Cultivo de Landoltia punctata na remoção de desreguladores endócrinos e no polimento de esgoto sanitário em lagoa com recirculação
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Data
2019-02-15
Autores
Zanetoni Filho, José Antônio
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Universidade Estadual Paulista (Unesp)
Resumo
A situação de escassez de recursos financeiros destinados ao tratamento e coleta de esgotos municipais, no Brasil, torna essencial a busca por tecnologias de tratamento que priorizem baixos custos de instalação e operação. Além da negligência que existe no tratamento de esgotos, os métodos utilizados, muitas vezes, não são capazes de remover os micropoluentes que estão presentes nos esgotos domésticos. Os micropoluentes podem ser desde fármacos, que são expelidos na urina ou descartados de maneira inadequada, a hormônios naturais ou sintéticos. Esse trabalho consistiu em realizar um processo de polimento do esgoto sanitário da cidade de Ilha Solteira – SP. O sistema de polimento é constituído por dois tanques, onde foi cultivada a macrófita Landoltia punctata. Foi também avaliado e feito a recirculação do efluente, no tratamento de esgoto. Neste sistema de polimento, foram avaliadas as eficiências de tratamento para os parâmetros de DBO, DQO, NT, NO3-, PT e ST. As maiores eficiências de remoção para DBO, DQO, NT, NO3-, PT e ST foram de 66,35%, 59,08%, 26,76%, 28,38%, 6,85% e 40,08%. Outro aspecto avaliado foi a taxa de crescimento da macrófita cultivada em esgoto sanitário. As maiores taxas de crescimento relativo foram de 3,84 e 3,17 g.m-2.d-1 MS. Considerando a presença de desreguladores endócrinos (DEs) no efluente da Estação de Tratamento de Esgoto (ETE) de Ilha Solteira, foi analisado a absorção dos estrógenos 17α-etinilestradiol (EE2) e o estriol (E3) pela macrófita, avaliando possíveis riscos no reaproveitamento dessa biomassa. As eficiências máximas alcançadas para remoção do E3 e EE2 foram de 83,63% e 83,50%, respectivamente. O tanque com recirculação foi maior efetivo na remoção do E3, enquanto que o tanque sem recirculação alcançou maiores eficiências de remoção de EE2. Os maiores valores de concentrações na biomassa das plantas foram de 1,52 µg.g-1 para o E3 e de 2,37 µg.g-1 para o EE2. Pode-se considerar que as taxas de crescimento relativo foram satisfatórias, mesmo com a utilização de um meio de cultivo diluído e pobre em nutrientes. A presença dos DEs no esgoto sanitário utilizado descarta a possibilidade de reaproveitamento de uma biomassa rica em proteína (33,57%), além de apresentar efeitos tóxicos na produção de biomassa da planta.
The scarcity of financial resources for the treatment and collection of municipal wastewater in Brazil makes search for treatment technologies essential with low installation and operation costs. In addition, the methods used are often not able to remove the micropollutants that are present in domestic sewage. Micropollutants can range from drugs that are expelled in the urine or inappropriately discarded to natural or synthetic hormones. This work consisted of a process to polishing the sanitary sewage of the city of Ilha Solteira - SP. The treatment system consists of two tanks, where the macrophyte Landoltia punctata was grown. In one of the tanks, a recirculation system was performed. In this polishing system, the treatment efficiencies for the BOD, COD, TN, NO3-, TP and ST parameters were evaluated. The highest removal efficiencies for BOD, COD, TN, NO3-, TP and ST were 66,35%, 59,08%, 26,76%, 28,38%, 6,85% and 40,08%. Another aspect evaluated was the growth rate of the macrophyte. The highest relative growth rates were 3.84 and 3.17 g.m-2.d-1 MS. Considering the presence of endocrine disrupters (DEs) in the effluent from the Sewage Treatment Plant (ETE) in Ilha Solteira - SP, 17α-ethinyl estradiol (EE2) and estriol (E3) were analyzed on the plant to evaluate possible risks on the reuse of the biomass. The maximum achieved efficiencies for removal of E3 and EE2 were 83.63% and 83.50%, respectively. The recirculation tank was more effective at removing E3, while the non-recirculated tank achieved higher EE2 removal efficiencies. The highest plant biomass values were 1.52 μg.g-1 for E3 and 2.37 μg.g-1 for EE2. Relative growth rates could be considered satisfactory, even with the use of a diluted culture medium. The presence of DEs in the sanitary wastewater discards the possibility of reuse a rich biomass in protein (33.57%), besides presenting toxic effects in the biomass production.
The scarcity of financial resources for the treatment and collection of municipal wastewater in Brazil makes search for treatment technologies essential with low installation and operation costs. In addition, the methods used are often not able to remove the micropollutants that are present in domestic sewage. Micropollutants can range from drugs that are expelled in the urine or inappropriately discarded to natural or synthetic hormones. This work consisted of a process to polishing the sanitary sewage of the city of Ilha Solteira - SP. The treatment system consists of two tanks, where the macrophyte Landoltia punctata was grown. In one of the tanks, a recirculation system was performed. In this polishing system, the treatment efficiencies for the BOD, COD, TN, NO3-, TP and ST parameters were evaluated. The highest removal efficiencies for BOD, COD, TN, NO3-, TP and ST were 66,35%, 59,08%, 26,76%, 28,38%, 6,85% and 40,08%. Another aspect evaluated was the growth rate of the macrophyte. The highest relative growth rates were 3.84 and 3.17 g.m-2.d-1 MS. Considering the presence of endocrine disrupters (DEs) in the effluent from the Sewage Treatment Plant (ETE) in Ilha Solteira - SP, 17α-ethinyl estradiol (EE2) and estriol (E3) were analyzed on the plant to evaluate possible risks on the reuse of the biomass. The maximum achieved efficiencies for removal of E3 and EE2 were 83.63% and 83.50%, respectively. The recirculation tank was more effective at removing E3, while the non-recirculated tank achieved higher EE2 removal efficiencies. The highest plant biomass values were 1.52 μg.g-1 for E3 and 2.37 μg.g-1 for EE2. Relative growth rates could be considered satisfactory, even with the use of a diluted culture medium. The presence of DEs in the sanitary wastewater discards the possibility of reuse a rich biomass in protein (33.57%), besides presenting toxic effects in the biomass production.
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Palavras-chave
Lagoas de Lemnas, Desreguladores endócrinos, Polimento de esgoto, Estriol (E3), 17α-etinilestradiol (EE2), Duckweed ponds, Endocrine disrupters, Wastewater polishing