Occurrence and removal of antibiotics in a municipal wastewater reclamation plant in Beijing, China.

In this study, we investigated the occurrences and fates of eight quinolones (QNs), nine sulfonamides (SAs), and five macrolides (MCs) in a wastewater reclamation plant (WRP) in Beijing, China. Among all the 22 antibiotics considered, quinolones were the dominant antibiotics in all samples (4916ngL(-1) in influents, 1869ngL(-1) in secondary effluents, 123ngL(-1) in tertiary effluents, and 9200μgkg(-1) in sludge samples), followed by sulfonamides (2961ngL(-1) in influents, 1053ngL(-1) in secondary effluents, 25.9ngL(-1) in tertiary effluents, and 63.7μgkg(-1) in sludge samples) and macrolides (365ngL(-1) in influents, 353ngL(-1) in secondary effluents, 24.7ngL(-1) in tertiary effluents, and 32.7μgkg(-1) in sludge samples). The removal efficiencies of the target antibiotics were limited (-32 to 78%) in the conventional treatment. This study indicated that quinolones were mainly removed from the secondary clarifier, and sulfonamides were degraded in the oxic tank; while macrolides were considered as persistent during the conventional treatment. After the advance treatment, the target antibiotics could be effectively removed at high rates (85-100%), and the risks of antibiotic contamination significantly decreased. However, risk assessment showed that the risk of ofloxacin and erythromycin on organisms in recycled water needed further investigations.