In this study, solid phase extraction (SPE) coupled with high-performance liquid chromatography-tandem triple quadrupole mass spectrometry (HPLC-MS/MS) was used to track the contamination of 17 benzodiazepines, 14 acidic pharmaceuticals, and 5 neutral pharmaceuticals in 4 hospital wastewater treatment systems and 3 municipal wastewater treatment plants in Guangzhou, Guangdong Province. The results showed that a total of 10 benzodiazepines, 8 acidic, and 3 neutral pharmaceuticals were detected in the hospital wastewater treatment systems with concentrations in the ranges of 0.41-23376 ng·L-1 and 0.11-22888 ng·L-1 in the influents and effluents, respectively; The 8 benzodiazepines, 8 acidic, and 4 neutral pharmaceuticals were detected in the municipal wastewater treatment plants with concentrations in the ranges of 0.4-1695 ng·L-1 (influents) and 0.1-1526 ng·L-1 (effluents). Among them, high levels of benzodiazepine compounds including lorazepam[(53.1±2.7) ng·L-1, H1], oxazepam[(39.5±4.1) ng·L-1, W2] and clozapine[(30.6±4.0) ng·L-1, W1] were detected. Ibuprofen[(19014±5430) ng·L-1, H1] and paracetamol[(2600±570) ng·L-1, H2] were found to have the highest concentrations for the acidic and neutral pharmaceuticals, respectively. Less than 30% of benzodiazepines were removed in hospital wastewater treatment systems and municipal wastewater treatment plants; however, acidic and neutral pharmaceuticals had higher removal rates. The municipal wastewater treatment plants had greater performance in the removal of acidic and neutral pharmaceuticals (mostly 60%-99%) than the hospital wastewater treatment systems (mostly 10%-60%). Finally, the usage and pollution emissions of 20 typical pharmaceuticals in Guangzhou and Guangdong Province were calculated based on the average emission per person. The total amount of usage in Guangzhou and Guangdong was 3942 kg·a-1 and 30371 kg·a-1, respectively. Paracetamol and ibuprofen had the greatest values, as did oxazepam and lorazepam benzodiazepines. The emission rate of these 20 pharmaceuticals in Guangzhou reached 1456 g·a-1 with concentrations ranging from 3.07 (mefenamic acid) to 378 g·a-1 (oxazepam).
Keywords: hospital wastewater; pharmaceuticals; removal; usage and emission amount; wastewater treatment plants.