Physical-chemical pre-treatment of sanitary landfill raw leachate by direct ascending filtration.

Several environmental problems in Brazil are caused by the accelerated urban and industrial growth and by the multiplicity of urban waste generated. Waste disposal in landfills is still common practice in Brazil. This work was conducted in sand filters and activated carbon column, proposing an alternative for the physical-chemical treatment of leachate as a pre-treatment to preserve the biological process. The results showed reductions of up to 74% for COD, 47% for BOD5, 93% for color, 90% for ammonia and an increase from 0.3 to 0.9 in the BOD5/COD ratio. Although the results obtained do not fall within the limits of the legislation, the results for ammonia concentration was reduced by 33.25% and 85.37% after filtration and activated carbon column treatment respectively. The use of activated carbon columns resulted in an excellent performance in the reduction of heavy metals in the leachate. The performance demonstrated a removal of 60-96%. Limitations were found in the length of the filtration races, as a limiting factor in the process. The results show the potential of using direct upward filtration with sand and activated carbon filters for the treatment of landfill leachate.

Otimização do dimensionamento em sistemas de bombeamento fotovoltaico: validação de modelo em sistema piloto na comunidade rural de Rio Belo, Orleans (SC) / Sizing optimization in Solar Photovoltaic Water Pumping System: model validation in a pilot unit located in the rural community of Rio Belo, Orleans/SC, Brazil

RESUMO A gestão dos recursos hídricos e energéticos é o principal desafio que a sociedade contemporânea enfrenta atualmente. Água e energia são fatores fundamentais para o desenvolvimento socioeconômico das comunidades, principalmente aquelas situadas em locais remotos, e, nesse cenário, a falta de energia é o aspecto mais preocupante. Os sistemas de bombeamento fotovoltaico apresentam vantagens para a inserção em comunidades isoladas, como fácil instalação e pouca manutenção durante o ciclo de vida, porém o dimensionamento inadequado pode gerar gastos desnecessários ou comprometer o abastecimento de água. Simular o desempenho favorece a concepção de sistemas e permite alcançar a otimização técnica e econômica em projetos da referida tecnologia. O estudo propõe um modelo matemático de simulação e a utilização do generalized reduced gradient (GRG) e de dados regionais de radiação solar, de consumo de água, de produtividade de poços e de capacidade do sistema de bombeamento para obter a referida otimização. A validação do respectivo modelo foi realizada em um sistema piloto, localizado em uma comunidade rural no município de Orleans, no Estado de Santa Catarina. A localidade apresenta uma das menores médias de radiação anual no país, aproximadamente 4,5 kWh.m-2/dia. A simulação efetuada nas condições naturais do sistema piloto mostrou resultados bem próximos do comportamento monitorado, evidenciando, assim, a eficiência do modelo. O uso da ferramenta auxilia no processo de tomada de decisão quanto à concepção de projetos, além de beneficiar as comunidades com acesso à água e à energia, trazendo benefícios em todas as esferas: social, ambiental e econômica.

ABSTRACT The management of water and energy resources are the main challenges that contemporary society faces nowadays. Water and energy are fundamental factors for socio-economic development of the communities, especially those in remote locations, and in this case the lack of energy is the most worrying aspect. Solar photovoltaic pumping systems have advantages for insertion in isolated communities, such as easy installation and low maintenance during the life cycle, but inappropriate sizing can create unnecessary costs or affect the water supply. Simulating performance favors the system's sizing and allows achieving technical and economic optimization of these technology projects. This study proposes a mathematical model of simulation, use of the Generalized Reduced Gradient (GRG), solar radiation regional data, and water consumption, wells' productivity and pumping system capacity to obtain this optimization. The model was validated in a pilot system, located in a rural community in the city of Orleans, State of Santa Catarina, Brazil. The place has one of the lowest average annual radiation in the country, approximately 4.5 kWh / m2.day. The simulation performed in the natural pilot system conditions presented results very close to the monitored behavior, thus demonstrating its efficiency. Using this tool assists in the decision-making process in designing projects and benefits the communities with access to water and energy, bringing benefits in all spheres: social, environmental and economic.

Combination of electroflotation process and down-flow granular filtration to treat wastewater contaminated with oil.

One of the main problems faced by the oil industry is related to the amount of produced water generated during the oil extraction process. For proper disposal of this effluent, treatment processes should be applied to meet the requirements established by environmental agencies. Thus, the present study aimed to evaluate the efficiency of the combination of electroflotation process and down-flow granular filtration in the treatment of wastewater contaminated with oil. To this end, they were studied in a pilot system, to optimize the electroflotation process and combination of processes. The performance of the pilot system was determined by removal of oil and grease content (OG) in the treated effluent. According to the results, the electroflotation process had the best performance with an effluent input rate of 62 m3 m-2 d-1, current density of 80 A m-2 and NaCl concentration of 7900 mg L-1. Under these conditions, the mean removal of OG from synthesized solution after 720 minutes of treatment was 86.64% (59.51 mg L-1) for the electroflotation process and 61.52% (12.91 mg L-1) after down-flow granular filtration. By combining the processes studied, we obtained an initial OG removal (470.55 mg L-1) of over 98% (6.42 mg L-1) in 720 minutes of treatment, with an energy consumption of the electrochemical reactor of 1.47 kWh m-3. ABBREVIATIONS: ANOVA: analysis of variance; CCRD: Central Composite Rotational Delineation; DOC: dissolved organic carbon; DSA: dimensionally stable anodes; LAPOA: Laboratory of Water Potabilization; OG: oil and grease; OPER: operating parameters of the electrochemical reactor; TDS: total dissolved solids; UFSC: Federal University of Santa Catarina.

Pré-tratamento de lixiviados de aterros sanitários por filtração direta ascendente e coluna de carvão ativado / Landfill leachate pre-treatment by upflow direct filtration and column of activated carbon

Vários problemas ambientais no Brasil decorrem do acelerado crescimento dos setores produtivos e, consequentemente, da multiplicidade dos resíduos sólidos urbanos gerados. A disposição destes em aterros sanitários é prática comum; entretanto, essa deposição requer medidas de proteção ambiental, incluindo o tratamento dos lixiviados. Este trabalho, conduzido em filtros de areia e coluna de carvão ativado, trata de proposta de tratamento físico-químico do lixiviado como alternativa ao processo biológico. No que se refere ao processo de filtração, observaram-se reduções de até 74 por cento para DQO, 47 por cento para DBO, 93 por cento para cor, 90 por cento para amônia e aumento de 0,3 para 0,9 na relação DBO5/DQO. Constataram-se limitações com relação à duração das carreiras de filtração, para o que se sugere avaliar outras granulometrias de areia e até mesmo tecnologias de tratamento.

Several environmental problems in Brazil are due to the rapid growth of various productive sectors, and the resulting qualitative multiplicity of municipal solid waste that are generated. The disposal of solid waste in landfills is a common practice; however, it requires environment protection measures, including the treatment of leachate. This work conducted in sand filters and activated carbon column refers to physical and chemical treatment of leachate as an alternative to the biological process. Regarding the filtration process, the results showed reductions of up to 74 percent for COD, 47 percent for BOD, 93 percent for color, 90 percent for ammonia and an increase from 0.3 to 0.9 in BOD5/COD relation. Limitations were found in relation to filtration run, which suggests the evaluation of other size grains and even treatment technologies.

Filtração direta com pré-floculação e coagulação com sulfato de alumínio e hidroxicloreto de alumínio: estudo com água de manancial eutrofizado / Direct filtration with pre-flocculation and coagulation with aluminium sulfate and poly aluminium chloride: an eutrophicated water source case study

Neste trabalho são apresentados dados de um estudo sobre modificações em um sistema implantado de tratamento de água por filtração direta descendente, com o objetivo de melhorar o seu desempenho em função das características da água a ser tratada, caracterizada por baixa cor aparente e turbidez, porém com elevada concentração de fitoplâncton. Ensaios em jarteste precederam a realização de carreiras de filtração em sistema piloto, com ou sem pré-floculação em meio granular expandido. Foram testados sulfato de alumínio e hidróxicloreto de alumínio como coagulantes, e leitos filtrantes de antracito e areia ou apenas antracito. A adoção de um leito filtrante de maior granulometria, hidróxicloreto de alumínio e pré-floculação, reduziu o consumo de água de lavagem de 23,8 por cento para 5,5 por cento, resultando água filtrada com melhor qualidade em termos de cor aparente, turbidez e alumínio residual.

This paper presents the results of a case study on the modifications applied in a direct descending filtration water treatment system. The objective was to improve its performance according to the source water quality, characterized by low turbidity and apparent color levels, but high concentration of phytoplankton. Jar test procedures preceded the tests conducted in a small scale experiment, with or without a pre-flocculation step in expanded granular media. Aluminium sulfate and poly aluminium chloride were both tested as coagulant elements, and anthracite and sand or only anthracite were tested as the filtering media. The use of a large grain size filtering media with a poly aluminium chloride pre-flocculation step caused the washwater volume to reduce from 23.8 percent to 5.5 percent. This resulted in a better water quality outcome measured in apparent color, turbidity and residual aluminium concentrations.