Sewage classification
Based on the classification of hospitals, it is divided into infectious disease hospitals and general hospitals. Hospital sewage discharge after treatment is divided into two categories: discharged into natural water bodies and discharged into the city sewage treatment plant through municipal sewers.
Adoption of process
The three main processes used are: primary treatment to enhance the effectiveness of treatment, secondary treatment and simple biochemical treatment.
Selection principles
Hospital wastewater treatment process process selection principles are:
1, infectious disease hospitals must be used in the second level of treatment, and the need for pre-disinfection treatment.
2, treated effluent discharged into the natural water body of the county and county hospitals must use secondary treatment.
3, treated effluent discharged into the city sewers (downstream of the secondary sewage treatment plant) is recommended for general hospitals using secondary treatment, the use of primary treatment process must be strengthened treatment effect.
For economically underdeveloped areas of small general hospitals, the conditions do not have the use of simple biochemical treatment as a transitional treatment measures, and then gradually realize the secondary treatment or to strengthen the effect of primary treatment.
Wastewater process
Hospital wastewater treatment process: to strengthen the treatment effect of the primary treatment process for the treatment of effluent ultimately into the secondary treatment of municipal wastewater treatment plant of the hospital, need to strengthen the treatment effect of the SS removal rate, reduce the amount of disinfectant.
Process enhancement pathway
Enhancement of the primary treatment effect should be realized through two ways:
1, the existing primary treatment process to strengthen the removal effect of modification
2, the use of primary enhanced treatment technology.
The process for the general hospital (without infectious disease ward) sewage treatment can be used "pre-treatment → a strengthened treatment → disinfection" process.
Process Description
1, through the coagulation and precipitation (filtration) to remove viruses, germs, particles, improve the disinfection effect and reduce the amount of disinfectant, so as to avoid excessive disinfectant on the environment to produce adverse effects.
2, the first level of 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 is equipped with lifting pumps. After lifting, the sewage enters the coagulation and sedimentation tank for coagulation and sedimentation, and the water from the sedimentation tank enters the contact pool for disinfection, and the water from the contact pool meets the standard and is discharged.
3, regulating tank, coagulation and sedimentation tank, contact tank sludge and slag and other waste generated in the sewage treatment station centralized disinfection and transportation.
4, disinfection can be used pasteurized steam disinfection or adding lime and other ways.
Process features to strengthen the treatment effect of the first level of intensive treatment can improve the treatment effect, can carry viruses, germs particles removed, improve the effect of subsequent deepening disinfection and reduce the amount of disinfectant. Among them, the existing primary treatment process can be modified to make full use of existing facilities and reduce investment costs. Scope of application to strengthen the treatment effect of the first level of enhanced treatment is applicable to the treatment of effluent ultimately into the secondary treatment of municipal wastewater treatment plant for general hospitals.
Secondary treatment process
Process flow description
1, the second level of the treatment process for the "conditioning tank → biological oxidation → contact disinfection". Hospital sewage through the septic tank into the regulating tank. Automatic grating is set in front of the regulating tank. There is a lifting pump in the regulating tank, and the sewage enters the aerobic tank for biological treatment after lifting, and the effluent from the aerobic tank enters the contact pool for disinfection, and the effluent meets the standard and is discharged. 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 other methods.
2, secondary treatment process (non-infectious diseases and infectious diseases sewage): infectious diseases hospital sewage and fecal cheap collected separately.
a/Life sewage directly into the pre-sterilization pool for disinfection treatment into the regulating pool, the patient's feces should be disinfected independently first, through the sewers into the septic tank or separate treatment.
b/ Each structure shall be operated in an airtight environment, with ventilation through a unified ventilation system, and exhaust gases shall be discharged through disinfection.
c/Disinfection may be by ultraviolet light disinfection system.
Process characteristics
1, aerobic biochemical treatment unit to remove organic pollutants such as CODcr, BOD5, etc. Aerobic biochemical treatment can be selected from contact oxidation, activated sludge and high-efficiency aerobic treatment processes, such as membrane bioreactor, aerated biofilter and other processes
2, the use of high-efficiency aerobic treatment process with filtration function, can reduce the suspended air. aerobic treatment process, can reduce the concentration of suspended solids, conducive to subsequent disinfection.