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Enhanced bioremoval of refractory compounds from dyeing wastewater using optimized sequential anaerobic/aerobic process
Bae, W.; Han, D.; Kim, E.; de Toledo, R. A.; Kwon, K. & Shim, H.
Abstract
The upflow anaerobic sludge blanket process
followed by the biological aerated filter process was
employed to improve the removal of color and recalcitrant
compounds from real dyeing wastewater. The highest
removal efficiency for color was observed in the anaerobic
process, at 8-h hydraulic retention time, seeded with the
sludge granule. In the subsequent aerobic process packed
with the microbe-immobilized polyethylene glycol media,
the removal efficiency for chemical oxygen demand
increased significantly to 75 %, regardless of the empty bed
contact time. The average influent non-biodegradable soluble
chemical oxygen demand was 517 mg/L, and the
average concentration in effluent from the anaerobic reactor
was 363 mg/L, suggesting the removal of some recalcitrant
matters together with the degradable ones. The average nonbiodegradable
soluble chemical oxygen demand in effluent
from the aerobic reactor was 87, 93, and 118 mg/L, with the
removal efficiency of 76, 74, and 67 %, at 24-, 12-, and 8-h
empty bed contact time, respectively. The combined anaerobic
sludge blanket and aerobic cell-entrapped process was
effective to remove the refractory compounds from real
dyeing wastewater as well as in reducing organic loading to
meet the effluent discharge limits. This integrated process is
considered an effective and economical treatment technology
for dyeing wastewater.
Keywords
Biological aerated filter; Color removal; Microbial immobilization; Recalcitrant compounds removal; Upflow anaerobic sludge blanket
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