Treatment of hospital wastewater by electron beam technology: Removal of COD, pathogenic bacteria and viruses.

The effective treatment of hospital sewage is crucial to human health and eco-environment, especially during the pandemic of COVID-19. In this study, a demonstration project of actual hospital sewage using electron beam technology was established as advanced treatment process during the outbreak of COVID-19 pandemic in Hubei, China in July 2020. The results indicated that electron beam radiation could effectively remove COD, pathogenic bacteria and viruses in hospital sewage. The continuous monitoring date showed that the effluent COD concentration after electron beam treatment was stably below 30 mg/L, and the concentration of fecal Escherichia coli was below 50 MPN/L, when the absorbed dose was 4 kGy. Electron beam radiation was also an effective method for inactivating viruses. Compared to the inactivation of fecal Escherichia coli, higher absorbed dose was required for the inactivation of virus. Absorbed dose had different effect on the removal of virus. When the absorbed dose ranged from 30 to 50 kGy, Hepatitis A virus (HAV) and Astrovirus (ASV) could be completely removed by electron beam treatment. For Rotavirus (RV) and Enterovirus (EV) virus, the removal efficiency firstly increased and then decreased. The maximum removal efficiency of RV and EV was 98.90% and 88.49%, respectively. For the Norovirus (NVLII) virus, the maximum removal efficiency was 81.58%. This study firstly reported the performance of electron beam in the removal of COD, fecal Escherichia coli and virus in the actual hospital sewage, which would provide useful information for the application of electron beam technology in the treatment of hospital sewage.

COVID-19-inspired "artificial virus" to combat drug-resistant bacteria by membrane-intercalation- photothermal-photodynamic multistage effects.

COVID-19 threatens human life because of the super destructiveness produced from its coronal morphology and strong transmembrane infection based on spike glycoprotein. Inspired by the coronal morphology of COVID-19 and its means of infecting, we designed an "artificial virus" with coronal morphology based on the concept of "defeating superbacteria with superviruses" by self-assembling a transacting activator of transduction peptide with triple-shell porous graphitic carbon nitride (g-C3N4) embedded with cobalt nanoparticles to forcefully infect methicillin-resistant Staphylococcus aureus (MRSA). The results confirmed that this "artificial virus" had unique properties of crossing the bacterial cell membrane barrier, heating the internal bacterial microenvironment and triggering ROS outbreak, based on its coronal morphology, membrane penetration, temperature-rising and heat insulation, oxidase-like activity and excellent visible-light harvesting properties. It had a high sterilization efficiency of 99.99% at 20 min, which was 18.6 times that of g-C3N4, and the efficiency remained at 99.99% after 3 rounds of recycling and reuse. Additionally, it can rapidly inactivate bacteria in river water and accelerate wound healing.