Sulfonamide and quinolone antibiotics contaminated wastewater treatment by constructed rapid infiltration: efficiency and microbial community structure

Four antibiotics common in wastewater, namely sulfadiazine (SD), sulfamethoxazole (SMX), ciprofloxacin (CIP), and norfloxacin (NOR), were used in the treatment of wastewater by constructed rapid infiltration (CRI), using coke as filler material. Results showed that the removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH3-N) and the total phosphorus (TP) of the sulfonamide antibiotics infiltration column reached 75.01%, 40.79% and 91.22%, respectively, which were 6.61%, 12.13% and 2.68% lower than those of the quinolone antibiotics infiltration column. With increasing antibiotic concentration (2–10 mg/L), the removal of SD showed a downward trend. The average removal rates of CIP and NOR by the CRI reached 34.65% and 43.57%, respectively. Oxygen-containing functional groups of the coke played a positive role in the removal of antibiotics. The dehydrogenase (DH) activity in the sulfonamide infiltration column was 0.62 μg/(g·mL), which was 0.48 μg/(g·mL) lower than that of the quinolone infiltration column. Meanwhile, the activity of phosphatase (AKP) in the sulfonamide infiltration column was 0.06 mg/(g·h), 0.30 mg/(g·h) lower compared to that of the quinolone infiltration column. Microbial community was dominated by Actinomycetes (38.52–55.93%) at the phylum level and by Arthrobacter (34.00–49.20%) at the genus level, especially in the sulfonamide infiltration column. Based on Kyoto Encyclopedia of Genes and Genomes (KEGG) functional analysis, carbohydrate (10.79–11.52%) and amino acid metabolism (10.79–11.27%) were the main bacterial pathways. Overall, sulfonamide antibiotics more negative impacted wastewater treatment by the CRI than quinolone antibiotics. [Display omitted]