Assessment of a Ficus benjamina wood chip‐based aerated biofilter used for the removal of metformin and ciprofloxacin during domestic wastewater treatment

BACKGROUND Several studies have demonstrated that the pharmaceuticals detected in the influents and effluents of wastewater treatment plants (WWTPs) can cause endocrine disruption and bacterial resistance on different species, in an aquatic environment. Metformin (antidiabetic drug) and ciprofloxacin (antibiotic quinolones) are compounds found at higher concentrations than many other pharmaceuticals, and thus have a disproportionately large environmental impact. This study is focused on the assessment of an aerated biofilter packed with Ficus benjamina wood chips for the simultaneous removal of metformin, ciprofloxacin, organic matter expressed as chemical oxygen demand (COD) and ammoniacal nitrogen (NH3‐N) during domestic wastewater treatment, under different superficial hydraulic loading. RESULTS The maximum removals of metformin, ciprofloxacin, COD and NH3‐N from the wastewater treated in an aerated biofilter were 94, 81, 91 and 38%, respectively, by applying a superficial hydraulic loading of 0.18 m3 m–2 d–1 [hydraulic retention time (HRT) of 7 h]. The adsorption capacity of F. benjamina wood chips on the metformin and ciprofloxacin was 0.1 and 2.03 µg gsupport material–1, respectively. CONCLUSION The maximum removal rates for metformin, ciprofloxacin, COD and NH3‐N were obtained when the aerated biofilter was operated at HRT = 7 h. The F. benjamina wood chips showed sorption properties of pharmaceuticals. According to a scanning electron microscopy image, the F. benjamina wood chips showed available pores in their entire surface, thus indicating that this organic support medium has a high potential for carrying out the sorption processes. Likewise, the surface of the wood chips showed the development of a homogeneous biofilm. © 2019 Society of Chemical Industry