Abstract: aiming at the existing urban sewage treatment plant in the process of construction and operation management are exposed, from the aspects of construction scale and technology, comparative analysis, and put forward the corresponding attention to link.

Keywords: urban sewage treatment process selection of operation and management

Due to industrial wastewater treatment facilities generally small scale, strong technical, flexible technological combination, usually in the form of steel structure, even if the internal pipeline with more, operation maintenance is not too difficult. Industrial and city sewage wastewater treatment is technically similar, but if the design ideas of industrial wastewater treatment facilities, simple to use in the urban sewage treatment project will bring a lot of unexpected problems.

1. Reasonably determine the construction scale

The determination of municipal sewage plant construction rules touch is according to the overall urban planning and drainage planning, construction of sewage pipe network and sewage treatment plant by instalments, according to the water environment protection target, phased implementation, gradually put in place. Urban drainage engineering construction is a systematic project, involving urban pipe canal, sewage collection, transport (including pump station), sewage treatment and discharge, as well as the sludge disposal and so on questions in.

2. Choice of city sewage treatment plant process

The choice of specific engineering requirements include:

(1) technology is reasonable. Advanced technology and mature, strong adaptability to changes in water quality, water mark and high stability, sludge is easy to handle.

(2) economic and energy saving. Small power consumption, low cost, less land.

(3) easy to management. Operation management is convenient, reliable equipment.

(4) pay attention to the environment. The plant layout in harmony with the surrounding environment, pay attention to the governance of noise control and stench, greening, road and installment construction is good.

(1) aerobic biological treatment technology is adopted widely in urban sewage treatment plants in countries around the world sewage treatment process, divided into two kinds of activated sludge process and biofilm method. Activated sludge process is the artificially intensified water self-purification, is to "live" on the activated sludge microbial groups, active sludge in the reactor - aeration pool in slurry, extensive contacts with wastewater, the technology of sewage purification; Biological membrane method is the hardening artificial soil self-purification, is to make the microbial groups on the surface in a membrane attached, contact with water, the technology of sewage purification. Activated sludge process, biological membrane method and its variants change process, have their own characteristics and application conditions, when the choice, should be based on regional water quality, water quantity, receiving waters, climate, environment, economic conditions and other conditions.

(2) Activated sludge process technology in the purification mechanism, there is no breakthrough, after decades of development and innovation, now has on the basis of the traditional activated sludge process many kinds of operation mode, such as A/O phosphorus removal process, A/O denitrification process simultaneous denitrification and phosphorus removal process, A2 / O, oxidation ditch technology, A/B method, various kinds of SBR method, carrier activated sludge process, the integration of activated sludge process, and so on. In recent years, the biggest progress is to anaerobic activated sludge process mechanism is introduced into biochemical reaction tank, the anaerobic condition anaerobic-aerobic exist at the same time in the biochemical pool or repeated periodically, but the basic principle and standard method is consistent with the process.

(3) anaerobic - aerobic activated sludge method process (A/O method), is A biological selection function and function both nitrogen and phosphorus standard activated sludge method reform. The so-called anaerobic is dissolved oxygen in the biochemical reaction interval tends to zero state. In such circumstances forced obligate aerobic microorganisms - filamentous fungi to decrease metabolic function, restrain the breeding, have played an important role anaerobic biological choice, which can prevent the phenomenon of sludge bulking. A/O activated sludge process technology in A common front to join anaerobic activated sludge process, through the change of sludge load to realize the function of dephosphorization and denitrification. In the A/O method and developed on the basis of A2 / O method, namely in anaerobic/aerobic anoxic period in order to realize the synchronization of biological nitrogen removal, due to its small sludge load adaptation range, so often in the actual operation according to favor one of dephosphorization and denitrification function. A/O, A2 / O process due to the stable discharging water, energy consumption is not high, operation management is convenient wait for A characteristic, USES the most in the domestic and foreign large and medium-sized sewage plant.

(4) carrier activated sludge process, it is in the activated sludge process reaction pool dosing solid particles or soft and semi soft packing, in order to increase unit reaction space of microbial quantity, improve the reactor volume load. Is a good combination of activated sludge process and biological membrane method, generally suitable for sewage plant extract transformation, improve the processing ability, the core technology for patent packing, in recent years, Lin bubble technology applied in dalian as a representative of the the spring willows sewage plant and tieling sewage plant.

(5) oxidation ditch process, in the 50 s development, by the Dutch buss, mainly include the Carrousel (Carrousel), three groove type, integrated type, Mr Bell (Orbal) several technologies such as form. Oxidation ditch process is a closed biochemical ditches, brush to turn dish or turn to oxygen and water flow, the process is simple, with low requirement to the operation and management, more used to delay aeration, produce less quantity of sludge, easy sludge dewatering. Oxidation ditch process areas in the south of China and is widely applied in the central and western regions. turn

(6) A/B method (Absoption - Biodegradation), is A two-stage biochemical reaction system. Level for biological adsorption, high sludge loading, short reaction time (30 minutes); Level 2 for general biochemical reaction tank, sludge load as the common activated sludge process. A/B A, level 2 has its own secondary sedimentation tank and sludge return system, used in high concentration of sewage, its typical applications for urumqi hedong sewage treatment plant and Qingdao sea river sewage treatment plant.

Once the Sequencing Batch type activated sludge process (SBR - Sequencing Batch Reactor) was invented in 1914 by the British scholar Locket Ardern and water treatment technology. In the early 70 s, American Natre R.I Dame university professor rvine the laboratory scale of SBR process is used for system in-depth research, and in 1980 in the U.S. environmental protection agency (EPA), with the support of Culwer in indiana city reconstruction and production of the world's first SBR wastewater treatment plant.

Being the Intermittent Cyclic delay aeration activated sludge process (ICEAS - Intermittent Cyclic Extended System) is a new university of wales in 1968 by the Australian ABJ companies developed in partnership with the United States. In 1976, the world's first ICEAS process sewage plant operation. ICEAS compared with the traditional SBR, the biggest characteristic is: in the reactor inlet have a reaction zone, the entire process is continuous water, intermittent drainage, no obvious reaction and idle phase, so the processing cost is lower than traditional SBR. The technology in our country, the typical application for kunming third sewage treatment plant, in the domestic influence.

levies biological membrane method, which is another widely used method of wastewater biochemical treatment. This kind of treatment method is to make the kind of microbial bacteria and a fungus and protozoan and metazoan kind of microbial adhesion to grow in the carrier or the filter material, and is formed on the membrane biological sludge and biofilm. Sewage contact with biofilm, the organic pollutants in wastewater as nutrients uptake by biofilm on the microbial, purified water, propagate itself.

3. According to the above comparison and analysis technology, combined with the conditions of shihezi city sewage water that a suitable treatment process optimization as follows:

The first scheme: A/O process

Over the past twenty years the biggest progress is to anaerobic activated sludge process mechanism is introduced into the biochemical reaction tank, anaerobic and aerobic intermittent cycle operation bring new technical and economical effects to the activated sludge process, namely, biological denitrification, biological phosphorus removal, biological selection, etc.

Anaerobic - aerobic denitrification process of activated sludge system (A/O method), is A biological function of choice as well as the standard of both denitrification function activated sludge process reform.

The second solution: DAT IAT process

Aerobic Intermittent aeration system (DAT IAT - Demand AerationTank - Intermittent Tank) is a new process of SBR. It between traditional activated sludge process and the typical SBR, the continuous water continuous - intermittent aeration mode of operation, apply Yu Jinshui water change in large areas. Main body structure is made up of aerobic pool DAT IAT pool and intermittent aeration pool pool, DAT continuous water continuous aeration pool, the water from the middle wall into the IAT pool, continuous IAT pool water intermittent drainage. At the same time, the sludge DAT IAT pool pool. It belongs to delay aeration process, is actually A/O denitrification process combined with the traditional SBR, the industry has A low sludge loading, therefore has the characteristics of impact resistant capability is strong, and has the function of denitrification. The domestic application of tianjin industrial and technological development zone sewage treatment plant and sewage treatment plant, fushun treble the chariot is a kind of suitable for large water volume of the SBR process.