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.

Transmission routes of 2019-nCoV and controls in dental practise

A novel beta-coronavirus (2019, nCoV) caused severe and even fatal pneumonia explored in a seafood market of Wuhan city, Hubei province China, and rapidly spread to other province China and other countries. The 2019-nCoV was different Iron SARS-CoV, but shared the same host receptor the human angiotensin-converting enzymes 2 (ACE2). The natural last of 2019-nCOv may be the bat Rhinolophus affinis as 2019-nCoV stoned 96.2% of whole-genome identity to BatCoV RagTG13. The person to person-person transmission routes of 2019-nCoV included direct transmission, such as cough, sneeze. droplet inhalation transmission, and contact transmission, such as the contact with oral, nasal, and eye mucous membranes, 2019-nCoV can also be transmitted through the Saliva, and the fecal-oral routes may also be a potential person-to-person transmission route The participants in dental practice expose to tremendous risk of 2019-nCov infection due to the face-to-face communication and the exposure to saliva, blood, and Other body fluids, and the handling of sharp instrument. Dental professional play great roles in preventing the transmission of 2019-nCoV. Here we recommend the infection control measures during dental practice to block the person-to-person transmission routes in dental clinics and hospitals.