Avaliação da eficiência do processo foto-fenton combinado com lodo ativado aplicado no tratamento do lixiviado do aterro de Santa Tecla em Gravataí - RS
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Data
2019-02-19
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Almeida, Maria Cristina De
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A geração de lixiviado em aterros sanitários no Brasil tem sido amplamente discutida pela sociedade em geral, uma vez que são efluentes com elevadas cargas de poluentes recalcitrantes, de difícil degradação e de elevada toxicidade. Estes podem causar sérios impactos, tanto em solos, águas subterrâneas e organismos aquáticos de corpos hídricos. O presente trabalho descreve a aplicação do processo de oxidação avançada, método foto-fenton, combinado com tratamento por lodo ativado com etapa anóxica, como alternativa para o tratamento do efluente gerado no aterro Santa Tecla em Gravataí-RS. O modelo foi composto por um processo foto-fenton, para degradação de material recalcitrante e aumento da biodegradabilidade do efluente. Em seguida, um tratamento por lodo ativado, com etapa anóxica, para remoção da carga nitrogenada. O trabalho foi avaliado pela análise da eficiência remoção da demanda química (DQO) e bioquímica de oxigênio (DBO5), de nitrogênio total Kjeldalh e de toxicidade, pelo método de germinação e sementes de Lactuca sativa, (alface) em comparação com os resultados de no efluente bruto gerado no aterro, com vistas no enquadramento na legislação vigente de lançamento de efluentes em corpos receptores. O ensaio de tratamento por foto-fenton, mostrou uma eficiência de remoção de cor de 96,2%, DBO5 = 66,4%, DQO = 75,8 %, e Nitrogenio total kjeldalh = 30,2%, com dosagem de Fe+2 = 708 mg/L e razão molar H2O2/Fe+2 = 2,1. O tratamento combinação de foto-fenton com lodo ativado aeróbio, com etapa anóxica, mostrou uma eficiência de remoção de 87,5% na DQO, 89% na DBO5 e 80,2% no nitrogênio total kjeldahl. Em relação a toxicidade, para o lixiviado bruto, a taxa de germinação foi 100% na concentração de 12,5%, que corresponde a concentração em que não foi observado efeito inibitório. Nas concentrações de 25%, 50% e 100% a taxa de germinação foi zero. No efluente final, resultante do modelo de tratamento proposto, a germinação absoluta é de 93,33% para as concentrações de 25, 50 e 100% de efluente tratado, sendo as concentrações onde o efeito inibitório é
observado. Os dados demonstram que o tratamento foto-fenton combinado com lodo ativado, com etapa anóxica, aplicado no tratamento do lixiviado do aterro de Santa Tecla, obteve remoções suficientes para enquadrar os parâmetros de lançamento na da legislação vigente, com uma perspectiva de baixo custo.
The generation of leachate in landfills in Brazil has been widely discussed by society in general, since they are effluents with high loads of recalcitrant pollutants, difficult to degradation and high toxicity. These can cause serious impacts on both soil, groundwater and aquatic bodies of water bodies. The present work describes the application of the advanced oxidation process, photo-fenton method, combined with activated sludge treatment with anoxic step, as an alternative for the treatment of the effluent generated at the Santa Tecla landfill in Gravataí-RS. The model was composed by a photo-fenton process, for degradation of recalcitrant material and increase of the biodegradability of the effluent. Then, an activated sludge treatment, with an anoxic step, to remove the nitrogen load. The work was evaluated by the analysis of the chemical (COD) and biochemical oxygen demand (BOD5), total nitrogen Kjeldal, le toxicity by the germination method and Lactuca sativa seeds (lettuce) in comparison with the results of the gross effluent generated in the landfill, with a view to complying with the current legislation on the discharge of effluents into receiving bodies. The photo-fenton treatment assay showed a 96.2% color removal efficiency, BOD5 = 66.4%, COD = 75.8%, and total kjeldalh nitride = 30.2%, with Fe+2 = 708 mg/L and molar ratio H2O2 / Fe+2 = 2:1. The final treatment, combining photo-fenton with activated aerobic sludge, with an anoxic step, showed a removal efficiency of 87.5% in COD, 89% in BOD5 and 80,2% in total nitrogen kjeldahl. In relation to toxicity, the germination rate for the crude leachate was 100% at the concentration of 12.5%, which corresponds to the concentration in which no inhibitory effect was observed. At concentrations of 25%, 50% and 100% the germination rate was zero. In the final effluent, resulting from the proposed treatment model, the absolute germination is 93.33% for concentrations of 25, 50 and 100% treated effluent, the concentrations where the inhibitory effect is observed. The data demonstrate that the combined photo-fenton treatment with activated sludge, with an anoxic step, applied in the treatment of the leachate of the Santa Tecla landfill, obtained sufficient removals to fit the parameters of launch in the current legislation, with a low cost perspective.
The generation of leachate in landfills in Brazil has been widely discussed by society in general, since they are effluents with high loads of recalcitrant pollutants, difficult to degradation and high toxicity. These can cause serious impacts on both soil, groundwater and aquatic bodies of water bodies. The present work describes the application of the advanced oxidation process, photo-fenton method, combined with activated sludge treatment with anoxic step, as an alternative for the treatment of the effluent generated at the Santa Tecla landfill in Gravataí-RS. The model was composed by a photo-fenton process, for degradation of recalcitrant material and increase of the biodegradability of the effluent. Then, an activated sludge treatment, with an anoxic step, to remove the nitrogen load. The work was evaluated by the analysis of the chemical (COD) and biochemical oxygen demand (BOD5), total nitrogen Kjeldal, le toxicity by the germination method and Lactuca sativa seeds (lettuce) in comparison with the results of the gross effluent generated in the landfill, with a view to complying with the current legislation on the discharge of effluents into receiving bodies. The photo-fenton treatment assay showed a 96.2% color removal efficiency, BOD5 = 66.4%, COD = 75.8%, and total kjeldalh nitride = 30.2%, with Fe+2 = 708 mg/L and molar ratio H2O2 / Fe+2 = 2:1. The final treatment, combining photo-fenton with activated aerobic sludge, with an anoxic step, showed a removal efficiency of 87.5% in COD, 89% in BOD5 and 80,2% in total nitrogen kjeldahl. In relation to toxicity, the germination rate for the crude leachate was 100% at the concentration of 12.5%, which corresponds to the concentration in which no inhibitory effect was observed. At concentrations of 25%, 50% and 100% the germination rate was zero. In the final effluent, resulting from the proposed treatment model, the absolute germination is 93.33% for concentrations of 25, 50 and 100% treated effluent, the concentrations where the inhibitory effect is observed. The data demonstrate that the combined photo-fenton treatment with activated sludge, with an anoxic step, applied in the treatment of the leachate of the Santa Tecla landfill, obtained sufficient removals to fit the parameters of launch in the current legislation, with a low cost perspective.
Descrição
Palavras-chave
Foto-fenton; Lodo Ativado; Toxicidade; Efluente de aterro sanitário; Photo-fenton; Sludge Activated; Toxicity; Effluent from landfill
Citação
REIS, Israel Santos. Avaliação da eficiência do processo foto-fenton combinado com lodo ativado aplicado no tratamento do lixiviado do aterro de Santa Tecla em Gravataí - RS. 2018. Monografia (Graduação em Engenharia Ambiental) – Universidade do Vale do Taquari - Univates, Lajeado, 03 dez. 2018. Disponível em: http://hdl.handle.net/10737/2415.