CN204474402U - A kind of advanced treatment of wastewater denitrification bio-filter apparatus system - Google Patents

Abstract

The utility model relates to a denitrification biological filter device system for advanced sewage treatment. The top of the biological filter is open, and an overflow chamber, a suspended packing layer, a filter material layer and a water distribution and air distribution chamber are arranged in sequence from top to bottom inside; A suction water distributor is installed at the bottom of the suspended packing layer; a gas collection system is installed in the filter material layer; the gas collection system is connected with the suction water distributor; nitrogen generated during the denitrification process in the filter material layer is collected by the gas collection system After that, it enters the suspended packing layer through the suction water distributor, which plays the role of driving away the nitrogen in the biological filter. At the same time, the strong hydraulic stirring effect of nitrogen and the characteristics of the sufficient suspension and flow of the packing in the suspended packing layer can further accelerate the reduction of nitrogen in the sewage. The excess oxygen content maintains the denitrification conditions of the system; thus, it can realize self-priming nitrogen and oxygen removal, and effectively realize the denitrification treatment after the secondary biochemical process, and effectively ensure the denitrification effect of the sewage.

Description

A denitrification biological filter device system for advanced sewage treatment

technical field

The utility model relates to a denitrification biological filter device system for advanced treatment of sewage, which belongs to the field of sewage treatment.

Background technique

From the perspective of the development history of pollution control at home and abroad, the initial focus of sewage treatment is COD digestion, but with the improvement of people's environmental quality requirements, the requirements for the removal of nitrogen and phosphorus in sewage discharge are gradually becoming stricter. In contrast, phosphorus can be removed by chemical precipitation, while the degradation of nitrogen mainly relies on biological treatment, which requires the sewage treatment process unit to pay more attention to the issue of nitrogen removal.

Before 2002, the effluent standard of China's urban sewage plants was the second-level discharge standard, in which only the ammonia nitrogen (NH ₃ -N) index was required, and there was no total nitrogen index requirement. In this case, the aerated biological treatment process can oxidize NH ₃ -N It is nitrate nitrogen, which meets the discharge standard. However, with people's increasingly stringent water quality requirements, some places (urban key watersheds) have been required to directly use the sewage treated by urban treatment plants as landscape supplementary water. Among the various water quality indicators, COD _Cr , nitrogen (TN ) and other emission indicators are more stringent.

Table 1 Correspondence table of emission indicators at all levels

control item COD _Cr BOD ₅ SS animal and vegetable oil Petro total nitrogen Ammonia nitrogen unit mg/L mg/L mg/L mg/L mg/L mg/L mg/L secondary standard 100 30 30 5 5 — 25(30) Grade B 60 20 20 3 3 20 8(15) Grade A 50 10 10 1 1 15 5(8) Surface Water Environmental Quality Standard Class IV 30 6 0.5 1.5 1.5

At present, for the removal of TN in sewage, urban sewage treatment plants at home and abroad usually adopt deep denitrification upgrading after conventional secondary treatment. The upgrading and transformation of key projects have completed the utilization of waste water resources.

About denitrification and denitrification: the process of denitrification of wastewater by using denitrifying bacteria to reduce nitrate nitrogen in water to ammonia nitrogen and then remove it. A large number of denitrifying bacteria exist in sewage, and the reaction is carried out under anoxic conditions, and the dissolved oxygen in water should be less than 0.5mg/L. It is required that there is a certain amount of organic matter in the sewage (the secondary sedimentation sludge, methanol, acetic acid, etc. can be supplemented).

About the biofilter: One of the biofilters - the moving bed biofilm reactor (MBBR), by adding a certain amount of suspended filler to the reactor, when the sewage passes through the reactor continuously, the filler with a larger specific surface area will be stirred ( The aerobic reactor (air agitation) moves freely in the water, and gradually grows a biofilm on its surface. The heterooxygen and autotrophic microorganisms in the biofilm use the nutrients in the water to metabolize, thereby achieving the removal of pollutants in sewage and purification. purpose of water. Because the filler and water are both in motion, the mass transfer between gas, water and solid phase is better, and the activity of the biofilm on the filler is higher, which is stronger in impact load resistance and buffer capacity than the traditional biofilm method.

The second biological filter - biological aerated filter (BAF), fully draws on the design ideas of the contact oxidation method of sewage treatment and the fast water filter, and combines the two processes of biodegradation and adsorption filtration in the same unit reactor. With the granular filler filled in the filter (such as ceramsite, coke, quartz sand, activated carbon, etc.) The high concentration of active microorganisms in the biofilm attached to the filter material has strong oxidative decomposition and the characteristics of the small particle size of the filter material, giving full play to the biological metabolism of microorganisms, bioflocculation, physical adsorption and retention of biofilm and fillers, and the internal edge of the reactor. The graded predation of the food chain in the direction of water flow realizes the efficient removal of pollutants, and at the same time utilizes the existence of aerobic and anoxic regions in the reactor to realize the function of denitrification and phosphorus removal. The process has high organic matter volume load, stable effluent quality, and has the characteristics of small footprint and low investment.

About nitrogen and oxygen removal: use nitrogen to prevent oxygen or other substances in the air from interfering with the denitrification reaction, and blow off the oxygen in the reaction solution to ensure the anoxic process of the reaction process as much as possible.

Fully combining the advantages of MBBR and BAF (MBBR's impact load resistance, strong buffer capacity and BAF's high organic matter load, stable effluent water quality, small footprint, etc.), the secondary biochemical treatment effluent of urban sewage treatment plants is deeply treated Denitrification biological treatment to achieve better effluent quality.

The nitrogen generated in the denitrification process is used to deoxygenate the raw water to ensure that the sewage is efficiently denitrified during the entire biofilter reaction process, and the adsorption and degradation of organic matter and total phosphorus by the biological filler is used to realize the sewage at the same time. Deep carbon and phosphorus removal.

Utility model content

The purpose of this utility model is to provide a denitrification biofilter device for advanced sewage treatment in view of the improvement of the TN index requirements of the existing urban sewage treatment plants, and the change of dissolved oxygen in the influent water of the variable water level denitrification filter and the problem of nitrogen removal. The system can realize self-priming nitrogen and oxygen removal, and effectively realize the denitrification treatment after the secondary biochemical process, and effectively ensure the denitrification effect of sewage.

The utility model is achieved through the following technical solutions:

A denitrification biological filter device system for advanced sewage treatment, including a biological filter, the top of the biological filter is open, and the interior is sequentially provided with an overflow chamber, a suspended packing layer, a filter material layer and a water distribution tank from top to bottom. Air distribution chamber; the bottom of the suspended packing layer is provided with a suction water distributor; the filter material layer is provided with a gas collection system; a suspended packing support plate is provided between the suspended packing layer and the filter material layer. A filter hole is provided on the support plate of the suspended filler; a filter support plate is provided between the filter material layer and the water distribution chamber, and a long handle filter head is provided on the filter material support plate;

The suction water distributor is provided with a liquid inlet and a suction gas inlet; the gas collection system is connected to the suction gas inlet of the suction water distributor through a pipeline;

The pool wall of the overflow chamber is provided with an overflow outlet; the pool wall of the water distribution and air distribution chamber is provided with a liquid inlet and outlet and a recoil gas inlet I; the gas collection main pipe is provided with a recoil gas inlet II and gas regulating valve;

The liquid inlet and outlet on the pool wall of the water distribution and air distribution chamber are connected to the fresh water raw material pipeline through pipelines, and a backflush water regulating valve is provided on the connecting pipeline; the liquid inlet and outlet are also connected to the metering device through pipelines, and There is a water outlet regulating valve on the connecting pipeline;

A sewage storage tank, a lifting pump, a carbon source doser, a mixer and an air compressor are arranged outside the biological filter;

The sewage storage tank is provided with a sewage outlet; the lift pump is provided with an inlet and an outlet; the carbon source doser is provided with a carbon source outlet; the mixer is provided with an inlet I, an inlet II and an outlet; the sewage The sewage outlet of the storage tank is connected to the inlet of the lift pump through a pipeline, and a pre-pump control valve is provided on the connecting pipeline; the outlet of the lift pump is connected to the inlet I of the mixer through a pipeline; the carbon source The carbon source outlet of the doser is connected to the inlet II of the mixer through a pipeline; the outlet of the mixer is connected to the liquid inlet of the suction water distributor through a pipeline;

The air compressor is provided with a compressed gas outlet; the compressed gas outlet of the air compressor is connected to the recoil gas inlet I through a pipeline, and a recoil gas regulating valve I is provided on the connecting pipeline; the air compressor The compressed gas outlet of the machine is also connected to the recoil gas inlet II via a pipeline, and a recoil gas regulating valve II is arranged on the connecting pipeline.

A biofilter sewage denitrification advanced treatment process. The top of the biofilter is open, and an overflow chamber, a suspended packing layer, a filter material layer, and a water distribution and air distribution chamber are arranged in sequence from top to bottom inside the biofilter; A suction water distributor is provided at the bottom of the bottom; a collective system is provided in the filter material layer; the gas collection system is connected with the suction water distributor; a suspension is provided between the suspended packing layer and the filter material layer Packing support plate; filter holes are set on the suspension packing support plate; a filter support plate is set between the filter material layer and the water distribution air distribution chamber; a long handle filter head is set on the filter material support plate ; Described treatment process comprises the following steps:

(1) Start the lifting pump, distribute the sewage in the sewage storage tank through the suction water distributor and then enter the suspended packing layer, where the sewage will undergo denitrification, oxygen removal and homogenization in the suspended packing layer; then pass through the suspended packing support plate Enter the filter material layer for denitrification and filtration; the treated sewage enters the water distribution and air distribution chamber through the filter material support plate, and when the liquid level in the biofilter reaches the overflow outlet on the overflow chamber wall to overflow, then Open the water outlet regulating valve on the wall of the water distribution air distribution chamber, and the outlet water will be discharged after being measured by the metering device; Stablize;

(2) After normal operation, the carbon source doser is turned on, and the carbon source and sewage are quickly mixed through the mixer to form a mixed solution, which is distributed by the suction water distributor and then enters the suspended packing layer; at the same time, in the suction Under the suction effect of the water distributor, the nitrogen gas generated during the denitrification process in the filter material layer is sucked to the suction water distributor through the gas collection system, and then enters the suspended packing layer after being distributed by the suction water distributor. It plays the role of driving away nitrogen in the biological filter; at the same time, after nitrogen enters the suspended packing layer, the strong hydraulic agitation of nitrogen and the characteristics of the sufficient suspension flow of the packing in the suspended packing layer can further accelerate the reduction of the excess oxygen content in the sewage and maintain the system denitrification conditions;

(3) After running for a period of time, backwash the biofilter to remove the pollutants trapped in the biofilter: use fresh water as backwash water, and use an air compressor to provide backwash air; first turn off the lift pump, The carbon source doser, the water outlet regulating valve and the gas collecting regulating valve on the gas collecting system, and then the air compressor, the backflushing air regulating valve and the backflushing water regulating valve are turned on in stages, and the biofilter is sequentially air flushed, water Three-stage backwashing of air flushing and water flushing and backflushing of the gas collection system; the backflush gas is divided into two paths, entering from the water distribution and air distribution chamber of the biofilter and the gas collection system, and finally passing through the suspended packing After layering, it is discharged from the top of the biofilter; the backwash water enters from the water distribution chamber of the biofilter, and is discharged from the overflow outlet on the wall of the overflow chamber.

in,

Preferably, the suspended packing layer is filled with high-quality porous spherical polypropylene suspended packing with a particle size of 25 mm, a bulk specific gravity of 83 kg/m ³ and a specific surface area of 237 m ² /m ³ . Available in the market.

Preferably, the filter layer is filled with high-quality activated carbon with a particle size of 2-3 mm, a density of 0.45-0.55 g/cm ³ , a specific surface area of 800±50 m ² /g, and an iodine adsorption value of 800-850 mg/g.

Preferably, the height of the biological filter is 3.8-5.8m, the height of the suspended packing layer is 1-3m, and the height of the filter material layer is 1-3m.

Preferably, the suspended packing support plate is symmetrically provided with a plurality of filter holes along the center, and the diameter of the filter holes is 20±0.1mm; the ratio of the total area of the filter holes to the total area of the suspended packing support plate is 0.01-0.025:1 .

Preferably, a plurality of openings are symmetrically distributed along the center of the filter support plate, and a long-handle filter head is installed on the opening; the long-handle filter head includes a filter cap and a filter handle; the filter cap and the filter handle are both It is a hollow structure; the filter cap is located in the filter material layer, the top of the filter cap is sealed, and a plurality of filter slits are distributed on the side, and the bottom is connected with the filter handle; the bottom end of the filter handle is open and inserted into the Said water distribution and gas distribution room.

The sewage in the filter material layer enters the water distribution and air distribution chamber from the filter seam on the long-handle filter head on the filter material support plate; while the recoil water or recoil gas in the water distribution and air distribution chamber enters from the gap of the long-handle filter head filter layer.

Preferably, the cross section of the filter cap is circular, the longitudinal section is trapezoidal, and the height is 25-40mm; the width of the filter slit is 2±0.1mm; the length of the filter handle is 225-350mm.

Preferably, the ratio of the total area of the filter slits on the filter support plate to the total area of the filter support plate is 0.01-0.025:1.

Preferably, the suction water distributor includes a horizontally arranged spiral water distribution pipe, and a water distribution hole is opened on the water distribution pipe; one end of the spiral water distribution pipe is sealed, and one end is provided with a suction interface; The suction interface is connected with a liquid inlet and a suction gas inlet; the liquid inlet is connected with the outlet of the mixer through a pipeline; the suction gas inlet is connected with the gas collection system through a pipeline.

Preferably, the pipe diameter of the water distribution pipe is 25-100mm (combinable according to the flow rate); the aperture of the water distribution hole is 3-4mm; ° staggered arrangement on the tube wall.

Preferably, the gas collection system includes a gas collection main pipe and a plurality of gas collection branch pipes connected to the gas collection main pipe; the gas collection main pipe is located outside the biofilter, and a gas collection regulating valve is arranged on it; The gas-collecting branch pipe is located in the filter material layer, and an air-collecting hole is arranged on it; the gas-collecting main pipe is connected to the suction gas inlet of the suction water distributor through a pipeline.

Preferably, the gas-collecting branch pipe is arranged horizontally in the filter material layer and is circular; the pipe diameter of the gas-collecting branch pipe is 25-32mm; the aperture of the gas-collecting hole is 2±0.1mm; the The gas-collecting hole is arranged on the tube wall of the outer side of the circular ring of the gas-collecting branch pipe which is obliquely downward at 45°.

Preferably, the mixer is a tube mixer.

Preferably, a plurality of sampling ports are arranged on the pool wall of the filter material layer from top to bottom; a sampling valve is connected to the sampling ports.

Preferably, the pool wall of the water distribution and air distribution chamber is also provided with a vent port; the vent port is connected with a vent valve.

Preferably, a recoil air regulating valve I is provided on the connecting pipeline between the air compressor and the water distribution chamber.

Preferably, the air compressor is connected to the gas collection main pipe of the gas collection system via a pipeline, and a recoil gas regulating valve II is arranged on the connecting pipeline.

Preferably, the sewage storage tank is provided with a sewage inlet; the sewage inlet is connected to the sewage pipeline through a pipeline; the top of the sewage storage tank is also provided with an overflow port for controlling the water level in the sewage storage tank.

Preferably, an overflow regulating valve is connected to the overflow outlet of the overflow chamber. When the system is in normal operation, it can ensure the constant liquid level in the biofilter, and it can be used as the outlet of backwash water during backwashing.

Preferably, the metering device is a rotameter or an electromagnetic flowmeter.

Preferably, the sewage storage tank is provided with a water quality monitor; the water quality monitor and the carbon source doser are controlled and connected through a PLC control system.

The monitoring data of the water quality monitor is fed back to the PLC control system, and then the PLC control system can control and adjust the carbon source dosage of the carbon source doser accordingly.

Preferably, the hydraulic retention time of the biological filter is 0.2-0.5h.

Preferably, the volume load of the biological filter is 2-4 kgNO ₃ -N/m ³ .d, and the hydraulic load is 6-8 m ³ /m ² .h. Wherein NO ₃ -N refers to nitrate nitrogen.

Preferably, the carbon source is selected from methanol, sodium acetate and the like.

Preferably, the carbon source is methanol or sodium acetate; the mass ratio of methanol dosage to total nitrogen in sewage is less than 2.9; the ratio of sodium acetate dosage to total nitrogen in sewage is less than 5.

Preferably, the strength of the backwash water is 4.0-8.0L/sm ² .

Preferably, the strength of the recoil gas is 10.0-14.0L/sm ² .

Preferably, the duration of the air flush is 5-10 minutes; the duration of the air-water flush is 5-10 minutes; the duration of the water flush is 5-10 minutes. In the air water, the recoil water and recoil gas are turned on at the same time for flushing.

Technical effect and advantage of the present utility model are:

(1) The biological filter fully combines the advantages of the moving bed bioreactor and the biological aerated filter, and has multiple characteristics such as impact load resistance, high organic matter load, and stable effluent quality.

(2) The biological filter is equipped with a suspended packing layer and a suction water distributor, which can accelerate the refluxing nitrogen gas to remove the residual oxygen in the raw water, enhance the denitrification and denitrification effect of the biological filter, and ensure the stability of the system operation;

(3) The biofilter is equipped with a suspended packing layer and a suction water distributor, which can reduce the energy consumption of the nitrogen backwash pump or the stripping pipe (no additional energy consumption is required for the nitrogen removal operation of the filter), and the management and maintenance are more efficient. easy;

(4) The gas collection system set up in the biological filter can cooperate with the suction water distributor to accelerate the dissipation of nitrogen in the denitrification process in time, reduce the air resistance and head loss inside the filter, and stabilize the circulation of the filter system volume and backwash cycle.

(5) The enhanced adsorption of activated carbon is used in the biological filter to increase the load impact on the influent, and at the same time accelerate the denitrification of organic matter in the wastewater. Compared with the conventional deep bed denitrification filter, the volume load can be increased by 0.5 ~ 1kgNO ₃ -N/m ³ .d, small footprint (at least 20% savings), low investment (10-25% savings).

(6) Suspended filler support plate and filter material support plate can effectively prevent the loss and loss of filter material, without unnecessary addition or replacement.

(7) The backwash cycle time of the biofilter can reach 2-3 days.

Description of drawings

Figure 1 Schematic diagram of a biological filter device for advanced sewage treatment

Figure 2 Plane schematic diagram of suction water distributor;

Figure 3 Schematic diagram of the cross section of the water distribution pipe of the suction water distributor

Figure 4 Plane schematic diagram of the gas-gathering branch pipe of the gas-gathering system

Figure 5 Schematic diagram of the cross section of the gas collecting branch

Figure 6 Plane schematic diagram of filter material support plate

Figure 7 Plane schematic diagram of suspended packing support plate

Reference signs:

1. Biological filter; 2. Overflow chamber; 3. Suspended packing layer; 4. Filter material layer; 5. Water distribution and air distribution chamber; 6. Control valve in front of the pump; 7. Long handle filter head; 8. Gas collection branch ;9, gas collection main pipe; 10, suction water distributor; 11, sewage storage tank; 12, carbon source doser; 13, lift pump; 14, mixer; 15, air compressor; 16, metering device ;17, outlet water regulating valve; 18, recoil gas regulating valve Ⅰ; 19, recoil gas regulating valve Ⅱ; 20, gas collection regulating valve; 21, recoil water regulating valve; 22, venting valve; 23, overflow regulation Valve; 24, sampling valve; 25, water distribution pipe; 26, liquid inlet; 27, suction gas inlet; 28, water distribution hole; 29, gas collection hole; 30, filter support plate; 31, opening; 32, Fixed flange screw hole; 33, suspension packing support plate; 34, filter hole.

Detailed ways

The technical scheme of the utility model is illustrated below through specific specific examples. It should be understood that the one or more method steps mentioned in the present invention do not exclude that there are other method steps before and after the combination steps or other method steps can be inserted between these explicitly mentioned steps; it should also be understood that, These embodiments are only used to illustrate the utility model and not to limit the scope of the utility model. And, unless otherwise stated, the numbering of each method step is only a convenient tool for identifying each method step, rather than limiting the sequence of each method step or limiting the scope of the utility model, the change or adjustment of its relative relationship, In the case of no substantial change in technical content, it should also be regarded as the scope of the utility model that can be implemented.

The utility model provides a sewage advanced treatment denitrification biofilter device system, as shown in Figure 1, including a biofilter 1, the top of the biofilter 1 is open, and the interior is sequentially arranged from top to bottom Overflow chamber 2, suspended packing layer 3, filter material layer 4 and water distribution air distribution chamber 5; the bottom of the suspended packing layer 3 is provided with a suction water distributor 10; the filter material layer 4 is provided with a gas collection system ; between the suspended packing layer 3 and the filter material layer 4, a suspended packing support plate is provided, and a filter hole (34) is provided on the suspended packing support plate (33); the filter material layer (4) and the A filter material support plate (30) is provided between the water distribution and gas distribution chambers (5), and a long handle filter head (7) is provided on the filter material support plate (30);

The suction water distributor 10 is provided with a liquid inlet 26 and a suction gas inlet 27; the gas collection system is connected to the suction gas inlet 27 of the suction water distributor 10 through a pipeline;

The pool wall of the overflow chamber 2 is provided with an overflow outlet; the pool wall of the water distribution and gas distribution chamber 5 is provided with a liquid inlet and outlet and a recoil gas inlet I; the gas collecting main pipe 9 is provided with a recoil Gas inlet II and gas collection regulating valve 20;

The liquid inlet and outlet on the pool wall of the water distribution air distribution chamber 5 and the fresh water raw material pipeline are provided with a recoil water regulating valve 21 on the connecting pipeline; the liquid inlet and outlet are also connected to the metering device 16 through pipelines, and A water outlet regulating valve 17 is provided on the connecting pipeline;

The biofilter 1 is provided with a sewage storage tank 11, a lift pump 13, a carbon source doser 12, a mixer 14 and an air compressor 15;

The sewage storage tank 11 is provided with a sewage outlet; the lift pump 13 is provided with an inlet and an outlet; the carbon source doser 12 is provided with a carbon source outlet; the mixer 14 is provided with an inlet I, an inlet II and an outlet The sewage outlet of the sewage storage tank 11 is connected to the inlet of the lift pump 13 through a pipeline, and a pump front control valve 6 is provided on the connecting pipeline; the outlet of the lift pump 13 is connected to the inlet of the mixer 14 I is connected through pipelines; the carbon source outlet of the carbon source doser 12 is connected with the inlet of the mixer 14; II is connected through pipelines; the outlet of the mixer 14 is connected with the liquid inlet of the suction water distributor Port 26 is connected via a pipeline;

The air compressor 15 is provided with a compressed gas outlet; the compressed gas outlet of the air compressor 15 is connected to the recoil gas inlet I through a pipeline, and a recoil gas regulating valve I18 is provided on the connecting pipeline; The compressed gas outlet of the air compressor 15 is also connected to the recoil gas inlet II via a pipeline, and a recoil gas regulating valve II19 is arranged on the connecting pipeline;

As a preferred implementation situation: the suspended packing layer 3 is filled with high-quality porous spherical polypropylene suspended packing with a particle size of 25mm; bulk specific gravity 83kg/m ³ , specific surface area 237m ² /m ³ ; the suspended packing can be purchased have to.

As a preferred implementation situation: the filter material layer is filled with high-quality activated carbon with a particle size of 2-3 mm, a density of 0.45-0.55 g/cm ³ , a specific surface area of 800±50 m ² /g, and an iodine adsorption value of 800-850 mg/g.

As a preferred implementation situation: the height of the biological filter 1 is 3.8-5.8m, the height of the suspended packing layer 3 is 1-3m, and the height of the filter material layer 4 is 1-3m.

As a preferred implementation situation: the suspended packing support plate 33 is symmetrically provided with a plurality of filter holes 34 along the center, and the diameter of the filter holes 34 is 20 ± 0.1 mm; the total area of the filter holes 34 and the area of the suspended packing support plate 33 The ratio is 0.01-0.025:1.

As a preferred implementation situation: the filter support plate 30 is symmetrically distributed with a plurality of holes 31 along the center, and a long-handle filter head 7 is installed on the hole 31; the long-handle filter head 7 includes a filter cap and a filter cap. filter handle; both the filter cap and the filter handle are hollow structures; the filter cap is located in the filter material layer 4, the top of the filter cap is sealed, and a plurality of filter slits are distributed on the side, and the bottom communicates with the filter handle; The bottom end of the filter handle is open and inserted into the water distribution air distribution chamber 5;

As a further preferred implementation situation: the ratio of the total area of the filter slits on the filter support plate 30 to the total area of the filter support plate 30 is 0.01-0.025:1;

As a further preferred implementation situation: the cross section of the filter cap is circular, the longitudinal section is trapezoidal, and the height is 25-40mm; the width of the filter slit is 2±0.1mm; the length of the filter handle is 225-350mm.

As a preferred implementation situation: the pool wall of the filter material layer 4 is provided with a plurality of sampling ports from top to bottom; the sampling port is connected with a sampling valve 24;

As a preferred implementation situation: the pool wall of the water distribution and air distribution chamber 5 is also provided with a venting port; the venting port is connected with a venting valve 22;

As a preferred implementation situation: the sewage storage tank 11 is provided with a sewage inlet; the sewage inlet is connected to the sewage pipeline through a pipeline; the top of the sewage storage tank 11 is also provided with an overflow port;

As a preferred implementation situation: the overflow outlet of the overflow chamber 2 is connected with an overflow regulating valve 23;

As a preferred implementation situation: the mixer 14 is a tubular mixer 14;

As a preferred implementation situation: the metering device 16 is a rotameter or an electromagnetic flowmeter;

As a preferred implementation situation: the sewage storage tank 11 is provided with a water quality monitor; the water quality monitor and the carbon source doser 12 are controlled and connected by a PLC control system;

As a preferred implementation situation: the suction water distributor 10 includes a horizontally arranged spiral water distribution pipe 25, and a water distribution hole 28 is opened on the water distribution pipe 25; one end of the spiral water distribution pipe 25 is sealed, and the other end is sealed. A suction interface is provided; the suction interface is connected with the liquid inlet 26 and the suction gas inlet 27, see FIG. 2 .

As a further preferred implementation situation: the pipe diameter of the water distribution pipe 25 is 25-100mm (can be combined according to the flow rate); the aperture of the water distribution hole 28 is 3-4mm; Both sides of the water pipe 25 are staggeredly arranged on the pipe wall at an angle of 45° upward, as shown in FIG. 3 .

As a preferred implementation situation: the gas collection system includes a gas collection main pipe 9 and a plurality of gas collection branch pipes 8 communicated with the gas collection main pipe 9; the gas collection main pipe 9 is located outside the biofilter 1, its The gas-collecting regulating valve 20 is provided on it; the gas-collecting branch pipe 8 is located in the filter material layer 4, and an air-collecting hole 29 is arranged on it; the gas-collecting main pipe 9 and the suction water distributor The suction gas inlet 27 of 10 is connected through a pipeline;

As a further preferred implementation situation: the gas-collecting branch pipe 8 is arranged horizontally in the filter material layer 4 and is circular; the diameter of the gas-collecting branch pipe 8 is 25-32mm; the aperture of the gas-collecting hole 29 is 2±0.1mm; the gas-collecting hole 29 is located on the pipe wall at 45°C obliquely downward outside the ring of the gas-collecting branch pipe 8; see Figure 4 and Figure 5;

The processing technology matched with the device system includes the following steps:

(1) Start the lifting pump 13, distribute the sewage in the sewage storage tank 11 through the suction type water distributor 10 and enter the suspended packing layer 3, and the sewage will denitrify and deoxygenate and homogenize in the suspended packing layer 3; then Enter the filter material layer 4 through the suspended packing support plate 33 for denitrification and filtration; the treated sewage enters the water distribution and air distribution chamber 5 through the filter material support plate 30, and waits until the liquid level in the biofilter 1 reaches the wall of the overflow chamber 2 When the overflow outlet on the top overflows, open the water outlet regulating valve 17 on the pool wall of the water distribution air distribution chamber 5, and the outlet water will be discharged after being measured by the metering device 16; The regulating valve and the outlet regulating valve 17 stabilize the liquid level of the biofilter 1;

(2) After normal operation, the carbon source doser 12 is opened, and the carbon source and sewage are quickly mixed through the mixer 14 to form a mixed solution and enter the suspended packing layer 3 after being distributed by the suction water distributor 10; at the same time, Under the suction effect of the suction water distributor 10, the nitrogen generated during the denitrification process in the filter material layer 4 is sucked to the suction water distributor 10 through the gas collection system, and passed through the suction water distributor 10. After 10 is distributed, it enters the suspended packing layer 3 to play the role of driving away the nitrogen in the biological filter 1. At the same time, after the nitrogen enters the suspended packing layer 3, the strong hydraulic stirring effect of the nitrogen and the characteristics of the sufficient suspension flow of the filling in the suspended packing layer 3 can be used. Further accelerate the reduction of excess oxygen content in sewage and maintain the denitrification conditions of the system;

(3) After running for a period of time, the biofilter 1 is backwashed to remove the pollutants retained in the biofilter 1: fresh water is used as backflush water, and air compressor 15 is used to provide backflush gas; first close Lift pump 13, carbon source doser 12, water outlet regulating valve 17 and gas collecting regulating valve 20 on the gas collecting system, and then open air compressor 15, recoil gas regulating valve and recoil water regulating valve 21 in stages, sequentially Carry out three-stage backwashing of air flushing, water air flushing and water flushing to the biofilter 1 and backflushing of the gas collection system; chamber 5 and the gas collection system, and finally pass through the suspended packing layer 3 and then discharge from the top of the biofilter; backwash water enters from the water distribution chamber 5 of the biofilter, and overflows from the wall of the overflow chamber 2 outlet discharge;

The following is a specific embodiment of utilizing the device system of the present invention to carry out advanced treatment of sewage:

Refer to the device system shown in Figure 1-7 for advanced denitrification treatment of biofilter sewage, in which:

Biological filter: cylindrical shape, diameter 0.5m, height 3.8m, top overflow chamber 2 height 0.45m; suspended packing layer 3 height 1m, filter material layer 4 height 2m;

Suspended filler layer 3 is filled with high-quality porous spherical polypropylene suspended filler, with a particle size of 25mm, a bulk density of 83kg/m ³ , and a specific surface area of 237m ² /m ³ ;

The filter material layer 4 is filled with high-quality activated carbon, with a particle size of 2-3 mm, a density of 0.45-0.55 g/cm ³ , a specific surface area of 800±50 m ² /g, and an iodine adsorption value of 800-850 mg/g;

The suspension packing support plate, as shown in Figure 7, is provided with 13 filter holes symmetrically in the center and along the center in a circular shape, and the diameter of the filter holes is 20mm;

The filter material support plate 30, as shown in Figure 6, offers a total of 7 openings 31 with a diameter of 32mm in the center and along the center in a ring-shaped symmetry, and a long-handle filter head 7 is installed on the opening 31; the long-handle filter The head 7 includes a filter cap and a filter handle; the filter cap and the filter handle are both hollow structures; the filter cap is located in the filter material layer 4, the top of the filter cap is sealed, and a plurality of filter slits are distributed on the side, and the bottom and the filter The handles are connected; the bottom end of the filter handle is open and inserted into the water distribution and air distribution chamber 5; the cross section of the filter cap is circular, the longitudinal section is trapezoidal, and the height is 25mm; the width of the filter slit is 2±0.1mm The length of the filter handle is 225mm; the ratio of the total area of the filter seams on the filter support plate 30 to the total area of the filter support plate 30 is 0.02:1.

Suction type water distributor 10, as shown in Figure 2 and 3, the pipe diameter of water distribution pipe 25 is 32mm; The aperture of described water distribution hole 28 is 3mm; Arranged in a staggered manner on the pipe wall with an upward slope of 45°;

Gas collection system, as shown in Figure 1, Figure 4 and Figure 5, the diameter of the gas collection branch pipe 8 is 25mm; the aperture of the gas collection hole 29 is 2 ± 0.1mm; the gas collection hole 29 is located in the gas collection The outer side of the ring of the branch pipe 8 is obliquely downward at 45° on the pipe wall;

Mixer 14 is a tubular mixer 14, and metering device 16 is a rotameter;

The specific steps of advanced denitrification treatment using the above device system are as follows:

A) Close the sampling valve 24, the vent valve 22, the recoil gas regulating valve I18, the recoil gas regulating valve II19, the recoil water regulating valve 21, and the outlet water regulating valve 17;

B) adding sewage to be treated in the sewage storage tank 11;

C) Start the lifting pump 13, the sewage is distributed through the suction water distributor 10 and enters the suspended filter material layer 4, and then enters the filter material layer 4 through the suspended packing support plate for denitrification and filtration;

D) The fully mixed sewage enters the water distribution and air distribution chamber 5 through the filter support plate 30;

E) When the liquid level in the biofilter 4 overflows through the overflow outlet, open the outlet regulating valve 17, and the outlet water is metered by the metering device 16 and then discharged, and the outlet water is adjusted by adjusting the outlet regulator valve 17 and the control valve 6 in front of the pump. The liquid level of the biological filter is stable;

F) After normal operation, the carbon source doser 12 is opened, and the carbon source and sewage are quickly mixed through the mixer 14 to form a mixed solution and enter the suspended packing layer 3 together; Under the action of suction, the nitrogen generated during the denitrification process in the filter material layer 4 is sucked to the suction water distributor 10 through the gas collection system, and after being distributed by the suction water distributor 10, it enters the suspended packing layer 3 to play a role The effect of driving out nitrogen in the biological filter. At the same time, after nitrogen enters the suspended packing layer 3, the strong hydraulic agitation of nitrogen and the characteristics of the sufficient suspension and flow of the packing in the suspended packing layer 3 can further accelerate the reduction of the excess oxygen content in the sewage and maintain the system. denitrification conditions;

G) After running for 3 days, backwash the biofilter to remove the pollutants retained in the biofilter: use the nearest fresh water as backflush water, and use air compressor 15 to provide backflush gas; divided into air flushing , water air flushing and water flushing three stages of backwashing and the backwashing of the gas collection system, the backwashing time of each stage is 5min; first close the lift pump 13, carbon source doser 12, water outlet regulating valve 17 and the gas-gathering regulating valve 20 on the gas-gathering system, and then open the air compressor 15, the recoil gas regulating valve I18, the recoil gas regulating valve II19 and the recoil water regulating valve 21 in stages; the recoil gas is divided into two routes, Enter from the water distribution and air distribution chamber 5 of the biological filter 1 and the gas collection system respectively, and finally pass through the suspended packing layer 3 and then discharge from the top of the biological filter 1; the backwash water enters from the water distribution and air distribution chamber 5 of the biological filter 1, Discharge from the overflow outlet; when the recoil air flushing intensity is 14.0L/sm ² , the recoil water flushing intensity is 4.0L/sm ² .

H) The hydraulic retention time of the device system is about 0.2-0.5h, the volume load is 2-4kgNO ₃ -N/m ³ .d, and the hydraulic load is 6-8m ³ /m ² .h; the carbon source is methanol, and the dosage is the same as the total amount of sewage Nitrogen mass ratio <2.9;

1) Wastewater from urban sewage treatment plants can only reach the first-level A standard after secondary biochemical treatment and coagulation sedimentation, and can reach below the first-level A standard after being treated by the biological filter of the present embodiment, as shown in Table 2:

Table 2 Wastewater treatment effect of biofilter

project COD _Cr BOD ₅ TN NH ₃ -N SS TP before processing 60 20 twenty one 0.8 19 0.94 after treatment 28 5 1.2 0.2 7 0.27

The above is only a preferred embodiment of the utility model, and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the utility model should be included in the utility model. within the scope of the new protection.

Claims (14)

1. A biofilter device system for advanced sewage treatment denitrification, comprising a biofilter (1), characterized in that the top of the biofilter (1) is open, and the inside is sequentially provided with overflow from top to bottom flow chamber (2), suspended packing layer (3), filter material layer (4) and water distribution air distribution chamber (5); the bottom of the suspended packing layer (3) is provided with a suction water distributor (10); The filter material layer (4) is provided with a gas collection system; a suspended filler support plate (33) is provided between the suspended filler layer (3) and the filter material layer (4), and the suspended filler support plate (33) A filter hole (34) is provided on the top; a filter material support plate (30) is provided between the filter material layer (4) and the water distribution air distribution chamber (5), and a filter material support plate (30) is provided with There is a long handle filter head (7); The suction water distributor (10) is provided with a liquid inlet (26) and a suction gas inlet (27); the gas collection system and the suction gas inlet of the suction water distributor (10) (27) connected by pipeline; The pool wall of the overflow chamber (2) is provided with an overflow outlet; the pool wall of the water distribution and gas distribution chamber (5) is provided with a liquid inlet and outlet and a recoil gas inlet I; the gas collection main pipe (9 ) is equipped with a recoil gas inlet II and a gas collection regulating valve (20); The liquid inlet and outlet on the pool wall of the water distribution and gas distribution chamber (5) are connected to the fresh water raw material pipeline through a pipeline, and a backwash water regulating valve (21) is arranged on the connecting pipeline; the liquid inlet and outlet are also connected to the metering device (16) connected by a pipeline, and a water outlet regulating valve (17) is provided on the connecting pipeline; The biofilter (1) is externally provided with a sewage storage tank (11), a lift pump (13), a carbon source doser (12), a mixer (14) and an air compressor (15); The sewage storage tank (11) is provided with a sewage outlet; the lift pump (13) is provided with an inlet and an outlet; the carbon source doser (12) is provided with a carbon source outlet; the mixer (14) is provided with There are inlet I, inlet II and outlet; the sewage outlet of the sewage storage tank (11) is connected to the inlet of the lift pump (13) through a pipeline, and a pump control valve (6) is arranged on the connecting pipeline; The outlet of the lift pump (13) is connected with the inlet I of the mixer (14) through a pipeline; the carbon source outlet of the carbon source doser (12) is connected with the inlet II of the mixer (14) through a pipeline Connect; the outlet of the mixer (14) is connected with the liquid inlet (26) of the suction type water distributor (10) through a pipeline; The air compressor (15) is provided with a compressed gas outlet; the compressed gas outlet of the air compressor (15) is connected to the recoil gas inlet I through a pipeline, and a recoil gas regulating valve is provided on the connecting pipeline I (18); the compressed gas outlet of the air compressor (15) is also connected to the recoil gas inlet II via a pipeline, and a recoil gas regulating valve II (19) is arranged on the connecting pipeline. 2. A denitrification biological filter device system for advanced sewage treatment as claimed in claim 1, characterized in that, the suspended packing layer (3) is filled with high-quality porous spherical polypropylene suspended packing with a particle size of 25 mm. 3. A denitrification biological filter device system for advanced sewage treatment as claimed in claim 1, characterized in that the filter material layer (4) is filled with high-quality activated carbon with a particle size of 2-3mm. 4. A kind of sewage advanced treatment denitrification biological filter device system as claimed in claim 1, is characterized in that, the height of described biological filter (1) is 3.8～5.8m, and the suspended packing layer (3) The height is 1-3m, and the height of the filter material layer (4) is 1-3m. 5. A kind of sewage advanced treatment denitrification biofilter device system as claimed in claim 1, is characterized in that, described suspension filler support plate (33) is provided with a plurality of filter holes (34) symmetrically along the center, filter hole (34) The diameter is 20±0.1 mm; the ratio of the total area of the filter holes (34) to the total area of the suspended filler support plate (33) is 0.01-0.025:1. 6. A kind of sewage advanced treatment denitrification biological filter device system as claimed in claim 1, is characterized in that, on the described filter support plate (30) there are a plurality of openings (31) symmetrically distributed along the center, so A long-handle filter head (7) is installed on the opening (31); the long-handle filter head (7) includes a filter cap and a filter handle; both the filter cap and the filter handle are hollow structures; the filter cap is located on the In the filter material layer (4), the top of the filter cap is sealed, and a plurality of filter slits are distributed on the side, and the bottom is connected with the filter handle; the bottom end of the filter handle is open and inserted into the water distribution and air distribution chamber (5) Inside. 7. A kind of sewage advanced treatment denitrification biological filter device system as claimed in claim 6, is characterized in that, the ratio of the total area of the filter joints on the filter support plate and the total area of the filter support plate is 0.01 -0.025:1. 8. A kind of sewage advanced treatment denitrification biological filter device system as claimed in claim 6, is characterized in that, the cross section of described filter cap is circular, and longitudinal section is trapezoidal, high 25-40mm; Filter slit width 2±0.1mm; the length of the filter handle is 225-350mm. 9. A kind of sewage advanced treatment denitrification biological filter device system as claimed in claim 1, is characterized in that, described suction type water distributor (10) comprises a horizontally arranged spiral water distribution pipe (25), The water distribution pipe (25) is provided with a water distribution hole (28); one end of the spiral water distribution pipe (25) is sealed, and one end is provided with a suction interface; the suction interface is connected with a liquid inlet (26) and The suction gas inlet (27); the liquid inlet (26) is connected to the outlet of the mixer (14) through pipelines; the suction gas inlet (27) is connected to the gas collection system through pipelines. 10. A kind of sewage advanced treatment denitrification biological filter device system as claimed in claim 9, is characterized in that, the pipe diameter of described water distribution pipe (25) is 25-100mm; The diameter of described water distribution hole (28) The hole diameter is 3-4mm; the water distribution holes (28) are staggeredly arranged on both sides of the water distribution pipe (25) on the pipe wall with an angle of 45° upward. 11. A kind of advanced sewage treatment denitrification biological filter device system as claimed in claim 9, characterized in that, the gas collection system includes a gas collection main pipe (9) and is connected with the gas collection main pipe (9). A plurality of gas-collecting branch pipes (8); the gas-collecting main pipe (9) is located outside the biofilter (1), and the gas-collecting regulating valve (20) is provided on it; the gas-collecting branch pipe ( 8) It is located in the filter material layer (4), on which an air collecting hole (29) is arranged; the air collecting main pipe (9) and the suction air inlet (27) ) are connected by pipelines. 12. The denitrification biological filter device system for advanced sewage treatment as claimed in claim 11, characterized in that, the gas-collecting branch pipe (8) is arranged horizontally in the filter material layer (4) and forms a circular ring shape; the pipe diameter of the gas collecting branch (8) is 25 ~ 32mm; the aperture of the gas collecting hole (29) is 2 ± 0.1mm; the gas collecting hole (29) is located in the gas collecting branch (8) The outer side of the ring is obliquely downward at 45° on the pipe wall. 13. A sewage advanced treatment denitrification biological filter device system as claimed in claim 1, characterized in that it also includes any one or more of the following features: (a) the pool wall of the filter material layer (4) is provided with a plurality of sampling ports from top to bottom; the sampling port is connected with a sampling valve (24); (b) The pool wall of the water distribution and air distribution chamber (5) is also provided with a venting port; the venting port is connected with a venting valve (22); (c) The sewage storage tank (11) is provided with a sewage inlet; the sewage inlet is connected to the sewage pipeline through a pipeline; the top of the sewage storage tank (11) is also provided with an overflow port; (d) an overflow regulating valve (23) is connected to the overflow outlet of the overflow chamber (2); (e) The connection pipeline between the air compressor (15) and the water distribution chamber (5) is provided with a recoil gas regulating valve I (18); (f) The air compressor (15) is connected to the gas collection main pipe (9) of the gas collection system through a pipeline, and a recoil gas regulating valve II (19) is installed on the connecting pipeline. 14. A sewage advanced treatment denitrification biological filter device system as claimed in claim 1, characterized in that it also includes any one or more of the following features: (a) the mixer (14) is a tubular mixer; (b) The metering device (16) is a rotameter or an electromagnetic flowmeter.