Sewage treatment in medical institutions mainly refers to the treatment of sewage discharged from hospitals, laboratories, wards, laundry rooms, X-ray photography rooms and operating rooms. The source and composition of sewage are very complex. In addition to a large number of bacteria, viruses, eggs and other pathogens, the sewage of medical institutions also contains chemical agents and radioisotopes, which has several characteristics of space pollution, acute infection and latent infection. If medical sewage containing pathogenic microorganisms is directly discharged into urban sewers without disinfection, inactivation and other harmless treatment, it will often cause water and soil pollution, and seriously cause various diseases.
Characteristics of sewage in medical institutions
(1) Complex sources: Sewage mainly comes from different departments of the hospital, including consultation rooms, laboratories, patient laundry rooms, X-ray printing, isotope therapy and diagnosis, operating rooms and domestic sewage, etc.
(2) High ammonia nitrogen content: In general, in addition to receiving and treating patients, hospitals also admit patients’ relatives and friends several times more than the number of patients. These groups use the hospital facilities more than toilets, so hospital sewage is more expensive than living Sewage has a higher ammonia nitrogen content, so treatment facilities need to have the ability to remove ammonia nitrogen.
(3) There are many types of pollutants. One of the main pollutants in hospital sewage is fecal coliforms, coliforms, infectious bacteria and viruses and other pathogenic microorganisms; the other is Ph, BOD, COD, SS, total mercury, oil, radioisotopes and other toxic and harmful pollutants. physicochemical pollutants.
(4) Hospital sewage has the characteristics of space pollution, acute infection and latent infection.
(5) Although the composition of hospital pollutants is complex, the concentration is low and the treatment technology is mature.
Processing technology
The principle of sewage treatment in medical institutions, on the one hand, considers the type and quantity of bacteria and viruses in sewage, on the other hand, it should also consider the physical and chemical indicators and toxicological indicators of sewage, and more importantly, it is necessary to consider the discharge direction of sewage and the impact of water bodies on water quality. requirements. In addition, in July 2005, the State Environmental Protection Administration approved a new standard for the discharge of medical institutions, which clearly stipulates that hospital sewage needs to undergo secondary treatment before disinfection, which can not only reduce the consumption of disinfectants, improve the disinfection effect, but also reduce Make the pollution factors in the sewage reach the standard discharge. The quality of hospital sewage is similar to domestic sewage, but it contains a large number of pathogenic bacteria, and this water has strong biodegradability. Therefore, biochemical methods are often used as the secondary treatment process for hospital sewage.
Biological treatment can remove dissolved and colloidal organic pollutants from wastewater. The BOD removal rate is above 90%, and the BOD in the effluent can be reduced to less than 30mg/L. At the same time, it can also remove organic pollutants such as COD, phenol and cyanide. Conventional secondary biological treatment has limited removal of nitrogen and phosphorus, and needs to be treated with improved secondary treatment technology or tertiary treatment technology. The technologies with denitrification and phosphorus removal functions include A/O method, A/A/O method, SBR method, AB method, contact oxidation method and biofilm method.
Summarize  
Sewage treatment in medical institutions requires disinfection and inactivation steps before discharge. Disinfection treatment methods include physical methods (ultraviolet rays) and chemical methods (ozone method and chlorination method, such as chlorine dioxide, sodium hypochlorite, liquid chlorine, etc.). If medical sewage containing pathogenic microorganisms is directly discharged into urban sewers without disinfection, inactivation and other harmless treatment, it will often cause water and soil pollution, and seriously cause various diseases.