High-salinity wastewater denitrification sequencing batch denitrification biochemical pool

Abstract

The utility model relates to a high-salinity wastewater denitrification sequencing batch denitrification biochemical pool which is characterized in that the interior of a pool body is sequentially divided into a pretreatment area, a main reaction area and a rear settling area by two partition plates, the bottom ends of the partition plates are connected with the bottom of the pool body through grids, and a first stirring device is mounted in the pretreatment area; the second stirring device and the aeration device are mounted in the main reaction zone, the main reaction zone is filled with polyurethane porous spongy filler, the water outlet end of the water inlet pipe is respectively connected with the pretreatment zone and the main reaction zone, an inclined plate is arranged in the middle of the post-settling zone, the water decanter is mounted at the upper end of the post-settling zone and connected with a drain pipe, and a sludge discharge pipe is arranged at the lower end of the post-settling zone. According to the biochemical pool, an activated sludge and biological membrane process is adopted, a biological filler is filled, so that the biological filler and the activated sludge form a biological membrane, and high-concentration nitrate nitrogen is subjected to high-salt denitrification nitrogen removal treatment; meanwhile, internal circulation is increased, dissolved oxygen and wastewater concentration impact are reduced, and the denitrification reaction can be rapidly and stably operated.

Description

Technical Field

[0001] The utility model relates to the technical field of high-salt nitrogen-containing wastewater treatment, and particularly relates to a sequencing batch denitrification biochemical pool for high-salt wastewater denitrification. Background Art

[0002] At present, there are many studies on the biological denitrification technology of high-salt wastewater. The more representative ones are the simultaneous nitrification and denitrification technology and the short-cut nitrification and denitrification technology. In these technologies, the main role is played by nitrifying bacteria and denitrifying bacteria in the activated sludge. During the operation process, due to the unstable concentration of high-salt wastewater, the biological impact fluctuation is relatively large, which will affect the denitrification efficiency of the microorganisms in the pool and the sedimentation performance of the activated sludge, resulting in the concentration of the activated sludge MLSS being increased to 4000-12000 mg / L, leading to sludge bulking. At the same time, if it is not operated for a long time, the recovery period of salt-tolerant denitrifying bacteria and nitrifying bacteria is relatively long, thus affecting the growth and physiological metabolism function of the microorganisms in the biological denitrification system, and further affecting the denitrification effect of the system.

[0003] Therefore, it is necessary to design a sequencing batch denitrification biochemical pool for high-salt wastewater denitrification to overcome the above problems. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a sequencing batch denitrification biochemical pool for high-salt wastewater denitrification, which adopts the activated sludge + biofilm process. By filling biological fillers, the biological fillers and the activated sludge form a biofilm, and the formed biofilm is used for high-salt denitrification treatment of the high-concentration nitrate nitrogen in the high-salt wastewater. At the same time, the internal circulation is increased, the dissolved oxygen and the impact of wastewater concentration are reduced, so that the denitrification reaction can operate quickly and stably, and the formed biofilm is used for high-salt denitrification treatment of the high-concentration nitrate nitrogen in the high-salt wastewater.

[0005] A sequencing batch denitrification biochemical pool for high-salt wastewater denitrification provided by the utility model comprises: a pool body, a partition board, a grille, a water inlet pipe, a first stirring device, a second stirring device, an aeration device and a water decanter;

[0006] The pool body is sequentially divided into a pretreatment area, a main reaction area and a post-precipitation area by two partition boards. The bottom ends of the partition boards are connected to the bottom of the pool body through a grille. The first stirring device is installed in the pretreatment area. The second stirring device and the aeration device are installed in the main reaction area. The main reaction area is filled with polyurethane porous sponge-like fillers. The water outlet ends of the water inlet pipe are respectively connected to the pretreatment area and the main reaction area. An inclined plate is arranged in the middle of the post-precipitation area. The water decanter is installed at the upper end of the post-precipitation area and is connected to a drain pipe. A sludge discharge pipe is arranged at the lower end of the post-precipitation area.

[0007] Furthermore, the volume ratio of the pretreatment area, the main reaction area and the post-precipitation area is 2:3:1.5.

[0008] Further, the aeration device includes an aeration pipe, an air supply pipe, and a blower. The aeration pipe is arranged at the bottom of the main reaction zone, and a plurality of aeration holes are provided on the aeration pipe. The aeration pipe is connected to the air outlet end of the blower through the air supply pipe.

[0009] Further, a monitor is provided in the main reaction zone, including a dissolved oxygen meter detection probe, an MLSS analyzer, a liquid level gauge, and a nitrate nitrogen detection probe.

[0010] Further, the aperture of the grille is 8 - 15 mm.

[0011] Further, the second stirring device adopts a hyperbolic stirrer, which is a vertical low-speed large impeller stirring head made of fiberglass. The ratio of the impeller diameter to the tank width is 1:2 - 1:5.

[0012] Further, the filling volume ratio of the packing in the main reaction zone is 30 - 60%, the packing is a square structure with a side length of 20 - 40 mm, and the porosity is 70 - 90%.

[0013] Further, the inclination angle of the inclined plate is 45 - 60°.

[0014] Further, the sludge discharge pipe is connected to the pretreatment zone through a reflux pipe and a reflux pump.

[0015] Further, the pretreatment zone is connected to a chemical dosing pump through a chemical dosing pipe.

[0016] The utility model has the following advantages and beneficial effects:

[0017] 1. By dividing the traditional sequencing batch reactor into multiple zones through a partition board, reasonably adjusting the control system, controlling the startup and shutdown of operating equipment and the parameters of the monitor, further optimizing the biochemical reaction environment within a reasonable range, by changing and adjusting the periodic operation of the influent mode, aeration system, stirring device, drain pipe, and reflux pipe, the impact of influent fluctuations on organisms is reduced, and at the same time, the reaction process can operate effectively and stably, reducing the impact of wastewater with different concentrations on organisms. Controlling the internal circulation of the reactor can reduce the impact of sudden increase in dissolved oxygen during the aeration process on the activity of denitrifying bacteria in the denitrification process. The water body has further shock resistance, can prevent sludge bulking, is automated in operation management, can remove nitrogen and phosphorus, is easy to achieve plug-flow regime, has good effluent quality, and has small capital investment. The reactor structure is simple and efficient.

[0018] 2. Polyurethane-based packing is added in the reactor to form an activated sludge + biofilm process, enabling the biological nitrogen removal system to have a high biomass, having good tolerance to the impact of high-salt wastewater with different concentrations, being able to achieve rapid denitrification reaction, and being able to quickly recover stability after a long shutdown. The optimized hyperbolic stirrer can make the biological packing mix fully with the mud and water. Under the stirring of the stirring head, the mixture can circulate efficiently, promoting the stable and rapid biological nitrogen removal reaction. Description of the Drawings

[0019] Figure 1 This is a structural schematic diagram of a high-salt wastewater denitrification sequencing batch denitrification biochemical pool according to a preferred embodiment of the present invention;

[0020] Explanation of the reference numerals in the attached drawings:

[0021] 1. Pool body 1, 11. Baffle 11, 12. Grid 12, 13. Pretreatment area 13, 14. Main reaction area 14, 15. Post-precipitation area 15, 16. Inclined plate 16, 17. Inlet pipe 17, 18. Sludge discharge pipe 18,

[0022] 2. First stirring device 2,

[0023] 3. Second stirring device 3,

[0024] 4. Aeration device 4, 41. Aeration pipe 41, 42. Air supply pipe 42, 43. Blower 43,

[0025] 5. Decanter 5,

[0026] 6. Monitor 6,

[0027] 7. Return pipe 7, 71. Return pump 71,

[0028] 8. Chemical addition pipe 8, 81. Chemical addition pump 81. Detailed implementation manners

[0029] For a better understanding of the present invention, the following embodiments are further descriptions of the present invention, but the content of the present invention is not limited to the following embodiments only.

[0030] As Figure 1 shown, a high-salt wastewater denitrification sequencing batch denitrification biochemical pool includes: a pool body 1, a baffle 11, a grid 12, an inlet pipe 17, a first stirring device 2, a second stirring device 3, an aeration device 4 and a decanter 5.

[0031] The interior of the pool body 1 is successively divided into a pretreatment area 13, a main reaction area 14 and a post-precipitation area 15 by two baffles 11. The volume ratios of the pretreatment area 13, the main reaction area 14 and the post-precipitation area 15 are 2:3:1.5. A connection channel is provided between the bottom end of the baffle 11 and the bottom of the pool body 1, and a mesh stainless steel grid 12 is provided on the connection channel, and the mesh aperture is 8 - 15 mm. The pretreatment area 13 is connected to a chemical addition pump 81 through a chemical addition pipe 8, facilitating the addition of chemicals to the pretreatment area 13.

[0032] Meanwhile, the first stirring device 2 is installed in the pretreatment area 13, and the sludge discharge pipe 18 is connected to the pretreatment area 13 through the reflux pipe 7 and the reflux pump 71. The second stirring device 3 and the aeration device 4 are installed in the main reaction area 14. The second stirring device 3 uses a hyperboloid stirrer, which is a vertical low-speed large impeller stirring head made of fiberglass. The ratio of the impeller diameter to the tank width is 1:2 to 1:5. Moreover, polyurethane porous sponge-like fillers are filled in the main reaction area 14, and the filling volume ratio of the fillers is 30 to 60%. The fillers are square structures with side lengths of 20 to 40 mm and a porosity of 70 to 90%. The filled fillers are combined with the activated sludge in the main reaction area 14 to form a biofilm evenly distributed on the fillers, increasing the specific surface area. Through the stirring of the hyperboloid stirrer, the fillers and the activated sludge do not form agglomeration phenomena. The fillers have a large porosity and are not easily adhered by oil in the water, affecting the treatment effect. At the same time, they have high compressive strength, high salt and corrosion resistance, good hydrophilicity, making it easy for microorganisms to attach, and strong chemical and biological stability, without dissolving harmful substances to cause secondary pollution. Among them, the water outlet ends of the water inlet pipe 17 are respectively connected to the pretreatment area 13 and the main reaction area 14, and the water outlet end connected to the main reaction area 14 in the water inlet pipe 17 extends to the bottom of the main reaction area 14.

[0033] The aeration device 4 includes an aeration pipe 41, a gas supply pipe 42, and a blower 43. The aeration pipe 41 is arranged at the bottom of the main reaction area 14. A plurality of aeration holes are provided on the aeration pipe 41. The aeration pipe 41 is connected to the air outlet end of the blower 43 through the gas supply pipe 42 to introduce air into the main reaction area 14. During the process of air bubbling and floating, the liquid in the main reaction area 14 is stirred. In order to better monitor the reaction situation in the main reaction area 14, a monitor 6 is provided in the main reaction area 14, including a dissolved oxygen meter detection probe, an MLSS analyzer, a liquid level gauge, and a nitrate nitrogen detection probe, which respectively conduct on-line monitoring of the sludge biochemical state in the biochemical reaction area of the tank body 1.

[0034] Meanwhile, a lamella 16 is provided in the middle of the post-precipitation area 15. The inclination angle of the lamella 16 is 45 to 60°. The decanter 5 is installed at the upper end of the post-precipitation area 15 and is connected to the drain pipe. A sludge discharge pipe 18 is provided at the lower end of the post-precipitation area 15, and the sludge discharge pipe 18 is connected to the pretreatment area 13 through the reflux pipe 7 and the reflux pump 71. In this embodiment, control valves are provided on each connecting pipe to facilitate adjustment and control.

[0035] To improve the treatment efficiency, the first stirring device 2, the second stirring device 3, the aeration device 4, the decanter 5, the monitor 6, and each control valve can all be controlled and connected by a control device for comprehensive and efficient adjustment and control.

[0036] Treatment method one, the steps are as follows:

[0037] Step 1: The high-salt nitrogen-containing wastewater enters the pool body 1 through the inlet pipe 17. The aeration device 4 in the main reaction zone 14 is turned on, and the working aeration volume is 1 - 5 m 3 / h, and the aeration time is controlled within 0.5 - 1.5 h. At this time, an aerobic zone is formed in the main reaction zone 14 for nitrification reaction, and the pretreatment zone 13 and the post-precipitation zone 15 are anoxic zones for partial denitrification reaction under the disturbance of the water flow.

[0038] Step 2: The aeration stops. The dissolved oxygen in the main reaction zone 14 is consumed through the nitrification reaction and decreases due to dissipation to the pretreatment zone 13 and the post-precipitation zone 15. At this time, denitrification reaction occurs in the entire pool body 1. Under the agitation of the first agitation device 2 and the second agitation device 3, the activated sludge is fully mixed with the high-nitrogen wastewater. Observe the monitor 6 in the main reaction zone 14. When the nitrate nitrogen concentration hardly continues to decline, glucose is added as a carbon source, and the dosage is 50 - 150 mg / l.

[0039] Under anoxic conditions, the microorganisms on the biofilm formed by the polyurethane-based filler and the activated sludge are used to carry out denitrification reaction on the high-salt nitrogen-containing wastewater. During the anoxic period, the dissolved oxygen is controlled at 0.2 - 0.5 mg / l. The high-concentration nitrate nitrogen contained in the high-salt nitrogen-containing wastewater is converted into nitrogen gas under the action of salt-tolerant denitrifying bacteria, so as to be removed from the wastewater. The high-salt nitrogen-containing wastewater can degrade 8 - 30 mg / l of nitrate nitrogen per hour during the reaction residence time in the pool body 1.

[0040] Step 3: When the dissolved oxygen in the main reaction zone 14 is consumed to 1 - 1.5 mg / l through the reaction, the control valve of the reflux pipe 7 and the reflux pump 71 are opened, and the internal circulation is started. By means of the internal circulation, the influence of dissolved oxygen on the denitrifying bacteria is reduced, so that the denitrifying bacteria can quickly form a dominant flora in the pool body 1, and the nitrogen removal rate is increased.

[0041] Step 4: The first agitation device 2 and the second agitation device 3 are turned off, so that the reacted mud-water mixture is allowed to settle statically. The settling time is controlled within 0.5 - 1 h. After the settling is completed, the supernatant is separated for drainage. The decanter 5 is opened, and the supernatant flows into the drain pipe through the decanter 5 for discharge. The drainage time is controlled within the volume time of 1 / 4 - 1 / 3 of the inflow rate of the pool body 1.

[0042] Step 5: After the drainage is completed, the decanter 5 is closed, and the valve of the sludge discharge pipe 18 is opened for sludge discharge. The sludge discharge cycle needs to be determined according to the wastewater treatment situation; the sludge discharge volume each time is controlled at 1 / 10 of the pool volume.

[0043] Treatment method two: Intermittent continuous operation is adopted when the influent concentration is relatively low. The steps are as follows:

[0044] Step 1: The high-salt nitrogen-containing wastewater enters the pool body 1 through the inlet pipe 17. The aeration device 4 in the main reaction zone 14 is turned on, and the working aeration volume is 1 - 5 m3 / h, and the aeration time is controlled within 0.5 - 1.5 h. At this time, an aerobic zone is formed in the main reaction zone 14 for nitrification reaction, and the pretreatment zone 13 and the post - precipitation zone 15 are anoxic zones for denitrification reaction.

[0045] Step 2: Stop aeration. The dissolved oxygen in the main reaction zone 14 is consumed through the nitrification reaction and dissipated to the pretreatment zone 13 and the post - precipitation zone 15, thus decreasing. At this time, denitrification reactions occur in the entire pool body 1. During the anoxic period, control the dissolved oxygen at 0.2 - 0.5 mg / l. Under the agitation of the first stirring device 2 and the second stirring device 3, the activated sludge is fully mixed with the high - nitrogen wastewater. Observe the monitor 6 in the main reaction zone 14. When the nitrate nitrogen concentration hardly continues to decrease, add glucose as the carbon source, and the dosage is 20 - 75 mg / l.

[0046] Under anoxic conditions, using the microorganisms on the biofilm formed by polyurethane - type fillers and activated sludge, denitrification reaction is carried out on the high - salt nitrogen - containing wastewater. The low - concentration nitrate nitrogen contained in the high - salt nitrogen - containing wastewater is converted into nitrogen gas under the action of salt - tolerant denitrifying bacteria, thus being removed from the wastewater. The high - salt nitrogen - containing wastewater can degrade 8 - 30 mg / l of nitrate nitrogen per hour during the reaction residence time in the pool body 1.

[0047] Step 3: When the dissolved oxygen in the main reaction zone 14 is consumed to 1 - 1.5 mg / l during the reaction, open the control valve and the reflux pump 71 of the reflux pipe 7, and start the internal circulation. By means of the internal circulation, reduce the influence of dissolved oxygen on denitrifying bacteria, enabling the denitrifying bacteria to quickly form a dominant flora in the pool body 1 and increasing the denitrification rate.

[0048] Step 4: When the nitrate nitrogen in the water body reaches the specified requirements, stop the internal circulation. Let the muddy water flowing into the post - precipitation zone 15 pass through the inclined plate 16 to separate the muddy water. Control the sedimentation time within 0.5 - 1 h. After sedimentation is completed, separate the supernatant for drainage. Open the decanter 5, and the supernatant flows into the drain pipe through the decanter 5 for drainage. Control the drainage time within the volume time of 1 / 8 - 1 / 10 of the volume of the water flowing into the pool body 1 per hour of the influent flow rate. At the same time, open the control valve of the inlet pipe 17 to make the flow rate and volume of the influent and the drainage basically the same.

[0049] This biochemical pool adopts the activated sludge + biofilm process. By filling bio - fillers, the bio - fillers and the activated sludge form a biofilm, and use the formed biofilm to carry out high - salt denitrification and nitrogen removal treatment on the high - concentration nitrate nitrogen in the high - salt wastewater; at the same time, increase the internal circulation, reduce the dissolved oxygen and the impact of wastewater concentration, enabling the denitrification reaction to operate quickly and stably, and use the formed biofilm to carry out high - salt denitrification and nitrogen removal treatment on the high - concentration nitrate nitrogen in the high - salt wastewater.

[0050] The above are the preferred embodiments of the present utility model. Of course, the scope of rights of the present utility model cannot be limited thereby. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present utility model, several improvements and modifications can be made, and these improvements and modifications are also regarded as the protection scope of the present utility model.

Claims

1. A sequencing batch denitrification biochemical tank for denitrification of high-salinity wastewater, characterized in that: include: A tank body, a baffle, a grille, a water inlet pipe, a first stirring device, a second stirring device, an aeration device and a decanter; The tank body is divided into a pretreatment zone, a main reaction zone and a post-sedimentation zone in sequence by two partitions. The bottom end of the partition is connected to the bottom of the tank body through a grid. The first stirring device is installed in the pretreatment zone, the second stirring device and the aeration device are installed in the main reaction zone, the main reaction zone is filled with polyurethane porous sponge filler, the outlet end of the water inlet pipe is connected to the pretreatment zone and the main reaction zone respectively, an inclined plate is provided in the middle of the post-sedimentation zone, a decanter is installed at the upper end of the post-sedimentation zone and connected to the drain pipe, and a mud discharge pipe is provided at the lower end of the post-sedimentation zone.

2. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as claimed in claim 1, characterized in that: The tank capacity ratio of the pretreatment area, main reaction area and post-sedimentation area is 2:3:1.

5.

3. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as described in claim 1, characterized in that: The aeration device comprises an aeration pipe, an air supply pipe and a blower. The aeration pipe is arranged at the bottom of the main reaction zone. A plurality of aeration holes are arranged on the aeration pipe. The aeration pipe is connected to the air outlet end of the blower through the air supply pipe.

4. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as claimed in claim 1, characterized in that: The main reaction area is equipped with monitoring instruments, including dissolved oxygen meter detection probe, MLSS analyzer, liquid level meter, and nitrate nitrogen detection probe.

5. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as claimed in claim 1, characterized in that: The aperture of the grid is 8 to 15 mm.

6. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as claimed in claim 1, characterized in that: The second stirring device adopts a hyperbolic stirrer, which is a vertical low-speed large impeller stirring head made of fiberglass. The ratio of impeller diameter to pool width is 1:2 to 1:

5.

7. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as claimed in claim 1, characterized in that: The filling volume ratio of the filler in the main reaction zone is 30-60%, the filler is a square structure with a side length of 20-40 mm, and the porosity is 70-90%.

8. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as claimed in claim 1, characterized in that: The inclination angle of the inclined plate is between 45 and 60 degrees.

9. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as claimed in claim 1, characterized in that: The sludge discharge pipe is connected to the pretreatment area through a return pipe and a return pump.

10. The high-salinity wastewater denitrification sequencing batch denitrification biochemical pool as claimed in claim 1, characterized in that: The pretreatment area is connected to the dosing pump via a dosing pipe.

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