[pt] Para a avaliação da toxicidade aguda através do método respirométrico,
foram empregados quatro compostos intoxicantes: Cu2+, fenol, surfactante e
antibiótico, em distintas concentrações, os quais foram mantidos em contato
durante 15 minutos com quatro tipos de lodo ativado: um oriundo de uma
indústria farmacêutica, dois provenientes de indústria alimentícia e o outro
aclimatado com efluente produzido sinteticamente. O reator biológico
experimental foi montado e operado de modo contínuo para simular as condições
encontradas nas indústrias. Os testes consistiram da medição da taxa de consumo
de oxigênio pelos micro-organismos durante 5 minutos. Os valores obtidos pelos
ensaios eram comparados de modo a entender o comportamento dos microorganismos
entre os contaminantes e os diferentes lodos ativados utilizados. O
lodo da indústria farmacêutica, por conter diversos compostos tóxicos, possui uma
maior adaptabilidade dos micro-organismos, apresentando maior resistência aos
compostos tóxicos introduzidos no teste; já o lodo ativado de uma indústria
alimentícia, por conter concentrações significativas de óleos e graxas, sugere que
haja bloqueio das células, apresentando comportamento similar ao da indústria
farmacêutica, indicando que compostos tóxicos e óleos e graxas atuam da mesma
forma na respiração do lodo ativado. O método respirométrico é eficaz para a
determinação de toxicidade em processos de lodos ativados; foi verificado,
também, que quando há descarga de compostos tóxicos e/ou óleos e graxas nas
ETEs, os micro-organismos tornam-se mais resistentes, dificultando a detecção da
presença do elemento intoxicante. / [en] The main aim of this work was to investigate the behaviour of industrial
wastewater activated sludges exposed to sudden contamination by copper ions,
phenol, surfactant and amoxicillin, in various concentrations, in order to attempt
to obtain a better understanding of the respiration changes of the sludge. Four sets
of assays were carried out with samples of sludge from: pharmaceutical industry;
two types of food industries; an, a synthetic effluent fed with microorganisms.
The contact period between the wastewater and microorganisms was about 15
minutes and the respiration time was 5 minutes. The experiments were conducted
and operated continuously in order to simulate real conditions found in industry.
All the samples were taken for respiration rate measuring. The values obtained
from the assays were used to study the microorganisms behavior by comparing
intoxicating compounds and all types of activated sludge tested. The sludge from
the pharmaceutical industry has higher adaptability to sudden contact with toxic
compounds, as the microorganisms in this type of sludge have normally acquired
resistance to many toxic compounds that are commonly present in this type of
effluent. However, the activated sludge from food industry, that has high
concentrations of oil and grease, presented a similar respiration behavior in
comparison to pharmaceutical industry sludge, leading to the conclusion that the
oil and grease promote cell blockage, preventing contact between food and
microorganisms, and causing respiration interferences. The respirometric method
was significantly tested and the result is that this technique promotes efficient
determination of activated sludge even under adapted activated sludge to toxic
compounds, by which measure become slightly rugged.
| Identifer | oai:union.ndltd.org:puc-rio.br/oai:MAXWELL.puc-rio.br:15510 |
| Date | 26 April 2010 |
| Creators | VICTOR SURERUS LEAL COSTA |
| Contributors | LUIZ ALBERTO CESAR TEIXEIRA |
| Publisher | MAXWELL |
| Source Sets | PUC Rio |
| Language | Portuguese |
| Detected Language | English |
| Type | TEXTO |
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