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 (4916 ng L-1 in influents, 1869 ng L-1 in secondary effluents, 123 ng L-1 in tertiary effluents, and 9200 mu g kg(-1) in sludge samples), followed by sulfonamides (2961 ng L-1 in influents, 1053 ng L-1 in secondary effluents, 25.9 ng L-1 in tertiary effluents, and 63.7 mu g kg(-1) sludge samples) and macrolides (365 ng L-1 in influents, 353 ng L-1 in secondary effluents, 24.7 ng L-1 in tertiary effluents, and 32.7 mu g kg(-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. (c) 2013 Elsevier Ltd. All rights reserved.