Adriano Luiz Tonetti

Evaluation of a simple system of wastewater treatment aiming at use in rural areas

Brazil faces problems related to the large population which lives in the rural areas and discharges the wastewater directly into water bodies. This occurrence contributes not only to environmental damage but also to public health problems. In this case, the use of simple treatments would be beneficial, since the local wastewater could be treated with low cost and be built and operated by local labor even though it is not specialized. A system investigated in UNICAMP and which has these characteristics is, undoubtedly, the association of anaerobic filters with sand filters. The results from the research showed that the effluent had an organic matter concentration lower than the maximum permitted by Brazilian law (Brasil, 2005). Regarding the nitrogen compounds, the sand filters showed a great capacity of nitrification and, in reference to phosphorus, in the deepest depths (0.75 and 1.00 m), the removal was more than 98%Brazil faces problems related to the large population which lives in the rural areas and discharges the wastewater directly into water bodies. This occurrence contributes not only to environmental damage but also to public health problems. In this case, the use of simple treatments would be beneficial, since the local wastewater could be treated with low cost and be built and operated by local labor even though it is not specialized. A system investigated in UNICAMP and which has these characteristics is, undoubtedly, the association of anaerobic filters with sand filters. The results from the research showed that the effluent had an organic matter concentration lower than the maximum permitted by Brazilian law (Brasil, 2005). Regarding the nitrogen compounds, the sand filters showed a great capacity of nitrification and, in reference to phosphorus, in the deepest depths (0.75 and 1.00 m), the removal was more than 98%.

Coconut shells as filling material for anaerobic filters

In rural areas of developing countries, there is a lack of sanitation services and the installation of such infrastructure is hampered by the high investment costs for initial implementation and by the limited availability of qualified personnel. An alternative to traditional sanitation services include an anaerobic filter, but the high cost of appropriate filling material can be an obstacle to its wide-spread implementation. To decrease this construction cost, the objective of this work was to study the use of coconut shells as filling material for anaerobic filters. Anaerobic filters were built and filled with the studied material and operated with up flow and hydraulic retention time of 9 hours. The reactors provided a removal of 79 ± 16% in BOD terms, indicating that the coconut shell filling had efficiency consistent with the literature data. In addition, the husks were found to retain their tensile strength following use in the reactors. Coconut husks have more empty bed volume than other low cost materials, such as crushed stone, nearing properties of traditional materials. The results of this study indicate that coconut husks may prove to be a low cost alternative to traditional fillers for anaerobic treatment in rural communities.

Tratamento de esgoto e produção de água de reúso com o emprego de filtros de areia

Nesta pesquisa estudou-se um sistema composto pela combinacao de filtro anaerobio com filtro de areia para o tratamento de esgoto. Para isso, foram avaliados tres filtros anaerobios operados com tempo de detencao hidraulica de nove horas, que tinham o efluente disposto sobre quatro filtros de areia em distintas taxas de aplicacoes. No primeiro filtro de areia aplicaram-se 50 L.m-2 uma vez por dia. No segundo, terceiro e quarto filtros, essa mesma carga foi disposta em dois, tres e quatro horarios, espacadas entre as 9:00 e as 16:00 horas. O sistema apresentou um efluente final com qualidade que atendia os padroes para reuso e demanda bioquimica de oxigenio abaixo do limite para o lancamento em corpos hidricos (Decreto de Paulista no 8.468/1976), indicando a viabilidade de disposicao de taxas superiores as sugeridas pela NBR 13969/1997, a qual orienta os aspectos construtivos para esta forma de tratamento.In this research it was studied a system composed by the anaerobic filter combined with a sand filter for the wastewater treatment. For this, three anaerobic filters were operated with hydraulic detention time of nine hours which had the effluent disposed over four sand filters in different frequencies of application. On the first sand filter, 50 L.m-2 were applied once a day. On the second, the third and the fourth filters, the same load was disposed in twice, three and four times a day, distributed between 9 a.m. and 4 p.m. The system presented a final effluent suitable for the COD and BOD legislation maximum limit to be discharged into water body (Decreto Paulista no 8,468/1976), showing the viability of dispose a higher quantity of effluent then the one suggested by NBR 13969/1997, which guides the constructive aspects for this kind of treatment.

Avaliação de um sistema simplificado de tratamento de esgotos visando a utilização em áreas rurais

Brazil faces problems related to the large population which lives in the rural areas and discharges the wastewater directly into water bodies. This occurrence contributes not only to environmental damage but also to public health problems. In this case, the use of simple treatments would be beneficial, since the local wastewater could be treated with low cost and be built and operated by local labor even though it is not specialized. A system investigated in UNICAMP and which has these characteristics is, undoubtedly, the association of anaerobic filters with sand filters. The results from the research showed that the effluent had an organic matter concentration lower than the maximum permitted by Brazilian law (Brasil, 2005). Regarding the nitrogen compounds, the sand filters showed a great capacity of nitrification and, in reference to phosphorus, in the deepest depths (0.75 and 1.00 m), the removal was more than 98%Brazil faces problems related to the large population which lives in the rural areas and discharges the wastewater directly into water bodies. This occurrence contributes not only to environmental damage but also to public health problems. In this case, the use of simple treatments would be beneficial, since the local wastewater could be treated with low cost and be built and operated by local labor even though it is not specialized. A system investigated in UNICAMP and which has these characteristics is, undoubtedly, the association of anaerobic filters with sand filters. The results from the research showed that the effluent had an organic matter concentration lower than the maximum permitted by Brazilian law (Brasil, 2005). Regarding the nitrogen compounds, the sand filters showed a great capacity of nitrification and, in reference to phosphorus, in the deepest depths (0.75 and 1.00 m), the removal was more than 98%.

Avaliação da partida e operação de filtros anaeróbios tendo bambu como material de recheio

In this paper, three anaerobic filters with 500 L volume were constructed and filled up with bamboo rings, operating with a nine hour hydraulic retention time. The aim was to determinate the start up period without using adapted sludge and reaching efficiency in a wastewater treatment, by deploying hydraulic detention time lower than the 12 hours suggested by the NBR 7229. In the system evaluation, it was used the dissolved organic carbon, chemical oxygen demand, biochemical oxygen demand, pH, and alkalinity, showing in terms of dissolved organic carbon, the need of 19 weeks to reach dynamic equilibrium in the reactors. After this period, the removal achieved 81.4 ± 6.4%. Results showed that using an alternative package in anaerobic filters made possible to have an efficacy similar to the one reached with traditional materials, even with the hydraulic detention time lower than the one suggested by the Brazilian law.

Remoção de matéria orgânica, coliformes totais e nitrificação no tratamento de esgotos domésticos por filtros de areia

According to IBGE (2000) 73% of the Brazilian cities are considered small communities with population smaller than 20,000 inhabitants. The majority of domestic wastewater of these places is normally disposed in rivers with no treatment. As a consequence, the irregular disposal may cause health and environmental problems. To reduce this risk it is necessary to develop treatment systems that are simple, efficient, sustainable and of low cost. The treatment of wastewater using up flow anaerobic filter combined with sand filters would be able to satisfy these exigencies, producing an effluent that could be disposed in rivers or even be reused, safeguarding the sources of potable water. The system achieved BOD removal of 96% and complete nitrification for the application of low loads. The increase of the applied loads caused a reduction in the efficiency; however the final values were still satisfactory.

Pós-tratamento de efluente de filtros anaeróbios operados com baixo tempo de detenção hidráulica por escoamento superficial no solo

In this investigation the post-treatment of anaerobic filters operated with low hydraulic retention time (HRT) through overland flow system was studied. For that, it was built four reactors whose volume was 500 L, filled up with bamboos rings and a ramp with 40.0 m of length and inclination of 3.5%, covering with Tifton 85 (Cynodon sp) grass. It was evaluated the wastewater treatment from Limeira city (SP), operating anaerobic filters with 3 hour HRT and the effluent application in superficial drain of 0.10; 0.20; 0.30 e 0.40 m3.h-1.m-1 rates. In these operational conditions, the effluent was suitable to be discharged into receiving waters until the rate application of 0.20 m3.h-1.m-1. Over this value, there was a worse final quality in DBO and phosphorus concentration.

Ammonia removal from landfill leachate by struvite formation: an alarming concentration of phosphorus in the treated effluent

This study examined the removal of ammonia nitrogen from the leachate of a landfill site using the chemical precipitation of struvite (MgNH4PO4.6H2O). This procedure achieved a reduction in the ammonia concentration that was higher than 99% when the molar ratio of 1.8:1.0:1.4 for Mg2+:NH4+:PO43- was adopted. The metal concentration found in the precipitate formed was lower than the limits set by Brazilian and American regulations (CONAMA 375/2006 and US EPA, 40 CFR 503.1993). This demonstrates the potential use for this practice in agriculture. However, the effluent obtained from the tests presented a phosphorus concentration higher than the one in the raw leachate. This shows that removing this compound from the effluent must be further studied. Otherwise, adopting the chemical precipitation of ammonia by the formation of struvite may become unfeasible.

Characterization of sewage sludge from different treatment systems

The Vacuum Filtration and the Capillary Suction Time tests can be used for coagulant dosage evaluation. The tests indicate that there is an optimal range of synthetic polymer dosage to ensure the best performance of the coagulated sludge compared to the raw sludge. Tests with FeCl3 indicate that increasing the coagulant dose decreases time for sludge filtration.

METODOLOGIA DE DESENVOLVIMENTO ECO-SISTÊMICO APLICADO AO PARADIGMA DO SANEAMENTO DESCENTRALIZADO

As boas praticas de saneamento sao acoes fundamentais de prevencao de doencas, promocao da saude, bem estar humano e protecao do meio ambiente. Contudo, a utilizacao do saneamento como instrumento de promocao de qualidade de vida pressupoe a superacao de entraves tecnologicos, politicos e gerenciais que dificultam a extensao desses beneficios as populacoes que habitam areas rurais e municipios e localidades de pequeno porte. O presente artigo expoe a complexidade envolvida no alcance do saneamento basico a essas pequenas comunidades e aporta algumas ideias de como e possivel encarar a problematica a partir da Metodologia de Desenvolvimento Eco-sistemico, calcado no Pensamento Complexo de Edgar Morin e Pensamento Eco-Sistemico elaborado por M.C. Moraes. Para tanto, apresenta-se tambem a proposta formulada por pesquisadores da UNICAMP para a aplicacao da educacao ambiental como ferramenta para o engajamento social na busca de melhoria do saneamento em comunidade rural no municipio de Campinas (SP).