Biotreatment of sulfate-rich wastewater in an anaerobic/micro-aerobic bioreactor system.
Environ Technol
; 26(9): 993-1001, 2005 Sep.
Article
en En
| MEDLINE
| ID: mdl-16196408
ABSTRACT
The focus of this study was on sulfate-rich wastewater treatment in a novel anaerobic/micro-aerobic bioreactor system. The system was composed of an upward-flow anaerobic sludge blanket (UASB) reactor and a floated bed micro-aerobic reactor, which was packed with elastic porous carriers and was controlled in a situation of dissolved oxygen below 0.5 mg l(-1). The floated bed micro-aerobic reactor was developed for accumulating a higher amount of biomass in carriers with a short hydraulic retention time (HRT) for biological oxidation of hydrogen sulfide to elemental sulfur. During long-term steady state operation, experimental results showed that an average of 70 +/- 6% of sulfate was transformed to hydrogen sulfide in UASB reactor. Moreover, the overwhelming majority of sulfide was oxidized to elemental sulfur and sulfate in micro-aerobic reactor; and the recirculation of effluent to UASB reactor reduced effectively the degree of inhibition caused by sulfate-rich wastewater. In UASB reactor, chemical oxygen demand (COD) removal efficiency increased with COD loading, in contrast, the performance of sulfate removal decreased with the increase in sulfate loading in a range of 1.0-1.75 kg SO4(2-) m(-3) d(-1). In micro-aerobic reactor, sulfide was removed almost completely under the operation of HRT 2.8 h. Furthermore, experimental results of continuous operations revealed that oxidation-reduction potential (ORP) was an adequate parameter for controlling biological oxidation of sulfide. When ORP was regulated in a lower range of -250 to -300 mV, the amount of regenerated sulfate was reduced significantly in micro-aerobic reactor.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Sulfatos
/
Bacterias Anaerobias
/
Bacterias Aerobias
/
Eliminación de Residuos Líquidos
/
Reactores Biológicos
Idioma:
En
Revista:
Environ Technol
Asunto de la revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Año:
2005
Tipo del documento:
Article
País de afiliación:
Taiwán
Pais de publicación:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM