Effect of fluoxetine on enhanced biological phosphorus removal using a sequencing batch reactor

In this work, the potential impact of emerging pollutant Fluoxetine (FLX) on enhanced biological phosphorus removal (EBPR) was systematically investigated using the sequencing batch reactor. The experimental results showed that even 200 μg/L FLX had no significant effect on EBPR during the short-term exposure. However, in the long-term exposure test, high dosage of FLX inhibited EBPR. 200 μg/L FLX induced biological phosphorus removal efficiency dropped to 71.3 ± 2.1%, significantly lower than that of the blank. The mechanism investigation showed that high concentration of FLX reduced anaerobic phosphorus release and oxic phosphorus absorption, and the consumption of organic matter during the anaerobic period. In addition, FLX decreased the synthesis of intracellular polymer polyhydroxyalkanoates (PHA), but promoted the metabolism of glycogen and polyhydroxyvalerate. FLX reduced the activity of key enzymes in EBPR and the relative abundance of Accumulibacter, but improved the relative abundance of Candidatus Competibacter.