The removal of ciprofloxacin (CIP) in sulfur-mediated bioprocesses, e.g., sulfate-reducing bacteria (SRB)-mediated process and sulfur-oxidizing bacteria (SOB)-mediated process, was examined for the first time. The results showed that the SRB-mediated process had more efficient CIP removal than that in SOB-mediated process. Adsorption was the primary removal pathway of CIP in SRB-mediated process and SOB-mediated process with the specific adsorption removal rate of 131.4±1.1 μg/g-SS/d and 30.1±1.4 μg/g-SS/d, respectively, at influent CIP concentration of 500 μg/L. In addition, extracellular polymeric substances (EPS) also played an important role on CIP migration and removal in both types of sludge. Further study was conducted to specify the different adsorption of CIP in these two sludge systems from the perspective of sludge properties. The results indicated that there are more potential adsorption sites exist on the SRB-mediated sludge for CIP adsorption than SOB-mediated sludge since the higher protein (PN) content and more kinds of aromatic amino acid substances in EPS, more negative zeta-potential and stronger and more numbers of functional groups in SRB-mediated sludge compared to SOB-mediated sludge. The findings of this study provide insights into the sludge properties affecting CIP removal in sulfur-mediated bioprocesses, and are of guiding significance to employ sulfur-mediated biological systems for treating CIP-containing wastewaters.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |