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Scope of application
It is suitable for wastewater with high CODcr concentration, complex components and difficult biodegradation.
Basic principles
By improving the position of the return water, optimizing the hydrodynamics of the tank, the unique design of the three-phase separator and adopting a new control mode, the technology has achieved better treatment effect than the traditional EGSB process.
technological process
The pretreated wastewater is mixed with the return water from the expanded granular sludge bed reactor (pi-egsb reactor) and the return sludge from the rear sedimentation tank and enters the bottom of the pi-egsb reactor. A water distribution device is set at the bottom of the reactor to evenly arrange the water in the whole reactor. The organic matter in the reactor is fully degraded. A special three-phase separator is set at the top of the reactor to separate water, sludge and generated biogas. The effluent enters the sedimentation tank. After the sludge and suspended solids contained in the effluent are precipitated in the sedimentation tank, the effluent flows to the next level sewage treatment structure for further treatment. The sludge separated by the three-phase separator is re settled into the reactor, and the biogas is collected and used as energy.
Key technology or design features
Through the establishment of 3D model, the simulation test research on hydrodynamics is carried out, and several different three-phase separator forms and reflux modes with good separation performance are emphatically determined, so as to achieve the purpose of efficient separation of wastewater from sludge and biogas.
Typical scale
Modular design, which can be combined freely according to water volume, is suitable for various water volume scales.
Promotion
The technology has been successfully applied in Chongqing Huafeng Chemical production wastewater treatment project.
classic case
（1） Project overview
The designed daily treatment capacity of Chongqing Huafeng Chemical production wastewater treatment project is 3960m3 / D, and the sewage comes from Ka unit wastewater, AA unit wastewater and domestic sewage of the chemical plant (the amount of domestic sewage is very small). The construction started in March 2011, and the commissioning was completed and put into operation in June 2012.
（2） Technical indicators
The effluent of the project meets the requirements of class III standard of national integrated wastewater discharge standard (GB8978-1996). Ka unit wastewater: CODcr ＜ 3000 mg / L, containing cyclohexane, cyclohexanol, cyclohexanone and trace benzene. AA plant wastewater: CODcr ＜ 6000 mg / L, containing monobasic acid and dibasic acid below C6, and nitric acid content less than 1.68% (mass fraction). The process can be used to remove carbon source pollutants (CODcr ≤ 500mg / L, BOD5 ≤ 300mg / L), and the annual reduction of CODCr is 5180t / A.
（3） Investment cost
The total investment of the project is about 20 million yuan, including 8.1 million yuan for equipment, 11.9 million yuan for infrastructure and 5050 yuan for tons of water.
（4） Operating costs
According to the actual operation since it was put into operation, the annual sewage treatment is 1445400 tons, the annual operation cost is 302100 yuan, and the operation cost per ton of water is 209 yuan.