The transformation and toxicity of anthraquinone dyes during thermophilic (55°C) and mesophilic (30°C) anaerobic treatments
We studied in batch assays the transformation and toxicity of anthraquinone dyes during incubations with anaerobic granular sludge under mesophilic (30°C) and thermophilic (55°C) conditions. Additionally, the electron shuttling capacity of the redox mediator anthraquinone-2-sulfonic acid (AQS) and s...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | Brasil |
| Institución: | Universidade Federal do Ceará (UFC) |
| Repositorio: | Repositório Institucional da Universidade Federal do Ceará (UFC) |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.ufc.br:riufc/71744 |
| Acceso en línea: | http://www.repositorio.ufc.br/handle/riufc/71744 |
| Access Level: | acceso abierto |
| Palabra clave: | Anthraquinone dyes Colour removal Textile wastewater Anaerobic treatment Mesophilic Thermophilic Redox mediators Toxicity |
| Sumario: | We studied in batch assays the transformation and toxicity of anthraquinone dyes during incubations with anaerobic granular sludge under mesophilic (30°C) and thermophilic (55°C) conditions. Additionally, the electron shuttling capacity of the redox mediator anthraquinone-2-sulfonic acid (AQS) and subsequent increase on decolourisation rates was investigated on anthraquinone dyes. Compared with incubations at 30°C, serum bottles at 55°C presented distinctly higher decolourisation rates not only with an industrial wastewater containing anthraquinone dyes, but also with model compounds. Compared with batch assays at 30°C, the first-order rate constant “k” of the Reactive Blue 5 (RB5) was enhanced 11-fold and 6-fold for bottles at 55°C supplemented and free of AQS, respectively. However, the anthraquinone dye Reactive Blue 19 (RB19) demonstrated a very strong toxic effect on volatile fatty acids (VFA) degradation and methanogenesis at both 30°C and 55°C. The apparent inhibitory concentrations of RB19 exerting 50% reduction in methanogenic activity (IC50-value) were 55mgl−1 at 30°C and 45mgl−1 at 55°C. Further experiments at both temperatures revealed that RB19 was mainly toxic to methanogens, because the glucose oxidizers including acetogens, propionate-forming, butyrate-forming and ethanol-forming microorganisms were not affected by the dye toxicity. |
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