Emerging contaminants in hospital wastewater: A critical review of characteristics, fate, risks, and treatment

Hospital wastewater (HWW) represents a critical source of environmental and public health concerns, particularly in the post-epidemic era marked by frequent infectious disease outbreaks. This review offers a comprehensive overview of the characteristics, fate, risks, and remediation strategies of emerging contaminants (ECs) in HWW. The characteristics and properties of typical ECs reported in HWW are systematically analyzed. Six major classes of pharmaceuticals and ten classes of antibiotics have been detected. Statistical analysis reveals that iodinated contrast media (ICMs) are detected at the highest concentrations (up to 1050 μg/L), whereas antibiotics show the highest detection frequencies. The occurrence of last-resort antibiotic resistance genes (LARGs) in HWW has also been frequently reported. Analysis of environmental fate shows that ECs are probably transformed via photolysis, hydrolysis, biotransformation, adsorption, and deposition. Ecotoxicological risk assessment indicates that the LC 50 for sensitive organisms occurs at HWW proportions of only 0.508%–6.1% (v/v) over exposure durations of 12–96 h. Particularly, the effectiveness of advanced oxidation processes (AOPs) is evaluated in real HWW treatment. The removal rates of COD, TOC, NH 3 -N, ARGs, and ECs (where reported) across electrochemical AOPs, photochemical AOPs, ozonation, and persulfate activation are statistically analyzed. Moreover, the performance, advantages, and limitations of various AOPs are critically compared to guide tailored HWW management. Pilot-scale devices have also been evaluated for real HWW treatment, demonstrating considerable promise for practical application. This review is expected to serve as a valuable reference for academic researchers and practicing engineers engaged in HWW treatment and environmental risk control.