Formation and microbial community analysis of chloroanilines-degrading aerobic granules in the sequencing airlift bioreactor.
OBJECTIVE
This paper investigates a selection-based acclimation strategy for improving the performance and stability of aerobic granules at a high chloroanilines loading.


RESULTS
The experiments were conducted in a sequencing airlift bioreactor (SABR) to develop aerobic granules fed with chloroanilines (ClA). The evolution of aerobic granulation was monitored using image analysis and scanning electron microscopy, and PCR-DGGE analysis of microbial community was performed. The sludge granulation was apparently developed by decreased settling time and gradual increased ClA loading to 0.8 kg m(-3) day(-1). A steady-state performance of the granular SABR was reached at last, as evidenced by biomass concentration of 6.3 g l(-1) and constant ClA removal efficiency of 99.9%. The mature granules had a mean size of 1.55 mm, minimal settling velocity of 68.4 m h(-1), specific ClA degradation rate of 0.181 g gVSS(-1) day(-1). Phylogenetic analysis of aerobic ClA-degrading granules confirmed the dominance of beta-, gamma-Proteobacteria and Flavobacteria.


CONCLUSIONS
The chosen operating strategy involving step increase in ClA loading and enhancement of major selection pressures was successful in cultivating the aerobic ClA-degrading granules.


CONCLUSIONS
This research could be helpful for improving the stability of aerobic granules via optimizing operating conditions and developing economic feasible full-scale granular bioreactor.
Zhu
L
L
Department of Environmental Engineering, Zhejiang University, Hangzhou, China.
Xu
X
X
Luo
W
W
Cao
D
D
Yang
Y
Y
D000064:Acclimatization; D000332:Aerobiosis; D001420:Bacteria, Aerobic / Q000302:isolation & purification* / Q000502:physiology; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D002733:Chlorophenols / Q000378:metabolism*; D005240:Feasibility Studies; D007091:Image Processing, Computer-Assisted; D008855:Microscopy, Electron, Scanning; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D002733:Chlorophenols; D014874:Water Pollutants, Chemical