A sewage treatment advanced denitrification and phosphorus removal and suspended substance reduction system and a regulation and control method

Abstract

The sewage treatment deep denitrification and phosphorus removal and suspended solids reduction system and regulation method of the present application mainly comprises a water inlet unit, a water distribution unit, a biological unit and a reagent distribution unit. The water inlet unit is provided with an adjusting tank for water quality and quantity balancing adjustment, the water distribution unit is provided with multiple water distribution points, the biological unit is provided with a nitration liquid internal reflux pipeline, and the reagent distribution unit is provided with a reagent feeding device, multiple reagent feeding points and a mixing device. The reagent distribution unit can adjust the reagent feeding amount according to the water inlet quantity, the secondary sedimentation tank mud level and other information, thereby ensuring the treatment effect while reducing the reagent feeding cost. The reagent distribution unit is erected on the pipeline between the biological unit and the secondary sedimentation tank, has a smart structure, is easy to lay, is simple to operate, can ensure the quick separation of mud and water in the secondary sedimentation tank, the clarity of supernatant, the low SS of effluent and the stable effluent quality, and finally realizes the purpose of denitrification, phosphorus removal and suspended solids reduction, and solves the problem of low efficiency of biological sewage treatment for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, in particular to a sewage treatment system and a treatment method, in particular to a sewage treatment system and a treatment method for deep denitrification, phosphorus removal and suspended solids reduction. BACKGROUND

[0002] The traditional activated sludge process for sewage treatment has the disadvantages of long sedimentation time, large footprint of sedimentation tank, and unsatisfactory biological denitrification and phosphorus removal effect, which has attracted people's attention and research on the efficiency of the sewage treatment system. The existing sewage treatment system optimizes the operation parameters, excavates the process potential, and uses advanced control technology and treatment chemicals to improve the efficiency of sewage denitrification and phosphorus removal and reduce suspended solids.

[0003] In the operation process of the sewage plant, too little dosage of the chemicals cannot achieve the effect, and too much dosage often has the opposite effect, which not only increases the treatment cost, but also may cause trouble to the process operation. The traditional biological-chemical method for sewage treatment often uses a relatively independent way, and the chemical method is used after biochemical treatment, and coagulation and sedimentation facilities are set up to improve the treatment efficiency. Due to historical reasons, many sewage plants do not have coagulation and sedimentation facilities, in order to ensure the treatment effect, chemicals are often added in the biological tank to strengthen the effect of sewage treatment. However, the reaction time of the chemicals and the mixed liquid and the dosage both affect the treatment effect. In the actual operation of the sewage plant, once the dosage point is determined, the dosage point is generally not changed, and the dosage is rarely changed, and the dosage is often too much. This fixed dosage strategy lacks flexibility, increases the cost of chemical dosage, and the effluent quality is also unstable.

[0004] As known, the influent quantity of the sewage plant often has a large variation coefficient due to the influence of factors such as season, surrounding pipe network supporting perfection, surrounding population quantity, and industrial wastewater quantity, and the actual influent quantity is about 10% to 150% of the designed influent quantity. Too little or too much influent quantity both affect the sludge settling efficiency of the secondary sedimentation tank. The former may cause floating sludge in the secondary sedimentation tank, and the latter may cause sludge running in the secondary sedimentation tank. The performance of the secondary sedimentation tank affects the quantity of the dominant bacteria (especially nitrifying bacteria, denitrifying bacteria, and phosphorus accumulating bacteria) in the front-end anaerobic tank or anoxic tank and the suspended solids concentration of the effluent. As can be seen, reasonable dosage of chemicals in the secondary sedimentation tank is very important to improve the treatment effect. It is of great significance to improve the operation and management of the system to achieve the purpose of deep denitrification, phosphorus removal and suspended solids reduction in sewage treatment by using appropriate methods.

[0005] Therefore, it is of important practical and scientific significance to improve sewage denitrification, phosphorus removal and suspended solids reduction at low cost. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a sewage treatment deep denitrification and phosphorus removal and suspended solids reduction system and a regulation and control method, which has the function of strengthening the removal of nitrogen, phosphorus and suspended solids.

[0007] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0008] A sewage treatment deep denitrification and phosphorus removal and suspended solids reduction system, comprising a water inlet unit, a water distribution unit, a biological unit, a dosing unit, a sedimentation unit and a reflux unit.

[0009] The water inlet unit is provided with a water inlet and an adjusting tank.

[0010] The water distribution unit is connected with the water inlet unit and is provided with a water distribution point.

[0011] The biological unit is provided with a pre-anoxic tank, an anaerobic tank, an anoxic tank, a first aerobic tank, a second aerobic tank and an oxygen depletion zone.

[0012] The dosing unit is provided with a reagent feeding device, a reagent feeding point and a mixing device.

[0013] In the sedimentation unit, a secondary sedimentation tank and a water outlet are arranged.

[0014] In the reflux unit, a sludge reflux pump and a residual sludge discharge port are arranged, and the residual sludge is refluxed to the pre-anoxic tank of the biological unit.

[0015] A booster pump is further arranged between the water inlet unit and the water distribution unit.

[0016] The water distribution point of the water distribution unit is provided with a first water distribution point, a second water distribution point and a third water distribution point.

[0017] The water distribution unit is further provided with a valve and a flowmeter.

[0018] In some embodiments of the present application, the biological unit comprises:

[0019] The aerobic tank comprises a first aerobic tank and a second aerobic tank, and an aerator is arranged at the bottom of each tank.

[0020] An air blower is arranged in the first aerobic tank.

[0021] A nitrification liquid reflux pipeline is further arranged, and a flowmeter and an internal circulation pump are arranged on the pipeline.

[0022] The connecting ports between the tanks are arranged at the upper or lower part.

[0023] A stirrer is arranged in the oxygen depletion zone.

[0024] The aerator is a microporous aerator.

[0025] In some embodiments of the present application, the dosing unit comprises:

[0026] The medicament adding point is provided with a first adding point, a second adding point and a third adding point.

[0027] The medicament adding device is further provided with a medicament adding pump.

[0028] A check opening is further provided for checking the working state of the medicament adding pump.

[0029] The sedimentation unit is provided with a mud level measuring device, and the mud level measuring device is provided with a one-way valve.

[0030] The reflux unit is further provided with a valve and a flow meter.

[0031] A sewage treatment advanced denitrification and phosphorus removal and suspended solids control method comprises the following steps:

[0032] 1) Inoculating activated sludge in the reactor of the biological unit and carrying out nitrification domestication, and after domestication for 3-7 days, the ammonia nitrogen concentration of the effluent is less than 1 mg / L, indicating that the nitrification domestication of the sludge is completed, and the nitrification sludge is refluxed from the oxygen depletion zone to the anoxic tank.

[0033] 2) The sewage is first pumped from the adjusting tank into the water distribution unit, and the water distribution unit controls the water inflow and distribution ratio so as to enter the biological unit for nitrification treatment.

[0034] 3) The suspended sludge after the nitrification treatment of the biological unit enters the mixing device and is mixed with the medicament.

[0035] 4) The effluent after the above step treatment enters the sedimentation unit for sedimentation, and the supernatant is discharged in accordance with the standard, and the bottom sludge is pumped into the biological unit for continuous nitrification treatment through the reflux unit.

[0036] 5) The mud level of the secondary sedimentation tank is measured every 2-4 hours by the mud level measuring device.

[0037] The mixing time of the medicament and the sludge in the mixing device is 1-3 minutes, and the hydraulic retention time of the sludge between the medicament adding point and the water inlet of the secondary sedimentation tank is the medicament reaction time.

[0038] The medicament adding amount is 5-60 μL / L.

[0039] Compared with the prior art, the present application has the following characteristics and beneficial effects:

[0040] (1) Unlike the prior art of directly adding reagent in the biological unit, the application is specially provided with a reagent dispensing unit at the outlet of the biological unit reactor, which comprises a mixing device and a plurality of reagent adding points, etc., and the reagent adding point is adjusted according to the water inflow, when the water inflow is large, the adding point is in front, and when the water inflow is small, the adding is in the back. Generally speaking, the hydraulic retention time of sludge between the reagent adding point and the water inlet of the secondary sedimentation tank is the reagent reaction time. Thus, the mixing time of the reagent in the pipeline is met, and the mixing effect is ensured. The reagent dispensing unit is erected on the pipeline between the biological unit reactor and the secondary sedimentation tank, which is flexible in structure and easy to lay; simple in operation and easy to operate, which can ensure that the sludge and water in the secondary sedimentation tank are quickly separated, the supernatant is clear, the effluent SS is low, and the effluent quality is stable, and finally the purpose of denitrification, phosphorus removal and suspended solids reduction is realized.

[0041] In the embodiment of the application, the mixing time of the reagent and the sludge is preferably 1-3 minutes, and the short mixing reaction time of the reagent and the sludge affects the flocculation effect, and the long time will break the flocculant in the flow.

[0042] (2) The reagent adding device in the reagent dispensing unit of the application has the function of automatically adjusting the reagent adding amount, can adjust the reagent adding amount according to the water inflow, the mud level of the secondary sedimentation tank and other information, can guarantee the treatment effect, reduce the reagent adding amount and the reagent adding cost. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of a sewage treatment deep denitrification, phosphorus removal and suspended solids reduction system and a control method of the embodiment of the application.

[0044] Among them, 1 is a water inlet, 2 is a regulating tank, 3 is a lifting pump, 4 is a first water distribution point, 5 is a second water distribution point, 6 is a third water distribution point, 7 is a pre-anoxic tank, 8 is an anaerobic tank, 9 is an anoxic tank, 10 is a valve, 11 is a flowmeter, 12 is a first aerobic tank, 13 is a second aerobic tank, 14 is an oxygen depletion zone, 15 is a blower, 16 is an internal circulating pump, 17 is a reagent adding device, 18 is a stirrer, 19 is a first adding point, 20 is a second adding point, 21 is a third adding point, 22 is a mixing device, 23 is a secondary sedimentation tank, 24 is a water outlet, 25 is a sludge return pump, 26 is a residual sludge discharge port, and 27 is an inspection port.

[0045] Figure 2 It is a schematic diagram of the secondary sedimentation tank mud level measuring device of the sewage treatment deep denitrification, phosphorus removal and suspended solids reduction system and the control method of the embodiment of the application.

[0046] Among them, 231 is a transparent pipeline main body, 232 is a one-way valve, and 233 is a scale.

[0047] Figure 3The medicament adding amount calculation schematic diagram of the sewage treatment deep denitrification and phosphorus removal and suspended solids reduction system and the regulation and control method. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present application clearer, the following will be further described in detail in combination with specific embodiments and with reference to the drawings.

[0049] The present application provides a sewage treatment deep denitrification and phosphorus removal and suspended solids reduction system and a regulation and control method. The specific technical methods and devices of the present application are described in detail and completely below in combination with the drawings and specific embodiments. The specific embodiments described are only part of the examples of the present application, but not all examples. All other examples obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0050] In addition, all the expressions of "first" and "second" in the embodiments of the present application are used to distinguish two same name but different entities or different parameters. It can be seen that "first" and "second" are only for the convenience of description and should not be understood as a limitation of the embodiments of the present application. The subsequent embodiments will not be described one by one.

[0051] As shown in Figure 1 The sewage treatment deep denitrification and phosphorus removal and suspended solids reduction system of the present application comprises a water inlet unit, a water distribution unit, a biological unit, a medicament distribution unit, a sedimentation unit and a reflux unit.

[0052] The water inlet unit is provided with a water inlet 1 and an adjusting tank 2 for adjusting water quality and quantity.

[0053] The water distribution unit is connected with the water inlet unit and is provided with a water distribution point for adjusting the water inlet quantity of the biological unit.

[0054] The biological unit is provided with a pre-anoxic tank 7, an anaerobic tank 8, an anoxic tank 9, a first aerobic tank 12, a second aerobic tank 13 and an oxygen-consuming zone 14.

[0055] The medicament distribution unit is provided with a medicament adding device 17, a medicament adding point and a mixing device 22.

[0056] In the sedimentation unit, a secondary sedimentation tank 23 and a water outlet 24 are arranged.

[0057] In the reflux unit, a sludge reflux pump 25 and a residual sludge discharge port 26 are arranged, and the residual sludge is refluxed to the pre-anoxic tank 7 of the biological unit.

[0058] A booster pump 3 is further arranged between the water inlet unit and the water distribution unit.

[0059] The water distribution points of the water distribution unit are provided with a first water distribution point 4, a second water distribution point 5 and a third water distribution point 6.

[0060] The water distribution unit is also provided with a valve 10 and a flow meter 11 for adjusting and metering the water distribution amount.

[0061] In the embodiment of the present application, the biological unit comprises:

[0062] The aerobic tank comprises a first aerobic tank 12 and a second aerobic tank 13, and the bottom of each tank is provided with an aerator;

[0063] The first aerobic tank 12 is provided with a blower 15 for aeration of the aerobic tank;

[0064] A nitrification liquid reflux pipeline is also provided, and a flow meter and an internal circulation pump 16 are arranged on the pipeline for controlling the reflux amount of the nitrification liquid;

[0065] The connecting ports between the tanks are arranged at the upper or lower part for reducing the occurrence of short flow;

[0066] The deoxygenation zone 14 is provided with a stirrer 18 for preventing sludge settlement.

[0067] The aerator is a microporous aeration disc.

[0068] In the embodiment of the present application, the dosing unit comprises:

[0069] The medicament dosing points are provided with a first dosing point 19, a second dosing point 20 and a third dosing point 21;

[0070] A dosing pump is also provided, preferably a diaphragm pump, and the dosing pump comprises a matching flow adjusting measure;

[0071] An inspection port 27 is also provided for checking whether the dosing pump can work normally, and a measuring cylinder and a stopwatch are used to manually measure the medicament dosing amount, and the flow of the dosing pump is verified, and the actual manually measured flow is used as the standard.

[0072] In the sedimentation unit, the secondary sedimentation tank 23 is provided with a sludge level measuring device, and the sludge level measuring device is provided with a one-way valve 232.

[0073] The reflux unit is also provided with a valve 10 and a flow meter 11 for controlling and metering the water distribution amount.

[0074] A sewage treatment deep denitrification and phosphorus removal and suspended solids control method comprises the following steps:

[0075] 1) Inoculating activated sludge in the reactor of the biological unit and performing nitrification domestication, and after domestication for 3-7 days, the ammonia nitrogen concentration of the effluent port 24 is less than 1 mg / L, indicating that the nitrification domestication of the sludge is completed, and the nitrification sludge is refluxed from the deoxygenation zone 14 to the anoxic tank 9;

[0076] 2) The sewage is pumped from the adjusting tank 2 into the water distribution unit first, and then into the biological unit through the water distribution points of the water distribution unit to be nitrified;

[0077] 3) The suspended sludge after nitrification in the biological unit is mixed with the reagent in the mixing device 22 of the reagent distribution unit. The mixing time of the suspended sludge and the reagent is short, which affects the flocculation effect, and the mixing time is long, which may cause the flocs to be broken in the flow. Therefore, the reagent adding point needs to be adjusted according to the water inflow. When the water inflow is large, the reagent adding point is in front, and when the water inflow is small, the reagent adding point is at the back.

[0078] 4) The effluent after the above steps is settled in the sedimentation unit. The supernatant is discharged up to the standard, and the sludge at the bottom is pumped into the biological unit through the reflux unit for further nitrification.

[0079] 5) The sludge level of the secondary sedimentation tank needs to be measured every 2-4 hours. The sludge level is measured by the sludge level measuring device. When the sludge level measuring device is stretched to the bottom of the tank, the one-way valve 232 is opened until it touches or passes through the sludge-water interface. When the sludge level measuring device is lifted, the one-way valve is closed, so that the water depth of the clear water part is measured. According to the effective water depth of the secondary sedimentation tank 23, the sludge level height can be calculated. Generally, the depth of the clear water part should be greater than 0.7 m. When it is less than 0.7 m, flocculants should be added to reduce the sludge level to prevent the sludge from running out of the secondary sedimentation tank and affecting the water quality of the effluent.

[0080] In this embodiment, the water distribution flow and distribution ratio, the flow of the internal circulation pump 16, the flow of the sludge external reflux pump 25, the aeration amount of the aerobic tank, and the reagent addition amount are all determined according to the effective volume of the biological unit reactor body.

[0081] In the water distribution unit, the first water distribution point 4, the second water distribution point 5, and the third water distribution point 6 enter the pre-anoxic tank 7, the anaerobic tank 8, and the anoxic tank 9 respectively. A valve 10 and a flow meter 11 are provided on each water distribution point. The valve 10 and the flow meter 11 are provided on the water distribution pipeline to control and measure the water distribution amount. The water distribution inlet is provided at the inlet of each tank. The flow of the first water distribution point 4 generally accounts for 5%-10% of the total water inflow, the flow of the second water distribution point 5 generally accounts for 20%-40% of the total water inflow, and the flow of the third water distribution point 6 generally accounts for 50%-75% of the total water inflow.

[0082] The hydraulic retention time of the pre-anoxic tank 7 is generally 0.25-1 h, the hydraulic retention time of the anaerobic tank 8 is generally 2-4 h, the hydraulic retention time of the anoxic tank 9 is generally 3-5 h, and the hydraulic retention time of the aerobic tank is generally 6-12 h. An aerator is provided at the bottom of the aerobic tank. Preferably, the air aeration heads at the bottom of the aerobic tank are all microporous aeration discs.

[0083] The oxygen-consuming zone 14 has a hydraulic retention time of 0.2-0.5 h, and is provided with a stirrer to prevent sludge settlement. Nitration liquid in the oxygen-consuming zone 14 is returned to the anoxic tank 9 by an internal circulation pump 16, and the internal return flow accounts for 50%-300% of the water inflow, and the external return flow accounts for 50%-150% of the water inflow.

[0084] In the dosing unit, the mixing device 22 is a flocculant and suspended sludge rapid mixing reaction device, the mixing time can be 1 min-3 min, and the dosing amount of the reagent can be 5 μL-60 μL / L. The hydraulic retention time of sludge between each reagent dosing point and the water inlet of the secondary sedimentation tank 23 is the reagent reaction time.

[0085] The reagent dosing point is a multi-point dosing facility. In the embodiment of the present application, in order to meet the mixing time of the reagent in the pipeline and ensure the mixing effect, three reagent dosing points, i.e., the first dosing point 19, the second dosing point 20 and the third dosing point 21, are provided. The short mixing reaction time of the reagent and the sludge affects the flocculation effect, and the long mixing reaction time may cause the flocs to be broken in the flow. Therefore, the dosing point needs to be adjusted according to the water inflow, i.e., the dosing point is in front when the water inflow is large, and the dosing point is behind when the water inflow is small.

[0086] Figure 2 The secondary sedimentation tank sludge level measuring device of the embodiment of the present application is shown, mainly comprising a transparent pipeline main body 231, a one-way valve 232 at the bottom and a scale 233 on the inner wall of the main body. When the one-way valve 232 extends to the bottom of the secondary sedimentation tank 23, the one-way valve 232 is opened until it contacts or penetrates the sludge-water interface. When the measuring device is lifted, the one-way valve 232 is closed, and the water depth of the clear water part is measured. According to the effective water depth of the secondary sedimentation tank 23, the sludge level height can be calculated. Generally, the depth of the clear water part should be greater than 0.7 m, and when it is less than 0.7 m, the flocculant should be added to reduce the sludge level and prevent the secondary sedimentation tank from running mud to affect the water quality.

[0087] Specifically, according to Figure 3 As shown, the actual daily reagent dosing amount (L / d) of the sewage plant is: K*(water inflow+external return flow)*5 L / (kg MLSS)*oxygen tank sludge concentration, wherein k is a variation coefficient, generally 1-3, and increases with the increase of the sludge concentration. When the supernatant depth of the secondary sedimentation tank is less than or equal to 0.7 m, the k value is appropriately increased, and when the supernatant depth of the secondary sedimentation tank is greater than 1.0 m, the k value is appropriately reduced. According to the calculated dosing amount, the flow of the dosing pump is adjusted. In the embodiment of the present application, a multi-point water distribution mode is adopted, and the water distribution points are at the water inlets of the pre-anoxic tank, the anoxic tank and the anaerobic tank to ensure the reaction time. The pre-anoxic tank is provided to utilize the organic matter in the water inflow as an electron donor to remove nitrate in the sludge external return flow and promote the absorption of the organic matter in the water inflow by the microorganisms such as phosphorus accumulating organisms in the activated sludge. The organic matter obtained by water distribution promotes biological denitrification in the denitrification process.

[0088] The present application is provided with a dosing unit at the outlet of the biological unit reactor, which comprises a mixing device and a plurality of dosing points, etc., and the dosing points are adjusted according to the water inflow, i.e., when the water inflow is large, the dosing points are in front, and when the water inflow is small, the dosing points are behind. Generally, the hydraulic retention time of sludge between the dosing points and the water inlet of the secondary sedimentation tank is the reaction time of the reagent, so as to meet the mixing time of the reagent in the pipeline and ensure the mixing effect. The dosing unit is arranged on the pipeline between the biological unit reactor and the secondary sedimentation tank, which is flexible in structure and easy to lay; simple in operation and easy to operate, and can ensure the rapid separation of sludge and water in the secondary sedimentation tank, the clarity of the supernatant, the low SS of the effluent, and the stable effluent quality, and finally achieve the purpose of denitrification, phosphorus removal and suspended solids reduction.

[0089] In the embodiment of the present application, the mixing time of the reagent and the sludge is preferably 1-3 minutes. The short mixing reaction time of the reagent and the sludge affects the flocculation effect, and the long mixing reaction time will break the flocculants in the flow.

[0090] The reagent dosing device in the dosing unit of the present application has the function of automatically adjusting the reagent dosage, can adjust the reagent dosage according to the water inflow, the sludge level of the secondary sedimentation tank, etc., can guarantee the treatment effect, reduce the reagent dosage, and reduce the reagent dosage cost.

[0091] The embodiments of the present application are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure of the present application. The present application can also be implemented or applied through other different specific embodiments, and the details in the present application can be modified or changed based on different views and applications without departing from the spirit of the present application.

[0092] Embodiment 1:

[0093] Taking sewage treatment of a sewage plant as an example, the design scale of the sewage plant is 50,000 tons / d, the water volume in dry season is about 40,000 tons / d, and the water volume in rainy season is about 60,000 tons / d. The concentrations of COD, SS, TN, and TP in the effluent are high, and the average values of COD, SS, TN, TP, and ammonia nitrogen in the effluent in rainy season are 37 mg / L, 12 mg / L, 11 mg / L, 0.53 mg / L, and 2.5 mg / L respectively; and the average values of COD, SS, TN, TP, and ammonia nitrogen in the effluent in dry season are 45 mg / L, 11 mg / L, 16 mg / L, 0.46 mg / L, and 0.5 mg / L respectively.

[0094] After the sewage treatment deep denitrification, phosphorus removal and suspended solids reduction system and the control method of the present application are used, the reagent is added at the first dosing point 19 in rainy season, and the dosage is only 16 μL / L; the reagent is added at the third dosing point 21 in dry season, and the average dosage of the reagent is 25 μL / L.

[0095] After the sewage treatment advanced denitrification and phosphorus removal and suspended solids reduction system and regulation method of the embodiment is used, the effluent indexes are as follows:

[0096] The average influent COD concentration is about 293 mg / L, the effluent COD concentration is less than 35 mg / L, the average influent ammonia nitrogen is about 37 mg / L, the effluent ammonia nitrogen is less than 0.5 mg / L, the average influent TN concentration (total nitrogen concentration) is about 41 mg / L, the effluent TN concentration is less than 10 mg / L, the average influent TP concentration (total phosphorus concentration) is about 6 mg / L, the effluent TP concentration is less than 0.45 mg / L, the influent SS is about 180 mg / L, the effluent SS (suspended solids) is less than 10 mg / L, and the sludge settling performance SVI is less than 50 mL / g. The effluent quality of the sewage plant is good, and the operation is stable.

[0097] Table 1 comparison table of each index of the effluent quality of the sewage plant in embodiment 1 before and after

[0098]

[0099] Embodiment 2:

[0100] The design scale of a sewage plant is 80,000 tons / d, and the normal water volume is about 60,000 tons / d. The original dosing method is to dose before the aerobic tank, and the dosing amount is 30 μL / L;

[0101] After the sewage treatment advanced denitrification and phosphorus removal and suspended solids reduction system and regulation method of the embodiment is used, the dosing amount at the third dosing point 21 is reduced to 20 μL / L, and the amount of the drug used is reduced by about 33%, so the cost of the drug is also reduced by about 33%. The effluent indexes are shown in Table 2:

[0102] Table 2 comparison table of each index of the effluent quality of the sewage plant in embodiment 2 before and after

[0103] Index (mg / L) Original effluent water quality Effluent water quality of Example 2 of the present application COD 37 32 TN 12 10 TP 0.46 0.41 SS 9 7 Ammonia nitrogen 0.6 0.2

[0104] From the above two embodiments, it can be seen that after the present application is used, the effluent quality is stable, and each index is also obviously improved; the dosing amount of the drug can be accurately calculated; through the regulation and control of the drug preparation unit, the drug and the sludge can be fully mixed on the pipeline between the biological unit and the secondary sedimentation tank, so that the sludge and water are quickly separated in the secondary sedimentation tank, and the final effluent quality is better than that of the original method.

[0105] Those skilled in the art should understand that the above discussion of any embodiment is only intended to be exemplary in nature and is not intended to suggest the scope of the disclosure (including the claims) is limited to these examples. Many modifications, variations, and changes in detail can be made to the described embodiments or other embodiments within the spirit and principle of the application, and the above-described embodiments or technical features among different embodiments can also be combined, and there are many other changes of different aspects of the application as described above. In order to be brief, they are not provided in details. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A method for controlling deep nitrogen, phosphorus and suspended solids removal in wastewater treatment, based on a deep nitrogen, phosphorus and suspended solids removal system for wastewater treatment, the system consisting of an influent unit, a water distribution unit, a biological unit, a chemical dosing unit, a sedimentation unit and a reflux unit; The water inlet unit is provided with an inlet (1) and a regulating tank (2); The water distribution unit is connected to the water inlet unit and is equipped with a water distribution point; The biological unit consists of a pre-anoxic tank (7), an anaerobic tank (8), anoxic tank (9), a first aerobic tank (12), a second aerobic tank (13), and an oxygen-depleting zone (14); The drug preparation unit is equipped with a drug dosing device (17), drug dosing points, and a mixing device (22); there are multiple drug dosing points. The sedimentation unit is equipped with a secondary sedimentation tank (23) and an outlet (24); the dosing unit is installed on the pipeline between the biological unit reaction tank and the secondary sedimentation tank (23). The dosing point is adjusted according to the influent flow rate. When the influent flow rate is large, the dosing point is earlier, and when the influent flow rate is small, the dosing point is later; the hydraulic retention time of the sludge between the dosing point and the inlet of the secondary sedimentation tank is the reaction time of the dosing agent; the secondary sedimentation tank (23) is equipped with a sludge level measuring device, and the sludge level measuring device is equipped with a one-way valve (232); The reflux unit is equipped with a sludge reflux pump (25) and a residual sludge discharge port (26), and the residual sludge is refluxed to the pre-anoxic tank (7) of the biological unit. Its features are, Includes the following steps: 1) Inoculate activated sludge into the reactor of the biological unit and carry out nitrification acclimatization. After acclimatization for 3 to 7 days, the ammonia nitrogen concentration at the effluent (24) is less than 1 mg / L, indicating that the sludge nitrification acclimatization is completed and the nitrified sludge is returned from the deoxygenated zone (14) to the anoxic tank (9). 2) Wastewater is first pumped from the equalization tank (2) into the water distribution unit, and the influent volume and distribution ratio are adjusted by each water distribution point of the water distribution unit so that it can enter the biological unit for nitrification treatment; 3) The suspended sludge after nitrification in the biological unit enters the mixing device (22) of the dosing unit to mix and react with the reagents; The daily dosage of the agent is: k*(influent flow + external return flow)*5L / (kg MLSS)*aerobic tank sludge concentration, where k is a variation coefficient, which is 1-3 and increases with the increase of sludge concentration; when the supernatant depth of the secondary sedimentation tank (23) is less than or equal to 0.7m, the value of k is increased; when the supernatant depth of the secondary sedimentation tank (23) is greater than 1.0m, the value of k is decreased. The flow rate of the dosing pump is adjusted according to the calculated dosage. 4) The effluent after the above steps enters the sedimentation unit for sedimentation. Under the action of the secondary sedimentation tank (23), the supernatant is discharged in compliance with the standard, and the bottom sludge is pumped into the biological unit through the return unit for further nitrification treatment. 5) The mud level in the secondary sedimentation tank is measured at intervals of 2 to 4 hours, and the mud level is measured by a mud level measuring device.

2. The method for deep nitrogen and phosphorus removal and suspended solids reduction in wastewater treatment according to claim 1, characterized in that, The mixing time between the agent and sludge in the mixing device (22) is 1 min to 3 min, and the hydraulic residence time of the sludge between the agent addition point and the inlet of the secondary sedimentation tank (23) is the agent reaction time.

3. The method for deep nitrogen and phosphorus removal and suspended solids reduction in wastewater treatment according to claim 1 or 2, characterized in that, The dosage of the reagent is 5μL-60μL / L.

4. The method for deep nitrogen and phosphorus removal and suspended solids reduction in wastewater treatment according to claim 1, characterized in that, The wastewater treatment deep nitrogen, phosphorus removal and suspended solids reduction system also includes at least one of the following technical features: A booster pump (3) is also provided between the water inlet unit and the water distribution unit; The water distribution unit has a first water distribution point (4), a second water distribution point (5), and a third water distribution point (6); The water distribution unit is also equipped with a valve (10) and a flow meter (11).

5. The method for deep nitrogen and phosphorus removal and suspended solids reduction in wastewater treatment according to claim 1, characterized in that, The biological unit also includes at least one of the following technical features: Both the first aerobic tank (12) and the second aerobic tank (13) are equipped with aerators at the bottom; A blower (15) is provided in the first aerobic tank (12); It is also equipped with a nitration return pipeline, and a flow meter internal circulation pump (16) is installed on the pipeline; The connection points between the pools are located at the top or bottom; A stirrer (18) is provided in the deoxygenation zone (14).

6. The method for deep nitrogen and phosphorus removal and suspended solids reduction in wastewater treatment according to claim 1, characterized in that, The aerator is a microporous aeration disc.

7. The method for deep nitrogen and phosphorus removal and suspended solids reduction in wastewater treatment according to claim 1, characterized in that, The drug dispensing unit also includes at least one of the following technical features: The drug dosing points are provided with a first dosing point (19), a second dosing point (20), and a third dosing point (21); The drug dosing device (17) is also equipped with a dosing pump; It is also equipped with an inspection port (27) for checking the working status of the dosing pump.

8. The method for deep nitrogen and phosphorus removal and suspended solids reduction in wastewater treatment according to claim 1, characterized in that: The reflux unit is also equipped with a valve (10) and a flow meter (11).

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