Hospital wastewater is mainly generated by the hospital containing pathogens, heavy metals, disinfectants, organic solvents, acids, alkalis and radioactivity.
At the same time, sludge is generated, mainly from the sewage treatment process and septic tank sludge. Exhaust gas from the sewage treatment process.
Hospital departments with different functions, facilities and personnel composition, the main departments and facilities that produce sewage are: diagnostic and treatment rooms, laboratories, wards, laundries, X-ray photo printing, isotope therapy diagnosis, operating rooms and other drainage; hospital medical staff patients discharged living sewage, cafeteria, dormitories, family quarters drainage. Different sections of the sewage generated by the composition and volume of water are different, such as heavy metal wastewater, oily wastewater, printing wastewater, radioactive wastewater and so on. So the hospital sewage is relatively complex than the general sewage discharge: contains pathogenic microorganisms, toxic, harmful physical and chemical pollutants and radioactive pollution, with space pollution, acute infection and latent infection and other characteristics, without effective treatment will become an important pathway for the proliferation of epidemics and serious pollution of the environment.
Hospital sewage is contaminated by feces, infectious bacteria and viruses and other pathogenic microorganisms, infectious, can induce disease or cause injury.
Hospital sewage contains acid, alkali, suspended solids, BOD, COD and animal and vegetable oils and other toxic and harmful substances.
Dental treatment, scaling and laboratory processes produce sewage containing heavy metals, disinfectants, organic solvents, etc., some of which are carcinogenic, teratogenic or mutagenic, endangering human health and having a long-term impact on the environment.
Isotope therapy and diagnosis of radioactive wastewater. Radioisotopes produce a-, β-, and γ-radiation in the decay process, which is harmful to human health because it accumulates in the human body.
Hospital wastewater treatment is discharged into natural water bodies and municipal sewers discharged into the city sewage treatment plant two categories. Hospital wastewater treatment process must ensure that the treated water meets the standards, the three main processes used are: to strengthen the treatment effect of primary treatment, secondary treatment and A/O, A2/O and other biochemical treatment.
1, all hospitals must use secondary treatment, and the need for pre-disinfection sterilization treatment.
2, treated effluent discharged into the city sewers (downstream with a secondary sewage treatment plant) is recommended for general hospitals using secondary treatment, the need for primary treatment process must be strengthened to increase the effect of treatment. The primary enhanced treatment process hospital sewage through the septic tank into the regulating tank, regulating the front of the pool set up automatic grating, regulating the pool set up to enhance the water pump. Sewage after lifting into the coagulation sedimentation tank for coagulation and precipitation, sedimentation tank water into the contact pool for disinfection, contact pool water discharge standards. The sludge and slag of the regulating tank, the second sedimentation tank, the aerobic contact tank and other garbage generated in the sewage treatment station are centrally disinfected and transported out. Disinfection can be used pasteurized steam disinfection or lime and other ways
3, for small general hospitals, the conditions do not have the use of pre-treatment sterilization - biochemical system treatment - disinfection treatment process. Through coagulation and precipitation (filtration) ultraviolet sterilization and other methods to remove viruses, germs, particles, to improve the disinfection effect and reduce the amount of disinfectant in the later stage, thus avoiding the adverse effects of disinfectant overdose on the environment.
4, the first level of enhanced treatment to strengthen the treatment process for the treatment of effluent ultimately into the secondary treatment of municipal wastewater treatment plant of the general hospital, should be strengthened to improve the treatment effect, improve SS, COD and ammonia nitrogen removal rate, reduce the amount of disinfectant. Strengthen the effect of primary treatment should be realized through two ways: the existing primary treatment process to strengthen the removal effect of transformation and the use of primary enhanced treatment technology.
5, strengthen the treatment can carry viruses, bacteria particles removed, improve the subsequent deepening of the effect of disinfection and reduce the amount of disinfectant. One of the existing primary treatment process can be transformed to make full use of existing facilities,
Reduce investment costs
Hospital wastewater treatment process: domestic sewage directly into the pre-disinfection tank for disinfection and treatment into the regulating tank, the patient's feces into the septic tank after ultraviolet sterilization, wastewater tanks and then into the regulating tank, regulating the pool in front of the set of automatic grating, with lifting pumps, sewage by the After lifting into the ultraviolet sterilization into the anaerobic pool for anaerobic treatment, the effluent into the aerobic pool for biological nitrification of ammonia nitrogen, nitrification of the effluent into the flocculation pool for flocculation into the second sedimentation tank for mud-water separation, the effluent into the disinfection of sodium hypochlorite, so that the effluent discharge standards. Adjustment pool, biochemical treatment pool, contact pool sludge and slag and other waste generated in the sewage treatment station centralized disinfection and transported for incineration. Disinfection can be used pasteurized steam disinfection or adding lime and so on.
The radioactive wastewater needs to be treated by adding barium salt precipitation with milk of lime.
Process flow diagram