Sequentially alternating pollutant scenarios of phenolic compounds in a continuous aerobic granular sludge reactor performing simultaneous partial nitritation and o-cresol biodegradation.

Abstract

Industrial wastewater treatment plants must operate properly during the transient-state conditions often found in the industrial production. This study presents the performance of simultaneous partial nitritation and o-cresol biodegradation in a continuous aerobic granular reactor under sequentially alternating pollutant (SAP) scenarios. Three SAP scenarios were imposed during the operation of the granular reactor. In each one, a secondary recalcitrant compound (either p-nitrophenol (PNP), phenol or 2-chlorophenol (2CP)) were added for a short period of time to the regular influent containing only ammonium and o-cresol. Partial nitritation and o-cresol biodegradation were not inhibited by the presence of PNP or phenol and both compounds were fully biodegraded. On the contrary, the presence of 2CP strongly inhibited both processes within 2days. However, the reactor was recovered in a few days. These findings demonstrate that treatment of complex industrial wastewaters with variable influent composition is feasible in a continuous aerobic granular reactor.