Review of advanced oxidation processes for treating hospital sewage to achieve decontamination and disinfection

Hospital sewage contains various harmful pharmaceutical contaminants (e.g., antibiotics, anti-inflammatory agents, and painkillers) and pathogens (e.g., bacteria, viruses, and parasites), whose direct discharge into the environment will induce diseases and pose a powerful threat to human health and safety, and environmental ecology. In recent years, advanced oxidation processes (AOPs), particularly photocatalysis, electrocatalysis, and ozone catalysis have been developed as widespread and effective techniques for hospital sewage treatments. However, there is a lack of systematic comparison and review of the prior studies on hospital sewage treatment using AOPs systems. This review elaborates on the mechanisms, removal efficiencies, and advantages/disadvantages of these AOPs systems for hospital wastewater decontamination and disinfection. Meanwhile, some novel and potential technologies such as photo-electrocatalysis, electro-peroxone, Fenton/Fenton-like, and piezoelectric catalysis are also included and summarized. Moreover, we further summarize and compare the capacity of these AOPs to treat the actual hospital wastewater under the impact of the water matrix and pH, and estimate the economic cost of these technologies for practical application. Finally, the future development directions of AOPs for hospital wastewater decontamination and disinfection have been prospected. Overall, this study provides a comparison and overview of these AOP systems in an attempt to raise extensive concerns about hospital wastewater decontamination and disinfection technologies and guide researchers to discover the future directions of technologies optimization, which would be a crucial step forward in the field of hospital sewage treatment.