. Torna-se, portanto, fundamental compreender os mecanismos que estão envolvidos no transporte de contaminantes e os dispositivos geotécnicos para mitigar e/ou remediar os impactos. Neste trabalho, é apresentada a utilização de modelagens matemáticas aplicadas aos resultados dos experimentos realizado por Ritter, em 1998, para determinar o transporte dos principais íons inorgânicos, encontrados no lixiviado do aterro Jardim Gramacho (K+, Cl-, Na+ e NH4 +), por difusão química e sorção. O Aterro de Resíduos Urbanos de Jardim Gramacho está localizado em Duque de Caxias, no estado do Rio de Janeiro, e operou por mais de 30 anos, de 1978 a 2012. Para a compreensão dos mecanismos de transporte, foi utilizada uma solução semi-analítica denominada de camada contaminada equivalente (CCE), proposta por Paz, em 2015, com o objetivo de traçar, no tempo e no espaço, o comportamento desses contaminantes ao longo da amostra de solo utilizada. A vantagem da utilização dessa solução analítica é que ela atende com maior rigor as condições de contorno dos experimentos analisados, quando comparadas com as soluções disponíveis na literatura. Os resultados mostram que os coeficientes de difusão efetivo determinados pela solução CCE apresentam-se dentro dos intervalos indicados na literatura.

ABSTRACT The implementation of the National Solid Waste Policy (Law No. 12.305, of August 2, 2010) was a milestone for the final disposal and treatment of solid waste in the country. The contamination due to negligence in the disposal of urban solid waste reaches natural resources and systems vital to human existence. It is, therefore, essential to understand the mechanisms involved in the transport of contaminants and the best geotechnical devices to mitigate and/or remediate impacts. This paper presents the use of mathematical models applied to the results of the experiments carried out by Ritter, in 1998, to determine the transport of the main inorganic ions found in the leachate of Jardim Gramacho landfill (K+, Cl-, Na+, and NH4 +), by chemical diffusion and sorption mechanisms. The Jardim Gramacho Urban Waste Landfill was located in Duque de Caxias, state of Rio de Janeiro, and operated for more than 30 years, from 1978 to 2012. In order to understand these transport mechanisms, a semi-analytical solution, denominated Equivalent Contaminated Layer (ECL) proposed by Paz, in 2015, was used to trace, in time and space, the behavior of these contaminants along the soil sample used. The advantage of using this analytical solution is that it meets more accurately the boundary conditions of the analyzed experiments, when compared with the solutions available in the literature. The results show that the effective diffusion coefficients determined by the ECL solution are within the ranges indicated in the literature.

Análise de recalques em longo prazo no vazadouro de Marambaia, Nova Iguaçu, Rio de Janeiro / Long-term settlement analysis of the dump site of Marambaia, Nova Iguaçu, Rio de Janeiro, Brazil

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.

Emissão de gases do efeito estufa de um aterro sanitário no Rio de Janeiro / Greenhouse gases emissions from a landfill in Rio de Janeiro

RESUMO A emissão de metano (CH4) e dióxido de carbono (CO2) em aterros sanitários representa uma das mais importantes fontes de gases de efeito estufa em regiões metropolitanas. O presente trabalho quantificou a taxa de emissão de gases do efeito estufa (GEEs) pela camada de cobertura intermediária do aterro sanitário de Seropédica, Rio de Janeiro, Brasil, assim como a concentração desses gases na atmosfera acima das células do aterro. Um total de 21 amostras na camada de cobertura e 31 na atmosfera acima do aterro foi coletado. Foram utilizadas duas câmaras de fluxo de 0,66 m2 de área e 33,2 L de volume, e amostras foram retiradas com seringas de polipropileno de 60 mL em intervalos de 5 minutos, durante 15 minutos. As amostras foram coletadas em locais com e sem fissura na camada de cobertura intermediária. A análise das amostras foi feita por cromatografia de fase gasosa, por múltiplos detectores. As taxas de emissão dos GEEs observadas variaram entre 0,1 e 575,0 g m-2 dia-1 para CH4 e entre 0,1 e 316,0 g m-2 dia-1 para CO2. As concentrações no ar ambiente variaram entre 3,5 e 150,0 ppm e entre 333 e 655 ppm, para CH4 e CO2, respectivamente. As maiores emissões foram constatadas nos pontos que continham as maiores fissuras no momento da coleta.

ABSTRACT The emission of methane (CH4) and carbon dioxide (CO2) from landfills is one of the most important sources of greenhouse gases in metropolitan areas. This study quantified the emission rate of greenhouse gases (GHGs) by the intermediate cover layer of Seropédica landfill, in Rio de Janeiro, Brazil, as well as the concentration of these gases in the atmosphere above the landfill cells. A total of 21 samples from the cover layer and 31 samples from the atmosphere above the landfill was collected. Two flow chambers with 0.66 m2 and 33.2 L were used, and the samples were collected with 60 mL polypropylene syringes at five-minute intervals, for 15 minutes. The samples were collected in areas with and without cracks in the intermediate cover layer. Sample analysis was performed by gas chromatography, by multiple detectors. GHGs emission rates varied from 0.1 to 575.0 g m-2 day-1 for CH4 and 0.1 to 316.0 g m-2 day-1 for CO2. The ambient air concentrations ranged from 3.5 to 150.0 ppm and 333 to 655 ppm for CH4 and CO2, respectively. Higher emissions were found in areas containing the larger cracks at the time of collection.

BTEX Emissions from the Largest Landfill in Operation in Rio de Janeiro, Brazil.

The emission rates and the ambient air concentrations of benzene, toluene, ethyl benzene and xylenes (BTEX) were measured over the intermediate cover layer and atmosphere of the Seropédica landfill, Rio de Janeiro, Brazil. BTEX were sampled using coconut shell charcoal cartridges, followed by extraction with dichloromethane and analysis by gas chromatography with mass spectrometry. Thirteen samples were collected in areas with and without cracks in the cover layer, and six samples were collected from the ambient air. The average emission rates were 11.7, 492.2, 153.7, 67.2, and 21.7 µg m- 2 day- 1, respectively, for benzene, toluene, ethyl benzene, m + p-xylenes and o-xylene. No benzene concentrations above the detection limit were observed in ambient air samples. The average concentrations of toluene, ethyl benzene, m + p-xylenes and o-xylene in ambient air samples were 2.14, 1.35, 0.49 and 0.08 µg m- 3, respectively. Higher emissions were found in locations containing larger cracks during the collection.

Migration of inorganic ions from the leachate of the Rio das Ostras landfill: a comparison of three different configurations of protective barriers.

Batch tests and diffusion tests were performed to analyze the efficiency of a protective barrier in a landfill consisting of compacted soil with 10% bentonite compared to the results obtained for only compacted soil and for compacted soil covered with a 1-mm-thick HDPE geomembrane; the soil and leachate were collected from the Rio das Ostras Landfill in Rio de Janeiro, Brazil. The diffusion tests were performed for periods of 3, 10 and 60 days. After the test period, the soil pore water was analyzed and the profiles for chloride, potassium and ammonium were determined along a 6-cm soil depth. The results of the batch tests performed to define sorption parameters were used to adjust the profiles obtained in the diffusion cell experiment by applying an ion transfer model between the interstitial solution and the soil particles. The MPHMTP model (Multi Phase Heat and Mass Transfer Program), which is based upon the solution of the transport equations of the ionic contaminants, was used to solve the inverse problem of simultaneously determining the effective diffusion coefficients. The results of the experimental tests and of the model simulation confirmed that the compacted soil with 10% bentonite was moderately efficient in the retention of chloride, potassium and ammonium ions compared to the configurations of compacted soil with a geomembrane and compacted soil alone, representing a solution that is technically feasible and requires potentially lower costs for implementation in landfills.

Chemical healthcare waste management in small Brazilian municipalities.

The disposal of healthcare waste (HCW) seems to have been solved in developed countries, while in most developing countries the problem persists because the disposal methods are expensive and larger than the budget of small- and medium-sized municipalities. The current study evaluates the encapsulation process for the disposal of medical chemical waste. The experiment was developed in the Piraí municipality (Rio de Janeiro State, Brazil) and the chemical wastes were produced in the local public hospital, as well as the 12 units of primary care health services. Chemical waste generated at health services units may include the liquid waste from cleaning materials and disinfectants, expired and unused pharmaceutical products, and cytotoxins. These are all considered hazardous waste products and they must be disposed of via an authorised system at approved sites (e.g. industrial landfills). The process of encapsulating chemical medical waste in concrete (cement, crushed stones and sand) followed by their disposal at sanitary landfills is a procedure that is not considered in Brazilian Legislation. Despite the oversight, this method of disposal was used in the municipality of Piraí, with the approval of the Rio de Janeiro State Agency for Environmental Control. The safety aspects of this method and the limits of its applicability, particularly in small municipalities, were evaluated in this study. The results indicate that, within certain parameters, this method may provide a viable solution for the disposal of HCW in small municipalities.

Wetlands para tratamento de lixiviados de aterros sanitários: experiências no aterro sanitário de Piraí e no aterro metropolitano de Gramacho (RJ) / Landfill leachate treatment using wetlands: experiences in Piraí municipality solid waste landfill and Gramacho metropolitan solid waste landfill

O Grupo de Resíduos Sólidos do Programa de Pós-Graduação em Engenharia Ambiental (PEAMB/UERJ) vem realizando, há cinco anos, pesquisas utilizando wetlands construídos em tratamento de lixiviados de aterros sanitários. Esses sistemas promovem a absorção de nutrientes pelas plantas e facilitam a degradação de material orgânico por microrganismos do solo e aderidos às raízes. Experiências desenvolvidas no Aterro Sanitário de Piraí mostram remoções, em termos de concentração de poluentes, de 41 por cento de DQO e 51 por cento de nitrogênio amoniacal. Os resultados obtidos no Aterro Metropolitano de Gramacho apresentam redução, em termos de carga de poluição, de 86 por cento de DQO e 89 por cento de nitrogênio amoniacal. Os sistemas implantados mostram-se boas alternativas no tratamento de lixiviados, sobretudo em regiões de clima tropical, onde as elevadas temperaturas potencializam a evapotranspiração.

The Group of Solid Waste of Environmental Engineering Program (PEAMB/UERJ) has been conducting research using constructed wetlands in landfill leachate treatment in the last five years. These systems promote the absorption of nutrients by the vegetation and facilitate the degradation of organic material by microorganisms in the soil and the ones adhered to the roots. Experiments carried out in Piraí Municipality Landfill show removal of pollutants about 41 percent of COD and 51 percent of ammonium nitrogen. The results obtained in Gramacho's landfill, present a reduction of 86 percent of COD load and 89 percent of ammonium nitrogen load. Wetlands seens to be a good alternative in the treatment of landfill leachate, especially in regions of tropical climate, where high temperatures improve effects of evapotranspiration.