Technology innovation
Domestic sewage treatment technology
In order to select the most reliable, the most economical and most economical urban sewage treatment system on the investment, combined with the actual situation of the local area, we have studied the mature experience and development trend of domestic and foreign sewage treatment plants and compared them.
At present, domestic and foreign urban sewage treatment plant treatment processes are mostly used and a secondary treatment. Primary treatment is the use of physical methods, mainly through the grid interception, precipitation and other means to remove large amounts of suspended solids and sand in waste water and other substances. This process has been mature at home and abroad, the difference is not big. Secondary treatment is the use of biochemical methods, mainly through the life of microorganisms and other means to remove the waste water in the suspension, dissolved organic matter and nitrogen, phosphorus and other nutrients. At present, this process has a variety of methods, summed up, the representative of the main process of traditional activated sludge, oxidation ditch, A / O or A2 / O process, SBR and CCAS process. At present, these representatives of the process at home and abroad have practical applications.
The more commonly used treatment processes are:
① sewage treatment tank → the first sedimentation tank → biological contact oxidation tank → secondary sediment pool → water, biological contact oxidation is the most widely used method, the main advantage is the residence time is short, easy to hang film, especially for equipment, buried construction Much favored by environmental companies and users, but due to maintenance management and equipment corrosion and other aspects of the problem, in recent years the application is limited. However, if the construction of underground reinforced concrete form, set up personnel for maintenance, such underground construction in the district water treatment has a larger market, but this approach generally deal with smaller, the daily discharge of less than a few hundred tons of sewage more ideal. For thousands of tons of sewage treatment area, recommended the use of ground construction, biological treatment part of the contact oxidation can be used, can also be used SBR or its improved CASS process, aeration recommended low-noise fan or underwater aerator.
② sewage → adjust the pool → coagulation sedimentation → filtration → water, the degree of treatment is not high, and the water is small, you can use this process, with a small footprint, odor is small, simple management and so on. In addition, before the aerobic biological treatment with acidification hydrolysis, is conducive to reducing energy consumption, improve the total removal rate of the system. Living area usually has a large green area, if the sewage treatment after the water used to irrigate the green, road, flush the car, should be treated in the water after the disinfection or other supplementary measures.