Characteristics of draft tube gas–liquid–solid fluidized‐bed bioreactor with immobilized living cells for phenol degradation

Biological phenol degradation in a draft tube gas‐liquid‐solid fluidized bed (DTFB) bioreactor containing a mixed culture immobilized on spherical activated carbon particles was investigated. The characteristics of biofilms including the biofilm dry density and thickness, the volumetric oxygen mass transfer coefficient, and the phenol removal rates under different operating conditions in the DTFB were evaluated. A phenol degradation rate as high as 18 kg/m3‐day with an effluent phenol concentration less than 1 g/m3 was achieved, signifying the high treatment efficiency of using a DTFB.