Elisabeth Ritter

Wetlands para tratamento de lixiviados de aterros sanitários: experiências no aterro sanitário de Piraí e no aterro metropolitano de Gramacho (RJ)

ABSTRACT The Group of Solid Waste of Environmental Engineering Program (PEAMB/UERJ) has been conducting research using constructed wetlands in landfi ll leachate treatment in the last fi ve 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 Pirai Municipality Landfi ll show removal of pollutants about 41% of COD and 51% of ammonium nitrogen. The results obtained in Gramacho’s landfi ll, present a reduction of 86% of COD load and 89% of ammonium nitrogen load. Wetlands seens to be a good alternative in the treatment of landfi ll leachate, especially in regions of tropical climate, where high temperatures improve effects of evapotranspiration. KEYWORDS: Constructed wetlands , leachate treatment, evapotranspiration, Gramachos’ metropolitan landfi ll, Pirai’s Landfi ll. C AMILLE F ERREIRA M ANNARINO Mestre em Engenharia Ambiental - PEAMB/UERJ. Engenheira Civil - Enfase em Engenharia Sanitaria e Ambiental – FEN/UERJ. Bolsista CNPq/ PROSAB

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.

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.

Avaliação da implantação da Resolução n. 307/2002 do CONAMA sobre gerenciamento dos resíduos de construção civil

O gerenciamento da crescente massa de residuos solidos gerados e um dos principais problemas do mundo atual, considerando os riscos de esgotamento dos recursos naturais e os impactos ao meio ambiente e a saude publica. Neste c ontexto, este trabalho apresenta o panorama das construtoras em relacao ao gerenciamento de seus residuos solidos, com o objetivo de analisar o efeito da resolucao no 307/2002 - CONAMA, enfocando com maior detalhamento a reciclagem de RCD nos canteiros de obra, como forma de insercao dos residuos passiveis de reciclagem no processo produtivo. Verifica-se que a questao ambiental, por si so, nao funciona como motivadora para a implantacao do gerenciamento de RCD pelas construtoras e, para a incorporacao de no vas tecnologias, como a reciclagem de RCD no proprio canteiro de obra; e que a resolucao no 307/2002 do CONAMA ainda nao produziu os efeitos desejados. The management of the increasing volume of generated solid wastes is one of the main problems of the current world, considering the risks of exhaustion of the natural resources and the impacts to the environment and the public health. In this context, this work presents an overall view of the constructors related to the management of their solid wastes, a s established the objective to analyze the effect of the resolution no 307/2002 - CONAMA. Focusing, the recycling of CD and that the resolution no 307/2002 of the CONAMA still did not produce the expected results.

Ammonium and BPA Sorption for GCL

The trend of using GCL for liners from MSW landfill in developing countries is growing. Leachate in general presents high ammonium and chlorides concentrations and there are noticeable with high migration possibility. Recent studies indicate a presence of several emerging organic compounds, among them bisphenol A (BPA) which is considered an endocrine disrupting chemical (EDCs). This article presents batch tests for bentonite and geotextile, carried out separately using ammonium and BPA mono solutions with maximum concentrations in the range of 1600–1800 mg.L−1 and 1000 pg.L−1, respectively. The maximum value of ammonium adsorbed by bentonite was 10,61 mg.L−1, and no sorption for geotextile. The BPA sorption tended to 3,72 mg.L−1 for bentonite whereas for the geotextile BPA adsorbed was in order of 6,52 pg.L−1.

AVALIAÇÃO DE EMISSÕES DE BIOGÁS EM CAMADAS DE COBERTURA DE UM ATERRO SANITÁRIO

Os gases oriundos da biodegradacao dos residuos nos aterros sanitarios provocam um serio problema de poluicao atmosferica a niveis local e global. Nesse contexto, empregam-se os sistemas de cobertura que possuem dentre os seus objetivos, a retencao das emissoes fugitivas de biogas para a atmosfera. A pesquisa foi realizada na fase de operacao de um aterro sanitario e tem por objetivo comparar as emissoes fugitivas de biogas, enfocando o metano, em tres sistemas de cobertura construidos em celula experimental: convencional, barreira capilar e evapotranspirativa. As investigacoes de campo consistiram em ensaios de placa de fluxo para mensurar a composicao do biogas e o fluxo pelas camadas de cobertura. Os resultados indicaram que as emissoes de biogas na camada convencional variaram de 7,5 a 389,0 g/m 2 .dia para o CH 4 .Na camada de barreira capilar, as emissoes de CH 4 variaram de 7,2 a 369,2 g/m 2 .dia A camada evapotranspirativa proporcionou o melhor desempenho em relacao as demais camadas de cobertura, apresentando variacao de 5,0 a 68,9 g/m 2 .dia para as emissoes de CH 4 . A vegetacao neste tipo de cobertura mostrou-se um fator decisivo para a protecao da camada, reduzindo as emissoes de biogas para a atmosfera. Palavras-chave: Aterro sanitario; Camada evapotranspirativa; Barreira capilar; Fluxo de gas.

Comparação da eficiência de três materiais na sorção e difusão dos íons metálicos através de ensaios experimentais e simulação computacional

The present study aims to quantify basic parameters for the transport and retention of metal ions in contention barrier systems. A synthetic leachate with pH 1 and known concentrations of ions chromium, cadmium and copper was used. Sorption and molecular diffusion experiments were carried out in compacted soil, soil mixture with 10% sodium bentonite and compacted soil overlaid with geomembrane. It was implemented in the program MPHMTP (Multi Phase Heat and Mass Transfer Program) where the equations describe ion behavior under adjusted parameters obtained from sorption and diffusion tests. The geomembrane’s presence minimizes ion migration through a diffusive process, and eliminates the need for the soil sorption capacity. But the soil with the bentonite option proved to be the most predominant specific alternative due to its cadmium sorption capacity.

Water resources contamination: A study of São Pedro da Aldeia’s open dump

O trabalho apresenta os resultados de monitoramento das aguas subterrâneas e lagoas superficiais adjacentes ao lixao de Sao Pedro da Aldeia (RJ). Seis piezometros, tres lagoas e um poco cacimba a jusante foram utilizados para coleta de amostras. Sao apresentados os parâmetros fisicoquimicos determinados no campo: pH, condutividade eletrica (CE), potencial redox (Eh), e os resultados de ions analisados em laboratorio: Cl-, Na+, K+, e NH4+. Os resultados mostraram que a influencia do lixao sobre as aguas superficiais e subterrâneas, apos 17 anos em atividade, atinge entre 150 e 200 metros de distância, nao se observando uma atenuacao. Palavras-chave: lixao, contaminacao, recursos hidricos, Sao Pedro da Aldeia (RJ).

Simulação computacional da difusão molecular de poluentes líquidos de aterros em solos organo argilos – Aterro Metropolitano de Gramacho, RJ

Um dos principais problemas ambientais causados pelo acumulo de lixo e a liberacao de lixiviado no solo. O trabalho realizado compreende a utilizacao de dois instrumentos computacionais na avaliacao da difusao de ions dissolvidos na massa liquida proveniente de aterro sanitario. O software POLLUTE e o modelo computacional (MPHMTP) Multi Phase Heat and Mass Transfer Program, Castro (2000), inicialmente desenvolvido para simulacoes de processos siderurgicos e posteriormente adaptado ao calculo do escoamento e a interacao quimica de efluentes resultantes da decomposicao umida de rejeitos solidos urbanos e industriais em meios porosos (Pinto, 2004 e Forster, 2006). O modelo utiliza o metodo de volumes finitos para a realizacao das simulacoes de difusao molecular dos ions cloreto, sodio calcio, magnesio, potassio e amonio. Os ions analisados sao os que possuem maior concentracao no lixiviado e no solo orgânico argiloso do Aterro Metropolitano de Gramacho, localizado no municipio de Duque de Caxias, Rio de Janeiro. Os resultados mostram a validade e adequacao dos modelos POLLUTE e MPHMTP utilizados, quando foram comparados os resultados numericos dos modelos com os obtidos experimentalmente, atraves da escala de laboratorio proposta. Palavras-chave: Simulacao Computacional, Difusao Molecular, Meios Porosos e Volumes Finitos.