Degradation of phenolics, nitrogen-heterocyclics and polynuclear aromatic hydrocarbons in a rotating biological contactor

► Exiguobacterium aurantiacum on RBC discs facilitated treatment of biomass gasifier wastewater. ► COD reduction was 90-93% at pseudo steady state at HRT of 24 h or higher. ► Removal of phenol and PAHs was 93% and 85-90%, respectively, at 24 h HRT. ► Nitrogen-heterocyclics and benzene were completely degraded at HRT of 24 h. ► Batch abiotic studies revealed 4.5-21% loss for various components after 24 h.