This study investigated diclofenac (DFC) removal in a vertical flow constructed wetland, in which manganese ores were used as substrates, and dissimilatory metal reducing bacteria (Geobactermetallireducens, GS-15) were added as inoculum. The results indicated that maximum average removal of DFC was 23.56% in this wetland. After analyzing the manganese ores by XRD and XRF before and after the experiments, Mn was identified as the key element participating DFC removal. The main DFC removal pathway in the wetland is the dissimilatory Mn(IV) reduction. In this process, DFC was degraded by GS-15using manganese ores as the electron acceptor. In addition, LC-MS/MS analysis was used to identify the degradation intermediates of DCF. Three intermediates are identified, namely 5-hydroxydiclofenac (5-OH-DCF), diclofenac-2, 5-iminoquinone (DCF-2, 5-IQ), and 1,3-dichlorobenzene (1,3-DCB). The results of this research provide new insight and theoretical guidance on the advanced technologies for pharmaceutical treatment in wastewater.
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