Municipal wastewater treatment targeting pharmaceuticals by a pilot-scale hybrid attached biofilm and activated sludge system (Hybas™)

Kai Tang, Gordon Tze Hoong Ooi, Elena Torresi, Kamilla Marie Speht Kaarsholm, Adam Hambly, Kim Sundmark, Sabine Lindholst, Christina Sund, Caroline Kragelund, Magnus Christensson, Kai Bester, Henrik Rasmus Andersen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review


A hybrid wastewater treatment process with combined attached biofilm (moving bed biofilm reactor) and activated sludge, named as Hybas™, was implemented for the treatment of municipal wastewater. The system consisted of six staged reactors in series including pre-denitrification and nitrification in the Hybas™ line and post-denitrification in a pure MBBR. In addition to the significant removal of nutrients and organic matter from municipal wastewater, Hybas™ also showed removal capacity for pharmaceuticals. Of particular interest was the enhanced removal for pharmaceuticals (i.e. X-ray contrast media) compared to other biological systems. Spiking experiments showed that the maximum removal rate constants (k, h−1) for 10 out of the 21 investigated pharmaceuticals (including diclofenac) were observed to occur within the two aerobic Hybas ™ reactors, operated in a flow-shifting mode that allows even biofilm growth of nitrifying bacteria. In total, 14 out of the 21 pharmaceuticals were removed by more than 50% during continuous flow operation in the all Hybas™ line and post-denitrification MBBR. The calculated and estimated removal contributions of pharmaceuticals by each individual reactor were also assessed.
Original languageEnglish
Article number127397
Publication statusPublished - 2020


  • MBBR
  • pharmaceuticals
  • HybasTM
  • wastewater
  • activated sludge

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