Common basic code
Common basic concepts
Common wastewater treatment processes
I. Oxidation ditch process (secondary treatment of sewage, suitable for the full range)
Oxidation ditch process, as a mature activated sludge wastewater treatment process, has been widely used throughout the country. It is a variant of the activated sludge process. Its aeration tank is a closed ditch, so it is in hydraulic flow state. It is different from the traditional activated sludge method, but a circulating flow aeration ditch connected end to end, and the sewage infiltrates and is purified.
Second, A2 / O process (secondary treatment of sewage, focusing on nitrogen and phosphorus removal)
A2 / O process is the English abbreviation of Anaerobic-Anoxic-Oxic, and is the abbreviation of anaerobic-hypoxic-aerobic biological nitrogen and phosphorus removal process. The efficiency of this process can generally reach: BOD5 and SS are 90% to 95%, total nitrogen is more than 70%, phosphorus is about 90%, and it is generally suitable for large and medium-sized urban sewage plants that require nitrogen and phosphorus removal. However, the A2 / O process's capital construction and operating costs are higher than the ordinary activated sludge method, and the operation and management requirements are high. Therefore, for the current national conditions in China, http://euhowblog.com
, the treated sewage is discharged into a closed environment. This process is only used when eutrophication is caused by the water body or slow-flowing water body, which affects the water supply source.
3. Activated sludge process (secondary sewage treatment, used in large sewage treatment plants)
Activated sludge process is one of the most widely used aerobic biochemical treatment technology for wastewater. It mainly consists of aeration tank, secondary sedimentation tank, aeration system and sludge return system.
Fourth, SBR process (secondary sewage treatment, suitable for intermittent discharge)
The treatment process is mainly completed by several purification processes including initial removal and adsorption, microbial metabolism, floc formation and flocculation and sedimentation performance. The core of the SBR technology is the SBR reaction tank, which integrates functions such as homogenization, primary sedimentation, biodegradation, and secondary sedimentation in one pond, and has no sludge return system. It is especially suitable for occasions with intermittent emissions and large changes in flow.
Five, A / O process (secondary sewage treatment, widely used in small and medium cities)
The A / O process was created in the 1970s, and because of its simultaneous degradation of organic matter and denitrification, and convenient operation and management, it has been widely used. Because the sewage treatment process is determined based on various factors such as the amount of sewage, water quality, effluent requirements, and local actual conditions, small and medium-sized urban domestic sewage treatment stations
generally use A / O and other processes.
Sixth, MBBR process (secondary sewage treatment, often used in sewage plant upgrading)
The MBBR process is based on the basic principle of the biofilm method. This process uses a certain amount of suspended carriers into the reactor to form suspended growing activated sludge and attached biofilm. This makes the moving bed biofilm use the entire The reactor space gives full play to the superiority of both the adherent and suspended phase organisms, making them strong and avoiding disadvantages and complementing each other. The MBBR process is commonly used in aerobic or anoxic tanks for in-situ reformation in wastewater plant upgrades, enhancing biochemical activity and improving water treatment efficiency.
Seven, denitrification deep-bed filter process (three-stage sewage treatment, widely used in sewage plant upgrading)
Denitrification deep bed filter is a technology that integrates filtration and biochemistry. It often uses volcanic rock or quartz sand as the filter material. By adding phosphorus removal agent and carbon source, the sewage is removed by microflocculation in the filter bed to remove SS and TP. : //euhowblog.com
At the same time, microorganisms formed on the surface of the filter material degrade organic pollutants and nitrate nitrogen and other pollutants, and the removal of nitrogen and phosphorus has been widely used in the upgrading of sewage plants. At present, there are two schools of denitrification deep bed filter technology on the market. Downward flow filter technology from abroad, represented by manufacturers such as Djola and Salamer, and domestic upward flow filter technology from Shenzhen Qingquan. Compared with the downflow denitrification deep bed filter, the upflow denitrification deep bed filter has higher filtration speed, less carbon source consumption (savings 20% -30%), and stronger sewage holding capacity (5 times Above), no need to drive nitrogen.