1 The principle of whole process control. Control the whole process of hospital wastewater generation, treatment and discharge.
2 principle of reduction. Strict hospital internal health and safety management system, strict control and separation of sewage and dirt at the source of occurrence, living sewage in the hospital and sewage in the hospital area are collected separately, that is, source control, clean and sewage diversion. It is strictly prohibited to dispose of hospital sewage and dirt into the sewers at will.
3 local treatment principle. In order to prevent pollution and hazards in the hospital sewage conveyance process, in the hospital must be treated locally.
4 classification guidance principle. According to the nature of the hospital, scale, sewage discharge destination and regional differences in hospital sewage treatment classification guide.
5 standards and risk control principle. Comprehensive consideration of general hospitals and infectious disease hospitals to meet the basic requirements of sewage discharge, while strengthening the awareness of risk control, process technology, engineering construction and supervision and management to improve the ability to deal with unexpected events.
6 ecological safety principle. Effective removal of toxic and hazardous substances in sewage, reduce the production of disinfection by-products in the treatment process and control of excessive residual chlorine in the effluent, to protect the safety of the ecological environment. The secondary biochemical treatment process for hospital sewage treatment are: activated sludge method, biofilm method and so on. Medical sewage how to deal with the effect is better, need to choose different treatment processes according to the treatment objectives, the following we introduce several different treatment processes:
Grid well
The sewage contains a large number of large suspended and floating matter, the role of the grille is to intercept and remove the above substances, the pump and subsequent treatment unit to play a role in the protection. Grating well is located in the lift well directly above, using steel concrete structure and regulating pool built into one, above the grating well built a grating room, to prevent the slag spread virus, in order to harmonize the surrounding environment, can be outside the grating well for landscaping treatment. Operators can regularly disinfect, clean and transport the slag, as medical waste incineration. In order to reduce the operator's labor intensity, and improve the working environment, to ensure that the effect of sewage slagging, grating well set up a mechanical grating and a basket grating. Mechanical grille and basket grille made of stainless steel, corrosion-resistant, mechanical grille automatically clean slag from sewage, easy to manage, less failure, low maintenance rate.
Lifting well
Improve the water level, improve the utilization rate of regulating pool, reduce the amount of land excavation, less investment. The lifting well adopts underground closed steel concrete structure, which is built together with other treatment units to save infrastructure investment, and the top of the pool is covered with soil. For the convenience of inspection and maintenance, there are inspection holes at the corners of the lifting well, so that the lifting well can be maintained regularly.
Regulation pool
Regulation of sewage water quality and quantity. Adopting underground closed steel concrete structure, the regulating pool is built together with other treatment units to save infrastructure investment, the top of the pool is covered with soil, and for the convenience of inspection and maintenance, there are inspection holes at the corners of the regulating pool, which can be regularly maintained; the regulating pool is equipped with a submersible mixer, which can be regularly stirred to prevent suspended particles from settling.
Flocculation sedimentation tank
For the removal of suspended pollutants in the sewage, reducing the interference of suspended matter on the disinfectant, saving the amount of disinfectant, and providing a good environment for the residual chlorine online automatic monitoring. In order to reduce the footprint, the vertical flow sedimentation tank is used, with an in-ground reinforced concrete structure, which is built together with other treatment units, and the top of the tank is covered with soil. For the convenience of inspection and maintenance, there are inspection holes at the corners of the flocculation sedimentation tank, which can be used to maintain the regulating tank on a regular basis. Sludge is deposited in the sludge hopper and regularly discharged into the sludge thickening tank through the sludge pump via the sludge pipe, and the effluent flows into the disinfection contact pool.
Disinfection contact pool
The water from the sedimentation tank enters into the disinfection contact pool, so that the sewage and the disinfectant maintain a certain contact residence time to ensure that the disinfectant effectively kills the bacteria in the water, and the effluent is discharged into the municipal pipe network. According to the "discharge standards for water pollutants in medical institutions" (GB18466-2005), the contact time for sewage from infectious disease hospitals should not be less than 1.5 hours, and the contact time for sewage from general hospitals should not be less than 1.0 hours. A hospital in Beijing is a general hospital containing an infectious disease department, so the hydraulic retention time of the contact pool is 1.5 hours. Adopting underground reinforced concrete structure, it is built together with other treatment units to save infrastructure investment. The top of the pool is covered with soil, and for the convenience of inspection and maintenance, inspection holes are provided at the corners of the contact oxidation pool, so that the conditioning pool can be maintained regularly. The contact pool is equipped with a guide wall to avoid short flow, and the chlorine residual automatic monitoring equipment is set up at the exit of the contact pool so as to adjust the dosage of disinfectant in time.
Sludge storage tank
Collecting and storing sludge produced by the flocculation and sedimentation tank, regularly adding lime to the tank to disinfect the sludge, after sludge dewatering, the dry sludge is transported out of the tank, and the filtrate is refluxed into the regulating tank. Adopting underground reinforced concrete structure, it is built together with other treatment units to save infrastructure investment, the top of the tank is covered with soil, and for the convenience of inspection and maintenance, there are inspection holes at the corners of the sludge storage tank, so that the regulating tank can be maintained regularly. There is a submersible mixer in the sludge storage tank for mixing when the sludge is dosed and sterilized.