Analysis on Pollution Characteristics and Ecological Risk Assessment of Pharmaceuticals and Personal Care Products (PPCPs) in Rural Domestic Sewage in Typical Areas of North China

The rapid economic growth and enhancement of living standards in rural areas of China have led to the widespread presence of emerging contaminants (ECs), particularly pharmaceuticals and personal care products (PPCPs), in these areas. To assess the pollution status of emerging contaminants in domestic wastewater in rural areas, liquid chromatography-mass spectrometry (LC-MS/MS) was employed to analyze the characteristics of PPCPs in the influent and effluent of wastewater treatment stations across five representative rural areas in North China. The findings reveal the detection of 16 PPCPs in both the influent and effluent of wastewater treatment stations, with concentrations ranging from non-detectable levels to 226 ng·L^-1. Among them, lincomycin (LIN), aspirin (ASA), DEET and caffeine (CAF) were consistently identified in all water samples. The three PPCPs exhibiting the highest concentrations in the influent were caffeine (CAF), norfloxacin (NOR) and acetaminophen (ACT). A comparative analysis of the influent PPCP concentrations across the five rural areas indicat that the source type of wastewater and the methods employed for the collection of black and gray water were significant influencing factors. Compared with urban and rural wastewater in other regions at home and abroad, the overall concentration range of PPCPs in rural domestic wastewater in the five typical areas of this study is approximately one-tenth of that in urban wastewater. However, the concentrations of certain contaminants, such as roxithromycin (ROX) and norfloxacin (NOR), were found to exceed those observed in some urban wastewater. The ecological risk of emerging contaminants in the effluent water from the waste water treatment stations was evaluated by the risk quotient (RQs) method. Ofloxacin (OFL), norfloxacin (NOR) and aspirin (ASA) were classified as high-risk emerging contaminants, while acetaminophen (ACT) was categorized as medium-risk. The remaining emerging contaminants were assessed as low risk or non-risk. Consequently, there is a pressing need for increased attention to the presence of emerging contaminants such as PPCPs in rural domestic wastewater.