Antibiotic pollution of the Yellow River in China and its relationship with dissolved organic matter: Distribution and Source identification

• Published in: Water research (Oxford) 2023-05, Vol.235, p.119867-119867, Article 119867
• Main Authors: Su, Zhaoxin, Wang, Kun, Yang, Fengchun, Zhuang, Tao
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - analysis; Antibiotics; aquatic environment; China; Dissolved Organic Matter; Erythromycin; fluorescence; Fluorescence dissolved organic matter (DOM); humification; Mainstream of the Yellow River; Parallel factor analysis (PARAFAC); pollution; quinolones; rivers; Sources; Spectrometry, Fluorescence; Sulfadoxine; Sulfamethoxazole; Sulfanilamide; Sulfonamides; wastewater treatment; water; watersheds; Yellow River
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2023.119867

•Most antibiotics pose insignificant risks in the Yellow River.•Different classes of antibiotics vary significantly in upstream and downstream.DOM can be used to indicate antibiotic pollution levels of the river.•Differential contribution of antibiotics to rivers from point and nonpoint sources.•SMX, SDX and ERY are mainly discharged from wastewater treatment plants. Understanding the sources of antibiotics is important for managing antibiotic contamination and preventing environmental risks in the aquatic environment. In this study, the distribution of dissolved organic matter (DOM) and 24 antibiotics from four typical classes (quinolones, macrolides, sulfonamides and tetracyclines) in the Yellow River basin containing distinct sources of pollution was investigated. In particular, relationships between the antibiotic concentrations and fluorescent properties of DOM were to be established to identify antibiotic sources. A total of 22 antibiotics were detected, with maximum concentrations ranging from 0.27 to 30.14 ng/L in the mainstream of the Yellow River. Of these antibiotics, only erythromycin (ERY) and sulfamethoxazole (SMX) posed potential risks to aquatic organisms. Spatially, tetracyclines were mainly distributed in the upstream reaches of the river, and quinolones were largely distributed in the midstream. High levels of sulfonamides were present downstream of the investigated river. Only EYR belonging to the macrolide group was detected and had a high downstream concentration. EEM-PARAFAC analysis showed that DOM was composed of visible fulvic acid-like fluorescence fraction (C1), ultraviolet fulvic acid-like fluorescence fraction (C2) and protein-like fraction (C3). Using Pearson correlation analysis, this study demonstrated a close relationship between DOM spectral parameters and antibiotic concentrations in the Yellow River basin. Specifically, r (C3, C2) was significantly and positively correlated with the concentrations of SMX, sulfadoxine (SDX), and ERY, while humification index (HIX) had an opposite relationship with these antibiotics. These results suggested that SMX, SDX and ERY were mainly discharged from wastewater treatment plants into the mainstream of the Yellow River. This work provides a powerful demonstration that DOM plays an important role in indicating the occurrence and sources of antibiotics in the aquatic environment. [Display omitted]