Sewage treatment station upgrading and transformation treatment system and sewage treatment method

Abstract

The present invention discloses a sewage treatment station upgrading and transformation treatment system and sewage treatment method, the system includes a biochemical treatment system, the biochemical treatment system includes a biochemical tank and a secondary sedimentation tank, the biochemical tank transformation includes transforming the original aerobic tank into an aerobic tank 1, an anaerobic tank and an aerobic tank 2, adding biological carriers, activated sludge and anchoring agents into the transformed biochemical tank, and transforming the secondary sedimentation tank into a high-efficiency sedimentation tank. The present invention also discloses a method for treating sewage using the above-mentioned treatment system. The sewage treatment system after upgrading and transformation of the present invention uses the AOAO process and the high-efficiency sedimentation method, which can still achieve high-efficiency carbon removal, nitrogen removal and phosphorus removal in the sewage treatment system while having the advantages of low construction cost and low cost operation.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a sewage treatment station upgrading and transformation treatment system and a sewage treatment method. Background Art

[0002] At present, the current status of water resources is in short supply, low per capita possession, uneven regional distribution, increasing water pollution, and prominent urban water shortage. In order to improve and enhance the quality of the water environment, it is inevitable to raise the urban sewage treatment discharge standards. At present, more stringent effluent discharge standards have been proposed for new construction or expansion of sewage treatment plants, including COD Cr Under the new standards, the upgrading and transformation of sewage treatment plants (stations) has become more urgent.

[0003] The upgrading and transformation of sewage treatment plants (stations) is based on the status quo of the original projects, adhering to economic and energy-saving benefits, optimizing processes, technologies, equipment, operating parameters and other conditions, and enhancing the treatment capacity of sewage treatment plants (stations) to meet higher effluent discharge standards. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a sewage treatment station upgrading and transformation system in view of the deficiencies of the prior art. By transforming the aerobic tank and setting up a high-efficiency sedimentation tank, the removal rates of COD, NH3-N, TN and TP can be effectively improved, so as to achieve the purpose of energy saving, efficiency improvement and capacity expansion, which is very suitable for upgrading and transformation of existing old sewage treatment plants (stations). The present invention also provides a method for treating sewage by transforming the post-treatment system.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A sewage treatment station upgrading and transformation treatment system comprises a biochemical treatment system, wherein the biochemical treatment system comprises a biochemical pool and a secondary sedimentation pool, wherein the biochemical pool transformation comprises adding two stainless steel plates to an original aerobic pool, wherein the original aerobic pool is transformed into an aerobic pool 1, an anaerobic pool and an aerobic pool 2, wherein the biochemical pool after transformation comprises an A1 anoxic pool + an O1 aerobic pool + an A2 anaerobic pool + an O2 aerobic pool.

[0007] Preferably, the water inlet modification of the biochemical treatment system includes adding a water inlet pipeline from the lifting tank to the aerobic tank.

[0008] Preferably, a nitrification liquid reflux pipeline is provided between the O2 aerobic tank and the A1 anoxic tank.

[0009] Preferably, a concentration tank is provided behind the high-efficiency sedimentation tank for storing sludge produced in the sedimentation tank.

[0010] Preferably, a stirrer is provided in the A2 anoxic tank to facilitate the turning of the carrier.

[0011] Preferably, a scraper is provided in the high-efficiency sedimentation tank for cleaning the precipitated sludge into a concentration tank.

[0012] Furthermore, the stainless steel plate is provided with 6 I-shaped nails and is fixed in the water pool.

[0013] Preferably, a grille hole is left on the stainless steel plate; more preferably, the sizes of the two stainless steel plates are determined according to the size of the original aerobic pool.

[0014] Furthermore, carriers, activated sludge and anchoring agents are added to the A1 anoxic tank, the O1 aerobic tank, the A2 facultative oxic tank and the O2 aerobic tank.

[0015] The volume filling rate of the biological carrier is 10-40%, the volume of activated sludge added is 20-40% of the volume of the reaction tank; and the amount of anchoring agent added is 0.1-0.2 ppm.

[0016] Preferably, the carrier is a patented product of a modified polyethylene microbial carrier filler disclosed in CN108946933B; more preferably, the volume filling rate of the biological carrier is 10-40%.

[0017] Preferably, the anchoring agent is a biological anchoring agent disclosed in CN112707517A and its preparation method and application patent product.

[0018] Furthermore, the secondary sedimentation tank is transformed into a high-efficiency sedimentation tank.

[0019] Preferably, the chemical phosphorus removal method of adding PAC is used to assist the pre-biochemical phosphorus removal in the high-efficiency sedimentation tank; more preferably, the mass concentration of PAC is 5-10%, and the addition amount is 15-100 mg / L.

[0020] Furthermore, a grid is added to the overflow from the anoxic tank to the aerobic tank 1; and a grid is added to the overflow from the aerobic tank 2 to the high-efficiency sedimentation tank to prevent the loss of the carrier.

[0021] The sewage treatment station upgrading and transformation treatment system described in the present invention has the following operating steps:

[0022] Step 1: The sewage first passes through a grit chamber to remove coarse particles such as mud and sand, and then passes through a regulating tank to stabilize the pH value at 6 to 9;

[0023] Step 2: After the sewage is pre-treated in the regulating tank, it is pumped into the A1 anoxic tank through the lifting pump and mixed with the refluxed nitrification liquid to release phosphorus and ammoniation by polyphosphate bacteria. The facultative acidifying bacteria in the sludge decompose the macromolecular organic matter in the water into low-level fatty acids for polyphosphate bacteria to absorb. At the same time, the polyphosphate bacteria convert the polyphosphate stored in the body into PO4 3- -P is released in order to gain energy;

[0024] Step 3: The effluent from the A1 anoxic pool flows into the O1 aerobic pool for a series of reactions such as nitrification, phosphorus absorption by polyphosphate bacteria, and COD removal. By aerating the pool, nitrifying bacteria convert ammonia nitrogen and organic nitrogen into nitrate nitrogen under aerobic conditions, and absorb phosphorus in the sewage, thereby achieving the purpose of removing ammonia nitrogen and total phosphorus, and removing some pollutants in the water at the same time;

[0025] Step 4: The effluent from the O1 aerobic pool flows into the A2 facultative aerobic pool and mixes with the sewage flowing in through the diversion inlet pipe. The nitrite nitrogen and nitrate nitrogen in the sewage are reduced to N2 for denitrification. At the same time, the remaining refractory COD after treatment in the O1 aerobic pool is further hydrolyzed.

[0026] Step 5: The effluent from the A2 facultative aerobic tank flows into the O2 aerobic tank. The biological fillers in the O2 aerobic tank form an anaerobic-facultative aerobic microenvironment from the inside out, which improves the efficiency of COD degradation and denitrification, increases the biomass in the system, and reduces the amount of excess sludge produced; sufficient aeration is performed to remove the remaining COD, ammonia nitrogen and total nitrogen in the sewage;

[0027] Step 6: The effluent from the O2 aerobic pool flows into the high-efficiency sedimentation tank, where chemical phosphorus removal is used. By adding flocculant PAC and stirring, the soluble phosphate (PO4 3- ) and Al 3+ After sufficient reaction, AlPO4 precipitate is formed and the supernatant is discharged as effluent.

[0028] Furthermore, carriers, activated sludge and anchoring agents are added to the A1 anoxic tank, the O1 aerobic tank, the A2 facultative oxic tank and the O2 aerobic tank.

[0029] The volume filling rate of the biological carrier is 10-40%, the volume of activated sludge added is 20-40% of the volume of the reaction tank; and the amount of anchoring agent added is 0.1-0.2 ppm.

[0030] Preferably, the carrier is a patented product of a modified polyethylene microbial carrier filler disclosed in CN108946933B; more preferably, the volume filling rate of the biological carrier is 10-40%.

[0031] Preferably, the anchoring agent is a biological anchoring agent disclosed in CN112707517A and its preparation method and application patent product.

[0032] Furthermore, the treatment system can process water of 1200±240m 3 / d; in the biochemical treatment system, the total residence time of wastewater in the biochemical pool is 6.3-9.5h, and the residence time in the high-efficiency sedimentation pool is 1.5-3h.

[0033] Preferably, the hydraulic retention time of the A1 anoxic tank is 0.7-1h; the hydraulic retention time of the O1 aerobic tank is 2.1-3h, and the dissolved oxygen DO is controlled at 3-5mg / L; the hydraulic retention time of the A2 facultative oxygen tank is 0.9-1.4h, and the dissolved oxygen DO is controlled below 0.5mg / L; the hydraulic retention time of the O2 aerobic zone is 2.7-6.3h, and the dissolved oxygen DO is controlled at 3-5mg / L.

[0034] Preferably, the residence time of the high-efficiency sedimentation tank includes a PAC flocculation time of 0.5-1 h and a sedimentation time of 1-2 h.

[0035] Beneficial effects: The biochemical pool transformation of the present invention includes transforming the original aerobic pool into aerobic pool 1, facultative aerobic pool and aerobic pool 2, adding biological carriers, activated sludge and anchoring agents into the transformed biochemical pool, and transforming the secondary sedimentation tank into a high-efficiency sedimentation tank. The sewage treatment system after the upgrading and transformation of the present invention uses the AOAO process and high-efficiency sedimentation method, which can still achieve high-efficiency carbon removal, nitrogen removal and phosphorus removal in the sewage treatment system with the advantages of low construction cost and low cost operation. It is suitable for upgrading and transformation of domestic sewage stations with high requirements for effluent water quality, tight land use, limited funds, and large fluctuations in influent. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a design drawing of the front pool type of the sewage treatment station transformation of the present invention;

[0037] Figure 2 It is the pool design drawing after the sewage treatment station is transformed according to the present invention;

[0038] Figure 3 This is a process flow chart for upgrading and transforming the treatment system of the present invention.

[0039] Among them, the figure markings are: 1. grit chamber; 2. regulating tank; 3. lifting tank; 4. A1 anoxic tank; 5. O1 aerobic tank; 6. A2 facultative anoxic tank; 7. O2 aerobic tank; 8. high-efficiency sedimentation tank; 9. concentrating tank; 10. agitator; 11. stainless steel plate; 12. I-nail. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0041] Example 1

[0042] like Figure 1-3As shown, a sewage treatment station upgrading and transformation treatment system is based on the original process ( Figure 1 ): based on inlet → grit tank → regulating tank → anoxic tank → aerobic tank → secondary sedimentation tank → effluent, two stainless steel plates 11 are added to the original aerobic tank, and the biochemical tank after transformation includes A1 anoxic tank 4 + O1 aerobic tank 5 + A2 facultative aerobic tank 6 + O2 aerobic tank 7, and the secondary sedimentation tank is transformed into a high-efficiency sedimentation tank 8, and an inlet pipeline from the lifting tank 3 to the A2 facultative aerobic tank 6 is added.

[0043] Combination Figure 2 and Figure 3 The sewage treatment station upgrading and transformation treatment system of the present invention comprises a grit chamber 1, a regulating chamber 2, a lifting chamber 3, a biochemical chamber, a high-efficiency sedimentation chamber 8 and a concentration chamber 9 which are arranged in sequence, wherein the biochemical chamber comprises an A1 anoxic chamber 4, an O1 aerobic chamber 5, an A2 facultative anoxic chamber 6 and an O2 aerobic chamber 7 which are arranged in sequence, a water inlet pipeline is arranged between the lifting chamber 3 and the A2 facultative anoxic chamber 6, and a nitrification liquid reflux pipeline is arranged between the O2 aerobic chamber 7 and the A1 anoxic chamber 4.

[0044] The O1 aerobic pool 5 and the A2 anoxic pool 6, and the A2 anoxic pool 6 and the O2 aerobic pool 7 are separated by a stainless steel plate 11; the stainless steel plate 11 is fixed by an I-shaped nail 12, and the I-shaped nail 12 is fixed in the biochemical pool; the A2 anoxic pool 6 is provided with an agitator 10, and the high-efficiency sedimentation pool 8 is provided with a mud scraper. There are grille holes on the stainless steel plate 11, and a grille net is added to the overflow from the A1 anoxic pool 4 to the O1 aerobic pool 5; a grille net is added to the overflow from the O2 aerobic pool 7 to the high-efficiency sedimentation pool 8.

[0045] Example 2

[0046] A method for treating sewage by using the optimized treatment system of Example 1 through an AOAO process integrated high-efficiency sedimentation method comprises the following steps:

[0047] Step 1: The sewage first passes through the grit chamber 1 to remove coarse particles such as mud and sand, and then passes through the regulating tank 2 to stabilize the pH value at 6-9.

[0048] Step 2: After the sewage is pre-treated in the regulating tank 2, it is pumped into the A1 anoxic tank 4 through the lifting pump set in the lifting tank 3, and mixed with the nitrification liquid returned from the nitrification liquid return pipeline. In the A1 anoxic tank 4, polyphosphate bacteria release phosphorus and ammoniation. The facultative acidifying bacteria in the sludge decompose the macromolecular organic matter in the water into low-level fatty acids for polyphosphate bacteria to absorb. At the same time, the polyphosphate bacteria convert the polyphosphate stored in the body into PO4 3- -P is released in order to gain energy.

[0049] Biological carrier, anchoring agent and activated sludge are added to the A1 anoxic tank 4. The carrier is a patented product of a modified polyethylene microbial carrier filler disclosed in CN108946933B, and the volume filling rate of the biological carrier is 10-40%. The anchoring agent is a biological anchoring agent disclosed in CN112707517A and its preparation method and application patented product, and the anchoring agent dosage is 0.1-0.2ppm. The volume of activated sludge added is 20-40% of the volume of the reaction tank. Step 3: The effluent of the A1 anoxic tank 4 flows into the O1 aerobic tank 5, and oxygen is provided by the aeration fan. Under aerobic conditions, nitrifying bacteria convert ammonia nitrogen and organic nitrogen into nitrate nitrogen, and absorb phosphorus in the sewage, so as to achieve the purpose of removing ammonia nitrogen and total phosphorus, and remove some pollutants in the water at the same time.

[0050] Bio-carrier, bio-anchoring agent and activated sludge are added to the O1 aerobic pool 5. Among them, the carrier is a patented product of modified polyethylene microbial carrier filler disclosed in CN108946933B, and the volume filling rate of the bio-carrier is 10-40%. The anchoring agent is a patented product of a bio-anchoring agent and its preparation method and application disclosed in CN112707517A, and the anchoring agent dosage is 0.1-0.2ppm. The volume of activated sludge added is 20-40% of the volume of the reaction tank.

[0051] Step 4: The effluent from the O1 aerobic pool 5 flows into the A2 facultative anoxic pool 6, and the wastewater and biological filler are mixed evenly by the agitator 10. The nitrite nitrogen and nitric nitrogen in the wastewater are reduced to N2 for denitrification. At the same time, the remaining refractory COD after treatment in the O1 aerobic pool 5 is further hydrolyzed;

[0052] A2 facultative oxygen tank 6 is added with biological carrier, biological anchoring agent and activated sludge. Among them, the carrier is a modified polyethylene microbial carrier filler patent product disclosed in CN108946933B, and the volume filling rate of the biological carrier is 10-40%. The anchoring agent is a biological anchoring agent disclosed in CN112707517A and its preparation method and application patent product, the anchoring agent addition amount is 0.1-0.2ppm, and the volume of activated sludge added is 20-40% of the volume of the reaction tank.

[0053] Step 5: The effluent from the A2 facultative aerobic tank 6 flows into the O2 aerobic tank 7, and oxygen is provided by the aeration fan. The biological fillers in the O2 aerobic tank 7 form an anaerobic-facultative aerobic-aerobic microenvironment from the inside to the outside, thereby improving the efficiency of COD degradation and denitrification, increasing the biomass in the system, and reducing the amount of excess sludge generated; sufficient aeration is performed to remove the remaining COD, ammonia nitrogen and total nitrogen in the sewage;

[0054] Bio-carrier, bio-anchor and activated sludge are added to the O2 aerobic tank 7. The carrier is a patented product of modified polyethylene microbial carrier filler disclosed in CN108946933B, and the volume filling rate of the bio-carrier is 10-40%. The anchor is a patented product of a bio-anchor disclosed in CN112707517A and its preparation method and application, and the anchor dosage is 0.1-0.2ppm. The volume of activated sludge added is 20-40% of the volume of the reaction tank.

[0055] Step 6: The effluent from the O2 aerobic pool 7 flows into the high-efficiency sedimentation pool 8, and chemical phosphorus removal is performed by adding flocculant PAC and stirring. The PAC mass concentration is 5-10%, and the addition amount is 15-100 mg / L. The soluble phosphate (PO4 3- ) and Al 3+ After sufficient reaction, AlPO4 precipitate is formed and the supernatant is discharged as effluent.

[0056] Application Example 1

[0057] A sewage treatment plant with a treatment capacity of 1200m 3 / d, and the effluent complies with the limit value standard of "Discharge Standard of Major Water Pollutants from Urban Sewage Treatment Plants" (DB 33 / 2169-2018). The treatment system of Example 1 and the treatment method of Example 2 are used for sewage treatment.

[0058] Table 1 Designed inlet and outlet water quality

[0059]

[0060] 4A1 anoxic pool design residence time 0.8h, size 40m 3 .

[0061] The design retention time of 5O1 aerobic pool is 2.4h, the dissolved oxygen DO is controlled at 3-5mg / L, and the size is 113m 3 .

[0062] The design retention time of 6A2 facultative oxygen pool is 1.1h, the dissolved oxygen DO is controlled below 0.5mg / L, and the size is 113m 3 .

[0063] The design retention time of 7O2 aerobic pool is 3.3h, the dissolved oxygen DO is controlled at 3-5mg / L, and the size is 113m 3 .

[0064] 8 High-efficiency sedimentation tank uses honeycomb inclined tube sedimentation, with an average rising velocity of 11.6m / h, a designed residence time of 3h, and a size of 11.7×2.6×5.5m 3 .

[0065] This upgrading and renovation project only adds one water inlet pump, one submersible mixer and one mud scraper, with a power consumption of 0.423 kWh / m 3 , 1 ton of water chemical fee is 0.168 yuan / m 3 .

[0066] Table 2 Water quality and treatment effect of sewage treatment station inlet and outlet water before transformation

[0067]

[0068]

[0069] Table 3 Water quality test results of inlet and outlet water after transformation

[0070]

[0071] As shown in Tables 2 and 3, the present invention has good removal effects on COD, NH3-N, TP, TN and other indicators of wastewater, and the corresponding removal rates are 75%, 97%, 94% and 68%, respectively. These four indicators are lower than the limit values ​​of the "Emission Standards of Major Water Pollutants from Urban Wastewater Treatment Plants" (DB 33 / 2169-2018), meeting the requirements for upgrading and transformation.

[0072] Technical features not described in the present invention can be achieved through or by adopting existing technologies and will not be described in detail here. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A method for treating sewage by upgrading and transforming a sewage treatment station treatment system, characterized in that: The following steps are involved: Step 1: The sewage is passed through a grit chamber to remove coarse sand particles, and then passed through a regulating tank to stabilize the pH value at 6-9; Step 2: After being pre-treated in the regulating tank, the sewage enters the A1 anoxic tank through the lifting tank for phosphorus release and ammoniation by polyphosphate bacteria; Step 3: The effluent from the A1 anoxic pool flows into the O1 aerobic pool for nitrification, phosphorus absorption by polyphosphate bacteria and COD removal; Step 4: The effluent from the O1 aerobic pool flows into the A2 facultative aerobic pool, where the nitrite nitrogen and nitric nitrogen in the wastewater are reduced to N2 for denitrification, and the remaining refractory COD after treatment in the O1 aerobic pool is further hydrolyzed; Step 5: The effluent from the A2 facultative aerobic tank flows into the O2 aerobic tank. The biological fillers in the O2 aerobic tank form an anaerobic-facultative aerobic microenvironment from the inside out, fully aerating to remove the remaining COD, ammonia nitrogen and total nitrogen in the sewage; Step 6: The effluent from the O2 aerobic pool flows into the high-efficiency sedimentation tank, where chemical phosphorus removal is used. By adding flocculant PAC and stirring, the soluble phosphate PO4 in the sewage is reduced. 3- With Al 3+ After sufficient reaction, AlPO4 precipitation is formed and discharged through mud discharge means; the chemical phosphorus removal method of adding PAC in the high-efficiency sedimentation tank assists the pre-biochemical phosphorus removal; the mass concentration of PAC is 5-10%, and the addition amount is 15-100 mg / L; The sewage treatment station upgrading and transformation treatment system comprises a grit chamber (1), a regulating chamber (2), a lifting chamber (3), a biochemical chamber and a high-efficiency sedimentation chamber (8) which are arranged in sequence, wherein the biochemical chamber comprises an A1 anoxic chamber (4), an O1 aerobic chamber (5), an A2 facultative aerobic chamber (6) and an O2 aerobic chamber (7) which are arranged in sequence, and a water inlet pipeline is arranged between the lifting chamber (3) and the A2 facultative aerobic chamber (6); the O1 aerobic chamber (5) and the A2 facultative aerobic chamber (6), and the A2 facultative aerobic chamber (6) and the O2 aerobic chamber (7) are separated by a stainless steel plate (11). The stainless steel plate (11) is fixed by an I-shaped nail (12), and the I-shaped nail (12) is fixed in the biochemical pool; biological carriers, activated sludge and anchoring agents are added to the A1 anoxic pool, the O1 aerobic pool, the A2 facultative oxic pool and the O2 aerobic pool; wherein the volume filling rate of the biological carrier is 10-40%, the volume of activated sludge added is 20-40% of the volume of the reaction pool; the amount of anchoring agent added is 0.1-0.2 ppm; and the removal rates corresponding to the COD, NH3-N, TP and TN indicators of the effluent water quality are 75%, 97%, 94% and 68% respectively.

2. The method for treating sewage according to claim 1, characterized in that: A nitrification liquid return pipeline is provided between the O2 aerobic tank (7) and the A1 anoxic tank (4), and a concentration tank (9) is further provided after the high-efficiency sedimentation tank (8).

3. The method for treating sewage according to claim 1, characterized in that: The A2 anoxic tank (6) is provided with a stirrer (10), and the high-efficiency sedimentation tank (8) is provided with a sludge scraper.

4. The method for treating sewage according to claim 1, characterized in that: The treatment system can process 1200±240m3 of water. 3 / d; the total residence time of wastewater in the biochemical pool is 6.3-9.5h, and the residence time in the high-efficiency sedimentation tank is 1.5-3h.

5. The method for treating sewage according to claim 1, characterized in that: The hydraulic retention time of the A1 anoxic tank is 0.7-1h; the hydraulic retention time of the O1 aerobic tank is 2.1-3h, and the dissolved oxygen DO is controlled at 3~5mg / L; the hydraulic retention time of the A2 facultative oxygen tank is 0.9-1.4h, and the dissolved oxygen DO is controlled below 0.5mg / L; the hydraulic retention time of the O2 aerobic zone is 2.7-6.3h, and the dissolved oxygen DO is controlled at 3~5mg / L.

6. The method for treating sewage according to claim 1, characterized in that: The residence time of the high-efficiency sedimentation tank includes a PAC flocculation time of 0.5-1h and a sedimentation time of 1-2h.

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