Overview of medical sewage from hospital sewage treatment equipment
1、 Analysis of medical sewage
1. Phase washing wastewater treatment
The waste water of phase washing mainly comes from the photo printing of radiology department. In addition, it also contains silver from the fixing solution, which can be used for recovery. Silver recovery methods include electrolytic silver extraction and chemical deposition. Low concentration silver containing wastewater can also be treated by ion exchange method and activated carbon adsorption method.
2. Mercury containing wastewater treatment mercury containing wastewater mainly comes from the mercury used in various dental clinics and measuring instruments. Mercury can be converted into organic mercury after entering the water body and concentrated in the food chain. The treatment methods of mercury containing water include iron filings reduction, chemical deposition, activated carbon adsorption and ion exchange.
3. Acid wastewater treatment hospital acidic wastewater mainly comes from inspection items or chemical cleaning agents. Acid waste water corrodes the drainage pipeline and reacts with metal to produce hydrogen. When the concentration is high, it releases heat by touching water and explodes when touching salt. Acid wastewater causes the change of pH value of wastewater and other chemical substances. Sodium nitride and other substances can form sodium azide (NaN3) under acidic conditions, which causes explosion and has strong toxicity. Neutralization treatment is often used for acidic water. Sodium hydroxide and lime are used as neutralizing agents, which are mixed into the acid wastewater to achieve the desired results.
4. Treatment of infectious virus wastewater hospital sewage contains a lot of pathogenic microorganisms, viruses and chemicals. With the characteristics of space pollution, acute infection and latent infection, virus wastewater can be treated by disinfectant and ultraviolet irradiation.
5. Other waste water treatment
The waste water discharged from the hospital also contains many organic solvents, disinfectants, insecticides and other chemicals used in the hospital. The toxic and harmful wastewater containing these special pollutants must be collected and treated well, and can not be discharged at will.
2、 Characteristics of medical sewage:
Hospital sewage contains some special pollutants, such as drugs, disinfectants, diagnostic agents, detergents, COD, BOD5, ammonia nitrogen, SS, pathogenic microorganisms, parasitic eggs and various viruses, such as Ascaris eggs, hepatitis virus, tuberculosis and dysentery bacteria. Compared with industrial wastewater and daily sewage, it has the characteristics of small water volume and strong pollution. If it is allowed to discharge, it will inevitably pollute the water source and transmit diseases.
3、 Discharge standard of medical sewage treatment
According to the analogy of similar projects, biochemical treatment + disinfection treatment can be selected. After being treated, the wastewater will be discharged after reaching the discharge standard specified in Table 2 of the discharge standard of water pollution for medical institutions (GB 18466-2005) and "summarizing the discharge limits of water pollutants for medical institutions and other medical institutions".
Selection of medical sewage process
There are many organic impurities in hospital sewage, CODcr and BOD5 are high, and the value of BOD5 / CODcr is more than 0.4, so the biochemical function is good. Therefore, it is better to choose biochemical treatment process with disinfection. Due to the small amount of sewage, biochemical equipment is selected as hospital sewage treatment equipment.