Several chemical industries produce
wastewaters containing both,
ammonium and phenolic compounds. As an alternative to treat this kind of complex industrial
wastewaters, this study presents the simultaneous partial nitritation and
o-cresol biodegradation in a continuous airlift reactor using aerobic granular biomass. An aerobic granular sludge was developed in the airlift reactor for treating a high-strength
ammonium wastewater containing 950 ± 25 mg N-NH4(+) L(-1). Then, the airlift reactor was bioaugmented with a
p-nitrophenol-degrading activated sludge and
o-cresol was added progressively to the
ammonium feed to achieve 100 mg L(-1). The results showed that stable partial nitritation and full biodegradation of
o-cresol were simultaneously maintained obtaining a suitable effluent for a subsequent anammox reactor. Moreover, two
o-cresol shock-load events with concentrations of 300 and 1000 mg L(-1) were applied to assess the capabilities of the system. Despite these
shock load events, the partial nitritation process was kept stable and
o-cresol was totally biodegraded. Fluorescence in situ hybridization technique was used to identify the heterotrophic bacteria related to
o-cresol biodegradation and the
ammonia oxidising bacteria along the granules.