Application of a Moving Bed Biofilm Reactor in Removal of Ciprofloxacin From Real Hospital Effluent: Effect of Operational Conditions

Abstract

The presence of pharmaceutical wastewater containing antibiotic compound is one of the new problems relating to the environmental pollution. Antibiotic ciprofloxacin (CIP), widely used in medical treatments, can induce antibiotic resistance in low concentrations in the ecosystem and aqueous solutions. In this study, CIP was removed using moving bed biofilm reactor (MBBR) from real hospital-derived wastewater. This study was carried out at Beasat hospital in Hamadan, Iran. CIP (100 mL) was applied in 2 sets of plexiglass tubular columns as MBBR. Microorganisms were grown on the suspended carriers. To achieve this purpose, polyethylene kaldnes (K1) was chosen as reactor bed in 500 m2 /m3 specific area. The effect of operating parameters such as mixed liquor suspended solid (MLSS) (100, 1000, 3000 mg/L), hydraulic retention time (HRT) (8, 12, 24 hours), and support media with carrier K1 (30%, 50%, 70%) were evaluated. According to the results, the yield of CIP removal at 30%, 50%, and 70% of K1, reaction of 24 hours at MLSS 3000 mg/L was obtained 50.5%, 68.9%, and 97.6% respectively. In the same conditions, chemical oxygen demand (COD) removal was achieved 26.78%, 30.49%, and 80.07%, respectively. Results indicated that the MBBR process can be used as an effective approach for removing CIP and COD from hospital effluent. Moreover, these data suggested that the K1 carrier could be useful in terms of mineralization and efficiency. Furthermore, development of biofilm in MBBR was mostly affected by K1.