1, the source of rural sewage
Since the reform and opening up, especially since the 17th National Congress of the Communist Party of China, our country has obviously accelerated the pace of the construction of new rural areas, and vigorously develop the construction of new rural areas or small towns, for the drive of the rural economy or small towns is a major strategy for the development of the countryside. However, in the development of rural economy or small town economy at the same time, but also brought about the problem of environmental pollution, control pollution to protect the environment, is another major initiative for sustainable development.
China's new rural areas and small town construction, involving environmental issues, mainly rural sewage pollution and rural garbage pollution in two aspects. In the rural sewage pollution, mainly domestic sewage pollution, livestock breeding sewage pollution, pesticide and fertilizer pollution, but also some industrial pollution and other pollution. These pollutants are mixed with domestic sewage discharged, so rural sewage is actually a general term for the above sewage.
2, rural sewage characteristics
1, small sewage area, sewage volume, the coefficient of variation is large, water quality and water fluctuations.
(2), some rural industrial wastewater and domestic sewage combined discharge, to the water quality caused by a certain impact.
(3), management can not keep up with the reasons such as rain does not flow, and in some cases there is groundwater infiltration.
(4), the rural areas may appear to jump in development, the recent sewage volume is relatively small, while the long-term sewage volume is larger.
(5), due to financial problems, poor infrastructure, weak technical force, even if the sewage treatment station is built, the community may be difficult to maintain the high energy consumption, high maintenance, complex management of the treatment system. Therefore, China's new rural sewage treatment should choose economic, efficient, energy-saving, simple and easy to use, good treatment effect, shock resistance, stable operation of the new sewage treatment process and new technology.
New rural areas are generally divided into three types of communities of 1,000 people, 2,000 people community, 3,000 people community, community per capita drainage 0.15m?/d, pollutant concentration of CODcr <900㎎/L, PH value of 6.5 ~ 7.5, BOD5 <350mg/L, SS <700mg/L, chromaticity (dilution multiplier method) <200, containing a certain amount of Nitrogen and phosphorus, good biochemistry, but water quality and water quantity fluctuations. It can be seen that the rural sewage water quality indicators are significantly higher than urban sewage, and the use of low-load process technology, large footprint, large investment, high operating costs, therefore, the use of high-load sewage treatment process, "Infiltration Aeration Biofilter" to deal with rural sewage, especially suitable for China's rural sewage treatment and the construction of small towns sewage treatment needs.
3, sewage treatment methods
China's sewage treatment started late, the development of fast, sewage treatment process is mainly biochemical treatment, the common process of contact oxidation, AB method, A/O method, oxidation ditch, SBR, aeration biofilter, inflow aeration biofilter and so on.
Conductive aeration biofilter is China's independent intellectual property rights of the new process of sewage treatment, according to the different subsequent treatment processes, it is divided into: hydrolysis-conductive aeration biofilter, anaerobic-conductive aeration biofilter, air flotation-conductive aeration biofilter, fast sedimentation-conductive aeration biofilter, ultrasonic-conductive aeration biofilter, microwave-conductive aeration biofilter, ozone-conductive aeration biofilter and so on. aeration biofilter, ozone-ducted flow aeration biofilter, etc.
Conductive aeration biofilter in the upgrading, nitrogen and phosphorus removal, water reuse with other processes, the development of AB method - conductive aeration biofilter; A/O method - conductive aeration biofilter; A2/O method - conductive aeration biofilter; oxidation ditch - conductive aeration biofilter; SBR - conductive aeration biofilter; biological contact oxidation - conductive aeration biofilter and other deep treatment processes. Depth treatment process.
Two, infusion aeration biofilter process technology introduction
1, the source of technology
Influent aeration biofilter is based on the traditional aeration biofilter, fully drawing on the downward-flow aeration biofilter method, upward-flow aeration biofilter law, contact oxidation, biofilm method, artificial fast filtration, sedimentation and separation, no pump sludge reflux method, fast filtration of feedwater, and so on. Eight design techniques, and secondary or tertiary sewage treatment process and the development of sewage treatment processes, new technologies. 2005 to obtain a national patent, Patent No.: ZL200420033672.4.
Conductive aeration biofilter has been in China's Beijing, Shandong, Hebei, Guizhou, Shanxi, Sichuan, Inner Mongolia, Heilongjiang, Jiangsu, Jilin, Henan, Hubei, Tianjin and other places have engineering examples, cases and hospitals, life, chemical industry, slaughtering, food, flax, alcohol, pharmaceutical and other wastewater treatment, a large number of applications have proved that: the effluent quality of CODcr is generally in the 20mg / L below, the minimum of 5.95mg / L; BOD5 is generally in the 10mg / L below, the minimum of 3.50mg / L; SS is generally in the 20mg / L below, the minimum of 6.55mg / L. 6.55mg / L.
2, technical characteristics
Conduction Current Biofilter (referred to as CCB), so that the sewage in the same treatment tank, to complete the process of aeration → sedimentation → secondary aeration → secondary sedimentation, etc., to solve the other wastewater treatment needs to be four pools to complete the process. Especially in the continuous water intake conditions, the realization of water intake → aeration → precipitation → water outlet gap aeration, at the same time, the realization of sludge reflux, the entire operation of no idle, the advantages of its more prominent than other sewage treatment methods, the treatment effect is superior to the remarkable, infusion aeration biofilter is AB method, SBR method, A2O method, contact oxidation method, as well as two aeration and two sedimentation, gap aeration method of sewage treatment of the replacement product. In August 2009, the State Ministry of Science and Technology as "innovation projects" project code 09C26215205564; in December 2009, the State Ministry of Environmental Protection will be listed as the product "national encouragement for the development of environmental protection technology catalog" (Huanfa) (2009) No. 146; in May 2010, the Ministry of Science and Technology, the Ministry of Environmental Protection, the Ministry of Commerce, the State General Administration of Quality Supervision, Inspection and Quarantine review recognized "inflow aeration biofilter" as "national key new products", its number is 2010GR467010; in July 2012, the State Ministry of Environmental Protection will be In July 2012, the Ministry of Environmental Protection of the State will be classified as the "National Encouragement for the Development of Environmental Protection Technology Catalog" during the Twelfth Five-Year Plan (Ministry of Environmental Protection 2012) No. 39.
Conduction Current Biofilter (CCB for short), so that the sewage in the same treatment tank, to complete the process of aeration → sedimentation → secondary aeration → secondary sedimentation, to solve the problem of other sewage treatment requires four pools to complete the process. Especially in the continuous water intake conditions, the realization of water intake → aeration → precipitation → water outlet gap aeration, at the same time, the realization of sludge reflux, the entire operation of no idle, the advantages of its more prominent than other sewage treatment methods, the treatment effect is superior to the remarkable, infusion aeration biofilter is AB method, SBR method, A2O method, contact oxidation method, as well as two aeration and two sedimentation, gap aeration method of sewage treatment of the replacement product. In August 2009, the State Ministry of Science and Technology as "innovation projects" project code 09C26215205564; in December 2009, the State Ministry of Environmental Protection will be listed as the product "national encouragement for the development of environmental protection technology catalog" (Huanfa) (2009) No. 146; in May 2010, the Ministry of Science and Technology, the Ministry of Environmental Protection, the Ministry of Commerce, the State General Administration of Quality Supervision, Inspection and Quarantine review recognized "inflow aeration biofilter" as "national key new products", its number is 2010GR467010; in July 2012, the State Ministry of Environmental Protection will be In July 2012, the Ministry of Environmental Protection of the State will be listed in the 12th Five-Year Plan as the "National Encouragement for the Development of Environmental Protection Technology Catalog" (Ministry of Environmental Protection 2012) No. 39.
Three, inflow aeration biofilter technology performance
1), technology forward-looking
Influent aeration biofilter fully draws on eight sewage treatment design techniques, is a typical high-load, submerged, immobilized biobed three-phase inflow, denitrification and removal of phosphorus reactor, treated sewage better than the discharge standard, to achieve the reuse of water quality, so the technical Forward-looking.
2), process innovation
Conductive aeration biofilter so that the sewage in the same treatment tank, to solve other sewage treatment requires four pools to complete the process. The whole operation without idling. Therefore the process is innovative.
3), the project investment economy
Influent aeration biofilter BOD5 volumetric load is the conventional secondary biological treatment of 5 to 10 times, plus microbial amount of up to 10-15g / L, also do not need to set up the secondary sedimentation tank, so the project investment economy.
4), the stability of the treatment effect
To make the device in the presence of aerobic and anoxic environment, nitrification, denitrification can be realized, there is no sludge expansion, not subject to the impact of the hydraulic load, resulting in the loss of microorganisms, even if the sewage is reduced by half, or water supply and then start again, it only takes a very short period of time, it will be able to operate normally, so the stability of the treatment effect.
5) Simplification of the treatment process
Because of the inflow aeration biofiltration method will be two aeration tanks, two sedimentation tanks, two filtration tanks into one, so that the treatment process can be simplified, and therefore the simplification of the treatment process.
6), investment and operating costs of economic
Because of the infusion aeration biofiltration process is short, the pool capacity is small, occupies an area of the province, so that the project cost is greatly reduced. Coupled with the device to use the filter media cutting, blocking, finely crushed bubbles, strengthen the gas and liquid mass transfer effect, increase the contact area and time of microorganisms and air, resulting in the filter pool oxygenation efficiency is greatly improved, so the investment and operating costs economic.
7), operation and management simplicity
Through the liquid level sensing, dissolved oxygen meter, timer, frequency converter, PLC program control system, so that all the infusion aeration biofilter automation, so operation and management simplicity.
8) Typical denitrification and phosphorus removal
①Basic principle of denitrification and phosphorus removal by inflow aeration biofiltration method
The principle of denitrification of inflow aeration biofiltration method is that, on the basis of converting organic nitrogen to ammonia nitrogen, through the action of nitrifying and denitrifying bacteria, ammonia nitrogen is converted to nitrite nitrogen and nitrate nitrogen by nitrification and nitrate nitrogen is converted into ammonia by denitrification, thereby achieving nitrogen removal from wastewater. Thus, the purpose of nitrogen removal from wastewater is achieved.
The principle of phosphorus removal by inflow aeration biofiltration is that under anaerobic conditions, the polyphosphorus bacteria will convert the organic phosphorus in their cells into inorganic phosphorus and release it, and utilize the energy generated in the process to ingest the dissolved organic matter of the wastewater to synthesize PHB, so that under aerobic conditions, the polyphosphorus bacteria will degrade the PHB in order to provide the energy required for ingesting the phosphorus from the wastewater to complete the polyphosphorus effect. .
)Temperature and operation mode adaptability
Because a large number of microorganisms will not be lost, even if it is not in operation for a long time can maintain the activity of its strains, coupled with the high microbial population unique to the infiltration aeration biofiltration tank, which makes it adaptable to changes in temperature.
10)Convenience of maintenance and replacement
The main rotating equipments of the inflow aeration biofilter are placed on the ground, plus the main equipments and materials are all made in China, so it is convenient for maintenance and replacement.
11), engineering and construction flexibility
Conductive aeration biofiltration system unit for the modular structure, can be designed centrally, but also separately designed, but also conducive to expansion, can better adapt to the landscape of each region, for the upgrading of the old sewage treatment works are also time favorable.