Notice of RetractionFormation and Properties of Aerobic Granular Sludge in a Continuous Airlift Fluidized Bed

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE´s Publication Principles.

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Formation and properties of the aerobic granular sludge were studied in a continuous airlift fluidized bed (CAFB). Sheer stress, exerted on sludge surface and caused by liquid flow, played a key role on aggregation of sludge to accelerate the formation of granular due to continuous operation and complete mix flow pattern, compared to the conventional sequence batch reactor (SBR). The results showed that large amount of aerobic granular sludge formatted in 4 to 5 days running with average diameter of 800-1000 μm and plenty biofacies. COD removal efficiency maintained around 93% to 97%, even though organic loading up to 13 kg COD·m^-3·d^-1 was carried out in the CAFB. However, high COD removal efficiency resulted in low COD concentration (30-80 mg·L^-1) in the CAFB, and multiplication of tricho-bacteria, led to granular loss and decrease of MLSS. Therefore, the CAFB was appropriate for relatively high organic loading.