1）Improved AO+MBBR process
Improved AO+MBBR process flow chart
This process is one of the most common processes in the purification tank. It has the characteristics of simple process and convenient maintenance. Our company has improved the original process, which is slightly different from the ordinary AO process. Anaerobic-anaerobic-aerobic (A2O) process is mainly composed of grille, sedimentation separation tank, facultative filter bed, anaerobic filter bed, biological filler filter, treatment tank and disinfection tank. After removal of large suspended particulates, floats and sediments by grille interception, domestic sewage flows to sedimentation separation tank for further precipitation, in which supernatant enters facultative oxygen filter biochemical tank, denitrification reaction is carried out by heterotrophic microorganisms to remove NH3-N and degrade organic matter in sewage, and then quantitatively transfers into filler by intermittent transfer pump. In aeration and biofilter, autotrophic aerobic microorganisms degrade organic matter and nitrate ammonia nitrogen in sewage. Nitrite is returned to anaerobic filter bed biochemical tank for biological denitrification treatment. Finally, the treated tank is discharged into disinfection tank. The backwash water of the biofilm filler is returned to the solid-liquid separation tank regularly.
2）improved AO+MBR process
Improved AO+MBR process flow chart
This process is one of the most popular sewage treatment technologies at present. It is a new sewage treatment technology that combines membrane separation technology with biotechnology. It uses membrane separation equipment to intercept activated sludge and macromolecule organic matter in biochemical reaction tank, thus eliminating secondary sedimentation tank. As a result, the concentration of activated sludge is greatly increased. The hydraulic retention time (HRT) and sludge retention time (SRT) can be controlled separately, while the refractory substances are continuously reacted and degraded in the reactor.
Compared with traditional biological treatment methods, membrane-bioreactor technology greatly strengthens the function of bioreactor through membrane separation technology. It has the advantages of high biochemical efficiency, strong resistance to load impact, stable effluent quality, small area, long sludge discharge period and easy to realize automatic control.
3、Large Intelligent Integrated Sewage Treatment Equipment
In view of the centralized residential areas in rural areas and new rural areas, the company has developed large and medium-sized intelligent domestic sewage purification tanks for centralized residence of more than 100 people. Through laying sewage collection pipelines, it has established sewage treatment stations for centralized treatment.
Large-scale intelligent integrated sewage treatment equipment, process selection mainly adopts two types of process: improved AO + MBBR and improved AO + MBR.
1）FRP winding type
Specification of Large Intelligent Domestic Sewage Purification Tank (FRP Winding Type)
3)Carbon steel anticorrosive type
4) Combined Container Type
Modified A3O+MBBR process flow chart
Modified A3O+MBBR process
Based on the traditional A2/O, the pre-desalination zone is added. Sludge reflux system returns sludge from sedimentation tank to pre-denitrification zone in order to remove nitrate from reflux activated sludge under anoxic conditions, and then enter anaerobic zone, so as to achieve zero nitrate reflux and avoid the influence on phosphorus accumulating bacteria, which can greatly improve the ability of biological sludge to release phosphorus in anaerobic zone and make the aerobic zone absorb phosphorus. The phosphorus removal efficiency has been fully improved and the phosphorus removal effect of the system has been strengthened. Nitrite reflux system returns nitrate-nitrogen mixture to anoxic zone for denitrification to complete denitrification.
Moving-bed biofilm reactor (MBBR) is used in aerobic zone. The core part is that suspended fillers with a specific gravity close to water are directly added to the aeration zone as active carriers of microorganisms. The fillers are fluidized by aeration and water flow in the aeration zone. Biofilm with different thickness is grown inside and outside the fillers. Anaerobic bacteria or facultative bacteria are the main bacteria, and the external bacteria are well cultured. Each carrier is equivalent to a micro-reactor, which increases the microbial flora and quantity. On the basis of organic carbon degradation, nitrification and denitrification exist simultaneously, thus improving the overall treatment efficiency of sewage. Aerobic zone adopts the aeration system which combines small and medium bubble aeration system with micro-porous aeration, which has uniform aeration distribution, low air resistance and high oxygen utilization rate; the reactor adopts ring water distribution design to make the water flow turbulent, the sludge water is fully mixed, and there is no dead angle; the nitrate and sludge reflux are in the form of air stripping without power, reducing energy consumption and reducing energy consumption. Few fault points.