Water tank matched with sludge-free circulating A / O sewage treatment reactor and design method thereof

Abstract

The application provides a complete water tank of a sludge-free circulating A / O sewage treatment reactor and a design method, and relates to the technical field of environmental protection treatment. The water tank comprises a shell, a baffle and a partition. The shell has a containing space, and is provided with a total water inlet, a total water outlet, an internal circulation water inlet and an internal circulation water outlet. The shell has a first wall and a second wall. The first wall is adjacent to the total water inlet, and the total water outlet is arranged on the second wall. A circulating water pump is arranged near the total water inlet. The number of the baffles is multiple. The multiple baffles are alternately distributed along the top wall and the bottom wall of the shell, forming an up-and-down staggered flow channel. The partition separates the flow channel into a first area and a second area. The internal circulation water outlet is communicated with the first area, the total water outlet is communicated with the second area, and the first area and the second area are communicated near the first wall. The application can accurately design a water tank with a suitable size according to the production site of an enterprise, so that the vertical baffling biological reactor can play its due role in actual production.

Description

Technical Field

[0001] This application relates to the field of environmental protection treatment technology, specifically to a water tank and design method for a sludge-free circulating A / O wastewater treatment reactor. Background Technology

[0002] Currently, the treatment of urban domestic sewage and most industrial wastewater both domestically and internationally almost entirely utilizes the activated sludge process. Within the activated sludge process, A / O or A2 / O3 is the most common method. 2 The main process is / O. A / O and A 2 The A / O process is an inverted wastewater treatment technology primarily designed for denitrification. After long-term practice, it has achieved excellent results and has become a mainstream wastewater treatment process. A / O and A 2 / O wastewater treatment process is an abbreviation for Anaeroxic-Oxic and Anaeroxic-Anoxic-Oxic. The main function of the A / O tank is denitrification, while simultaneously hydrolyzing organic matter in the influent; the main function of the O tank is nitrification, while further oxidizing organic matter. Due to these different functions, the distribution and function of the microbial communities in the A / O and O tanks differ significantly. 2 In the A / O wastewater treatment process, wastewater first flows into tank A and then into tank O. The wastewater in tank O is then returned to tank A at a ratio of 200%–300% to fully utilize the organic matter in the raw water as electron donors, thereby reducing the nitrates flowing in from tank O. However, traditional A / O or A / O wastewater treatment processes... 2 In A / O wastewater treatment processes, wastewater circulates between tanks A and O along with sludge. Therefore, the activated sludge in tanks A and O is constantly mixed during long-term operation, leading to similar or identical microbial communities in both tanks. This significantly reduces the efficiency of nitrification and denitrification reactions. To address this, a sludge-free A / O wastewater treatment process has been developed, which significantly improves wastewater treatment efficiency compared to traditional A / O processes (Lu et al., Sci. Total Environ. 2022, 834:155166.). Simultaneously, an invention patent has been applied for and granted for this process and equipment (ZL201910930412.8). Its foundation is the Vertical Baffled Bio-Reactor (VBBR). Currently, reactors developed based on this patented technology have been applied to some extent in wastewater treatment projects, achieving good results. The sludge-free A / O wastewater treatment process combining anoxic and aerobic processes has enormous application potential. The operating principle of this technology is as follows: Figure 1As shown in the diagram, denitrifying and nitrifying biofilms are formed inside reactors A and O, respectively. During actual operation, these biofilms are immobilized within reactors A and O, while wastewater circulates between the reactors and the tank under the drive of a pump, following the trajectory shown in the diagram. Figure 1 As shown by the arrow in the image.

[0003] Since the wastewater treatment process mainly takes place in reactors A and O, the function of the circulating water tank is to ensure that there is enough space for the water pump to drive the wastewater to circulate between two or more reactors. At the same time, after the aging or dead biofilm fragments flow out during operation, they can settle in the water tank, which actually also acts as a secondary sedimentation tank, making the total effluent very clear.

[0004] Therefore, the design of the water tank structure and size is very important.

[0005] If the water tank is too large, it occupies a large area and increases the cost. Conversely, if the water tank is too small, it cannot guarantee the normal operation of the water pump, and especially cannot guarantee sufficient settling time for aging and dead biofilm fragments flowing out of the reactor. Therefore, to ensure that this technology can be more effective in actual production, it is crucial to design a circulating water tank specifically suited to the anoxic / aerobic VBBR system, based on the size of the enterprise's production site. Summary of the Invention

[0006] The purpose of this application is to provide a matching water tank for a sludge-free circulating A / O wastewater treatment reactor, which can be more accurately adapted to the production site and improve the problem of unreasonable water tanks affecting the actual use of enterprises.

[0007] Another objective of this application is to provide a design method that can be used to accurately design the supporting water tank for the aforementioned sludge-free circulating A / O wastewater treatment reactor.

[0008] The embodiments of this application are implemented as follows:

[0009] The embodiments of this application provide a matching water tank for a sludge-free circulating A / O wastewater treatment reactor. The vertical baffle bioreactor includes an A reactor and an O reactor, which are connected to each other. It includes: an outer shell, baffles, and partitions.

[0010] The housing has an accommodation space. The housing is provided with a total water inlet, a total water outlet, an internal circulation water inlet, and an internal circulation water outlet. On opposite side walls in the length direction of the housing are a first wall and a second wall respectively. The first wall is adjacent to the total water inlet, and the total water outlet is provided on the second wall. The vicinity of the total water inlet is for arranging a circulation water pump. The circulation water pump can be connected to the A reactor through the internal circulation water inlet. The O reactor can be connected to the accommodation space through the internal circulation water outlet. The number of the baffle plates is multiple, and the multiple baffle plates are alternately distributed in sequence along the top wall and the bottom wall of the housing to form an upper and lower staggered flow channel in the accommodation space. One end of the partition plate is connected to the second wall, and the other end of the partition plate is close to the first wall. The partition plate divides the flow channel into a first region and a second region. The internal circulation water outlet is connected to the first region, and the total water outlet is connected to the second region. The first region and the second region are connected near the first wall;

[0011] The length L of the partition plate satisfies that,

[0012] The overall length L0 of the housing satisfies that L0 = L + W / 2;

[0013] Where, Q is the maximum flow rate of the internal circulation water, t is the sedimentation time of the biofilm fragments, W is the width of the housing, and H is the height of the housing.

[0014] In addition, the supporting water tank of the sludge-free circulation A / O sewage treatment reactor provided by the embodiment of the present application may further have the following additional technical features:

[0015] In an optional embodiment of the present application, the number of the partition plates is multiple, and the multiple partition plates are spaced apart in sequence along the width direction of the housing to divide the flow channel so that the water flow flows in a zigzag manner;

[0016] At this time, the length L of the partition plate satisfies that, δ is a baffle coefficient, satisfying 0 < δ < 1.

[0017] In an optional embodiment of the present application, the supporting water tank of the sludge-free circulation A / O sewage treatment reactor further includes a baffle. The baffle surrounds the vicinity of the total water inlet and forms a water pump space with the inner wall of the housing. The water pump space is for installing the circulation water pump. The height of the baffle is lower than the liquid level height, and the height of the baffle is higher than the height of the water inlet of the circulation water pump.

[0018] In an optional embodiment of the present application, 1.6m ≤ W ≤ 3m; 1.2m ≤ H ≤ 1.3m.

[0019] In an optional embodiment of the present application, the supporting water tank of the sludge-free circulation A / O sewage treatment reactor further includes a circulation water pump, which is arranged inside the outer shell and close to the total water inlet to pump the water at the total water inlet completely into the A reactor.

[0020] An embodiment of the present application provides a design method for the supporting water tank of a sludge-free circulation A / O sewage treatment reactor, which is used to design the supporting water tank of the sludge-free circulation A / O sewage treatment reactor described in any one of the above. The method includes:

[0021] Obtain the spatial dimension information of the installation site;

[0022] Obtain the water volume data q to be treated and determine the maximum internal circulation flow rate Q accordingly;

[0023] Determine data H and data W according to the obtained spatial dimension information of the installation site;

[0024] Obtain the sedimentation time t of the biofilm fragments;

[0025] Determine the partition length L, and L satisfies the formula:

[0026] Determine the overall length L0 of the outer shell of the supporting water tank of the sludge-free circulation A / O sewage treatment reactor.

[0027] In an optional embodiment of the present application, in the step of obtaining the water volume data q to be treated and determining the maximum internal circulation flow rate Q accordingly, 5q ≤ Q ≤ 6q.

[0028] In an optional embodiment of the present application, in the step of obtaining the sedimentation time t of the biofilm fragments, the sedimentation time t of the biofilm fragments under the corresponding data H and data W can be obtained according to experimental tests.

[0029] In an optional embodiment of the present application, in the step of determining according to the obtained spatial dimension information of the installation site, when it is determined that the length space of the installation site is limited, the partition is set as multiple to make the water flow meandering, and the length L of the partition satisfies δ is the baffle coefficient, and 0 < δ < 1.

[0030] In an optional embodiment of the present application, according to the calculation results, further determine that the number of supporting water tanks of the sludge-free circulation A / O sewage treatment reactor is set to one or more.

[0031] The beneficial effects of the present application are:

[0032] The supporting water tank of the present application can ensure that the aging and dead biofilm fragments flowing out of the reactor have sufficient settling time by setting partition plates, so that the effluent quality meets the requirements and is better than the effluent quality of the water tanks in the prior art. With corresponding design methods, the supporting water tank with appropriate size can be accurately designed according to the production site of the enterprise, so that the vertical plug-flow bioreactor can play its due role in actual production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 Schematic diagram of a vertical plug-flow bioreactor in general technology;

[0035] Figure 2 Layout schematic diagram of the supporting water tank of the sludge-free circulation A / O sewage treatment reactor provided by the embodiment of the present application;

[0036] Figure 3 Top view of the supporting water tank of the sludge-free circulation A / O sewage treatment reactor provided by the embodiment of the present application;

[0037] Figure 4 Side view of the supporting water tank of the sludge-free circulation A / O sewage treatment reactor provided by the embodiment of the present application;

[0038] Figure 5 Schematic diagram of the supporting water tank of the sludge-free circulation A / O sewage treatment reactor provided by the embodiment of the present application after installing baffles;

[0039] Figure 6 For Figure 5 side view;

[0040] Figure 7 Schematic diagram of the supporting water tank of the sludge-free circulation A / O sewage treatment reactor provided by the embodiment of the present application with multiple partition plates installed;

[0041] Figure 8 Flow chart of the design method of the supporting water tank of the sludge-free circulation A / O sewage treatment reactor provided by the embodiment of the present application.

[0042] Icons: 10-Outer shell; 12-Main outlet; 14-Internal circulation outlet; 101-First wall; 102-Second wall; 20-Baffle plate; 30-Baffle; 40-Baffle; 100-First zone; 200-Second zone; F-Flow channel; M-Circulating water pump. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0046] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product is conventionally placed during use. These terms are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0047] In the description of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0048] Example

[0049] Please combine Figure 2This application provides a matching water tank for a sludge-free circulating A / O wastewater treatment reactor. The sludge-free circulating A / O wastewater treatment reactor can be understood in conjunction with general techniques, and includes an A reactor and an O reactor (such as...). Figure 1 As shown in the diagram, reactor A is connected to reactor O. Its specific structure and working principle remain unchanged in this application, and therefore will not be described further.

[0050] Further integration Figure 3 and Figure 4 The supporting water tank of the sludge-free circulating A / O wastewater treatment reactor in this embodiment includes: outer shell 10, baffle plate 20 and partition plate 30;

[0051] The outer casing 10 has an accommodating space. The outer casing 10 is provided with a main water inlet, a main water outlet 12, an internal circulation water inlet, and an internal circulation water outlet 14. The two opposite side walls along the length of the outer casing 10 are respectively a first wall 101 and a second wall 102. The first wall 101 is adjacent to the main water inlet, and the main water outlet 12 is located on the second wall 102. The positions of the main water inlet and the main water outlet 12 can be referenced. Figure 1 This diagram illustrates the locations of the main inlet and outlet of a typical water tank. The circulating water pump M is located near the main inlet. Figure 2 The location of the circulating water pump M is indicated by position S. The circulating water pump M can pass through the internal circulation inlet (the location of the internal circulation inlet can be referenced). Figure 1 The circulating water pump of the general water tank is connected to reactor A (the opening position of the pump when it leaves the water tank). Reactor O can be connected to the containment space through the internal circulation outlet 14. There are multiple baffles 20, which are alternately distributed along the top and bottom walls of the outer shell 10 to form an interlaced flow channel F in the containment space. One end of the partition 30 is connected to the second wall 102, and the other end of the partition 30 is close to the first wall 101. The partition 30 divides the flow channel into a first region 100 and a second region 200. The internal circulation outlet 14 is connected to the first region 100, and the main outlet 12 is connected to the second region 200. The first region 100 and the second region 200 are connected near the first wall 101.

[0052] The length L of the partition 30 is satisfied.

[0053] The overall length L0 of the outer shell 10 satisfies L0 = L + W / 2;

[0054] Where Q is the maximum flow rate of the internal circulating water, t is the settling time of the biofilm fragments, W is the width of the outer shell 10, and H is the height of the outer shell 10. Optionally, 1.6m ≤ W ≤ 3m; 1.2m ≤ H ≤ 1.3m. It is understood that the numerical ranges here are merely examples of feasible embodiments and do not limit the width and height to these ranges. Those skilled in the art can design circulating water tanks of suitable sizes to meet actual needs based on the design methods described below.

[0055] Optionally, the supporting water tank for the sludge-free circulating A / O wastewater treatment reactor also includes a circulating water pump M. The circulating water pump M is located inside the outer casing 10 and near the main inlet to completely pump water from the main inlet into reactor A. By directly integrating the circulating water pump M into the outer casing 10, subsequent installation is eliminated, avoiding any impact on the structure of the outer casing 10 during on-site installation. For example, it avoids the uncontrollable impact of on-site welding quality, allowing the supporting water tank of this application to perform its intended function. Furthermore, supporting water tanks of suitable sizes can be designed for some common production sites, and different specifications of circulating water pumps M can be configured for selection. This makes the product versatile, allowing some enterprises to directly select suitable specifications as supporting water tanks, reducing the waiting period for production and improving the convenience of actual use for enterprises.

[0056] Furthermore, please combine Figure 5 and Figure 6 The sludge-free circulating A / O wastewater treatment reactor's supporting water tank also includes a baffle 40. The baffle 40 surrounds the main inlet and, together with the inner wall of the outer shell 10, forms a pump space. This pump space is used to install the circulating water pump M. The height of the baffle 40 is lower than the liquid level and higher than the inlet height of the circulating water pump M. The flow rate of the circulating water pump M is much greater than the inlet flow rate, ensuring that the raw water just fed into the circulating water tank is directly pumped into reactor A, fully utilizing the organic carbon source in the raw water to reduce nitrates in the circulating water. It is understood that the baffle 40 shown in the diagram is "L"-shaped from a top view, but it is not limited to this form. For example, it can be curved or a combination of curves and broken lines from a top view, as long as it can form a certain space with the interior of the outer shell 10 and is higher than the inlet of the circulating water pump M, so that all water entering through the main inlet is directly pumped to reactor A. Of course, the height of the baffle 40 can be further designed to ensure that the raw water pump from the main inlet can be sent away, while avoiding excessive height that would affect the smoothness of the circulating water pump M in pumping other water in the water tank.

[0057] Please combine Figure 7Alternatively, the number of baffles 30 can be multiple, with multiple baffles 30 distributed sequentially at intervals along the width direction of the outer shell 10 to divide the flow channel, so that the water flows in a tortuous manner; in this case, the length L of the baffles 30 satisfies... δ is the baffle coefficient, satisfying 0 < δ < 1. Furthermore, this application provides examples of single baffles 30 and multiple baffles 30 below to illustrate the benefits of different numbers of baffles 30 for different applications. In addition, the baffles 20 mentioned above... Figure 7 Although not illustrated, the removal of the baffle 20 is not mandatory. Those skilled in the art can determine whether or not to install the baffle 20 based on the required settling time of the biofilm fragments.

[0058] In the prior art, when wastewater flows into the water tank from the outlet of the circulation pipe inside the aerobic reactor (O), it is near the main outlet 12.

[0059] Through practical experience, the inventors discovered that during operation, some aged biofilm fragments would flow out with the effluent from the aerobic reactor (O). Because the internal circulation flow rate is much greater than the influent and effluent flow rates, most of the water flow would follow... Figure 1 The arrows shown indicate a cyclical flow, but because it is close to the outlet, some biofilm fragments inevitably flow out of the main outlet through the bypass, thus affecting the water quality of the effluent.

[0060] The water tank of the sludge-free circulating A / O wastewater treatment reactor of this application is equipped with a baffle 30, which allows biofilm fragments to settle fully during the circulation process, thus preventing biofilm fragments from affecting the effluent quality.

[0061] Furthermore, by combining practical experience and understanding the actual needs of enterprises, the length of the baffle 30 was designed to meet the corresponding formula obtained by the inventors. This allows for a more reasonable relationship between the length of the baffle 30 and the length of the outer shell 10, avoiding both excessive size leading to waste and reduced treatment efficiency, and insufficient size resulting in biofilm fragments remaining at the main outlet 12 and affecting the treatment effect. This makes the design of the matching water tank more accurate and efficient, eliminating the need for multiple experiments to obtain the appropriate baffle 30 size, and demonstrating practical application value.

[0062] For details, please refer to... Figure 1, in the prior art, the circulation water tank is an essential component of the vertical baffled bioreactor. However, the existing circulation water tanks are only made according to experience. For different enterprises, the sizes of their production sites vary, and the fabricated circulation water tanks may not fit the installation sites. They may be too large, occupying too much space and affecting the layout of the enterprise's equipment and facilities or the material flow; or there may be insufficient space, resulting in insufficient sedimentation time, making the outflow water still not meet the requirements. Therefore, this application proposes a design method for designing the supporting water tank of the above sludge-free circulating A / O sewage treatment reactor, so as to make a more accurate design according to the site size, enabling the technology of the vertical baffled bioreactor to better play its role.

[0063] Please combine Figure 8 , an embodiment of this application provides a design method for the supporting water tank of a sludge-free circulating A / O sewage treatment reactor to accurately design the supporting water tank of this application (which can also be called the common name circulation water tank). The method includes:

[0064] Obtain the spatial dimension information of the installation site;

[0065] Obtain the water volume data q to be treated and determine the maximum internal circulation flow rate Q based on this;

[0066] Determine the data H and data W according to the obtained spatial dimension information of the installation site;

[0067] Obtain the sedimentation time t of the biofilm fragments;

[0068] Determine the length L of the baffle 30, and L satisfies the formula:

[0069] Determine the overall length L0 of the outer shell 10 of the supporting water tank of the sludge-free circulating A / O sewage treatment reactor. Among them, L0 can refer to the above introduction, that is, L0 satisfies L0 = L + W / 2.

[0070] Among them, in the step of obtaining the spatial dimension information of the installation site, this step mainly involves the enterprise providing its site data to understand the size of the available site and what size is suitable.

[0071] In the step of obtaining the water volume data q to be treated and determining the maximum internal circulation flow rate Q based on this, 5q ≤ Q ≤ 6q. Among them, q can be determined according to the requirements of the enterprise. For example, the enterprise can require the daily treatment volume to reach a certain amount, and thus determine the value of the unit hourly treatment volume q.

[0072] In obtaining the biofilm debris settling time t, the settling time t can be determined based on experimental test data H and W. Since H and W can be easily determined, the experimental test t does not require excessive time, allowing for faster parameter determination during actual design. Furthermore, for some common site dimensions, t under different H and W conditions can be obtained through pre-experimentation. For sites with conventional dimensions, the t can be directly retrieved, and the length L of the baffle 30 can be quickly calculated based on the maximum internal circulation volume Q. Moreover, as more and more companies use the water tanks provided by this application, the design method will continuously accumulate data in long-term practice, resulting in higher accuracy of the biofilm debris settling time t. Designers can then more quickly select the corresponding t directly from site data, further shortening the design cycle.

[0073] When the length of the installation site is limited based on the steps of obtaining the spatial dimensions of the installation site, multiple baffles 30 are set to allow the water flow to bend, and the length L of the baffles 30 is satisfied. δ is the deflection coefficient, which satisfies 0 < δ < 1.

[0074] Based on the calculation results, the number of supporting water tanks for the sludge-free circulating A / O wastewater treatment reactor was further determined to be one or more. That is, in addition to setting up one supporting water tank for flow deflection, multiple supporting water tanks can be selected to ensure that biofilm fragments settle in place, and also to flexibly adapt to the size of the application site, not limited to using only one water tank.

[0075] For details, please refer to... Figure 4 and Figure 5 The following is an introduction to the formula for calculating the length of the partition 30 in the design method of this application.

[0076] Based on practice and summarization, the inventors of this application derived and simplified the length calculation of the baffle 30, thereby making the design of the baffle 30 more efficient and accurate, so that the final size of the entire water tank can be confirmed, which greatly promotes the effectiveness of the vertical baffle bioreactor in enterprises, allowing more enterprises to modify and design according to existing sites, which is conducive to practical promotion and application.

[0077] Specifically, assume the effective height of the water tank, i.e., the height of the water surface, is H (cm), the length of the internal partition 30 is L (cm), and the width of the water tank is W (cm). The difference between the length of the internal partition 30 (L) and the length of the water tank is taken as half the width of the water tank (W / 2). In the actual sewage treatment process, the total influent flow rate is equal to the total effluent flow rate, assumed to be q (m³). 3 / h), while the flow rate of circulating water pump M is Q(m 3 / h), usually Q>>q.

[0078] Based on the operating characteristics of VBBR, the concentration of sporadic biofilm debris in the water is not high. Therefore, the vertical settling rate of biofilm debris in the pool can be calculated using the Stokes formula:

[0079]

[0080] Where, r v ρ is the vertical settling velocity of the particles (cm / s); d is the average diameter of the biofilm fragments (cm); ρ s ρ and μ are the densities of the biofilm fragments and water, respectively (g / cm³); g is the acceleration due to gravity (cm / s²); and μ is the adhesion coefficient of water (Pa·s). Therefore, the settling time t in still water is:

[0081]

[0082] Because of the circulating water flow within the tank during actual operation, biofilm fragments do not settle vertically, but rather at an angle following the water flow. Their settling rate, r, is thus accelerated, and its calculation formula is:

[0083]

[0084] Where, r H The horizontal velocity of the water flow has the following value:

[0085]

[0086] Assuming the settlement time t remains constant, the actual settlement distance l is:

[0087]

[0088] Therefore, the horizontal distance l traversed by biofilm debris during sedimentation H for:

[0089]

[0090] Therefore, to ensure that biofilm debris flowing out of the circulation pipe in the aerobic reactor (O) has sufficient time to settle in the circulating water tank and is not carried out with the effluent, the length L of the tank baffle 30 should meet the following conditions:

[0091]

[0092] If the wastewater treatment flow rate (q) is known based on the water treatment process, and the required water treatment effect is used to set the internal circulation flow rate (Q) of the reactor, and the tank width (W) and height (H) are set according to the actual site conditions, then the formula for calculating the length of the tank partition 30 is:

[0093]

[0094] Therefore, in the specific design process, the length (L+W / 2), width (W), and height (H) of the water tank are determined based on the actual conditions of the production site. The total influent flow rate (q) is determined based on the hydraulic retention time (HRT) and wastewater removal efficiency of the wastewater in the reactor, taking into account the different wastewater qualities being treated. The flow rate (Q) of the internal circulating water is determined based on the mass transfer efficiency of the wastewater flowing on the biofilm surface. After determining these factors, substituting them into the above formulas will achieve a highly efficient wastewater treatment effect. Furthermore, in the actual engineering design process, for simplification, the settling rate r or settling time t of the biofilm fragments can be tested experimentally. The following formula can be obtained from formula (8) for calculation:

[0095]

[0096] Accordingly, the formula for calculating the length L of the water tank baffle 30 is:

[0097]

[0098] Furthermore, when multiple partitions 30 need to be designed to adapt to the terrain, Formula 10 can be further transformed into:

[0099]

[0100] The following examples illustrate how the method described in this application is implemented.

[0101] Example 1:

[0102] An industrial wastewater treatment plant plans to use an anoxic / aerobic VBBR reactor. The user requires a maximum daily wastewater treatment capacity of 120 m³. 3 / h, meaning the hourly processing capacity q is 5m³. 3 / h. Based on the reactor's operating characteristics, the maximum internal circulation flow rate is designed to be 30m³ / h. 3 / h. Considering the actual situation on site, the water tank has a maximum width of more than 2 meters, while there is no particular restriction on the length. For ease of manual control during actual operation, the height H of the water tank is designed to be 1.3m (the actual water surface height H' is 1.2m), and the width W of the water tank is designed to be 1.6m. According to the experimental measurements, the longest settling time of biofilm fragments is 10 minutes. According to formula (10), in order to ensure that the biofilm fragments have enough time to settle during the flow of the water tank, the length L of the baffle 30 inside the water tank can be calculated according to formula (10):

[0103]

[0104] This length, plus half the width of the water tank, equals 5.6m. Therefore, a total tank length of 5.6m ensures that no floating sludge or debris will appear in the effluent. In actual design, the total length of the circulating water tank is designed to be 6m for ease of manufacturing.

[0105] Example 2:

[0106] The sewage treatment capacity of a certain town is 2000m³ 3 / d, which means a processing capacity of 250m per hour. 3 / h. The domestic sewage is treated using both anoxic and aerobic VBBR reactors. Due to site constraints, there are limitations on the length of the tank, but no limitations on its width. Therefore, improvements can be considered to the aforementioned tank design. A multi-baffle design can be used to extend the flow length, such as... Figure 7 The diagram shows two sets of baffles (e.g.) Figure 7 As shown by the arrow, the water flow from right to left and then to right forms one set of baffles, and the three baffles 30 can form two sets of baffles.

[0107] Based on the characteristics of wastewater treatment, the width (W) and height (H) of each group of circulating water tanks are selected as 3m and 1.3m respectively (with a water surface of 1.2m). The internal circulating water flow rate (Q) is selected as 5 times the influent flow rate, i.e., 1250m³, according to the characteristics of domestic sewage. 3 / h. The experimentally measured settling time of the floating sludge fragments was 15 min. Similarly, these data were substituted into formula (10) for calculation:

[0108]

[0109] Because multiple baffles 30 are installed in the water flow direction, and the deflection coefficient δ is taken as 0.7, as long as the length of the baffles 30 in the circulating water tank is greater than 112 meters, it can be ensured that biofilm fragments will not flow out. Based on the above calculation results, this example designs the circulating water tank into three groups, each with an actual length of 45m. According to the above design, clear effluent can be achieved at the outlet, reaching the effect of the secondary sedimentation tank in traditional sewage treatment processes.

[0110] In summary, the water tank in this application, with its baffle 30, ensures sufficient settling time for aging and dead biofilm fragments flowing from the reactor, resulting in effluent quality that meets requirements and is superior to that of existing water tanks. Combined with appropriate design methods, a suitable water tank of appropriate size can be accurately designed according to the enterprise's production site, enabling the vertical baffle bioreactor to function effectively in actual production.

[0111] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A matching water tank for a sludge-free circulating A / O wastewater treatment reactor, the vertical baffled bioreactor comprising an A reactor and an O reactor, wherein the A reactor and the O reactor are connected, characterized in that, Comprising: A housing, folding plates and partition plates; The housing has a receiving space, and the housing is provided with a total water inlet, a total water outlet, an internal circulation water inlet, and an internal circulation water outlet. On the two opposite side walls in the length direction of the housing are respectively a first wall and a second wall. The first wall is adjacent to the total water inlet, the total water outlet is arranged on the second wall, and a circulation water pump is arranged near the total water inlet. The circulation water pump can be connected to the A reactor through the internal circulation water inlet, and the O reactor can be communicated with the receiving space through the internal circulation water outlet. The number of the folding plates is multiple, and the multiple folding plates are alternately distributed along the top wall and the bottom wall of the housing in sequence to form an upper and lower staggered flow channel in the receiving space. One end of the partition plate is connected to the second wall, and the other end of the partition plate is close to the first wall. The partition plate divides the flow channel into a first region and a second region. The internal circulation water outlet is communicated with the first region, the total water outlet is communicated with the second region, and the first region and the second region are communicated near the first wall; The length L of the partition plate satisfies the following condition. ; The overall length L0 of the housing satisfies L0 = L + W / 2; Where, Q is the maximum flow rate of the internal circulation water, t is the sedimentation time of the biofilm fragments, W is the width of the housing, and H is the height of the housing.

2. The supporting water tank of the sludge-free circulating A / O sewage treatment reactor according to claim 1, wherein The number of the partition plates is multiple, and the multiple partition plates are spaced apart in sequence along the width direction of the housing to divide the flow channel so that the water flow flows tortuously; At this time, the length L of the partition plate satisfies the following: δ is the deflection coefficient, which satisfies 0 < δ < 1.

3. The supporting water tank of the sludge-free circulating A / O sewage treatment reactor according to claim 1, characterized in that, The supporting water tank of the sludge-free circulation A / O sewage treatment reactor further includes a baffle. The baffle surrounds the vicinity of the total water inlet and forms a water pump space with the inner wall of the housing. The water pump space is used to install the circulation water pump. The height of the baffle is lower than the liquid level height, and the height of the baffle is higher than the height of the water inlet of the circulation water pump.

4. The supporting water tank of the sludge-free circulating A / O sewage treatment reactor according to claim 1, characterized in that, 1.6m ≤ W ≤ 3m; 1.2m ≤ H ≤ 1.3m.

5. The supporting water tank of the sludge-free circulation A / O sewage treatment reactor according to claim 1, characterized in that, The supporting water tank of the sludge-free circulation A / O sewage treatment reactor further includes a circulation water pump. The circulation water pump is arranged in the housing and close to the total water inlet to pump the water at the total water inlet completely into the A reactor.

6. A design method for a matching water tank of a sludge-free circulating A / O wastewater treatment reactor, used to design the matching water tank of the sludge-free circulating A / O wastewater treatment reactor according to any one of claims 1-5, characterized in that, This method includes: Obtaining the spatial dimension information of the installation site; Obtaining the water volume data q to be treated and determining the maximum internal circulation flow rate Q accordingly; Determining the data H and data W according to the obtained spatial dimension information of the installation site; Obtaining the sedimentation time t of the biofilm fragments; Determine the length L of the partition, where L satisfies the formula: ; Determining the overall length L0 of the housing of the supporting water tank of the sludge-free circulation A / O sewage treatment reactor.

7. The design method for the supporting water tank of the sludge-free circulating A / O wastewater treatment reactor according to claim 6, characterized in that, In the step of obtaining the water volume data q to be treated and determining the maximum internal circulation flow rate Q accordingly, 5q ≤ Q ≤ 6q.

8. The design method for the supporting water tank of the sludge-free circulating A / O wastewater treatment reactor according to claim 6, characterized in that, In the step of obtaining the sedimentation time t of the biofilm fragments, the sedimentation time t of the biofilm fragments under the corresponding data H and data W is tested according to experiments.

9. The design method for the supporting water tank of the sludge-free circulating A / O wastewater treatment reactor according to claim 6, characterized in that, In the step of obtaining the spatial dimension information of the installation site, when it is determined that the length space of the installation site is limited, multiple baffles are set to make the water flow meander, and the length L of the baffles satisfies... δ is the deflection coefficient, which satisfies 0 < δ < 1.

10. The design method for the supporting water tank of the sludge-free circulating A / O wastewater treatment reactor according to claim 9, characterized in that, According to the calculation results, further determine that the number of the supporting water tanks of the sludge-free circulation A / O sewage treatment reactor is set to one or more.

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