First, the beautiful rural domestic sewage treatment equipment currently nitrogen-containing wastewater treatment technology is: biological nitrification method, ion exchange method, blow-off method, liquid film method, chlorination or adsorption method and wet catalytic oxidation method, etc., for the nitrogen concentration of tens of mg / L of secondary biochemical effluent, biological nitrification method, blow-off method and ion exchange method are more applications, when the nitrogen concentration is not high, it is advisable to use chlorination. Bionitrification debioberification is a process in which nitrifying bacteria and nitrosinous bacteria are converted into salts under aerobic conditions.
Both of these bacteria are auto-habitating bacteria, and under aerobic conditions, nitrosobacterium will oxidize to sub-salt, and then nitrify bacteria will further oxidize sub-salt to salt. Many domestic sewage treatment plants have biological nitrification function to remove nitrogen from sewage, and for treatment facilities that specifically consider biological nitrification, nitrogen in sewage can be removed to less than 2mg/L.
Split Membranes - Bioreactors set up membrane modules separately from bioreactors. The mixture in the bioreactor is pressurized by the circulation pump and hits the filter end of the membrane module, and the liquid in the mixed liquid passes through the membrane under pressure and becomes the system treatment water; the solids, macromolecular substances, etc. are intercepted by the membrane and returned to the bioreactor with the concentrate. The characteristics of the split membrane-bioreactor are stable and reliable operation, easy to clean, replace and add membranes, and the membrane flux is generally large. However, under general conditions, in order to reduce the deposition of pollutants on the surface of the membrane and prolong the cleaning cycle of the membrane, it is necessary to provide a higher cross-flow rate of the membrane surface with a circulation pump, the amount of water circulation is large, the power cost is high, and the shear force generated by the high-speed rotation of the pump will cause some microbial bacteria to produce inactivation.
Second, the process selection: Since the "Ninth Five-Year Plan", China has carried out a lot of research and exploration on the treatment technology and technology of various types of sewage, carried out experiments and practices in all aspects of domestic sewage treatment, effective successful experience, and gradually formed a treatment process based on biochemistry, combining biochemistry and physicochemical. Commonly used in biochemical methods are activated sludge method, biofilm method, anaerobic and aerobic combination method, hydrolysis acidification and aerobic combination and other processes. Engineering practice has confirmed that aerobic treatment of large and medium-sized domestic sewage is feasible, and it is more appropriate to use a combination of hydrolysis acidification and aerobic method for small scales.
Biochemical treatment generally uses the biofilm method for sewage treatment of similar scale. It roughly includes fixed bed biofilm method (contact oxidation), MBBR suspension carrier biofilm method, fluidized bed, aerated biological filter, biological turntable, membrane bioreactor and so on. Biological turntable is generally used in large-scale above-ground treatment facilities, covers a large area, and poor efficiency, easy to cause secondary pollution; although the aeration biological filter is more suitable for the treatment of domestic wastewater, there are many successful experiences, but because of its noise, the need for a special fan, and the amount of water in this project is small, so it is not recommended to use here; contact oxidation combined with new biological fillers, with high load, easy to hang film, mature process and other characteristics, so in this program the use of contact oxidation technology as the main treatment unit. In summary, according to the characteristics of this wastewater, we select the treatment process of the wastewater by regulating pool + hydrolysis acidification + contact oxidation method + MBR membrane reactor.
Third, the process description 1, grid: (for the water quality with large particles in the water, such as urban domestic sewage), remove sand, wood, plastic and other large debris
2. Regulation pool: adjust the water quantity and water quality, and reduce the impact load on the subsequent treatment structure
3. Mixer: The sewage is fully mixed and oscillated with the 1# and 2# additives added
4. Microwave reactor: physical and chemical reaction between pollutants and additives and microwave low-temperature catalyzed physicochemical reaction
5. Sedimentation and filtration integrated equipment: to achieve solid-liquid separation, to achieve the purpose of discharge or reuse, sludge is dehydrated and transported or used for other purposes. Under the joint action of additives and microwaves, violent catalytic, physicochemical reactions occur, converted into insoluble substances or gases separated from water, and macromolecular molecules and refractory organic pollutants in water are decomposed into small molecules under the joint action of microwaves and additives, and combined with additives to form rapid sedimentation flocide removal; Metal ions can be directly combined with additives to generate rapid sedimentation of flocs; Nitrogen is converted to gas to escape; Phosphorus in water is converted to insoluble phosphate precipitation removed.