MBBR with ozone pretreatment hybrid has shown better performance
compared to stand-alone MBBR without any ozone
pretreatment. Stand-alone MBBR has reported removals of 18.3%
of acid-extractable fraction (AEF) and 34.8% of naphthenic acids
(NAs), while the ozonation combined MBBR process showed
higher removal of AEF (41.0%) and NAs (78.8%).