Operation of stirred tank reactors (STRs) and fixed-bed reactors (FBRs) with free and immobilized Phanerochaete chrysosporium for the continuous removal of pharmaceutical compounds

Stirred tank reactors (STRs) and fixed-bed reactors (FBRs) were applied for the removal of diclofenac, ibuprofen, naproxen, carbamazepine and diazepam by Phanerochaete chrysosporium. The operation of STRs with free pellets and immobilized fungus attained stable operation for 50 days. Both bioreactors achieved high removal efficiencies for diclofenac, ibuprofen and naproxen while partial removal of carbamazepine and diazepam. The configuration of the FBR maintained a steady and feasible operation for 100 days with complete removal of diclofenac, ibuprofen and naproxen regardless of the aeration system (air or oxygen) and remarkably high removal percentages of carbamazepine and diazepam: 60–90%. The extraction of the target compounds from the biomass and the support showed low residual concentrations of all the compounds both on fungal pellets and on the support of the FBR. Only significant values were detected in the STR with immobilized mycelium, demonstrating partial adsorption. A tentative identification of the degradation products of the three anti-inflammatories was performed, indicating the presence of 4-hydroxy-diclofenac, 1-hydroxy-ibuprofen-, 6-O-desmethyl-naproxen, as the major degradation products of the three parent compounds.

► Efficient removal of anti-inflammatory compounds in the STRs and FBRs.
► Significant removal of CBZ and DZP were found in both bioreactors.
► The operation of STRs and FBRs was stable for 50 and 100 days, respectively.
► Gas supply in FBRs diversely affected the degradation efficiency of DZP and CBZ.
► The major degradation products of DCF, IBP and NPX were identified.