The wastewater mainly comes from the photo printing of radiology department, and the pollutants contained in it are mainly developer, fixer and bleach. In addition, it also contains silver from fixing solution, which can be recycled. Silver recovery methods include electrolytic silver extraction and chemical precipitation, and low-concentration silver-containing wastewater can also be treated by ion exchange and activated carbon adsorption.
2. Mercury-containing wastewater treatment
Wastewater containing mercury mainly comes from mercury used in various dental clinics and measuring instruments. Mercury is extremely harmful, which can be converted into organic mercury after entering the water body and enriched and concentrated through the food chain. The treatment methods of mercury-containing wastewater include iron filings reduction, chemical precipitation, activated carbon adsorption and ion exchange.
3. Acidic wastewater treatment
Hospital acid wastewater mainly comes from inspection items or chemical cleaning agents. Acidic wastewater corrodes drainage pipes and reacts with metals to produce hydrogen. When the concentration is high, it releases heat when it meets water and explodes when it meets salt. Acidic wastewater causes the change of pH value of wastewater as a whole, and also causes and promotes the change of other chemicals. Sodium nitride and other substances can generate sodium azide (NaN3) under acidic conditions, which causes explosion and is highly toxic. Neutralization is often used to treat acidic wastewater. Sodium hydroxide and lime, as neutralizers, are added to acidic wastewater and stirred to achieve the goal.
4. Treatment of infectious virus wastewater
Hospital sewage contains a large number of pathogenic microorganisms, viruses and chemicals. It has the characteristics of space pollution, acute infection and latent infection. Virus wastewater can be treated with disinfectant and ultraviolet radiation.
5. Other waste liquid and wastewater treatment
The wastewater discharged from hospitals also contains organic solvents, disinfectants, pesticides and other chemicals widely used in hospitals. Toxic and harmful wastewater containing these special pollutants must be collected and treated well and cannot be discharged at will.