Zijun Dong,Zhihao Han,Lulu Zhang,Xiaohui Sun,Chenyu Wang,Yifeng Yang
The pervasive use of antiviral drugs (ATVs) for treating viral infections (e.g., HIV, hepatitis, and influenza) has led to their widespread detection in aquatic environments. However, their incomplete removal in wastewater treatment plants (WWTPs) and associated ecological risks remain poorly quantified, particularly in megacities with high population density and medical facility density post-COVID-19. This study analyzed influent, effluent, and process-unit samples from 16 WWTPs and surface water samples from two major river basins via UPLC–ESI–MS/MS to systematically evaluate the occurrence, removal dynamics, and ecological risks of eight priority ATVs. Ecological risk quotients (RQs) were calculated using measured environmental concentrations (MECs) and predicted no-effect concentrations (PNECs) for aquatic organisms. Acyclovir (ACV) was ubiquitously detected in all WWTPs (197–21,334 ng/L) and rivers (139–431 ng/L), with WWTP removal rates varying drastically by process (15.6–99.9%). Oseltamivir (OS) dominated influents (18,251–21,334 ng/L) but was absent in surface waters, suggesting rapid environmental transformation. Risk assessment identified high-risk RQs (>1) for ACV and OS in effluents, threatening algae and fish. Hybrid processes (e.g., A2O+MBR) outperformed single-stage systems, yet overall ATV removal remained suboptimal (avg. 48.6%). This work underscores the urgent need for process optimization and regulatory frameworks to mitigate ATV-driven ecological hazards.
Dissolved black carbon (DBC) plays a critical role in the photochemical transformation of emerging contaminants in aquatic systems. However, the source-dependent molecular composition of DBC and its mechanistic influence on contaminant photodegradation remain poorly understood. Here, we characterize the optical properties and molecular structure of DBC derived from five crop straws and evaluate their effects on the photodegradation of antiviral drug abacavir. Results demonstrate that light absorption capacity of five DBC follows the order: DBC rice >DBC peanut >DBC sorghum >DBC wheat >DBC bamboo (DBC X , where X = crop straw). DBC rice is characterized by low molecular weight, high nitrogen content, and lignin-like components, with unsaturation provided by the carbon backbone. In contrast, DBC bamboo exhibits strong reducibility, high sulfur content, and protein-like constituents, where unsaturation is attributed to oxygen-containing functional groups. The distinct molecular composition and structure of DBC rice lead to a higher steady-state concentration of reactive intermediates than DBC bamboo , which accounts for the enhanced photodegradation rates of abacavir. The abacavir is easily transformed via photolysis in waters due to the presence of cyclopropyl and amino functional groups, and reaction pathways mainly involves with hydroxylation, oxidation, hydrogen abstraction, and C-N bond cleavage. This study highlights the critical role of source-specific molecular composition in dictating the photochemical activity of DBC, which is essential for accurately predicting the environmental fate of antiviral drugs in sunlit waters.
Wang Bin,Chen Yanfen,Wu Yuanya,Weng Bo,Liu Yingshuai,Li Chang Ming
Nitrogen- and iron-containing carbon dots (N,Fe-CDs) are synthesized by hydrothermal treatment of branched polyethylenimine (BPEI) and hemin at 180 °C. The N,Fe-CDs are mainly doped with nitrogen and trace amounts of iron(III). The N,Fe-CDs also display intrinsic fluorescence with excitation/emission maxima at 365/452 nm and a quantum yield of 27 %. The nanodots are shown to act as peroxidase mimics by catalyzing the oxidation of tetramethylbenzidine (TMB) by hydrogen peroxide to form a blue product whose quantity can be determined by photometry at 652 nm. This was exploited to design colorimetric and fluorometric assays for dopamine (DA). The colorimetric assay is based on the oxidation of DA by H 2 O 2 in presence of the N,Fe-CDs and TMB. It has an instrumental detection limit of 40 nM (at an S/N ratio of 3), and a visual detection limit of 0.4 μM. The fluorometric assay is based on an inner filter effect that is caused by the formation of oxidized TMB which overlaps (and absorbs) the emission of the N,Fe-CDs located at 452 nm. The fluorometric detection limit is as low as 20 nM (at an S/N ratio of 3).
Carbon dots containing nitrogen and iron (N,Fe-CDs) were synthesized by hydrothermal treatment of branched polyethylenimine and hemin. The N,Fe-CDs display excellent fluorescent properties, peroxidase-like activity and potential application in colorimetric and fluorometric detection of dopamine.
危险品化学品经营许可证（带存储）