Evaluation of integrated anaerobic/aerobic fixed-bed sequencing batch biofilm reactor for decolorization and biodegradation of azo dye Acid Red 18: Comparison of using two types of packing media

► Comparison of pumice stones and polyethylene media as biofilm support was performed. ► First-order decolorization kinetics with respect to dye concentration was observed. ► Detection and quantification of the dye metabolites by HPLC analysis were conducted. ► SEM analysis was used to investigate the attached-growth biofilm morphology. ► More than 92% of COD, 96% of dye and 63% of 1-naphthylamine-4-sulfonate was removed.