1. Treatment method of industrial sewage
A method for treating industrial sewage belongs to the technical field of sewage treatment. Introducing the sewage into the water collecting tank, adjusting the pH value of the grid at the end of the water collecting tank, lifting the sewage to the first-class pressure dissolving tank by a first-class dissolving pump, and simultaneously sucking air and coagulation decolorant, so that the first-class saturated dissolved air water in the first-class pressure dissolving tank is suddenly released to the first-class air flotation tank to form the first-class treated water; The primary treated water overflows into the buffer pool, then the primary treated water is lifted into the secondary pressure dissolved air tank by a secondary dissolved air pump to control the pH, and at the same time, air and coagulation decolorant are inhaled, so that the secondary saturated dissolved air water in the secondary pressure dissolved air tank is suddenly released into the secondary air flotation tank to form secondary treated water, which overflows into the sedimentation tank and is discharged after sedimentation; The floating mud in the primary and secondary air flotation tanks enters the floating mud tank, and is pressed into a filter cake, and the filtrate is returned to the water collection tank. The removal rates of CODcr, decolorization, SS and BOD [5] in the industrial wastewater treated by this method are 80-90%, 95%, 90% and 75-80%, respectively, reaching the first-class discharge standard of GB 8978- 1996.
2. Agricultural sewage treatment methods
Because agricultural sewage is widely distributed and scattered, it is difficult to collect and treat, so pollutants can only be removed by biological action, such as directly throwing high-density and efficient decontamination bacteria into polluted water bodies to achieve the purpose of purifying water.
3. Treatment methods of medical sewage
Hospital sewage treatment usually includes primary treatment and secondary treatment. Generally speaking, if the treated sewage is discharged into the municipal sewer, it is usually only treated at the first level; If the treated effluent is directly discharged into the river, primary treatment and secondary treatment are needed; In areas with strict emission standards, in order to prevent water eutrophication, three-stage phosphorus and nitrogen removal treatment is needed. Special hospital sewage such as acid wastewater, phase washing wastewater and radioactive wastewater should be strictly collected and treated. In order to alleviate the contradiction of water shortage in some areas, hospital sewage has been deeply treated and recycled. The actual treatment of hospital sewage should comprehensively consider many factors such as sewage source, sewage flow direction, local water supply and so on. In addition, a very important aspect of hospital sewage treatment is that it must be disinfected to kill various pathogenic microorganisms.
Second, the domestic sewage
[Rural domestic sewage treatment method]
For rural domestic sewage, the following treatment can be carried out:
The picture shows rural domestic sewage → septic tank → anaerobic pond → constructed wetland (plants with developed roots and strong absorption capacity such as canna, scallion and calamus are planted). After "filtration" treatment, it is mainly suitable for the treatment of scattered domestic sewage in rural areas. After completion, the operating cost is basically zero, and the service life exceeds 10 years.
[Treatment method of urban domestic sewage]
Domestic sewage treatment process For urban domestic sewage, the following treatment can be carried out:
Transport urban domestic sewage to the rural areas around the city, and use the vast land in rural areas to purify urban domestic sewage. This will be a good way once and for all. Take large and medium-sized cities that supply domestic tap water 100W cubic meter daily as an example: the cost of ordinary sewage treatment facilities is 1000 yuan/cubic meter. The construction cost is 65.438+0 billion yuan, and the annual operating cost is 654.38+000 w m3/day × 365× 0.5 yuan/m3 = 65.438+0.8 billion yuan/m3, and the annual operating cost of soil purification method is 654.38+000 w m3/day× 365× 0.6 million yuan/m3.