High-density sedimentation tank system and operation method thereof

Abstract

The invention relates to a high-density sedimentation tank system which comprises a high-density sedimentation tank main body, a high-density sedimentation tank accessory group and a control unit, the high-density sedimentation tank main body comprises a water inlet (1), a contact reaction zone (2), a coagulation reaction zone (3), a flocculation reaction zone (4), a sedimentation zone (5) and a water outlet (6) which are communicated in sequence, the high-density sedimentation tank accessory group comprises an active coke feeding device and a high-density sedimentation tank, a sludge return line; -an active coke separation means; an active coke recovery line; the control unit is configured to control starting and stopping of all accessories in the high-density sedimentation tank accessory set according to the waste water treatment load and the inflow water quality, so that the high-density sedimentation tank system operates in different modes. The invention also relates to a method for operating such a high-density sedimentation tank system.

Description

Technical Field

[0001] This invention relates to the field of water treatment, and more specifically to a high-density sedimentation tank system and its operation method. Background Technology

[0002] With the continuous improvement of wastewater treatment plant discharge standards, the requirements for organic matter removal are becoming increasingly stringent. Currently, many municipal wastewater treatment projects require effluent organic matter to meet the near-Class IV or even near-Class III surface water quality standards. This trend necessitates that conventional advanced treatment processes, in addition to removing suspended solids and total phosphorus, further enhance the capacity for simultaneous removal of recalcitrant dissolved organic matter.

[0003] On the other hand, in some industrial wastewater treatment scenarios, there is often a need to remove small amounts of recalcitrant dissolved organic matter (continuous or emergency). While ozone contact oxidation technology offers significant treatment results, it substantially increases investment and operating costs, and it is difficult to achieve synergistic removal of other pollutants (such as suspended solids and total phosphorus) within the same process unit, thus posing significant challenges from both a technical and economic perspective. Furthermore, considering that some industrial park wastewater treatment plants experience changes in effluent quality due to upstream enterprise process switching, downstream industrial park wastewater treatment plants must have timely response and adjustment measures in place.

[0004] In addition, considering that many wastewater treatment plants undergoing upgrades or some newly built wastewater treatment plants often face land shortages, higher requirements are placed on the treatment load of advanced treatment systems.

[0005] In response to the aforementioned market demands, conventional high-density sedimentation tanks have undergone several upgrades. For example, high-density carrier materials such as micro-sand or ore powder are introduced into the sedimentation tank to increase the settling velocity of flocs through the ballast effect of the carriers, thereby further increasing the treatment load. Another example is the addition of powdered activated carbon or similar adsorbents to enhance the removal of dissolved organic matter. However, each of these solutions still has certain drawbacks. While carriers such as micro-sand or ore powder can significantly increase the treatment load, they themselves lack adsorption capacity and are difficult to effectively remove dissolved organic matter. Powdered activated carbon, although possessing good adsorption performance, has a low density and limited settling properties, resulting in limited potential for increasing the treatment load and higher operating costs. Furthermore, the addition of multiple carrier materials may lead to increased separation difficulty and system complexity.

[0006] It is evident that the above-mentioned solutions each have their own shortcomings, and their functions are limited, making it difficult to cope with the changing treatment conditions of wastewater treatment plants (especially industrial wastewater treatment plants).

[0007] Therefore, there is an urgent need for a high-density sedimentation tank system and its operation method that is structurally sound, flexible in operation, and capable of stable operation under various working conditions, so as to simultaneously meet the requirements for efficient removal of suspended solids, total phosphorus, and dissolved organic matter, and adapt to changes in treatment load and influent water quality. Summary of the Invention

[0008] The technical problem to be solved by this invention is to provide a high-density sedimentation tank system that can efficiently remove pollutants such as suspended solids, total phosphorus, and dissolved organic matter, and has the function of flexibly switching between multiple modes. It can effectively remove multiple pollutants in the upgrading and renovation of sewage treatment plants, save land, and effectively cope with the operating conditions of fluctuating influent water quality.

[0009] To address the aforementioned technical problems, this invention proposes a high-density sedimentation tank system, which includes a high-density sedimentation tank body, a high-density sedimentation tank accessory assembly, and a control unit.

[0010] According to the present invention, the main body of the high-density sedimentation tank includes an inlet, a contact reaction zone, a coagulation reaction zone, a flocculation reaction zone, a sedimentation zone, and an outlet connected in sequence.

[0011] According to the present invention, the high-density sedimentation tank accessory assembly includes:

[0012] - An activated coke dosing device configured to add initial activated coke into the contact reaction zone;

[0013] - A sludge return pipeline, which connects the bottom of the sedimentation zone to the flocculation reaction zone, and is configured to return the sludge from the bottom of the sedimentation zone to the flocculation reaction zone;

[0014] - An activated coke separation device is configured to receive sludge containing activated coke, separate activated coke material from the sludge, and then transport the separated activated coke material to the flocculation reaction zone.

[0015] - An activated carbon recovery pipeline, which connects the bottom of the sedimentation zone to the activated carbon separation device, and is configured to transport the sludge containing activated carbon from the bottom of the sedimentation zone to the activated carbon separation device.

[0016] - A sludge discharge pipeline, which connects the bottom of the sedimentation zone to the first sludge discharge port, and is configured to transport the sludge at the bottom of the sedimentation zone to the first sludge discharge port.

[0017] According to the present invention, the control unit is configured to control the start and stop of each component in the high-density sedimentation tank component group according to the wastewater treatment load and the influent water quality, so that the high-density sedimentation tank system operates in different modes.

[0018] Within the scope of this invention, the initial activated carbon should be understood as non-recoverable activated carbon, which includes not only the activated carbon added initially, but also the activated carbon added subsequently.

[0019] According to one embodiment, the wastewater treatment load is the amount of water to be treated per unit time, and the influent water quality is the content of dissolved organic matter in the influent.

[0020] According to one embodiment, the control unit is configured as follows:

[0021] - When the dissolved organic matter content in the influent does not exceed the first threshold and the wastewater treatment load does not exceed the second threshold, the activated coke dosing device, the activated coke separation device and the activated coke recovery pipeline are shut down, and the sludge return pipeline and the sludge discharge pipeline are activated, so that the high-density sedimentation tank system operates in the first mode.

[0022] - When the dissolved organic matter content in the influent does not exceed the first threshold and the wastewater treatment load exceeds the second threshold, the activated coke dosing device, the activated coke separation device, and the activated coke recovery pipeline are activated, while the sludge return pipeline and the sludge discharge pipeline are deactivated, so that the high-density sedimentation tank system operates in the second mode.

[0023] When the dissolved organic matter content in the influent exceeds the first threshold, the activated coke dosing device, the activated coke separation device, the activated coke recovery pipeline, and the sludge discharge pipeline are activated, while the sludge return pipeline is deactivated, so that the high-density sedimentation tank system operates in the third mode.

[0024] According to one embodiment, the activated carbon dosing device is configured to intermittently add activated carbon in a second mode and continuously add activated carbon according to the content of dissolved organic matter in the influent in a third mode.

[0025] According to one embodiment, the activated coke separation device includes a first activated coke separation device and a second activated coke separation device connected in parallel, and the activated coke recovery pipeline includes a first activated coke recovery pipeline and a second activated coke recovery pipeline connected in parallel. The first activated coke separation device is connected to the bottom of the sedimentation zone through the first activated coke recovery pipeline, and the second activated coke separation device is connected to the bottom of the sedimentation zone through the second activated coke recovery pipeline. In a second mode, all three activated coke separation devices are activated, while in a third mode, only the first activated coke separation device and the first activated coke recovery pipeline are activated, or only the second activated coke separation device and the second activated coke recovery pipeline are activated.

[0026] According to one embodiment, the first activated carbon separation device and the second activated carbon separation device are respectively designed as hydrocyclones. The hydrocyclones are configured to separate the received sludge into heavier bottom material and lighter top material, separating the bottom material as activated carbon material and overflowing the top material to the second sludge discharge port.

[0027] According to one embodiment, there are a first pipe section and a second pipe section respectively connected to the bottom of the sedimentation zone, a third pipe section connected to the second activated coke separation device, a fourth pipe section connected to the first activated coke separation device, a fifth pipe section and a sixth pipe section respectively connected to the flocculation reaction zone, and a seventh pipe section and an eighth pipe section respectively connected to the first sludge discharge port.

[0028] The first and fifth pipe sections are connected to form the sludge return pipeline; the first and third pipe sections are connected to form the second activated carbon recovery pipeline; the second and fourth pipe sections are connected to form the first activated carbon recovery pipeline; and the second and eighth pipe sections are connected to form the sludge discharge pipeline.

[0029] The second and sixth pipe sections are connected to form the sludge return pipeline, the first and third pipe sections are connected to form the second activated coke recovery pipeline, the second and fourth pipe sections are connected to form the first activated coke recovery pipeline, and the first and seventh pipe sections are connected to form the sludge discharge pipeline.

[0030] According to one embodiment, a first pump is provided in a first pipe section for conveying sludge from the bottom of the sedimentation zone to the flocculation reaction zone, the second activated carbon separation device, or the first sludge discharge port, and a second pump is provided in a second pipe section for conveying sludge from the bottom of the sedimentation zone to the flocculation reaction zone, the first activated carbon separation device, or the first sludge discharge port.

[0031] According to one embodiment, the control unit includes a first valve disposed in a first pipe section, a second valve disposed in a second pipe section, a third valve disposed in a third pipe section, a fourth valve disposed in a fourth pipe section, a fifth valve disposed in a fifth pipe section, a sixth valve disposed in a sixth pipe section, a seventh valve disposed in a seventh pipe section, and an eighth valve disposed in an eighth pipe section. The first to eighth valves are configured to control the start and stop of the sludge return pipeline, the first activated carbon recovery pipeline, the second activated carbon recovery pipeline, and the sludge discharge pipeline by opening or closing the corresponding pipe sections.

[0032] According to one embodiment, the activated carbon has the following parameters: iodine value ≥350 mg / g, effective particle size of 50 to 300 μm, and true density of 1.6 to 2.0 g / cm³.

[0033] The present invention also proposes a method for operating one of the aforementioned high-density sedimentation tank systems, the method comprising:

[0034] Wastewater flows into the inlet and passes through the contact reaction zone, the coagulation reaction zone, the flocculation reaction zone, and the sedimentation zone in sequence before being discharged from the outlet. Coagulant is added in the coagulation reaction zone and flocculant is added in the flocculation reaction zone.

[0035] The start-up and shutdown of each component in the high-density sedimentation tank assembly are controlled according to the wastewater treatment load and influent water quality, so that the high-density sedimentation tank system can operate in different modes.

[0036] According to one embodiment, the method further includes:

[0037] - Monitor the influent water quality to determine whether the dissolved organic matter content in the influent exceeds the first threshold. If so, activate the activated coke dosing device, the activated coke separation device, the activated coke recovery pipeline, and the sludge discharge pipeline, and deactivate the sludge return pipeline, so that the high-density sedimentation tank system operates in the third mode; otherwise...

[0038] - Monitor the influent flow rate to determine if the wastewater treatment load exceeds the second threshold. If so, activate the activated coke dosing device, the activated coke separation device, and the activated coke recovery pipeline, and deactivate the sludge return pipeline and the sludge discharge pipeline, so that the high-density sedimentation tank system operates in the second mode; otherwise, deactivate the activated coke dosing device, the activated coke separation device, and the activated coke recovery pipeline, and activate the sludge return pipeline and the sludge discharge pipeline, so that the high-density sedimentation tank system operates in the first mode.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] By introducing activated carbon as a carrier material with both ballast and adsorption functions into the high-density sedimentation tank system, the effective removal of dissolved organic matter is achieved while improving the floc settling performance, thereby expanding the applicability of high-density sedimentation tanks.

[0041] By setting up an activated coke separation device and an activated coke recovery pipeline, the activated coke can be recycled and reused, reducing the consumption of activated coke and significantly reducing operating costs.

[0042] The control unit coordinates the start and stop of the activated coke dosing device, activated coke separation device, sludge return pipeline and sludge discharge pipeline, enabling the system to flexibly switch between normal mode, loading mode and loading carbon removal mode, effectively responding to changes in influent water quality and treatment load.

[0043] By setting up multiple activated coke separation devices and corresponding recovery pipelines in parallel, the reliability and redundancy of the system are improved while ensuring continuous operation.

[0044] Through reasonable pipeline layout, pump and valve configuration, the system achieves a compact structure and stable operation, making it suitable for application scenarios with limited land use in sewage treatment plant upgrading and new construction projects. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. The drawings are merely illustrative of embodiments of the present invention and are not intended to limit all embodiments of the present invention to them.

[0046] Figure 1 This is a schematic diagram of a high-density sedimentation tank system according to an embodiment of the present invention.

[0047] Figure 2 This is a schematic flowchart of a method for operating a high-density sedimentation tank system according to an embodiment of the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0049] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “an” or “a” and similar terms do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0050] The present invention will be described in detail below by way of example embodiments.

[0051] The high-density sedimentation tank system according to the present invention includes a high-density sedimentation tank body, a high-density sedimentation tank accessory assembly, and a control unit.

[0052] The high-density sedimentation tank consists of an inlet 1, a contact reaction zone 2, a coagulation reaction zone 3, a flocculation reaction zone 4, a sedimentation zone 5, and an outlet 6, all connected in sequence. Wastewater enters the system through inlet 1, undergoes treatment in each functional zone, and is finally discharged from outlet 6.

[0053] Contact reaction zone 2 is mainly used for the initial contact between activated coke and pollutants in wastewater, allowing the activated coke to adsorb dissolved organic matter and creating favorable conditions for subsequent coagulation and flocculation reactions. Coagulation reaction zone 2 is used to add coagulants, causing charge neutralization and initial aggregation of fine suspended particles in the water. Flocculation reaction zone 4 is used to add flocculants, allowing the tiny flocs to further grow into dense flocs under lower shear conditions. Sedimentation zone 5 is used to achieve mud-water separation; heavier flocs settle to the bottom of the sedimentation zone under gravity, while the supernatant is discharged through outlet 6.

[0054] The high-density sedimentation tank accessory set includes an activated coke dosing device, a sludge return pipeline, an activated coke separation device, an activated coke recovery pipeline, and a sludge discharge pipeline.

[0055] The activated carbon dosing device is used to add initial activated carbon to the contact reaction zone 2. The so-called initial activated carbon refers to non-recoverable activated carbon, which includes both the activated carbon added when the system is first started and the activated carbon added during operation to compensate for losses.

[0056] The sludge return pipeline connects the bottom of the sedimentation zone to the flocculation reaction zone 4, and is used to return the sludge from the bottom of the sedimentation zone to the flocculation reaction zone 4, thereby increasing the floc concentration and enhancing the flocculation effect.

[0057] The activated carbon separation unit is used to receive sludge containing activated carbon and separate the activated carbon from the sludge. The separated activated carbon material can be recycled back to flocculation reaction zone 4 or contact reaction zone 2.

[0058] The activated coke recovery pipeline connects the bottom of the sedimentation zone to the activated coke separation device, and is used to transport sludge containing activated coke to the activated coke separation device.

[0059] A sludge discharge pipeline connects the bottom of the sedimentation zone to the first sludge discharge port, used to discharge excess sludge from the bottom of the sedimentation zone into the system. The first sludge discharge port is also called the bottom sludge discharge port of the sedimentation zone. In one embodiment, the first sludge discharge port is located in a sludge storage tank (not shown) to discharge sludge into the sludge storage tank.

[0060] The control unit is used to start and stop each component in the high-density sedimentation tank assembly according to the wastewater treatment load and influent water quality, so that the system can work in different operating modes.

[0061] In one embodiment, the wastewater treatment load can be defined as the volume of water to be treated per unit time, and the influent water quality can be defined as the content of dissolved organic matter in the influent.

[0062] When the dissolved organic matter content in the influent does not exceed the first threshold and the wastewater treatment load does not exceed the second threshold, the system operates in the first mode (hereinafter also referred to as Mode A). At this time, the activated coke dosing device, activated coke separation device, and activated coke recovery pipeline are shut down, and the sludge return pipeline and sludge discharge pipeline are activated. The system is mainly used to remove pollutants such as suspended solids and total phosphorus.

[0063] When the dissolved organic matter content in the influent does not exceed the first threshold and the wastewater treatment load exceeds the second threshold, the system operates in the second mode (hereinafter also referred to as Mode B). At this time, the activated coke dosing device, activated coke separation device, and activated coke recovery pipeline are activated, while the sludge return pipeline and sludge discharge pipeline are deactivated, and the treatment load is increased through the ballast effect of activated coke.

[0064] When the dissolved organic matter content in the influent exceeds the first threshold, the system operates in the third mode (hereinafter also referred to as Mode C). At this time, the activated coke dosing device, activated coke separation device, activated coke recovery pipeline and sludge discharge pipeline are activated, and the sludge return pipeline is deactivated. Through the adsorption effect of activated coke and the partial discharge of saturated activated coke, the efficient removal of dissolved organic matter is achieved.

[0065] The three modes correspond to the normal type (mode A), the loaded type (mode B), and the loaded decarbonization type (mode C), respectively.

[0066] To meet the functional requirements of multi-mode operation, the activated carbon used should preferably have the following parameters: iodine value not less than 350 mg / g, effective particle size of 50 to 300 μm, and true density of 1.6 to 2.0 g / cm3.

[0067] In such Figure 1 In the preferred embodiment shown, the activated carbon separation device includes a first activated carbon separation device H1 and a second activated carbon separation device H2 connected in parallel, and the activated carbon recovery pipeline includes a first activated carbon recovery pipeline and a second activated carbon recovery pipeline connected in parallel. The first activated carbon separation device H1 is connected to the bottom of the sedimentation zone through the first activated carbon recovery pipeline, and the second activated carbon separation device H2 is connected to the bottom of the sedimentation zone through the second activated carbon recovery pipeline.

[0068] In the second mode, the first activated coke separation device H1, the first activated coke recovery pipeline, the second activated coke separation device H2, and the second activated coke recovery pipeline are activated, so that the sludge containing activated coke at the bottom of the sedimentation zone enters the two sets of separation devices for treatment, thereby achieving efficient recycling of activated coke.

[0069] In the third mode, only the first activated coke separation device H1 and the first activated coke recovery pipeline are activated, or only the second activated coke separation device H2 and the second activated coke recovery pipeline are activated, so that the other separation device is in standby mode.

[0070] In such Figure 1 In the illustrated embodiment, the first activated coke separation device H1 and the second activated coke separation device H2 are respectively designed as hydrocyclones. The hydrocyclones are configured to separate the received sludge into heavier bottom material and lighter top material. The bottom material is separated as activated coke material and transported to the flocculation reaction zone 4, while the top material overflows to the second sludge discharge port 8 for discharge. Therefore, the second sludge discharge port is also called the overflow sludge discharge port.

[0071] To construct sludge return pipelines, activated coke recovery pipelines, and sludge discharge pipelines, such as Figure 1 The system includes: a first pipe section, one end of which is connected to the bottom of the sedimentation zone, and a first pump P1 and a first valve V1 are installed in the first pipe section; a second pipe section, one end of which is connected to the bottom of the sedimentation zone, and a second pump P2 and a second valve V2 are installed in the second pipe section; a third pipe section, one end of which is connected to the second activated coke separation device H2 and the other end of which is connected to the other end of the first pipe section, and a third valve V3 is installed in the third pipe section; a fourth pipe section, one end of which is connected to the first activated coke separation device H1 and the other end of which is connected to the other end of the second pipe section, and a fourth valve V4 is installed in the fourth pipe section; and a fifth pipe section. The fifth pipe section is connected at one end to the flocculation reaction zone 4 and at the other end to the other end of the first pipe section, and a fifth valve V5 is provided in the fifth pipe section; the sixth pipe section is connected at one end to the flocculation reaction zone 4 and at the other end to the other end of the second pipe section, and a sixth valve V6 is provided in the sixth pipe section; the seventh pipe section is connected at one end to the first sludge discharge port 7 and at the other end to the other end of the first pipe section, and a seventh valve V7 is provided in the seventh pipe section; the eighth pipe section is connected at one end to the first sludge discharge port 7 and at the other end to the other end of the second pipe section, and an eighth valve V8 is provided in the eighth pipe section.

[0072] The first to eighth valves are designed as isolation valves, used to isolate or connect corresponding pipe sections in different modes to achieve pipeline configuration and / or mode switching.

[0073] In the first pipeline configuration, the sixth valve V6 and the seventh valve V7 are always closed, so that the first and fifth pipe sections form a sludge return pipeline, the first and third pipe sections form a second activated coke recovery pipeline, the second and fourth pipe sections form a first activated coke recovery pipeline, and the second and eighth pipe sections form a sludge discharge pipeline.

[0074] In the second pipeline configuration, the fifth valve V5 and the eighth valve V8 are always closed, so that the second and sixth pipe sections form a sludge return pipeline, the first and third pipe sections form a second activated coke recovery pipeline, the second and fourth pipe sections form a first activated coke recovery pipeline, and the first and seventh pipe sections form a sludge discharge pipeline.

[0075] Therefore, the conveying and separation requirements of all three modes can be met by using two sludge pumps (first pump P1 and second pump P2) and two hydrocyclones H1 and H2.

[0076] The functions, processing load, activated coke dosing methods, and mode switching descriptions of the three modes can be summarized as follows:

[0077] Mode A (Standard): Used to remove pollutants such as suspended solids and total phosphorus; treatment load up to 25 m³. 3 / m 2 / h; No activated coke is added; Both hydrocyclones are shut down, and the following is achieved by switching valves: one sludge pump is activated to return sludge to flocculation reaction zone 4, and another sludge pump is activated to discharge sludge to sludge storage tank.

[0078] Mode B (Loading Type): Used to remove pollutants such as suspended solids and total phosphorus; treatment load up to 30 m³. 3 / m 2 / h; Activated coke addition is "small amount supplementation" and the supplementation method is "intermittent"; Both hydrocyclones are in operation and are switched by valves to: activate two sludge pumps to transport sludge to the two hydrocyclones respectively to complete the continuous recycling of activated coke.

[0079] Mode C (Loaded Carbon Removal Type): Used to remove pollutants such as suspended solids, total phosphorus, and dissolved organic matter; treatment load up to 30 m³. 3 / m 2 / h; The amount of activated coke added is determined according to the operating conditions (such as the content of dissolved organic matter to be removed), and the replenishment method is "continuous"; One of the two hydrocyclones is in operation, and the other is on standby, and the switching is achieved through valves: one sludge pump is activated to transport sludge to the activated hydrocyclone to complete the continuous circulation and recovery of activated coke, and at the same time, one sludge pump is activated to discharge sludge to the sludge storage tank to complete the replacement of saturated activated coke.

[0080] like Figure 2As shown, in one embodiment of the method for operating a high-density sedimentation tank system, the influent water quality is monitored to determine whether dissolved organic matter needs to be removed, i.e., whether the dissolved organic matter content in the influent exceeds a first threshold. If so, the activated coke dosing device, the activated coke separation device, the activated coke recovery pipeline, and the sludge discharge pipeline are activated, and the sludge return pipeline is deactivated, so that the high-density sedimentation tank system operates in a third mode, mode C. Otherwise, the influent water volume is monitored to determine whether the wastewater treatment load is high, i.e., whether it exceeds a second threshold. If so, the activated coke dosing device, the activated coke separation device, and the activated coke recovery pipeline are activated, and the sludge return pipeline and the sludge discharge pipeline are deactivated, so that the high-density sedimentation tank system operates in a second mode, mode B. Otherwise, the activated coke dosing device, the activated coke separation device, and the activated coke recovery pipeline are deactivated, and the sludge return pipeline and the sludge discharge pipeline are activated, so that the high-density sedimentation tank system operates in a first mode, mode A.

[0081] Here, influent volume refers to the influent volume per unit time, i.e., the volume of water to be treated per unit time. The first threshold can correspond to the emission limit for dissolved organic matter according to the emission standard. The second threshold can correspond to the maximum treatment load of Mode A mentioned above, i.e., 25 m³. 3 / m 2 / h.

[0082] The following combination Figure 1 and Figure 2 The operation and switching methods of the three modes A, B, and C will be further explained.

[0083] (1) Operation and switching of Mode A (Normal):

[0084] When the influent flow rate is small and only suspended solids and total phosphorus need to be removed, mode A can be switched to. Mode A is a low (treatment) load operation mode, which can save operating costs while ensuring the quality of effluent.

[0085] In the first pipeline configuration mentioned above, the main valves and equipment status of the system under Mode A are as follows: sludge pumps P1 and P2 are running; hydrocyclones H1 and H2 are not running; valves V1, V2, V5, and V8 are open; valves V3, V4, V6, and V7 are closed.

[0086] In Mode A, coagulant is added in coagulation reaction zone 3 and flocculant is added in flocculation reaction zone 4. Part of the sludge at the bottom of the sedimentation zone is returned to flocculation reaction zone 4 by the first pump P1 for sludge recycling, and the other part is discharged as excess sludge to the sludge storage tank continuously or intermittently by the second pump P2.

[0087] (2) Operation and switching of Mode B (loading type):

[0088] When the influent volume is large and only suspended solids and total phosphorus need to be removed, mode B can be switched to. Mode B can ensure effluent quality while operating at high load.

[0089] In the first pipeline configuration mentioned above, the main valves and equipment status of the system under mode B are as follows: sludge pumps P1 and P2 are started and running; hydrocyclones H1 and H2 are started and running; valves V1, V2, V3, and V4 are open; valves V5, V6, V7, and V8 are closed.

[0090] In Mode B, activated carbon is initially added in contact reaction zone 2, with an initial concentration preferably of 1–6 g / L; coagulant is added in coagulation reaction zone 3, and flocculant is added in flocculation reaction zone 4. At this time, activated carbon acts as a carrier, and is periodically replenished in small amounts (i.e., intermittently) according to its loss rate. This loss is due to the presence of a small amount of activated carbon in the material discharged from the hydrocyclone. The sludge at the bottom of the sedimentation zone is pumped to hydrocyclones H1 and H2 via the first pump P1 and the second pump P2, respectively. After separation by the hydrocyclones, the heavier sludge (containing activated carbon), i.e., the activated carbon material, flows by gravity from the bottom of the hydrocyclone to flocculation reaction zone 4, while the lighter sludge (containing suspended solids, etc.) overflows from the top of the hydrocyclone to the sludge storage tank.

[0091] (3) Operation and switching of Mode C (Carbon Removal Loading):

[0092] If removal of not only suspended solids and total phosphorus is required, but also dissolved organic matter (DOP) needs to be removed—that is, when the DOP content in the influent exceeds the first threshold—then mode C can be switched to. Mode C can be used at high treatment loads (up to 30 m³ / s). 3 / m 2 While running at / h, it effectively removes dissolved organic matter.

[0093] In Mode C, activated carbon is initially added in contact reaction zone 2, with an initial concentration preferably of 1–6 g / L; coagulant is added in coagulation reaction zone 3, and flocculant is added in flocculation reaction zone 4. In this mode, the activated carbon acts as both a carrier and an adsorbent, and continuous replenishment is required in contact reaction zone 2 based on the content of dissolved organic matter removed, etc., to replace the activated carbon that is approaching adsorption saturation.

[0094] In the first pipeline configuration mentioned above, the main valves and equipment status of the system under mode C are as follows: sludge pumps P1 and P2 are started and running; hydrocyclone H2 is started and running; hydrocyclone H1 is stopped and running; valves V1, V2, V3, and V8 are open; valves V4, V5, V6, and V7 are closed.

[0095] In Mode C, the sludge at the bottom of the sedimentation zone is partially returned to the hydrocyclone H2 via the first pump P1, while the remaining sludge is directly discharged to the sludge storage tank via the second pump P2 to remove saturated activated carbon. Through the action of the hydrocyclone H2, heavier sludge (containing activated carbon) flows by gravity from the bottom of the hydrocyclone to the flocculation reaction zone 4 to fully recycle the unsaturated activated carbon, while lighter sludge (containing suspended solids, etc.) overflows from above the hydrocyclone H2 into the sludge storage tank.

[0096] This provides a high-density sedimentation tank system that efficiently removes pollutants such as suspended solids, total phosphorus, and dissolved organic matter. While ensuring effluent quality, it achieves a high treatment load (upward flow velocity) through carrier ballast and flow path configuration, thus saving space. Through control unit and valve switching, it allows for flexible switching between ordinary, loaded, and loaded carbon removal modes to cope with varying operating conditions in wastewater treatment plants. The carrier is activated carbon, and by limiting its iodine value, effective particle size, and true density, it simultaneously meets the comprehensive requirements of ballast and adsorption.

[0097] The multi-mode high-density sedimentation tank system according to the present invention also has the following technical effects:

[0098] (1) Technical effects of Mode A (Standard):

[0099] By operating solely through coagulation-flocculation-sedimentation and sludge recirculation without adding activated carbon, this mode can stably remove suspended solids and particulate pollutants such as total phosphorus from the influent. Under low treatment load conditions, by activating sludge recirculation and controlling excess sludge discharge, the effluent quality can be stably guaranteed to meet standards while minimizing carrier consumption and energy consumption, thereby achieving low operating costs and high economic efficiency.

[0100] (2) Technical effects of Mode B (loading type):

[0101] By adding activated coke to the contact reaction zone and continuously recycling it within the system, the activated coke, acting as a high-density carrier, significantly improves the effective density and settling velocity of the flocs, allowing the sedimentation zone to operate under higher surface hydraulic loads. Without increasing the volume of the structures, this method maintains good solid-liquid separation performance under high treatment loads, thus effectively saving floor space. Simultaneously, the activated coke is recycled through a hydrocyclone, requiring only intermittent small-scale replenishment of the portion lost with the overflow sludge, reducing carrier consumption and operating costs.

[0102] (3) Technical effects of Mode C (Carbon Removal Loading):

[0103] In Mode C, activated carbon serves not only as a ballast carrier but also as an adsorbent in the removal of dissolved organic matter. By continuously replenishing activated carbon according to the dissolved organic matter content in the influent, and combining the discharge of partially saturated activated carbon with the recycling of unsaturated activated carbon, synergistic and efficient removal of suspended solids, total phosphorus, and dissolved organic matter can be achieved under high treatment load conditions. This operating mode can improve the system's adaptability to complex and variable influent water quality while ensuring stable effluent quality compliance.

[0104] (4) Comprehensive technical effects of multi-mode collaborative operation:

[0105] By integrating three operating modes—ordinary, loaded, and loaded carbon removal—within the same high-density sedimentation tank system, and achieving rapid switching through the coordinated control of valves, pumps, and activated coke separation devices, this invention can flexibly adjust between energy-saving operation, high-load operation, and enhanced removal of dissolved organic matter according to actual working conditions. Thus, while ensuring effluent quality, it achieves comprehensive technical benefits such as simplified system configuration, increased treatment load, reduced operating costs, and enhanced adaptability to various operating conditions.

[0106] The foregoing description, with reference to preferred embodiments, details exemplary implementations of the high-density sedimentation tank system and its operation method proposed in this invention. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of this invention, and various combinations can be made to the various technical features and structures proposed in this invention without exceeding the protection scope of this invention.

Claims

1. A high-density sedimentation tank system, characterized in that, Includes the main body of the high-density sedimentation tank, the high-density sedimentation tank accessory assembly, and the control unit. The main body of the high-density sedimentation tank includes an inlet (1), a contact reaction zone (2), a coagulation reaction zone (3), a flocculation reaction zone (4), a sedimentation zone (5), and an outlet (6) connected in sequence. The high-density sedimentation tank accessory assembly includes: -Activated coke dosing device, configured to add initial activated coke into the contact reaction zone (2); - A sludge return pipeline, which connects the bottom of the sedimentation zone to the flocculation reaction zone (4), and is configured to return the sludge at the bottom of the sedimentation zone to the flocculation reaction zone (4). - An activated coke separation device is configured to receive sludge containing activated coke, separate activated coke material from the sludge, and then transport the separated activated coke material to the flocculation reaction zone (4). - An activated carbon recovery pipeline, which connects the bottom of the sedimentation zone to the activated carbon separation device, and is configured to transport the sludge containing activated carbon from the bottom of the sedimentation zone to the activated carbon separation device. - A sludge discharge pipeline, which connects the bottom of the sedimentation zone to the first sludge discharge port (7), and is configured to transport the sludge at the bottom of the sedimentation zone to the first sludge discharge port (7). The control unit is configured to control the start and stop of each component in the high-density sedimentation tank assembly according to the wastewater treatment load and influent water quality, so that the high-density sedimentation tank system can operate in different modes.

2. The high-density sedimentation tank system according to claim 1, characterized in that, The wastewater treatment load is the amount of water to be treated per unit time, and the influent water quality is the content of dissolved organic matter in the influent water.

3. The high-density sedimentation tank system according to claim 2, characterized in that, The control unit is configured as follows: - When the dissolved organic matter content in the influent does not exceed the first threshold and the wastewater treatment load does not exceed the second threshold, the activated coke dosing device, the activated coke separation device and the activated coke recovery pipeline are shut down, and the sludge return pipeline and the sludge discharge pipeline are activated, so that the high-density sedimentation tank system operates in the first mode. - When the dissolved organic matter content in the influent does not exceed the first threshold and the wastewater treatment load exceeds the second threshold, the activated coke dosing device, the activated coke separation device, and the activated coke recovery pipeline are activated, while the sludge return pipeline and the sludge discharge pipeline are deactivated, so that the high-density sedimentation tank system operates in the second mode. When the dissolved organic matter content in the influent exceeds the first threshold, the activated coke dosing device, the activated coke separation device, the activated coke recovery pipeline, and the sludge discharge pipeline are activated, while the sludge return pipeline is deactivated, so that the high-density sedimentation tank system operates in the third mode.

4. The high-density sedimentation tank system according to claim 3, characterized in that, The activated carbon dosing device is configured to intermittently add activated carbon in the second mode and continuously add activated carbon according to the content of dissolved organic matter in the influent in the third mode.

5. The high-density sedimentation tank system according to claim 3, characterized in that, The activated carbon separation device includes a first activated carbon separation device (H1) and a second activated carbon separation device (H2) connected in parallel. The activated carbon recovery pipeline includes a first activated carbon recovery pipeline and a second activated carbon recovery pipeline connected in parallel. The first activated carbon separation device (H1) is connected to the bottom of the sedimentation zone through the first activated carbon recovery pipeline, and the second activated carbon separation device (H2) is connected to the bottom of the sedimentation zone through the second activated carbon recovery pipeline. In the second mode, the first activated carbon separation device (H1), the first activated carbon recovery pipeline, the second activated carbon separation device (H2), and the second activated carbon recovery pipeline are all activated. In the third mode, only the first activated carbon separation device (H1) and the first activated carbon recovery pipeline are activated, or only the second activated carbon separation device (H2) and the second activated carbon recovery pipeline are activated.

6. The high-density sedimentation tank system according to claim 5, characterized in that, The first activated carbon separation device (H1) and the second activated carbon separation device (H2) are respectively designed as hydrocyclones. The hydrocyclones are configured to separate the received sludge into heavier bottom material and lighter top material, separating the bottom material as activated carbon material and overflowing the top material to the second sludge discharge port (8).

7. The high-density sedimentation tank system according to claim 5, characterized in that, The system includes a first pipe section and a second pipe section connected to the bottom of the sedimentation zone, a third pipe section connected to the second activated coke separation device (H2), a fourth pipe section connected to the first activated coke separation device (H1), a fifth pipe section and a sixth pipe section connected to the flocculation reaction zone (4), and a seventh pipe section and an eighth pipe section connected to the first sludge discharge port (7). The first and fifth pipe sections are connected to form the sludge return pipeline; the first and third pipe sections are connected to form the second activated carbon recovery pipeline; the second and fourth pipe sections are connected to form the first activated carbon recovery pipeline; and the second and eighth pipe sections are connected to form the sludge discharge pipeline. The second and sixth pipe sections are connected to form the sludge return pipeline, the first and third pipe sections are connected to form the second activated coke recovery pipeline, the second and fourth pipe sections are connected to form the first activated coke recovery pipeline, and the first and seventh pipe sections are connected to form the sludge discharge pipeline.

8. The high-density sedimentation tank system according to claim 7, characterized in that, A first pump (P1) is provided in the first pipe section for conveying the sludge at the bottom of the sedimentation zone to the flocculation reaction zone (4), the second activated coke separation device (H2), or the first sludge discharge port (7). A second pump (P2) is provided in the second pipe section for conveying the sludge at the bottom of the sedimentation zone to the flocculation reaction zone (4), the first activated coke separation device (H1), or the first sludge discharge port (7).

9. The high-density sedimentation tank system according to claim 8, characterized in that, The control unit includes a first valve (V1) in a first pipe section, a second valve (V2) in a second pipe section, a third valve (V3) in a third pipe section, a fourth valve (V4) in a fourth pipe section, a fifth valve (V5) in a fifth pipe section, a sixth valve (V6) in a sixth pipe section, a seventh valve (V7) in a seventh pipe section, and an eighth valve (V8) in an eighth pipe section. The first to eighth valves are configured to control the start and stop of the sludge return pipeline, the first activated coke recovery pipeline, the second activated coke recovery pipeline, and the sludge discharge pipeline by opening or closing the corresponding pipe sections.

10. The high-density sedimentation tank system according to claim 1, characterized in that, The activated carbon has the following parameters: iodine value ≥350 mg / g, effective particle size 50 to 300 μm, and true density 1.6 to 2.0 g / cm³.

11. A method for operating a high-density sedimentation tank system according to any one of claims 1 to 10, characterized in that, The method includes: Wastewater flows into the inlet and passes through the contact reaction zone (2), the coagulation reaction zone (3), the flocculation reaction zone (4), and the sedimentation zone (5) in sequence before being discharged from the outlet (6). Coagulant is added in the coagulation reaction zone (3) and flocculant is added in the flocculation reaction zone (4). The start-up and shutdown of each component in the high-density sedimentation tank assembly are controlled according to the wastewater treatment load and influent water quality, so that the high-density sedimentation tank system can operate in different modes.

12. The method according to claim 11, characterized in that, - Monitor the influent water quality to determine whether the dissolved organic matter content in the influent exceeds the first threshold. If so, activate the activated coke dosing device, the activated coke separation device, the activated coke recovery pipeline, and the sludge discharge pipeline, and deactivate the sludge return pipeline, so that the high-density sedimentation tank system operates in the third mode. otherwise - Monitor the influent flow rate to determine if the wastewater treatment load exceeds the second threshold. If so, activate the activated coke dosing device, the activated coke separation device, and the activated coke recovery pipeline, and deactivate the sludge return pipeline and the sludge discharge pipeline, so that the high-density sedimentation tank system operates in the second mode; otherwise, deactivate the activated coke dosing device, the activated coke separation device, and the activated coke recovery pipeline, and activate the sludge return pipeline and the sludge discharge pipeline, so that the high-density sedimentation tank system operates in the first mode.

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