Effects of azo dye on simultaneous biological removal of azo dye and nutrients in wastewater.
R Soc Open Sci
; 5(8): 180795, 2018 Aug.
Article
en En
| MEDLINE
| ID: mdl-30225070
The potential disrupting effects of Azo dye on wastewater nutrients removal deserved more analysis. In this study, 15 days exposure experiments were conducted with alizarin yellow R (AYR) as a model dye to determine whether the dye caused adverse effects on biological removal of both the dye and nutrients in acclimated anaerobic-aerobic-anoxic sequencing batch reactors. The results showed that the AYR removal efficiency was, respectively, 85.7% and 66.8% at AYR concentrations of 50 and 200 mg l-1, while higher AYR inlet (400 mg l-1) might inactivate sludge. Lower removal of AYR at 200 mg l-1 of AYR was due to the insufficient support of electron donors in the anaerobic process. However, the decolorized by-products p-phenylenediamine and 5-aminosalicylic were completely decomposed in the following aerobic stage at both 50 and 200 mg l-1 of AYR concentrations. Compared with the absence of AYR, the presence of 200 mg l-1 of AYR decreased the total nitrogen removal efficiency from 82.4 to 41.1%, and chemical oxygen demand (COD) removal efficiency initially decreased to 68.1% and then returned to around 83.4% in the long-term exposure time. It was also found that the inhibition of AYR, nitrogen and COD removal induced by a higher concentration of AYR was due to the increased intracellular reactive oxygen species production, which caused the rise of oxidation-reduction potential value and decreased ammonia monooxygenase and nitrite oxidoreductase activities.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
R Soc Open Sci
Año:
2018
Tipo del documento:
Article
Pais de publicación:
Reino Unido