Miguel Mansur Aisse

Aplicação de lodos de estações de tratamento de água e de tratamento de esgoto em solo degradado

O objetivo deste estudo foi avaliar o efeito da aplicacao de lodo de Estacao de Tratamento de Agua (ETA) em solo degradado, com presenca e ausencia de lodo de Estacao de Tratamento de Esgoto (ETE), na produtividade do milheto e nas caracteristicas de fertilidade desse solo. A area experimental foi resultante de deposito de materiais oriundos da construcao da ETE Padilha Sul, em Curitiba (PR). Os blocos casualizados foram arranjados em parcelas subdivididas e uma testemunha, sendo a parcela principal constituida por ausencia e presenca de lodo de ETE (77 Mg.ha-1 Solidos Totais - ST) e a subparcela por doses de lodo de ETA (24, 37 e 61 Mg.ha-1 (ST)). Concluiu-se que a aplicacao de lodo de ETA nao teve efeito sobre a produtividade de milheto, tampouco sobre os teores dos elementos avaliados no solo. No entanto, na presenca do lodo de esgoto, a sua aplicacao foi favoravel a dinâmica do nitrogenio do solo ate a dose de 37 Mg.ha-1 e a aplicacao do lodo de ETE neutralizou o aluminio trocavel, elevou o pH, o calcio, carbono, fosforo e a saturacao de bases, e reduziu a acidez potencial do solo.

Sorção de poluentes orgânicos emergentes em lodo de esgoto

The agricultural use of wastewater sludge promotes the recycling of nutrients and organic matter, bringing benefits to the plant development and the soil and water conservation. However, there is a growing concern about organic pollutants that may be in wastewater sludge. The presence of pharmaceuticals (antibiotics, tranquilizers, antiepileptics), hormones (natural and synthetic), musk fragrances, bactericides, and other organic pollutants in various environmental compartments is an emerging issue due to the lack of information on the potential impact associated with their occurrence, their fate and ecotoxicological effects. These compounds, termed emerging organic pollutants, may be removed during sewage treatment due to degradation, biological transformation, volatilization and/or sorption onto sludge particles. These processes are influenced by the physical-chemical properties of the pollutant and the conditions of sewage treatment. Information on physical and chemical characteristics, such as potential acidity and hydrophobicity, are important for understanding the patterns of removal and to adopt measures that favor the removal of these pollutants, such as changes in operating conditions and/or adoption of technologies. This literature review presents the physico-chemical emerging organic pollutants characteristics and their potential sorption on wastewater sludge.

Use of life cycle assessment to evaluate environmental impacts associated with the management of sludge and biogas

Upflow anaerobic sludge blanket (UASB) reactors used in sewage treatment generate two by-products that can be reused: sludge and biogas. At the present time in Brazil, most of this resulting sludge is disposed of in sanitary landfills, while biogas is commonly burned off in low-efficiency flares. The aim of the present study was to use life cycle assessment to evaluate the environmental impacts from four different treatment and final destination scenarios for the main by-products of wastewater treatment plants. The baseline scenario, in which the sludge was sanitized using prolonged alkaline stabilization and, subsequently, directed toward agricultural applications and the biogas destroyed in open burners, had the most impact in the categories of global warming, terrestrial ecotoxicity, and human non-carcinogenic toxicity. The scenario in which heat resulting from biogas combustion is used to dry the sludge showed significant improvements over the baseline scenario in all the evaluated impact categories. The recovery of heat from biogas combustion decreased significantly the environmental impact associated with global warming. The combustion of dried sludge is another alternative to improve the sludge management. Despite the reduction of sludge volume to ash, there are environmental impacts inherent to ozone formation and terrestrial acidification.

Impacto da incorporação de escuma em lodo de esgoto com fins agrícolas

Resumo Foram desaguados separadamente em leitos de secagem na ETE Vassoural, Guarapuava, PR, 5 lotes de escuma e de lodo, produzidos em reator tipo UASB tratando esgotos domesticos. Apos o desaguamento foram realizadas 3 misturas nas proporcoes 10, 20 e 50 % em massa de escuma em lodo. Os parâmetros avaliados foram: solidos totais e volateis, oleos e graxas, coliformes termotolerantes, Salmonella spp., ovos viaveis de helmintos, N (Kjedahl, NH 4 +, NO 2 - e NO 3 -3), C orgânico, a concentracao total dos elementos P, K, Na, S, Ca, Mg, Ar, Ba, Cd, Pb, Cu, Cr, Hg, Mo, Ni, Se e Zn. Os tratamentos nao apresentaram variância significativa (P 0,05 ) para nenhum dos parâmetros, indicando que a incorporacao de escuma nas proporcoes de 10, 20 e 50% em massa nao alterou a composicao do lodo de esgoto destinado ao uso agricola. Palavras-chave: escuma, lodo anaerobio de esgoto, reator UASB.