CN101514067B - Domestic sewage treatment system with anaerobic-aerobic combined biological filter - Google Patents

Abstract

The utility model relates to a domestic sewage treatment system with anaerobic-aerobic combined biological filter, which relates to a domestic sewage treatment system. The invention solves the problems that the existing domestic sewage treatment system has poor effect of removing P and N, poor effluent quality, and difficult to reach the prescribed discharge standard. The pretreatment device, biological floc filtration sedimentation tank, anaerobic biological filter tank, BIOFOR biological aerated filter tank, backwash waste water tank and clear water tank are arranged in sequence from left to right; the swirling sand sedimentation tank of the pretreatment device and The water distribution pipe of the biological floc filtration sedimentation tank is connected, the outlet channel of the biological floc filtration sedimentation tank is connected with the water distribution area of the anaerobic biological filter through the bottom inlet pipe, and the outlet channel of the anaerobic biological filter is connected with the BIOFOR aerated biological filter The water distribution area is connected, and the outlet channel of the biological aerated filter is connected with one end of the outlet pipe. The method of using the invention to treat domestic sewage has good denitrification and phosphorus removal efficiency, and all indexes of the treated water body can reach the prescribed discharge standard.

Description

Domestic sewage treatment system with anaerobic-aerobic combined biological filter

technical field

The invention relates to a domestic sewage treatment system.

Background technique

The "Discharge Standards of Pollutants for Urban Sewage Treatment Plants" (GB 18918-2002), which is being implemented in my country, puts forward higher requirements for the removal of P and N. However, the activated sludge method in the existing urban sewage treatment is difficult to achieve this goal. Therefore, it is necessary to build a new sewage plant or transform the existing sewage plant to have the function of removing P and N. At the same time, with the acceleration of urban development and the expansion of urban areas, sewage treatment facilities are getting closer to urban areas, and some are even built in urban areas. Therefore, land use for sewage plants is strictly restricted. Traditional sewage treatment plants inevitably produce peculiar smell and noise, and occupy a large area. Due to the above objective needs, it is necessary to find new sewage treatment technologies. Practice shows that the biological aerated filter (BAF) process is one of the most potential alternative processes.

Biological aerated filter (BAF) is a new wastewater treatment process developed abroad in recent years. The world's first biological aerated filter was put into operation in France in 1981, and then it was widely used in European countries. American countries such as the United States and Canada introduced this technology in the late 1980s, and Japan, South Korea and Taiwan, China also introduced this technology successively. At present, the world's largest environmental protection companies, such as France's Delimont Company, Germany's Philip Muller Company, and France's OTV Company, all promote it as a key product around the world. In mainland China, biological aerated filters are in the promotion stage. Its appearance is a submerged biological fixed bed developed by the inspiration of the water supply fast filter. It still belongs to the category of biofilm. It integrates the mechanisms of filtration, adsorption and biological oxidation, and can simultaneously serve as an ordinary biological aeration tank, The role of secondary sedimentation tank and sand filter. Its biggest feature is that it integrates biological oxidation and interception of suspended solids, saves the subsequent secondary sedimentation tank, and simplifies the treatment process on the premise of ensuring the treatment effect. In addition, the biological aerated filter process has high organic volume load, large hydraulic load, short hydraulic retention time, less infrastructure investment, low energy consumption and low operating cost. At the same time, the process has high effluent quality and has a certain denitrification effect.

The structure of the biological aerated filter is similar to that of the ordinary fast filter, the main difference is that an aeration system is added to the lower part or bottom of the biological aerated filter. According to the direction of water flow, it can be divided into two types: upward flow and downward flow. Early biological aerated filters mostly use downward flow, such as BIOCARBON type. Since the downflow biological aerated filter has low pollution-holding efficiency, is easy to block, and has a short operating cycle, the upflow method is now mostly used, that is, the air and water flow in the same direction, so that the water and air distribution are more uniform. At the same time, during the rising process of water vapor, the suspended pollutants intercepted at the bottom can be brought into the middle and upper part of the filter tank, which increases the dirt-holding capacity of the filter tank and prolongs the working cycle. At present, the upflow biological aerated filter has various forms such as BIOFOR, BIOSTY, COLOX, BIOTUR, etc., among which the BIOFOR type is the most widely used.

Although the BAF process has a good denitrification and phosphorus removal effect, but now, many large cities have required some sewage treatment plants built in the city to meet the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB 18918-2002) Grade A The standard, a single BAF process is difficult to achieve, so some BAF combination processes have emerged one after another. However, the method of treating domestic sewage by using the anaerobic-aerobic combined biological aerated filter technology that combines the traditional AO process with the BIOFOR pool type that is widely used in the BAF process has not been reported.

Contents of the invention

The present invention solves the problem that the existing domestic sewage treatment system has poor effect of P and N removal and poor effluent quality, and it is difficult to meet the standard of "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB 18918-2002) which is being implemented in my country. , and further provides a domestic sewage treatment system with an anaerobic-aerobic combined biological filter.

The technical solution adopted by the present invention to solve the above technical problems is: the domestic sewage treatment system with anaerobic-aerobic combined biological filter includes a pretreatment device, a biological floc filtration sedimentation tank, a backwash waste water tank and a clean water tank; The domestic sewage treatment system also includes anaerobic biological filter, BIOFOR biological aerated filter (aerobic biological filter), phosphorus removal dosing device, backwash water pump, nitrification liquid return pump, waste water return pump, nitrification liquid return flow Water pipes, backwash water pipes, waste water return pipes, bottom water inlet pipes, anaerobic biological filter backwash liquid outlet pipes, aerated biological filter backwash liquid outlet pipes, dosing pipes, water outlet pipes, several control valves and ultraviolet disinfection device; the pretreatment device, biological floc filtration sedimentation tank, anaerobic biological filter, BIOFOR aerated biological filter, backwash wastewater tank and clear water tank are arranged in sequence from left to right; the anaerobic biological filter consists of filter The pool body, filter plate, several long-handle filter heads, pebble supporting layer, filter material layer, steady flow plate, slope, backwash waste water channel and outlet channel are composed. The filter plate is set in the filter tank body and the filter tank body The inner cavity of the filter plate is divided into upper and lower parts. The lower cavity of the filter plate is the water distribution area. Several long-handle filter heads are evenly arranged on the filter plate and the water inlets of several long-handle filter heads are located in the water distribution area. A layer of pebble supporting layer is laid on the upper surface, and a filter material layer is laid on the pebble supporting layer. A slope is set at the outlet groove at the upper end of the right side wall of the filter tank body, and a stabilizing plate is set at the left end of the slope. The flushing wastewater channel and the outlet channel are arranged at the right end of the slope from left to right; the BIOFOR biological aerated filter consists of an aerobic pool body, an aerobic pool filter plate, several aerobic pool long handle filter heads, and aerobic pool pebbles Supporting layer, aerobic tank filter material layer, aerobic tank flow stabilization plate, aerobic tank slope, aerobic tank backwash wastewater channel, aerobic tank outlet channel, aeration device and aeration fan, aerobic tank filter The plate is set in the body of the aerobic pool to divide the inner cavity of the aerobic pool into upper and lower parts. The lower cavity of the filter plate of the aerobic pool is the water distribution area of the aerobic pool, and several long handle filter heads of the aerobic pool are evenly distributed. It is set on the filter plate of the aerobic pool and the water inlets of several long handle filter heads of the aerobic pool are located in the water distribution area of the aerobic pool. On the upper surface of the filter plate of the aerobic pool, there is a layer of supporting layer of aerobic pool pebbles, which is good The aerobic pool filter material layer is laid on the pebble supporting layer of the oxygen pool. There is an aerobic pool slope at the water outlet slot, and the aerobic pool stabilizer plate is set at the left end of the aerobic pool slope. The right end of the right end; the cyclone sedimentation tank of the pretreatment device is connected with the water distribution pipe of the bio-floc filtration sedimentation tank, the outlet channel of the bio-floc filtration sedimentation tank is connected with the water distribution area through the bottom water inlet pipe, and the outlet of the anaerobic biofilter The water channel is connected with the water distribution area of the aerobic pool, the outlet channel of the aerobic pool is connected with the clear water pool, the outlet channel of the aerobic pool is connected with one end of the outlet pipe, and the ultraviolet disinfection device is arranged on the other end of the outlet pipe; the nitrification liquid return pump is installed In the clean water tank, the nitrification liquid return pump is connected with the water distribution area through the nitrification liquid return pipe, and the backwash water pump is installed In the clear water tank, the backwash water pump is connected to the water distribution area and the aerobic pool water distribution area respectively through the backwash water pipe. The flushing wastewater channel is connected to the backwashing wastewater pool through the backwashing liquid outlet pipe of the anaerobic biological filter, and the backwashing wastewater channel in the aerobic tank is connected to the backwashing wastewater pool through the backwashing liquid outlet pipe of the aerated biological filter; phosphorus removal and dosing The device is composed of a dosing tank and a dosing pump, both of which are installed in the lower cavity between the grilles on the pretreatment device, the dosing tank and the dosing pump are connected, and the dosing pump is connected to the well through the dosing pipe. The water distribution area of the oxygen tank is connected; on the nitrification liquid return pipe, backwash water pipe, waste water return pipe, anaerobic biological filter backwash liquid outlet pipe, aerated biological filter backwash liquid outlet pipe, dosing pipe and water outlet pipe respectively With control valve.

The beneficial effect of the present invention is: utilize the present invention to process domestic sewage denitrification and dephosphorization (remove P and remove N) efficiency is good, and each index of the treated water body can all reach " pollutant discharge standard of urban sewage treatment plant " (GB 18918-2002) Class A standard. Using the invention to treat domestic sewage can reduce the labor intensity of workers and can fully realize automatic control. The present invention adopts the combination of anaerobic biological filter and aerated biological filter to treat domestic sewage with less residual sludge output and good denitrification effect. In addition, the present invention also has the advantages of not being prone to sludge bulking, stable operation, not susceptible to impact, small floor area, less infrastructure investment, and low operating costs. The invention is easy to clean the system itself and ensures the quality of effluent water. Using the invention to treat domestic sewage greatly improves the treatment effect and the quality of effluent water, so that the sewage can be discharged up to the standard. The use of the present invention realizes the high-standard up-to-standard discharge of domestic sewage in engineering, which is beneficial to popularization and application.

Description of drawings

Fig. 1 is a schematic structural view of the present invention.

Detailed ways

Specific embodiment one: as shown in Figure 1, the domestic sewage treatment system pretreatment device with anaerobic-aerobic combined biofilter described in this embodiment, biological floc filtration sedimentation tank, backwash waste water tank 20 And clear water pond 24; Described domestic sewage treatment system also comprises anaerobic biological filter, BIOFOR biological aerated filter (aerobic biological filter), dephosphorization dosing device, backwash water pump 23, nitrifying liquid backflow pump 28, Wastewater return pump 29, nitrification liquid return pipe 48, backwash water pipe 43, waste water return pipe 49, bottom water inlet pipe 11, anaerobic biological filter backwash liquid outlet pipe 51, aerated biological filter backwash liquid outlet pipe 52, Dosing pipe 53, water outlet pipe 54, several control valves 60 and ultraviolet disinfection device 32; said pretreatment device, biological floc filtration sedimentation tank, anaerobic biological filter tank, BIOFOR biological aerated filter tank, backwash wastewater tank 20 and the clear water pool 24 are arranged in turn from left to right; the anaerobic biological filter consists of a filter tank body 10, a filter plate 42, several long-handled filter heads 13, pebble supporting layer 15, filter material layer 14, and a steady flow plate 16. The slope 17, the backwash waste water channel 18 and the outlet channel 19 are composed. The filter plate 42 is arranged in the filter tank body 10 to divide the inner cavity of the filter tank body 10 into upper and lower parts. The lower cavity of the filter plate 42 is In the water distribution area 12, several long-handle filter heads 13 are uniformly arranged on the filter plate 42 and the water inlets of the several long-handle filter heads 13 are located in the water distribution area 12, and a layer of pebble supporting layer is laid on the upper surface of the filter plate 42 15. A filter material layer 14 is laid on the pebble support layer 15, a slope 17 is provided at the water outlet notch at the upper end of the right side wall of the filter tank body 10, and a stabilizing plate 16 is arranged at the left end of the slope 17 to backwash the waste water channel. 18. The outlet channel 19 is set at the right end of the slope 17 from left to right; the BIOFOR biological aerated filter consists of an aerobic tank body 110, an aerobic tank filter plate 142, several aerobic tank long-handled filter heads 113, a good Oxygen pool pebble supporting layer 115, aerobic pool filter material layer 114, aerobic pool stabilizer plate 116, aerobic pool slope 117, aerobic pool backwash waste water channel 118, aerobic pool outlet channel 119, aeration device 26 Composed of aeration fan 27, aerobic pool filter plate 142 is arranged in aerobic pool pool body 110 to divide the inner chamber of aerobic pool pool body 110 into upper and lower parts, and the lower cavity of aerobic pool filter plate 142 is preferably Oxygen pool water distribution area 112, several aerobic pool long handle filter heads 113 are evenly arranged on the aerobic pool filter plate 142 and the water inlets of several aerobic pool long handle filter heads 113 are located in the aerobic pool water distribution area 112, An aerobic pool pebble support layer 115 is laid on the upper surface of the aerobic pool filter plate 142, an aerobic pool filter material layer 114 is laid on the aerobic pool pebble support layer 115, and the aeration device 26 is arranged in the aerobic pool In the pebble supporting layer 115, the aeration fan 27 is connected with the aeration device 26, and the aerobic pool slope 117 is provided at the water outlet notch at the upper end of the right side wall of the aerobic pool body 110, and the aerobic pool stabilizing plate 116 is provided with At the left end of the aerobic pool slope 117, the aerobic pool backwash waste water channel 118, the aerobic pool outlet channel 119 Set at the right end of the slope 117 of the aerobic pool from left to right; the swirl sedimentation tank 3 of the pretreatment device is connected with the water distribution pipe 5 of the biological floc filtration sedimentation tank, and the outlet channel 6 of the biological floc filtration sedimentation tank passes through the bottom The water inlet pipe 11 is communicated with the water distribution area 12, the outlet channel 19 is communicated with the aerobic pool water distribution area 112, the aerobic pool outlet channel 119 is connected with the clear water pool 24, the aerobic pool outlet channel 119 is communicated with an end of the outlet pipe 54, and the ultraviolet The disinfection device 32 is arranged on the other end of the water outlet pipe 54; the nitrification liquid return pump 28 is installed in the clear water tank 24, the nitrification liquid return flow pump 28 communicates with the water distribution area 12 through the nitrification liquid return flow pipe 48, and the backwash water pump 23 is installed in the clear water tank In 24, the backwash water pump 23 communicates with the water distribution area 12 and the aerobic pool water distribution area 112 respectively through the backwash water pipe 43, and the waste water return pump 29 is installed in the backwash waste water pool 20, and the waste water return pump 29 is connected to the pre-treatment area through the waste water return water pipe 49. The water inlet of the treatment device is connected; the backwash wastewater channel 18 is communicated with the backwash wastewater tank 20 through the anaerobic biological filter backwash liquid outlet pipe 51, and the aerobic tank backwash wastewater channel 118 is discharged through the aerobic biological filter backwash liquid outlet pipe 51. The water pipe 52 communicates with the backwash waste water pool 20; the phosphorus removal and dosing device is composed of a dosing tank 30 and a dosing pump 31, and the dosing tank 30 and the dosing pump 31 are all installed in the lower cavity of the grid room 41 on the pretreatment device Inside, the dosing tank 30 communicates with the dosing pump 31, and the dosing pump 31 communicates with the aerobic tank water distribution area 112 through the dosing pipe 53; A control valve 60 is provided on the filter backwash liquid outlet pipe 51 , the biological aerated filter backwash liquid outlet pipe 52 , the dosing pipe 53 and the water outlet pipe 54 respectively.

The effluent of BIOFOR biological aerated filter (upward flow biological aerated filter) returns to the anaerobic biological filter through the water pump, and the return ratio is 120%. Anaerobic biological filter (upward flow anaerobic biological filter) is mainly used for denitrification and denitrification under anaerobic conditions. Most of the nitrogen in the sewage is in the form of ammonia nitrogen. The sewage is converted from ammonia nitrogen to nitrate nitrogen in the BIOFOR biological aerated filter, and the nitrified water in the BIOFOR biological aerated filter is returned to the anaerobic biological filter before it The raw water (sewage to be treated) enters the anaerobic biological filter together; the raw water provides the carbon source, and the return water provides the nitrate, and the nitrification reaction is carried out in the filter layer under the action of denitrifying bacteria, and the nitrogen in the raw water Finally, it is discharged from the anaerobic biological filter in the form of nitrogen.

Phosphorus removal dosing device feeds ferric chloride solution into BIOFOR biological aerated filter (phosphorus removal equation: Fe ³⁺ +PO ^3- ₄ =FePO ₄ ↓) for phosphorus removal.

Specific embodiment two: As shown in Figure 1, the pretreatment device in this embodiment is composed of a grid room 41, a coarse grid 1, a fine grid 2 and a swirl grit chamber 3, the coarse grid 1, The fine grids 2 are sequentially arranged in the upper cavity of the grid room 41 from left to right, and the swirl flow grit chamber 3 is arranged on the right side of the grid room 41 . The coarse grid is a rotary grid with a grid spacing of 10mm. The fine grid is a rotary drum grid with a grid spacing of 2mm. Coarse grid 1 and fine grid 2 have realized double interception. The size of the cyclone grit chamber 3 is determined according to the water inflow. Other components and connections are the same as those in the first embodiment.

Specific embodiment three: As shown in Figure 1, the biological floc filtration sedimentation tank in this embodiment is composed of a tank body 4, a water distribution pipe 5, an outlet channel 6 and a mud discharge pipe 9, and the outlet channel 6 is arranged on the tank body In the upper part of the tank body 4, several mud grooves 8 are provided on the bottom surface of the tank body 4, the water distribution pipe 5 is arranged in the lower part of the tank body 4 and one end of the water distribution pipe 5 passes through the side wall of the tank body 4, and the mud discharge pipe 9 is arranged In the lower part of the tank body 4 and below the water distribution pipe 5 , the mud discharge pipe 9 passes through several mud grooves 8 and one end of the mud discharge pipe 9 passes through the side wall of the tank body 4 . The high-efficiency biological floc filtration and sedimentation device is an existing technology, in which sewage is efficiently filtered and precipitated, and biological hydrolysis can also occur, which initially reduces the BOD load of sewage (BOD is biological oxygen demand, Biology Oxygen Demmand. It refers to the amount of oxygen consumed after the organic matter that can be degraded by microorganisms in water is degraded. However, it takes a long time to completely degrade the organic matter. In order to standardize and improve the detection efficiency, the state stipulates that the 5-day biological oxygen demand is used as the indicator of water quality. Standard, that is to say the total amount of oxygen consumed by biodegrading organic matter in water for 5 days), improves the biodegradability of sewage. Other components and connections are the same as those in the first embodiment.

Specific embodiment four: As shown in Figure 1, the domestic sewage treatment system in this embodiment also includes a backwash fan 21, a backwash air pipe 22 and two backwash control valves 61, and the backwash fan 21 is arranged on the anaerobic biological filter Between the tank and the BIOFOR biological aerated filter, the backwash fan 21 communicates with the water distribution area 12 and the aerobic tank water distribution area 112 respectively through the backwash air pipe 22, and the backwash air pipe 22 is provided with two backwash control valves 61. Such a design can realize the three-step backwashing of air washing, air-water backwashing and rinsing (water washing) for anaerobic biological filter and BIOFOR aerated biological filter. During normal operation, the valves of the control valves at the lower end of the backwash wastewater canal 18 and the aerobic pool backwash wastewater canal 118 are closed, and the sewage enters the next process unit through the outlet channel; when backwashing, the valve is opened, and the backwash wastewater passes through The backwash wastewater canal 18 and the aerobic pool backwash wastewater canal 118 respectively enter the backwash wastewater pool 20 . First, the water inlet valve of the filter is closed to stop the water intake, and then the backwash fan 21 and its corresponding valve are turned on, and the backwash gas enters the filter water distribution area 12 and the aerobic tank water distribution area 112 respectively through the backwash air pipe 22, and passes through the long handle The filter head 13 enters the filter material layer 14 and enters the aerobic tank filter material layer 114 through the long handle filter head 113 of the aerobic tank, and then loosens the filter material in the anaerobic biological filter tank and the filter material in the BIOFOR biological aerated filter tank, Air washing mainly plays the purpose of loosening the filter material; then, open the backwash water pump 23 and corresponding valves located in the clear water tank 24, and start air-water backwashing. Air-water backwashing is the main step of the backwashing program. Be full. After the air-water backwash is completed, only the backwash fan 21 is turned off, and the backwash water pump 23 is not turned off, and a period of rinsing is carried out. The purpose of rinsing is to further discharge the suspended solids and detachment from the biofilm washed by the air-water backwash system. Generally, the water backwash intensity is controlled to be about 20m3/(m ² ·h), and the air backwash intensity is about 50m ³ /(m2·h). The ratio of air washing time: air-water backwashing: rinsing time is controlled at about 1:5:2, and the specific implementation time depends on the specific situation. Other compositions and connections are the same as those in the first, second or third embodiment.

Utilize the operating process of the present invention to process domestic sewage:

The domestic sewage enters the pretreatment system, the biological floc filtration sedimentation tank, the anaerobic biological filter, the BIOFOR aerated biological filter, and the ultraviolet disinfection device in sequence, and then the water is discharged. 1. The sewage first enters the coarse grid 1 and the fine grid 2 of the pretreatment system, and after passing through the double grids to intercept larger debris, the sewage enters the swirl grit chamber 3, and the hydraulic surface of the swirl grit chamber 3 The load is controlled at about 130m ³ /m ² ·h, and the residence time is controlled at about 40s. 2. Subsequently, the sewage preliminarily treated by the pretreatment system enters the biological floc filtration sedimentation tank 4, and the sewage enters from the lower water distribution pipe 5 of the pool, and is discharged from the upper outlet channel 6. Through debugging, a sludge suspension layer 7 can be formed in the biological floc filtration sedimentation tank, which is similar to a filter layer, and can quickly intercept and absorb solid suspensions and most colloidal substances in sewage. And in this suspended sludge layer, a high concentration of facultative microorganisms can be produced, which can hydrolyze insoluble organic matter into soluble substances, and convert macromolecules and refractory substances into easily biodegradable substances. The sedimentation tank does not need to add coagulation agent, and the residence time is controlled at about 4 to 6 hours according to the quality of the influent water. The bottom sludge of the biological floc filter sedimentation tank is concentrated in the mud tank 8; when the sludge is discharged, the valve is opened, and the sludge is discharged from the system through the sludge discharge pipe 9 by hydraulic action. 3. Biological flocs filter the effluent from the sedimentation tank into the anaerobic biological filter. After the sewage and the reflux water of the effluent of the BIOFOR biological aerated filter are combined, they enter the water distribution area 12 through the bottom water inlet pipe 11, and the reflux ratio is 120%. Sewage enters the filter material layer 14 from the water distribution area 12 through the long handle filter head 13 . A support layer 15 composed of one deck of pebbles is laid on the bottom of the filter material layer. The filter layer is an anaerobic environment, in which the sewage is removed for BOD, COD, nitrate nitrogen, and SS. The outlet slot of the anaerobic biological filter is provided with a steady flow plate 16 and a slope 17 to prevent the filter material from running out during backwashing. The valve under the backwash waste water channel 18 is closed during normal operation, and the sewage enters the next process unit through the outlet channel. 4. The effluent from the anaerobic biological filter enters the BIOFOR biological aerated filter. The structure of the BIOFOR biological aerated filter is basically the same as that of the anaerobic biological filter, except that the aeration pipe 26 is laid in the support layer, and the gas source is provided by the aeration fan 27 . 5. Part of the effluent from the anaerobic biological filter flows into the clear water pool 24, and part of it is discharged after being sterilized. A part of the water flowing into the clear water pool 24 is returned to the anaerobic biological filter 10 by the digestive liquid return pump 28 to provide water source for backwashing. The backwash waste water is finally concentrated in the backwash waste water pool 20 and returned to the pretreatment device through the waste water return pump 29 . The dosing tank 30 stores ferric chloride solution, which is fed into the BIOFOR biological aerated filter through the dosing pump 31, and the chemical phosphorus removal reaction is completed in the BIOFOR biological aerated filter. The ultraviolet sterilizer 32 (ultraviolet sterilizer) that disinfection adopts is sterilized. After ultraviolet disinfection, the raw water can reach the first-class A discharge standard of the Discharge Standard of Pollutants for Urban Sewage Treatment Plants (GB 18918-2002).

BOD is Biological Oxygen Demand, Biology Oxygen Demmand, which refers to the amount of oxygen consumed after the organic matter degraded by microorganisms in water is degraded; however, it takes a long time to completely degrade organic matter. In order to standardize and improve detection efficiency, the state stipulates The 5-day biological oxygen demand is used as the standard to illustrate the water quality, that is to say, the total amount of oxygen consumed by biodegrading organic matter in water for 5 days.

COD is chemical oxygen demand, which is the amount of oxidant consumed when a certain strong oxidant is used to treat water samples under certain conditions. It is an indicator of the amount of reducing substances in water; the reducing substances in water include various organic substances, nitrite, sulfide, ferrous salt, etc., but the main ones are organic substances, so the chemical oxygen demand (COD) and It is often used as an index to measure the content of organic substances in water. The greater the chemical oxygen demand, the more serious the pollution of the water body by organic substances.

SS is the abbreviation of English (Suspended Substance), that is, suspended matter in water quality. Suspended matter in water quality refers to the solid matter that is trapped on the filter membrane by the water sample through the filter membrane with a pore size of 0.45 μm and dried at 103-105°C to constant weight. C represents the content of suspended solids in the water quality, and the measurement unit is mg/L.

Claims (4)

1. the domestic sewage processing system that has anaerobic-aerobic combined biological filter, described domestic sewage processing system comprise pretreatment unit, biofloculation body filtering settling pond, backwashing wastewater pond (20) and clean water basin (24); It is characterized in that: described domestic sewage processing system also comprises anaerobic biofilter, the BIOFOR BAF, the dephosphorization chemicals dosing plant, backwash pump (23), nitrification liquid reflux pump (28), return of waste water pump (29), nitrification liquid backflow water pipe (48), back flushing water pipe (43), return of waste water water pipe (49), bottom water inlet pipe (11), anaerobic biofilter counter-flushing liquid rising pipe (51), BAF counter-flushing liquid rising pipe (52), chemical feed pipe (53), rising pipe (54), several control valves (60) and ultra violet sterilizer (32); Described pretreatment unit, biofloculation body filtering settling pond, anaerobic biofilter, BIOFOR BAF, backwashing wastewater pond (20) and clean water basin (24) set gradually from left to right;

Anaerobic biofilter is by pond, filter tank body (10), filter plate (42), several strainer heads (13), cobble supporting layer (15), filter material layer (14), stabilier (16), slope (17), backwashing wastewater canal (18) and go out water channel (19) and form, filter plate (42) is arranged on the interior inner chamber with pond, filter tank body (10) of pond, filter tank body (10) and is divided into two parts up and down, the lower cavity of filter plate (42) is water distributing area (12), several strainer heads (13) are uniform to be arranged on that filter plate (42) is gone up and the water-ins of several strainer heads (13) are positioned at water distributing area (12), be equipped with one deck cobble supporting layer (15) on the upper surface of filter plate (42), be equipped with filter material layer (14) on the cobble supporting layer (15), the water outlet notch place of the right side wall upper end of pond, filter tank body (10) is provided with slope (17), stabilier (16) is arranged on the left end of slope (17), backwashing wastewater canal (18), go out the right-hand member that water channel (19) is successively set on slope (17) from left to right;

The BIOFOR BAF is by Aerobic Pond pond body (110), Aerobic Pond filter plate (142), several Aerobic Pond strainer heads (113), Aerobic Pond cobble supporting layer (115), Aerobic Pond filter material layer (114), Aerobic Pond stabilier (116), Aerobic Pond slope (117), Aerobic Pond backwashing wastewater canal (118), Aerobic Pond goes out water channel (119), aerating apparatus (26) and Aeration fan (27) are formed, Aerobic Pond filter plate (142) is arranged on the interior inner chamber with Aerobic Pond pond body (110) of Aerobic Pond pond body (110) and is divided into two parts up and down, the lower cavity of Aerobic Pond filter plate (142) is Aerobic Pond water distributing area (112), several Aerobic Pond strainer heads (113) are uniform to be arranged on that Aerobic Pond filter plate (142) is gone up and the water-ins of several Aerobic Pond strainer heads (113) are positioned at Aerobic Pond water distributing area (112), be equipped with one deck Aerobic Pond cobble supporting layer (115) on the upper surface of Aerobic Pond filter plate (142), be equipped with Aerobic Pond filter material layer (114) on the Aerobic Pond cobble supporting layer (115), aerating apparatus (26) is arranged in the Aerobic Pond cobble supporting layer (115), Aeration fan (27) is connected with aerating apparatus (26), the water outlet notch place of the right side wall upper end of Aerobic Pond pond body (110) is provided with Aerobic Pond slope (117), Aerobic Pond stabilier (116) is arranged on the left end of Aerobic Pond slope (117), Aerobic Pond backwashing wastewater canal (118), Aerobic Pond goes out the right-hand member that water channel (119) is successively set on Aerobic Pond slope (117) from left to right;

The eddy flow sedimentation basin (3) of pretreatment unit is communicated with the water distributing pipe (5) of biofloculation body filtering settling pond, the water channel (6) that goes out of biofloculation body filtering settling pond is communicated with water distributing area (12) by bottom water inlet pipe (11), the water channel (19) that goes out in the anaerobic biofilter is communicated with Aerobic Pond water distributing area (112), Aerobic Pond goes out water channel (119) and is connected with clean water basin (24), Aerobic Pond goes out water channel (119) and is communicated with an end of rising pipe (54), and described ultra violet sterilizer (32) is arranged on the other end of rising pipe (54); Nitrification liquid reflux pump (28) is installed in the clean water basin (24), nitrification liquid reflux pump (28) is communicated with water distributing area (12) by nitrification liquid backflow water pipe (48), backwash pump (23) is installed in the clean water basin (24), backwash pump (23) is communicated with respectively with water distributing area (12), Aerobic Pond water distributing area (112) by back flushing water pipe (43), return of waste water pump (29) is installed in the backwashing wastewater pond (20), and return of waste water pump (29) is communicated with the water-in of pretreatment unit by return of waste water water pipe (49); Backwashing wastewater canal (18) is communicated with backwashing wastewater pond (20) by anaerobic biofilter counter-flushing liquid rising pipe (51), and Aerobic Pond backwashing wastewater canal (118) is communicated with backwashing wastewater pond (20) by BAF counter-flushing liquid rising pipe (52); The dephosphorization chemicals dosing plant is made of dispensing jar (30) and dosing pump (31), dispensing jar (30) and dosing pump (31) are installed in the lower cavity of (41) between grid on the pretreatment unit, dispensing jar (30) and dosing pump (31) are communicated with, and dosing pump (31) is communicated with Aerobic Pond water distributing area (112) by chemical feed pipe (53); On nitrification liquid backflow water pipe (48), back flushing water pipe (43), return of waste water water pipe (49), anaerobic biofilter counter-flushing liquid rising pipe (51), BAF counter-flushing liquid rising pipe (52), chemical feed pipe (53) and rising pipe (54), be respectively equipped with control valve (60).

2. the domestic sewage processing system that has anaerobic-aerobic combined biological filter according to claim 1, it is characterized in that: described pretreatment unit is made of (41), coarse rack (1), fine fack (2) and eddy flow sedimentation basin (3) between grid, described coarse rack (1), fine fack (2) are successively set in the upper cavity of (41) between grid from left to right, and eddy flow sedimentation basin (3) is arranged on the right side of (41) between grid.

3. the domestic sewage processing system that has anaerobic-aerobic combined biological filter according to claim 1, it is characterized in that: described biofloculation body filtering settling pond is by pond body (4), water distributing pipe (5), going out water channel (6) and shore pipe (9) forms, describedly go out water channel (6) and be arranged in the top of pond body (4), offer several mud grooves (8) on pond body (4) bottom face, water distributing pipe (5) is arranged in the bottom of pond body (4) and an end of water distributing pipe (5) passes the sidewall of pond body (4), shore pipe (9) is arranged in the bottom of pond body (4) and is positioned at the below of water distributing pipe (5), and the end that shore pipe (9) passes several mud grooves (8) and shore pipe (9) passes the sidewall of pond body (4).

4. according to claim 1, the 2 or 3 described domestic sewage processing systems that have anaerobic-aerobic combined biological filter, it is characterized in that: described domestic sewage processing system also comprises back flushing blower fan (21), back flushing tracheae (22) and two back flushing control valves (61), back flushing blower fan (21) is arranged between anaerobic biofilter and the BIOFOR BAF, back flushing blower fan (21) is communicated with respectively with water distributing area (12), Aerobic Pond water distributing area (112) by back flushing tracheae (22), and back flushing tracheae (22) is provided with two back flushing control valves (61).

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