AO water treatment system

Abstract

The utility model discloses an AO water treatment system and belongs to the technical field of sewage treatment. The sewage treatment device comprises an AO tank, a primary sedimentation tank, a secondary sedimentation tank and a clean water tank which are sequentially arranged along the water flow direction, and sewage to be treated is treated by the AO tank, is subjected to secondary sedimentation by the primary sedimentation tank and the secondary sedimentation tank in sequence, and then enters the clean water tank; wherein a sludge scraping and sucking machine and a dissolved oxygen meter are arranged in the primary sedimentation tank, and the sludge scraping and sucking machine is used for discharging sludge settled in the primary sedimentation tank in time before the sludge floats upwards. According to the utility model, through secondary sedimentation treatment of the primary sedimentation tank and the secondary sedimentation tank, the amount of suspended matters entering the clean water tank can be greatly reduced, so that the suspended matters entering the clean water tank are effectively controlled, and the final effluent quality is ensured. Meanwhile, through the cooperation of the sludge scraping and sucking machine and the dissolved oxygen meter, sludge settled in the primary settling tank can be discharged into the tank in time before floating, so that the generation amount of suspended matters can be controlled from the source, and the final effluent quality can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewage treatment, and more specifically, relates to an AO water treatment system. Background Technique

[0002] Industrial wastewater refers to the wastewater, sewage and liquid waste generated during industrial production, which contains industrial production materials, intermediate products and pollutants in the production process that are lost with water. If it is discharged randomly without treatment, it will inevitably cause serious pollution to water bodies and seriously threaten the health and safety of humans. With the rapid development of social economy, the urbanization process has been continuously accelerated, and the urban water pollution problem has become increasingly prominent, which must be taken seriously. At present, there are many forms of industrial wastewater treatment systems, among which the AO sewage treatment process is the most common.

[0003] The AO process method is also called the anaerobic-aerobic process method. A (Anaerobic) is the anaerobic section, which is used for denitrification and phosphorus removal; O (Oxic) is the aerobic section, which is used for removing organic matter in water. Its superiority is that in addition to degrading organic pollutants, it also has a certain function of denitrification and phosphorus removal. It uses anaerobic hydrolysis technology as the pretreatment of activated sludge, so the AO method is an improved activated sludge method.

[0004] The traditional AO process flow is as follows: After the sewage is treated by a two-stage AO biochemical system, it is separated by a secondary sedimentation tank (biochemical sedimentation tank). The supernatant flows into the clear water tank by itself, and the sludge is lifted to the sludge tank by a pump suction machine and then refluxed to the pre-anoxic tank. However, it is found in actual use that due to abnormal sludge properties or process abnormalities, etc., some sludge will not settle completely and will be suspended on the surface of the secondary sedimentation tank. Once these suspended substances enter the clear water tank, the supernatant will contain a large amount of suspended substances or a large amount of sludge flowing out with the supernatant, which will not only affect the effluent quality, but also cause blockage of some on-line detection equipment.

[0005] After retrieval, in the patent of CN105107241A, a secondary sedimentation tank system and treatment method for improving the effluent quality of organic wastewater are disclosed. This application case includes a coagulation tank, a secondary sedimentation tank and an effluent collection tank. The coagulation tank, the secondary sedimentation tank and the effluent collection tank are connected in sequence along the water flow direction. The secondary sedimentation tank is a horizontal flow sedimentation tank. A sludge discharge tank with a water retaining dam is arranged along the width of the tank on the head pool wall, an effluent weir is arranged on the tail pool wall, and a plurality of sludge collection hoppers are arranged at the bottom of the tank. The sludge collection hoppers are arranged in rows along the width and length of the tank and cover the bottom of the tank. Each sludge collection hopper is provided with an independent sludge discharge pipe, and a walking type sludge scraper is arranged above the tank, which is used to drive the floating sludge on the water surface to the sludge discharge tank to keep the floating sludge away from the effluent weir, thereby improving the effluent quality.

[0006] For another example, in the patent of CN211885534U, an automatic sludge collection device for solving the problem of floating sludge in the secondary sedimentation tank of sewage is disclosed. This application case includes a secondary sedimentation tank, a sludge hopper is provided at the bottom of the secondary sedimentation tank, a sewage pipe passes through the sludge hopper and is placed above the inside of the secondary sedimentation tank, the sewage pipe is located at the tail of the secondary sedimentation tank and is placed on a water collection cylinder, a flushing water pipe is provided outside the water collection cylinder, a floating sludge collection box is provided on the inner wall of the secondary sedimentation tank, an overflow plate is provided at the upper edge of the upper part of the secondary sedimentation tank, the bottom of the floating sludge collection box is communicated with a sludge tank through a floating sludge discharge pipe, and the outside of the overflow plate is communicated with a sludge mixing reaction tank. In this application case, by opening the cut-off valve on the flushing water pipe, the floating sludge in the secondary sedimentation tank is driven and flushed into the floating sludge collection box, and the floating sludge collected by the floating sludge collection box is discharged into the sludge tank through the floating sludge discharge pipe.

[0007] The above application cases all involve technical improvements to the AO sewage treatment system, and at the same time can effectively treat the floating sludge to ensure water quality. However, in the above application cases, the treatment method of the floating sludge mainly focuses on the secondary sedimentation tank, so that the floating sludge may still enter the clear water tank, so its treatment effect needs to be further improved. Utility Model Content

[0008] 1. Problems to be Solved

[0009] Aiming at the problem that in the existing AO water treatment system, floating sludge is likely to enter the clear water tank and affect the water quality, the present utility model provides an AO water treatment system. Through the secondary sedimentation effect of the primary sedimentation tank and the secondary sedimentation tank, the present utility model can greatly reduce the amount of suspended solids entering the clear water tank; at the same time, through the cooperation of the sludge scraping and suction machine and the dissolved oxygen meter, the generation amount of suspended solids can be controlled from the source.

[0010] 2. Technical Solutions

[0011] In order to solve the above problems, the technical solutions adopted by the present utility model are as follows:

[0012] An AO water treatment system of the present utility model includes an AO tank, a primary sedimentation tank, a secondary sedimentation tank and a clear water tank arranged in sequence along the water flow direction. The sewage to be treated is treated by the AO tank and then enters the clear water tank through the primary sedimentation tank and the secondary sedimentation tank for secondary sedimentation in sequence;

[0013] A sludge scraping and suction machine and a dissolved oxygen meter are arranged in the primary sedimentation tank; among them, the dissolved oxygen meter is used for on-line monitoring of the dissolved oxygen content in the primary sedimentation tank; according to the monitoring results of the dissolved oxygen meter, the sludge scraping and suction machine is used to timely discharge the precipitated sludge in the primary sedimentation tank before it floats.

[0014] Further, the submersible pump of the sludge scraping and suction machine is located at the bottom of the primary sedimentation tank, and the sludge outlet of the submersible pump is divided into two branches, one branch is communicated with a sludge transfer tank through a pipeline, and the other branch is communicated with the AO tank.

[0015] Furthermore, sludge outlets are provided at the bottoms of the secondary sedimentation tank and the clear water tank respectively. The sludge outlets are connected to the AO tank through reflux pumps for returning the sediment in each tank to the AO tank.

[0016] Furthermore, the sludge outlet of the secondary sedimentation tank is funnel-shaped as a whole, and a diversion pipe communicating with the outlet of the primary sedimentation tank is provided in the secondary sedimentation tank. The diversion pipe is located on the central axis of the sludge outlet of the secondary sedimentation tank.

[0017] Furthermore, the AO tank includes an A tank and an O tank which are interconnected; among them, a stirrer is provided near the bottom of the A tank, and a first aeration pipe is provided near the bottom of the O tank.

[0018] Furthermore, the connection port between the A tank and the O tank is located near the top of the tank; the connection port between the O tank and the secondary sedimentation tank is located near the bottom of the tank.

[0019] Furthermore, the outlet of the reflux pump is connected to the A tank through a pipeline; one branch of the submersible sewage pump is connected to the O tank through a pipeline.

[0020] Furthermore, a second aeration pipe is provided near the bottom of the clear water tank.

[0021] Furthermore, the sludge transfer tank is connected to a sludge thickening tank; the clear water tank is connected to a Parshall flume.

[0022] 3. Beneficial effects

[0023] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0024] (1) For an AO water treatment system of the present utility model, through the settings of the primary sedimentation tank and the secondary sedimentation tank, first, the primary sedimentation tank performs the first sedimentation of the sludge to reduce the amount of sludge going into the secondary sedimentation tank; then, the secondary sedimentation tank performs the secondary sedimentation of the sludge and suspended matters, thereby greatly reducing the amount of suspended matters entering the clear water tank, effectively controlling the suspended matters entering the clear water tank, and ensuring the quality of the final effluent. At the same time, by setting a scraping and sucking sludge machine and a dissolved oxygen meter in the primary sedimentation tank, the sludge precipitated in the primary sedimentation tank is discharged from the tank in time before floating, thereby controlling the generation amount of suspended matters from the source, which is also beneficial to improving the quality of the final effluent.

[0025] (2) For an AO water treatment system of the present utility model, the sludge outlet of the submersible sewage pump is divided into two paths. One path returns a part of the sediment sludge scraped and sucked out from the primary sedimentation tank to the AO tank to ensure a constant sludge concentration in the AO tank system and ensure the water treatment capacity; the other path discharges the excess surplus sludge from the system in time, avoiding excessive sludge circulation in the system and affecting the quality of the final effluent.

[0026] (3) An AO water treatment system of the present utility model, through the setting of a reflux pump, in case of sludge accumulation in the secondary sedimentation tank and the clear water tank, it can be discharged in time to prevent sludge floating and affecting the final effluent quality in the clear water tank.

[0027] (4) An AO water treatment system of the present utility model designs the sludge outlet of the secondary sedimentation tank into a conical structure, and at the same time, through the setting of a diversion pipe, the sludge entering the secondary sedimentation tank can be concentrated near the sludge outlet, thus facilitating the subsequent discharge.

[0028] (5) An AO water treatment system of the present utility model, by arranging an aeration pipe in the clear water tank, during the cleaning of the clear water tank, the sludge settled at the bottom of the tank can be disturbed through aeration, which is beneficial to the sludge discharge operation. Description of the Drawings

[0029] Figure 1 is a structural schematic diagram of an AO water treatment system of the present utility model.

[0030] In the figure: 1, AO tank; 11, agitator; 12, first aeration pipe; 2, primary sedimentation tank; 21, dissolved oxygen meter; 3, secondary sedimentation tank; 31, diversion pipe; 4, clear water tank; 41, second aeration pipe; 5, scraping and sucking sludge machine; 51, submersible sewage pump; 6, sludge transfer tank; 7, sludge thickening tank; 8, reflux pump; 9, Parshall flume. Detailed Embodiments

[0031] To further understand the content of the present utility model, the present utility model will be described in detail in conjunction with the accompanying drawings.

[0032] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] The following further describes the present utility model in conjunction with specific embodiments.

[0034] As Figure 1 shown, an AO water treatment system of this embodiment includes an AO tank 1, a primary sedimentation tank 2, a secondary sedimentation tank 3, and a clear water tank 4 arranged in sequence along the water flow direction; the sewage to be treated is treated by the AO tank 1 and then enters the clear water tank 4 after secondary sedimentation through the primary sedimentation tank 2 and the secondary sedimentation tank 3 in sequence.

[0035] A primary sedimentation tank 2 is provided with a sludge scraping and suction machine 5 and a dissolved oxygen meter 21. Among them, the dissolved oxygen meter 21 is used for on-line monitoring of the dissolved oxygen content in the primary sedimentation tank 2; the sludge scraping and suction machine 5 is used to timely discharge the sedimented sludge in the primary sedimentation tank 2 before it floats up under anaerobic conditions according to the monitoring results of the dissolved oxygen meter 21. At the same time, the clear water tank 4 is connected to a Parshall flume 9 to further improve the water quality.

[0036] Specifically, in this embodiment, the AO tank 1 includes an A tank (i.e., an anaerobic tank) and an O tank (i.e., an aerobic tank) that are interconnected. Among them, a stirrer 11 is provided near the bottom of the A tank to ensure full mixing of the microorganisms and the influent, which helps to maintain the consistency of the anaerobic environment, promotes full contact between the microorganisms and the organic matter in the influent, and thus improves the removal efficiency of the organic matter.

[0037] A first aeration pipe 12 is provided near the bottom of the O tank to provide a good environment for the growth and reproduction of aerobic microorganisms, and then use these microorganisms to degrade the organic matter in the sewage.

[0038] Preferably, the connection port between the A tank and the O tank is located near the top of the tank; while the connection port between the O tank and the secondary sedimentation tank 3 is located near the bottom of the tank.

[0039] The submersible pump 51 of the sludge scraping and suction machine 5 is located at the bottom of the primary sedimentation tank 2, and the sludge outlet of the submersible pump 51 is divided into two branches. One branch is connected to the AO tank 1 and is used to return a part of the sedimented sludge scraped out from the primary sedimentation tank 2 to the AO tank 1 to ensure a constant sludge concentration in the AO tank 1 and ensure the water treatment capacity; the other branch is connected to a sludge transfer tank 6 through a pipeline to timely discharge the excess surplus sludge in the primary sedimentation tank 2, avoiding excessive sludge circulation in the system and affecting the final effluent quality.

[0040] Specifically in this embodiment, a part of the sludge discharged by the submersible pump 51 is returned to the O tank. At the same time, the sludge transfer tank 6 is connected to a sludge thickening tank 7 to reduce the moisture content and volume of the sludge, thereby reducing the cost of subsequent treatment and improving the efficiency of the entire treatment system.

[0041] The working principle of an AO water treatment system in this embodiment is as follows: The sewage to be treated enters the primary sedimentation tank 2 after biochemical treatment in the AO tank 1. At the same time, a sludge scraping and suction machine 5 is provided in the primary sedimentation tank 2 to discharge the sludge deposited at the bottom of the primary sedimentation tank 2 before it floats up due to anaerobic digestion. And the discharged sludge, on the premise of meeting the sludge reflux in the AO tank 1, transfers the surplus sludge generated by the system to the sludge transfer tank 6 according to the operating load and then discharges it;

[0042] After the supernatant in the primary sedimentation tank 2 flows into the secondary sedimentation tank 3 for further sedimentation of sludge and suspended solids, the supernatant in the secondary sedimentation tank 3 flows into the clear water tank 4 for further adjustment of water volume and quality, and then is discharged outside through the Parshall flume 9, avoiding the abnormal situation of the discharged sewage data caused by sludge floating and the effluent mixed with sludge.

[0043] As another preferred embodiment of this embodiment, sludge discharge ports are provided at the bottoms of both the secondary sedimentation tank 3 and the clear water tank 4, and the sludge discharge ports are connected to the AO tank 1 through the reflux pump 8. The reflux pump 8 is used to return the sediment in each tank to the AO tank 1 to prevent sludge floating from affecting the final effluent quality in the clear water tank 4.

[0044] Among them, the sludge discharge port of the secondary sedimentation tank 3 is integrally funnel-shaped, and a diversion pipe 31 communicating with the outlet of the primary sedimentation tank 2 is provided in the secondary sedimentation tank 3. The diversion pipe 31 is vertically arranged and is located directly above the sludge discharge port of the secondary sedimentation tank 3, so that the sludge entering the secondary sedimentation tank 3 can be concentrated near the sludge discharge port, facilitating the subsequent discharge.

[0045] At the same time, a baffle (not shown in the figure) is provided in the secondary sedimentation tank 3 to intercept sludge suspended solids, further reducing the possibility of suspended solids entering the clear water tank 4. Of course, according to the actual production situation, a reflux pump 8 can also be equipped in the primary sedimentation tank 2 to improve the sludge discharge efficiency in the primary sedimentation tank 2.

[0046] Specifically in this embodiment, all the sludge discharged by the reflux pump 8 is returned to the A tank. At the same time, two reflux pumps 8 are connected to each tank, one for standby and one for use.

[0047] In addition, since the bottom of the clear water tank 4 is designed as a flat surface as a whole, it is difficult to ensure that all the sludge deposited at the bottom of the tank can be discharged. Therefore, in this embodiment, a second aeration pipe 41 is provided near the bottom of the clear water tank 4, and the sludge settled at the bottom of the tank can be disturbed by periodically stopping water and aerating, which is beneficial to the operation of discharging the sludge completely.

[0048] An AO water treatment system of this embodiment, through the settings of the primary sedimentation tank 2 and the secondary sedimentation tank 3, first the primary sedimentation tank 2 performs the first sedimentation on the sludge to reduce the amount of sludge going into the secondary sedimentation tank 3; then, the secondary sedimentation tank 3 performs secondary sedimentation on the sludge and suspended solids, thereby greatly reducing the amount of suspended solids entering the clear water tank 4, effectively controlling the suspended solids entering the clear water tank 4 to ensure the final effluent quality. At the same time, by setting a scraping and sucking sludge machine 5 in the primary sedimentation tank 2, the sludge precipitated in the primary sedimentation tank 2 is discharged from the tank in time before floating, thereby controlling the generation amount of suspended solids from the source, which is also beneficial to improving the final effluent quality. In addition, the AO water treatment system of this embodiment can, on the basis of the original system, change the end aeration tank into a primary sedimentation tank and then be equipped with a corresponding scraping and sucking sludge machine, with a relatively small overall project volume.

[0049] Meanwhile, it should be noted that components such as agitators, dissolved oxygen meters, scraping and suction sludge machines, sludge thickening tanks, reflux pumps, and Parshall flumes mentioned in the above embodiments can all be directly purchased on the market, and their structures and working principles are all prior art.

[0050] The above schematically describes the present utility model and its implementation manners. This description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present utility model, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and, without departing from the purpose of the creation of the present utility model, design similar structural modes and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present utility model.

Claims

1. An AO water treatment system, characterized in that: It includes an AO tank (1), a primary sedimentation tank (2), a secondary sedimentation tank (3), and a clear water tank (4) arranged in sequence along the water flow direction. The sewage to be treated is treated in the AO tank (1) and then passes through the primary sedimentation tank (2) and the secondary sedimentation tank (3) for secondary sedimentation in sequence before entering the clear water tank (4). A sludge scraper and suction machine (5) and a dissolved oxygen meter (21) are arranged in the primary sedimentation tank (2). Among them, the dissolved oxygen meter (21) is used for on-line monitoring of the dissolved oxygen content in the primary sedimentation tank (2). According to the monitoring results of the dissolved oxygen meter (21), the sludge scraper and suction machine (5) is used to timely discharge the precipitated sludge in the primary sedimentation tank (2) before it floats up.

2. The AO water treatment system according to claim 1, characterized in that: The submersible pump (51) of the sludge scraper and suction machine (5) is located at the bottom of the primary sedimentation tank (2), and the sludge outlet of the submersible pump (51) is divided into two branches. One branch is connected to a sludge transfer tank (6) through a pipeline, and the other branch is connected to the AO tank (1).

3. An AO water treatment system according to claim 2, characterized in that: The bottoms of the secondary sedimentation tank (3) and the clear water tank (4) are both provided with sludge outlets, which are connected to the AO tank (1) through a reflux pump (8) for returning the sediment in each tank to the AO tank (1).

4. An AO water treatment system according to claim 3, characterized in that: The sludge outlet of the secondary sedimentation tank (3) is integrally funnel-shaped, and a diversion pipe (31) connected to the outlet of the primary sedimentation tank (2) is arranged in the secondary sedimentation tank (3), and the diversion pipe (31) is located on the central axis of the sludge outlet of the secondary sedimentation tank (3).

5. An AO water treatment system according to claim 3, characterized in that: The AO tank (1) includes an A tank and an O tank that are interconnected. Among them, a stirrer (11) is arranged near the bottom of the A tank, and a first aeration pipe (12) is arranged near the bottom of the O tank.

6. The AO water treatment system according to claim 5, characterized in that: The connection port between the A tank and the O tank is located near the top of the tank; the connection port between the O tank and the secondary sedimentation tank (3) is located near the bottom of the tank.

7. An AO water treatment system according to claim 5, characterized in that: The outlet of the reflux pump (8) is connected to the A tank through a pipeline; one branch of the submersible pump (51) is connected to the O tank through a pipeline.

8. The AO water treatment system according to claim 3, characterized in that: A second aeration pipe (41) is arranged near the bottom of the clear water tank (4).

9. The AO water treatment system according to claim 5, characterized in that: The sludge transfer tank (6) is connected to a sludge thickening tank (7); the clear water tank (4) is connected to a Parshall flume (9).

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