Pollution Characteristics and Ecological Risks of Bisphenol Compounds in Guangzhou Section of the Pearl River, River Swell and Pipeline Runoff

In order to investigate the pollution status, sources, and ecological risk of bisphenol compounds (BPs) in the Guangzhou section of the Pearl River before and after rainfall events, high-performance liquid chromatography and mass spectrometry were employed to analyze stormwater runoff from the Guangzhou section of the Pearl River as well as some surrounding pipes. The results revealed that 13 out of 14 types of BPs were detected before rainfall, while 12 types were detected after rainfall. The total concentrations of BPs ranged from 85.7 to 820 ng/L before rainfall and from 45.8 to 561 ng/L after rainfall. Rainfall exhibited a certain dilution effect on BPs concentrations. Bisphenol A (BPA) and bisphenol F (BPF) had detection rates of 100%, with average concentrations of 124 ng/L and 62.1 ng/L before rain, respectively, and concentrations of 85.4 ng/L and 29.3 ng/L after rain, respectively. The total concentration of BPs in stormwater runoff varied across different functional areas, with the highest level observed in the industrial area (2 950 ng/L), followed by the residential area (1 120 ng/L) and the cultural and educational area (980 ng/L). Notably, there was a significant disparity in BPA concentration between the cultural and educational areas (P<0.001). In the post-flood season (July-September), the discharge of BPs from piped stormwater runoff was 0.443 kg each month in cultural and educational areas, 2.58 kg each month in industrial areas, and 0.837 kg each month in residential areas, respectively. Meanwhile, the discharge of BPs in the Guangzhou section of the Pearl River reached 279 kg each month, which indicates that piped stormwater runoff is one of the major potential sources of BPs in receiving streams. The results of the ecological risk assessment indicated that BPs in the main stream of the Guangzhou section of the Pearl River were classified as low-risk, while their impact on the water environment in pipeline stormwater runoff was more significant, reaching a medium level of risk.