Overview of Medical Sewage in Hospital Sewage Treatment Equipment
I. Analysis of the occurrence of medical sewage
1. Washing phase wastewater treatment
The phase-washing wastewater mainly comes from radiographic photo printing, and the pollutants contained in it are mainly the developer, fixer and bleach. In addition, it also contains silver from the fixing solution, which can be retrieved. Silver recovery methods include electrolytic silver extraction and chemical deposition. Low-concentration silver-containing wastewater can also be treated by ion exchange and activated carbon adsorption.
2. Mercury-containing wastewater treatment Mercury-containing wastewater mainly comes from mercury used in various dental clinics and measuring instruments. The damage of mercury is extremely great. After entering the water body, it can be converted into organic mercury and enriched and concentrated by the food chain. Mercury-containing water treatment methods include iron filings, chemical deposition, activated carbon adsorption, and ion exchange.
3. Acid wastewater treatment Hospital acid wastewater mainly comes from inspection projects or chemical cleaning agents. Acidic wastewater corrodes the drainage pipe, hydrogen reacts with the metal, and when the concentration is high, it will release heat when it touches the water, and it will explode when it touches the salt. Acidic wastewater causes changes in the overall pH of the wastewater, and also causes and promotes changes in other chemicals. Sodium nitride and other materials can generate sodium azide (NaN3) under acidic conditions, cause explosion, and have strong toxicity. Neutralization treatment is often used for acidic water. Sodium hydroxide and lime are used as neutralizing agents to participate in the acidic wastewater through mixing to reach the intention.
4. Treatment of infectious virus wastewater Hospital sewage contains many pathogenic microorganisms, viruses and chemical agents. Virus wastewater with characteristics of space pollution, acute infection, and latent infection can be treated with disinfectants and ultraviolet light.
5. Other waste liquid wastewater treatment
The wastewater discharged from the hospital also contains many organic solvents, disinfectants, pesticides and other chemicals used in the hospital. Collection and treatment of toxic and hazardous waste water containing these special pollutants must be done and not discharged at will.
Second, the characteristics of medical sewage:
Hospital sewage contains some special pollutants, such as drugs, disinfectants, diagnostic agents, detergents, as well as COD, BOD5, ammonia nitrogen, SS, pathogenic microorganisms, parasite eggs and various viruses, such as roundworm eggs, hepatitis virus , Tuberculosis and dysentery. Compared with industrial wastewater and daily sewage, it has the characteristics of small amount of water and strong pollution. If left unchecked, it will inevitably pollute water sources and convey disease.
3. Discharge Specifications for Medical Sewage Treatment
According to analogous similar projects, biochemical treatment + disinfection treatment can be selected. The waste water is discharged after reaching the regular discharge specifications in Table 2 of the "Induction of Water Pollutant Discharge Limits of Medical Institutions and Other Medical Institutions" in Table 2 of GB18466-2005 "Water Pollution Discharge Specifications for Medical Institutions.
Selection of medical wastewater process
There are many organic impurities in hospital sewage, CODcr and BOD5 are both high, and the value of BOD5 / CODcr is greater than 0.4, and the biochemical function is better. Therefore, a biochemical-based process with disinfection should be selected. Due to the small amount of sewage water, hospital sewage treatment equipment was selected for biochemical equipment.