Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: Enhanced removal of aromatic amines

► Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. ► More than 65% of the dye total metabolites was completely mineralized. ► Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. ► Inhibition of biofilm growth was increased with increasing the initial dye concentration. ► Considerable porous morphology was observed in the SEM photographs of the biofilm.