Drying Technology
Buried domestic sewage treatment technology
The buried sewage treatment equipment is a modular high-efficiency biological sewage treatment equipment. It is a sewage biological treatment system with biofilm as the main body of purification. It makes full use of biofilm reactors such as anaerobic biofilter and contact oxidation bed. The characteristics of high biological density, strong pollution resistance, low power consumption, stable operation and convenient maintenance make the system have a wide application prospect and promotion value.
The working principle of anaerobic biological filter
1. Filtration
The filler traps large particles and suspended solids filtered into the water.
2. Hydrolysis
Anaerobic microorganisms can hydrolyze insoluble substances of large molecules into soluble substances of small molecules.
3. Absorption
Anaerobic microorganisms adsorb and absorb organic pollutants in the water, part of which is used for their own growth and reproduction, and part of it is sealed by U-shaped water in the form of biogas.
4. Denitrification
The denitrifying bacteria that return the effluent from the contact oxidation bed to the anaerobic microorganisms in the anaerobic filter can use the nitrate nitrogen in the return water and convert it into nitrogen to remove nitrogen in the sewage. After the rural sewage is treated by the anaerobic filter, the concentration of suspended solids, organic pollutants and nitrogen is reduced, and the subsequent load of contacting the oxidation bed is also reduced.
The principle of contact oxidation bed
1. Adsorption
During the growth and reproduction of aerobic microorganisms on the filler, they form a biofilm with a larger surface area and a higher concentration, which can absorb most of the organic pollutants in the water and reduce the concentration of pollutants.
2. Ingestion and decomposition
When the air is continuously vented into the reactor, aerobic microorganisms can take the adsorbed organic pollutants as nutrients and take them into the body for metabolism, part of their growth and reproduction, and part of them will be converted into carbon dioxide and water. The contact oxidation bed further reduces the concentration of organic pollutants in rural sewage, and the removal rate of CODcr and BOD5 in the effluent reaches more than 80%, which can reach the national second-level sewage discharge standard.
Working principle of sedimentation tank
1. Use gravity to make the suspended sludge with a specific gravity greater than water in the effluent contacting the oxidation bed sink to the bottom of the pool so that it can be removed from the water to ensure better effluent quality
2. The sludge settled to the bottom will automatically return to the contact oxidation bed to maintain the sludge concentration in the contact oxidation bed.
Process characteristics of buried domestic sewage treatment
Biological contact oxidation method
The biological contact oxidation method is a wastewater biological treatment method derived from the biological film method, that is, a certain amount of filler is filled in the biological contact oxidation tank, and the biofilm and sufficient oxygen that are attached to the filler are used. The organic matter in the wastewater is oxidized and decomposed to achieve the purpose of purification. It has the characteristics of the activated sludge method and the biofilm method has the advantages of both the activated sludge method and the biofilm method. Under biochemical conditions, good economic benefits have been achieved whether it is applied to the treatment of industrial wastewater, aquaculture wastewater, and domestic wastewater. This process is widely used in sewage treatment systems in all walks of life because of its high efficiency, energy saving, small footprint, impact load resistance, and convenient operation and management.
Residential sewage (through the septic tank) flows into the fine grid tank to remove large particles of sinkable solids and suspended solids in the water, and then flows into the regulating tank. The effluent of the regulating tank enters the biological contact oxidation tank, and the biological contact oxidation tank is filled with soft filler aeration wastewater flows through the filler layer to make the surface of the filler full of biofilm to increase the micro power, that is, the small blower blows to make the sewage fully and the biofilm under aerobic conditions The microorganisms in contact with the sewage gradually oxidize the residual organic matter in the sewage to carbon dioxide, water and cellular substances, and the sewage is purified. At the same time, the dissolved oxygen level is controlled to ensure that the ammonia nitrogen in the sewage is converted into nitrate nitrogen by nitrifying bacteria. The effluent is separated into solid and liquid through the sedimentation tank, and then introduced into the filter tank to be filled with hard-filled quartz sand, and the effluent from the sedimentation tank is further absorbed and precipitated to meet the discharge requirements. Finally, the sewage flows into the disinfection tank and the effluent is disinfected with chlorine dioxide and discharged outside the standard.
The buried domestic sewage treatment technology and biological contact oxidation process have the characteristics of small area and not easy to damage the surrounding community landscape. At the same time, the buried sewage device can also reduce the impact of noise and odor on the residents of the residential community to a minimum. The buried biological contact oxidation process applies micro power to change the state of insufficient oxygen supply and insufficient biological activity of the sewage treatment device, and improves the removal rate of pollutants. The micro-powered aeration tank unit is a modular structure, which can better meet the requirements of the phased construction of the district sewage treatment plant.
