Sewage treatment primary sedimentation tank system suitable for industrial park

Abstract

The utility model provides a sewage treatment primary sedimentation tank system suitable for industrial parks, which comprises a flocculation tank, a horizontal flow sedimentation tank and a middle water tank which are sequentially connected along the water flow direction, the water outlet side of the flocculation tank is connected with the water inlet end of the horizontal flow sedimentation tank, and the other end of the horizontal flow sedimentation tank is a water outlet end and is connected with the middle water tank through an overflow port of the horizontal flow tank. A heavy metal treatment unit is further arranged at the water inlet end of the flocculation tank in series and comprises a plurality of heavy metal treatment tanks which are arranged in series, each heavy metal treatment tank comprises a heavy metal capture tank and a thallium removal tank which are arranged in series, and the heavy metal capture tank is connected with a heavy metal capture agent adding pipeline; and the thallium removal tank is connected with a thallium removal agent adding pipeline. The device has the advantages that the primary precipitation treatment effect of heavy metal sewage is better, heavy metal pollutants can be better precipitated and treated, and the subsequent sewage treatment effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a sewage treatment primary sedimentation tank system suitable for an industrial park. Background Art

[0002] Urban domestic sewage is discharged to sewage treatment plants for treatment. When sewage treatment plants treat sewage, there is usually a treatment step of a preliminary sedimentation tank. The preliminary sedimentation tank is also called the primary sedimentation tank, which is used to achieve the initial sedimentation treatment of domestic sewage. Before the sewage enters the primary sedimentation tank, flocculants are usually added for stirring to assist the solid flocculation of pollutants into larger particles for easy precipitation. Sewage needs to be treated in the primary sedimentation tank before it can be more convenient and smooth to carry out the subsequent biochemical degradation treatment processes such as AO or A2O.

[0003] However, domestic sewage from industrial parks is often mixed with a large number of various heavy metal pollutants. It is difficult to treat the heavy metals in them by relying on the flocculation and stirring steps of conventional primary sedimentation tanks. This will affect the treatment effect of subsequent sewage treatment processes, making the final sewage not only substandard in heavy metal content, but also significantly reduce other treatment index data, making it difficult to meet wastewater treatment discharge standards.

[0004] In addition, the existing primary sedimentation tank system usually adopts a horizontal flow sedimentation tank to achieve sedimentation in the form of sewage horizontal flow. After the sewage is stirred by flocculant in the flocculation tank, it directly overflows along the overflow outlet above into the subsequent horizontal flow sedimentation tank. In this way, after the water is discharged from the overflow outlet, it is easy to flow directly forward in the horizontal direction. When the water flow rate is large and the water flow velocity is high, the effluent stays in the horizontal flow sedimentation tank for a short time, which affects its sedimentation effect. Utility Model Content

[0005] The purpose of the utility model is to provide a sewage treatment primary sedimentation tank system suitable for industrial parks in response to the above-mentioned problems. The technical problem to be solved is: how to provide a sewage treatment primary sedimentation tank system suitable for industrial parks, which has better preliminary sedimentation treatment effect for heavy metal sewage and can better precipitate and treat heavy metal pollutants to improve the subsequent sewage treatment effect.

[0006] In order to realize the above-mentioned technical features, the purpose of the utility model is realized as follows: a sewage treatment primary sedimentation tank system suitable for industrial parks, comprising a flocculation tank, a horizontal flow sedimentation tank and an intermediate water tank connected in sequence along the water flow direction, the flocculation tank is connected to a flocculant addition pipeline, and a flocculation mixer is arranged in the flocculation tank; the outlet side of the flocculation tank is adjacent to the water inlet end of the horizontal flow sedimentation tank, and a flocculation tank overflow is arranged on this side and connected to the horizontal flow sedimentation tank, the other end of the horizontal flow sedimentation tank is the outlet end and is connected to the intermediate water tank through the horizontal flow tank overflow, the water inlet end of the flocculation tank is also connected in series with a heavy metal treatment unit, the heavy metal treatment unit comprises a plurality of heavy metal treatment tanks arranged in series, the heavy metal treatment tank comprises a heavy metal capture tank and a thallium removal tank arranged in series with the water inlet, the heavy metal capture tank is connected with a heavy metal capture agent addition pipeline, and the thallium removal tank is connected with a thallium removal agent addition pipeline.

[0007] Preferably, the heavy metal treatment pool also includes two chelation breaking pools connected in series at the water inlet end of the heavy metal treatment pool, the first chelation breaking pool is connected to a hydrogen peroxide addition pipeline, and the second chelation breaking pool is connected to both a polyferric sulfate addition pipeline and a sodium hydroxide addition pipeline.

[0008] Preferably, a reaction stirring device is provided in the heavy metal treatment pool, and the reaction stirring device includes a support frame located above the heavy metal treatment pool, a stirring motor installed on the support frame, the stirring motor is downwardly connected to a rotating shaft located in the middle of the heavy metal treatment pool, and a stirring blade is installed on the rotating shaft.

[0009] Preferably, the support frame is a pedestrian bridge arranged in a cross shape, a stirring motor is installed at the middle cross position of the pedestrian bridge, and guardrails are arranged on both sides of the pedestrian bridge.

[0010] Preferably, the horizontal cross-section of the heavy metal treatment pool body is circular, and three vertically arranged flow-around protrusions are evenly distributed on the inner wall of the pool body.

[0011] Preferably, vertical downward baffles are arranged at intervals at the water inlet end of the heavy metal treatment pool body.

[0012] Preferably, a mixing tank is further provided at the water inlet end of the flocculation tank, the water inlet end of the mixing tank is connected to the heavy metal treatment unit, a sludge return pipeline is connected to the mixing tank, and a mixing agitator is further provided in the mixing tank.

[0013] Preferably, two mixing stirrers are arranged in the mixing tank; a spare flocculation tank is also arranged on one side of the flocculation tank, the mixing tank is connected to the flocculation tank and the spare flocculation tank respectively through control gate valves, and the flocculation tank and the spare flocculation tank are connected to each other through control gate valves.

[0014] Preferably, the overflow port of the flocculation tank on the outlet side of the flocculation tank has a water outlet trough extending outward into the horizontal flow sedimentation tank, the upper surface of the water outlet trough exceeds the water level of the horizontal flow sedimentation tank, and downward water outlet holes are evenly arranged at the bottom of the lower end of the water outlet trough to achieve uniform water distribution.

[0015] Preferably, tracks are provided on both sides of the horizontal flow sedimentation tank, a sludge scraper and suction machine is mounted above the track, and a sludge output pipe of the sludge scraper and suction machine is bypass-connected with a sludge return pipe to the mixing tank.

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

[0017] 1. The utility model has the advantages of better initial sewage sedimentation treatment effect and can better precipitate and treat heavy metal pollutants to improve subsequent sewage treatment effects.

[0018] 2. The utility model adds polyferric sulfate and sodium hydroxide through the polyferric sulfate adding pipeline and the sodium hydroxide adding pipeline respectively. The function of the polyferric sulfate is to completely decompose the complex and condense the decomposed metal ions, so as to facilitate the capture and precipitation in the two heavy metal treatment pools at the back.

[0019] 3. The utility model can improve the reaction treatment effect of adding reagents in the heavy metal treatment pool by adopting a reaction stirring device.

[0020] 4. The utility model can change the water inlet direction by means of the baffle plate, thereby preventing the sewage from short-flowing and directly flowing out of the outlet in the horizontal direction.

[0021] 5. The utility model can send part of the returned sludge into the mixing tank and stir and mix it with the incoming water, and utilize a large number of beneficial bacteria in the returned sludge to improve the flocculation reaction effect of the sewage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0023] Figure 1 It is a schematic diagram of the plan structure of the system of the embodiment of the utility model, which contains two sets of primary sedimentation tank systems in parallel.

[0024] Figure 2 for Figure 1 Cross-sectional view from the front.

[0025] Figure 3 for Figure 1 Front view of a single heavy metal treatment tank.

[0026] In the figure: flocculation tank 1, horizontal flow sedimentation tank 2, intermediate water tank 3, flocculation mixer 4, heavy metal capture tank 5, thallium removal tank 6, heavy metal capture agent addition pipeline 7, thallium removal agent addition pipeline 8, network breaking tank 9, hydrogen peroxide addition pipeline 10, polyferric sulfate addition pipeline 11, sodium hydroxide addition pipeline 12, support frame 13, stirring motor 14, rotating shaft 15, stirring blade 16, guardrail 17, bypass protrusion 18, baffle 19, mixing tank 20, spare flocculation tank 21, water outlet trough 22, water outlet hole 23, track 24, sludge scraper 25. DETAILED DESCRIPTION

[0027] The implementation modes of the present utility model are further described below in conjunction with the accompanying drawings.

[0028] See also Figure 1-3 As shown, a sewage treatment primary sedimentation tank system suitable for industrial parks includes a flocculation tank 1, a horizontal flow sedimentation tank 2 and an intermediate water tank 3 which are connected in sequence along the water flow direction. The flocculation tank 1 is connected to a flocculant addition pipeline (not shown in the figure) and a flocculation mixer 4 is arranged in the flocculation tank. The outlet side of the flocculation tank 1 is adjacent to the water inlet end of the horizontal flow sedimentation tank and a flocculation tank overflow is arranged on this side to connect with the horizontal flow sedimentation tank 2. The other end of the horizontal flow sedimentation tank is the outlet end and is connected to the intermediate water tank 3 through the horizontal flow sedimentation tank overflow. The system is characterized in that a heavy metal treatment unit is also arranged in series at the water inlet end of the flocculation tank, and the heavy metal treatment unit includes a plurality of heavy metal treatment tanks arranged in series, and the heavy metal treatment tank includes a heavy metal capture tank 5 and a thallium removal tank 6 which are arranged in series with the water inlet. The heavy metal capture tank 5 is connected with a heavy metal capture agent addition pipeline 7, and the thallium removal tank 6 is connected with a thallium removal agent addition pipeline 8.

[0029] In this way, before the flocculation tank enters, the water first passes through a heavy metal capture tank and a thallium removal tank. The heavy metal capture tank relies on the heavy metal capture agent adding pipeline to add heavy metal capture agents to achieve the capture and treatment of various heavy metal ions. At the same time, the thallium removal tank is connected to the thallium removal adding pipeline to add thallium removal agents to achieve the capture and removal of toxic metal thallium ions. This metal thallium can be released in many industrial and mining activities, which is extremely harmful. At the same time, metal thallium is difficult to be captured by the heavy metal capture agent reaction. Therefore, a thallium removal tank is set up separately to better ensure the capture and removal of various metal ions in the sewage, so that it generates precipitates. It is convenient to better treat the heavy metal pollutants in the sewage through precipitation in the future. Therefore, it is particularly suitable for sewage treatment in industrial parks with large heavy metal pollution.

[0030] Among them, the heavy metal treatment pool also includes two decomposition pools 9 connected in series at the water inlet end of the heavy metal treatment pool. The first decomposition pool is connected to a hydrogen peroxide addition pipeline 10, and the second decomposition pool is connected to both a polyferric sulfate addition pipeline 11 and a sodium hydroxide addition pipeline 12.

[0031] In this way, in the first complex breaking pool, the sewage is broken by adding hydrogen peroxide through the hydrogen peroxide adding pipeline, and the complexed heavy metals are decomposed into ions, such as Cu2+ and Ni2+, while also removing some organic matter. Then, in the second complex breaking pool, polyferric sulfate and sodium hydroxide are added through the polyferric sulfate adding pipeline and the sodium hydroxide adding pipeline respectively. The role of polyferric sulfate is to completely decompose the complex and condense the decomposed metal ions, so as to facilitate the capture and precipitation in the next two heavy metal treatment pools. At the same time, it also has the functions of decolorization, deodorization, dephosphorization and removal of organic matter in water. The role of adding sodium hydroxide can adjust the pH value and make the metal ions react with OH-roots to form sediments. This can better improve the subsequent capture and removal of heavy metal ions.

[0032] Among them, a reaction stirring device is arranged in the heavy metal treatment pool, and the reaction stirring device comprises a support frame 13 located above the heavy metal treatment pool, a stirring motor 14 installed on the support frame, and the stirring motor 14 is downwardly connected to a rotating shaft 15 located in the middle of the heavy metal treatment pool, and a stirring blade 16 is installed on the rotating shaft.

[0033] In this way, the reaction treatment effect of adding reagents in the heavy metal treatment tank is improved by stirring.

[0034] The support frame 13 is a pedestrian bridge arranged in a cross shape, a stirring motor is installed at the middle cross position of the pedestrian bridge, and guardrails 17 are arranged on both sides of the pedestrian bridge.

[0035] This makes it easier for workers to carry out maintenance and inspection, thus improving safety.

[0036] The horizontal cross-section of the heavy metal treatment pool is circular, and three vertically arranged flow-around protrusions 18 are evenly distributed on the inner wall of the pool.

[0037] In this way, it is possible to better prevent the sewage in the heavy metal treatment pool from generating laminar flow during stirring, thereby better improving the stirring and mixing effect.

[0038] Wherein, vertical downward baffles 19 are arranged at intervals at the water inlet end in the heavy metal treatment pool.

[0039] In this way, the baffle can be used to change the water inlet direction to prevent the sewage from short-circuiting and flowing out of the outlet directly in the horizontal direction.

[0040] A mixing tank 20 is also provided at the water inlet of the flocculation tank. The water inlet of the mixing tank 20 is connected to the heavy metal treatment unit. The mixing tank is connected to a sludge return pipeline (not shown in the figure). A mixing agitator is also provided in the mixing tank.

[0041] In this way, part of the returned sludge can be sent to the mixing tank and mixed with the incoming water, and the large amount of beneficial bacteria in the returned sludge can be used in combination with the added polyacrylamide (PAM) flocculant to improve the flocculation reaction effect on the sewage. In this solution, the structure of the mixing and flocculating mixer is basically the same as that of the reaction stirring device, which will not be described in detail here.

[0042] Wherein, two mixing and stirring machines are arranged in the mixing tank 20. In this way, one can work and the other can be standby, which is convenient for replacement and maintenance.

[0043] A standby flocculation tank 21 is also provided on one side of the flocculation tank 1. The mixing tank is connected to the flocculation tank and the standby flocculation tank through control gate valves, and the flocculation tank and the standby flocculation tank are connected to each other through control gate valves.

[0044] In this way, the gate valve can be switched to control one flocculation tank to work normally while the other is under maintenance.

[0045] Among them, the flocculation tank overflow port on the outlet side of the flocculation tank 1 has a water outlet trough 22 extending outward into the horizontal flow sedimentation tank. The upper surface of the water outlet trough 22 exceeds the water level of the horizontal flow sedimentation tank. Downward water outlet holes 23 are evenly arranged at the bottom of the lower end of the water outlet trough to achieve uniform water distribution.

[0046] In this way, the sewage enters the horizontal flow sedimentation tank in a downward direction along the water inlet end, and then flows forward horizontally, which prolongs the residence time of the sewage and improves the sedimentation effect of the sewage in the horizontal flow sedimentation tank.

[0047] Tracks 24 are provided on both sides of the horizontal flow sedimentation tank, and a sludge scraper 25 is arranged above the track. The sludge output pipe of the sludge scraper 25 is bypassed and connected with a sludge return pipe to the mixing tank.

[0048] In this way, the sludge scraping and suction treatment of the horizontal flow sedimentation tank can be better achieved, and the flocculation effect of the flocculation tank can be improved by relying on the sludge return.

[0049] In addition, during implementation, the addition of the agent in this scheme is controlled by a PLC control system. Specifically, each pipeline for adding the agent is connected to a container containing the corresponding agent, and a metering pump is used to accurately control the input of the agent. Sensors are used to detect the reaction effect of the agent addition and the corresponding water quality changes, liquid level fluctuations, flow and pressure parameters, and then rely on PLC feedback to achieve automatic control of the agent addition input. In this way, the PLC control system is used for centralized monitoring, and the number and time of equipment operation can be automatically adjusted according to the changes in parameters such as water quality, liquid level, flow, and pressure, so that the equipment is in the optimal state. The control system cabinet can be located in the instrument control room according to the principle of proximity. The PLC system adopts an integrated electrical and instrument monitoring method, and electrical equipment can realize remote control of the system and manual control on site, which has the advantages of convenient centralized maintenance, management, and automatic control of equipment operation; but this PLC control system belongs to the existing conventional technology in the field of electrical control, so the specific structure is not further described in detail here.

Claims

1. A sewage treatment primary sedimentation tank system suitable for industrial parks, characterized in that: The invention comprises a flocculation tank (1), a horizontal flow sedimentation tank (2) and an intermediate water tank (3) which are connected in sequence along the water flow direction. The flocculation tank (1) is connected to a flocculant addition pipeline, and a flocculation stirrer (4) is arranged in the flocculation tank (1); the outlet side of the flocculation tank (1) is arranged adjacent to the water inlet end of the horizontal flow sedimentation tank (2), and a flocculation tank overflow is arranged on this side to connect with the horizontal flow sedimentation tank (2); the other end of the horizontal flow sedimentation tank (2) is the outlet end and is connected to the intermediate water tank (3) through the horizontal flow sedimentation tank overflow; the water inlet end of the flocculation tank (1) is also connected in series with a heavy metal treatment unit, and the heavy metal treatment unit comprises a plurality of heavy metal treatment tanks arranged in series, and the heavy metal treatment tank comprises a heavy metal capture tank (5) and a thallium removal tank (6) which are arranged in series with the water inlet; the heavy metal capture tank (5) is connected to a heavy metal capture agent addition pipeline (7), and the thallium removal tank (6) is connected to a thallium removal agent addition pipeline (8).

2. A sewage treatment primary sedimentation tank system suitable for an industrial park according to claim 1, characterized in that: The heavy metal treatment pool also includes two chelation breaking pools (9) connected in series at the water inlet end of the heavy metal treatment pool, the first chelation breaking pool being connected to a hydrogen peroxide addition pipeline (10), and the second chelation breaking pool being connected to both a polyferric sulfate addition pipeline (11) and a sodium hydroxide addition pipeline (12).

3. A sewage treatment primary sedimentation tank system suitable for an industrial park according to claim 2, characterized in that: A reaction stirring device is arranged in the heavy metal treatment pool, and the reaction stirring device comprises a support frame (13) located above the heavy metal treatment pool, a stirring motor (14) mounted on the support frame (13), the stirring motor (14) being downwardly connected to a rotating shaft (15) located in the middle of the heavy metal treatment pool, and a stirring blade (16) being mounted on the rotating shaft (15).

4. The sewage treatment primary sedimentation tank system suitable for industrial parks according to claim 3 is characterized in that: The support frame (13) is a pedestrian bridge arranged in a cross shape, a stirring motor is installed at the middle cross position of the pedestrian bridge, and guardrails (17) are arranged on both sides of the pedestrian bridge.

5. The sewage treatment primary sedimentation tank system suitable for industrial parks according to claim 2 is characterized in that: The horizontal cross-section of the heavy metal treatment pool is circular, and three vertically arranged bypass protrusions (18) are evenly distributed on the inner wall of the pool.

6. The sewage treatment primary sedimentation tank system suitable for industrial parks according to claim 2, characterized in that: Vertically downward baffles (19) are arranged at intervals at the water inlet end of the heavy metal treatment pool body.

7. The sewage treatment primary sedimentation tank system suitable for industrial parks according to claim 1, characterized in that: A mixing tank (20) is also provided at the water inlet end of the flocculation tank. The water inlet end of the mixing tank (20) is connected to the heavy metal treatment unit. A sludge return pipeline is connected to the mixing tank. A mixing stirrer is also provided in the mixing tank (20).

8. The sewage treatment primary sedimentation tank system suitable for industrial parks according to claim 7, characterized in that: Two mixing stirrers are arranged in the mixing tank (20); A standby flocculation tank (21) is also provided on one side of the flocculation tank (1), and the mixing tank (20) is connected to the flocculation tank (1) and the standby flocculation tank (21) respectively through control gate valves, and the flocculation tank (1) and the standby flocculation tank (21) are connected to each other through a control gate valve.

9. The sewage treatment primary sedimentation tank system suitable for industrial parks according to claim 7, characterized in that: The flocculation tank overflow outlet on the outlet side of the flocculation tank (1) is provided with a water outlet trough (22) extending outwardly into the horizontal flow sedimentation tank (2), the upper end surface of the water outlet trough (22) exceeds the water level of the horizontal flow sedimentation tank, and downward water outlet holes (23) are evenly arranged at the bottom of the lower end of the water outlet trough to achieve uniform water distribution.

10. The sewage treatment primary sedimentation tank system suitable for industrial parks according to claim 7, characterized in that: Tracks (24) are also provided on both sides of the horizontal flow sedimentation tank. A sludge scraper (25) is mounted above the track (24). A sludge output pipeline of the sludge scraper (25) is bypassed and connected to a sludge return pipeline to the mixing tank.

Images