Short-process water supply plant sludge water treatment system

Abstract

The utility model relates to a short-process sludge water treatment system for a water supply plant. The short-process sludge water treatment system comprises a drainage tank, a sludge discharge tank, a membrane separation system, a balance tank and a sludge dewatering and temporary storage system which are connected in sequence. The process route is simple, the flow is short, recycled water without PAM can be produced, zero water discharge in the whole process is achieved, the investment and construction cost is low, and no water resource is wasted.

Description

TECHNICAL FIELD

[0001] The utility model relates to a sludge water treatment system of water supply plant, especially to a short process sludge water treatment system of water supply plant. BACKGROUND

[0002] The conventional treatment process of water supply treatment plant is raw water-coagulation sedimentation or clarification-filtration-disinfection, and a large amount of sludge water will be produced in the treatment process. The sludge water mainly includes sludge water of sedimentation tank or clarification tank and backwash water of filtration, which contains a large amount of suspended solids (SS) and a certain amount of organic pollutants, microorganisms and heavy metals, and the total solid content is generally 0.1%-2%. If the sludge water is directly discharged to natural water without treatment, it will cause pollution risk. At the same time, the SS content in the sludge water far exceeds the relevant provisions of the national standard "Integrated Wastewater Discharge Standard", and direct reuse will have higher water quality safety risk, which may impact the production of water plant. In order to ensure the water quality safety of sludge water reuse, many large water plants consider sludge water reuse measures in the design, but most of them directly recycle after adjustment and sedimentation.

[0003] In the prior art, the water supply plant adopts the traditional process of "adjustment-concentration-balance-dewatering" to treat the supernatant of sludge water to meet the standard and then discharge or reuse. For example, Chinese patent application CN116514368A discloses a sludge treatment system and process of water supply treatment plant, which includes a sludge water pool, a reuse water pool and a sludge concentration and dewatering workshop. Although the sludge concentration and dewatering workshop is built above the sludge pool and the reuse water pool, and compared with the traditional process, the land occupation area is saved, but the foundation of the sludge concentration and dewatering workshop uses the reinforced concrete box structure of the sludge pool and the reuse water pool as the house foundation, and the multi-layer structure of underground and aboveground is adopted, which has long construction difficulty and cycle. In addition, since the process pool body is built by steel concrete structure and the equipment room is built by reinforced concrete frame structure, the construction cycle is long, the investment is high, and the land occupation area is large. Chinese patent application CN110448940A discloses a sludge water treatment system and method of water purification plant. Although most of the civil pool bodies are changed into steel pool bodies, compared with the traditional process, the land occupation area is saved, and the construction cycle is shortened, but in the treatment process, the dewatering liquid of the dewatering system is discharged, which causes waste of water resources and does not realize the economic value of reuse. In the concentration stage, a dosing mechanism is arranged, the supernatant (containing medicament) produced by concentration returns to the water inlet of the water purification plant, which has reuse safety hidden danger. The above prior art all adds PAM in the concentration process. Since the PAM monomer has biological toxicity effect (the standard of some areas stipulates that the front end treatment of reused supernatant is prohibited to add organic coagulant aid such as PAM), the concentration supernatant and the dewatering liquid of the dewatering machine are difficult to reuse, direct discharge will cause waste of water resources, and it is difficult to realize the economic value of reuse.

[0004] Chinese patent application CN118598393A discloses a system and method for safe reuse of sludge water in a water supply plant, which sets an ultrafiltration membrane system at the supernatant outlet of a concentration tank, sets a dewatering conditioning tank, an ultrafiltration membrane system and a biological activated carbon filter tank downstream of a sludge dewatering workshop, etc., although the supernatant of the concentration tank and the sludge dewatering liquid are treated and reused respectively, the overall process is long, the treatment units are more, the construction period is long, the maintenance is more complex, the investment is higher, the dosing points of the air flotation and sludge dewatering units are more, the activated carbon filter material of the biological carbon filter tank should be replaced regularly and properly disposed, resulting in high operation cost. Chinese patent application CN105396335A discloses a sludge water treatment process for small and medium-sized water purification plants, although the process has fewer component units, the supernatant of the concentration tank is only discharged up to the standard, not reused, thus causing waste of water resources. Practical new type content

[0005] (I) Technical problem to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present utility model provides a short-process sludge water treatment system for a water supply plant, which solves the technical problems of long process, long construction period, high investment cost, large land occupation, high operation cost, influence of medicament in reused water on safety, and waste of water resources caused by partial technical sludge dewatering and external discharge, etc.

[0007] (II) Technical scheme

[0008] In order to achieve the above-mentioned purpose, the main technical scheme adopted by the present utility model comprises:

[0009] The present utility model provides a short-process sludge water treatment system for a water supply plant, which comprises a drainage tank, a sludge tank, a membrane separation system, a balancing tank and a sludge dewatering and temporary storage system connected in sequence; the drainage tank is used for collecting and adjusting the backwash water of the filter tank of the water supply plant; the sludge tank is used for collecting the sludge of the sedimentation tank and the drainage of the drainage tank of the water supply plant and homogenously adjusting; the membrane separation system concentrates the sludge water discharged from the sludge tank and produces concentrated liquid and reusable produced water; the balancing tank is used for collecting the concentrated liquid from the membrane separation system and homogenously treating the concentrated liquid; the sludge dewatering and temporary storage system is used for separating the sludge water from the concentrated liquid from the balancing tank to obtain separated water and sludge cake; the separated water is recycled to the sludge tank to homogenously adjust the sludge water of the sludge tank so as to enter the membrane separation system for treatment and reuse;

[0010] The sludge pool is connected with a membrane separation system, and concentrated liquid and water production are obtained after treatment of the membrane separation system; the water production is connected with a cleaning device of the membrane separation system and a clean water pool or a water distribution well of a water supply plant, and the concentrated liquid is transported to a balance tank; the concentrated liquid in the balance tank is treated in a sludge dewatering and temporary storage system to produce separated water and sludge cake, the sludge cake is temporarily stored in a sludge cake storage bin, and the separated water is returned to the sludge pool through a connecting pipeline.

[0011] According to the preferable embodiment of the present application, the flushing water of the membrane separation system is connected with the sludge pool through a water pipe; the sludge pool is connected with a drainage pool, so that the filter backwash water collected in the drainage pool is transported to the sludge pool, and a stirring device is arranged in the drainage pool. The stirring device homogenizes the water in the drainage pool.

[0012] According to the preferable embodiment of the present application, the drainage pool is arranged as two independent pool bodies, and the two pool bodies are operated in parallel, the effective water depth is 2-4 m, and the two pool bodies are respectively provided with an immersed stirring device, an ultrasonic liquid level meter and a submersible pump; the ultrasonic liquid level meter and the submersible pump are automatically controlled and linked, and the start and stop of the submersible pump are controlled according to the high / low liquid level in the pool body; and the submersible pump transports the water in the drainage pool to the sludge pool.

[0013] According to the preferable embodiment of the present application, the sludge pool is arranged as two independent pool bodies, and the two pool bodies are operated in parallel, the effective water depth is 2-4 m, and the two pool bodies are respectively provided with an immersed stirring device, an ultrasonic liquid level meter and a submersible pump; the ultrasonic liquid level meter and the submersible pump in the sludge pool are automatically controlled and linked, and the start and stop of the submersible pump are controlled according to the high / low liquid level in the sludge pool; and the submersible pump transports the sludge water in the sludge pool to the membrane separation system. The two pool bodies can improve the continuity of system operation, and when one of the pool bodies needs to be cleaned or maintained, the other pool body can operate normally.

[0014] According to the preferable embodiment of the present application, the effective depth of the balance tank is 2-4 m, and the balance tank comprises an immersed stirring device, an ultrasonic liquid level meter, an online concentration meter and a submersible pump; the ultrasonic liquid level meter and the submersible pump in the balance tank are automatically controlled and linked, and the start and stop of the submersible pump are controlled according to the high / low liquid level in the balance tank; and the submersible pump transports the concentrated liquid in the balance tank to the sludge dewatering and temporary storage system.

[0015] According to the preferable embodiment of the present application, the membrane separation system is an integrated device, and the integrated device integrates a water production pump, a circulating pump, a membrane assembly, a membrane pool, a cleaning device and instruments and meters; the membrane assembly is an ultrafiltration membrane, and the pore diameter of the ultrafiltration membrane is 0.01-0.08 μm. Preferably, the membrane material of the membrane assembly is one of PVDF organic membrane, PTFE organic membrane and ceramic organic membrane.

[0016] According to a preferred embodiment of the present invention, the sludge dewatering and temporary storage system comprises a conditioning tank, an automated PAC dosing device, a dewatering device, and a storage device; the conditioning tank receives concentrated liquid transported from the balancing tank, and the automated PAC dosing device adds conditioning agent PAC to the conditioning tank; the dewatering device performs pressure filtration dewatering on the concentrated liquid after adding conditioning agent PAC, the separated water after dewatering enters the sludge discharge tank, and the dewatered sludge cake is temporarily stored in the storage device; the dewatering device is a plate and frame filter press.

[0017] According to a preferred embodiment of the present invention, the preparation tank includes an immersion stirring device and an ultrasonic level gauge; the preparation tank is modularly manufactured according to the size of the site and is made of stainless steel.

[0018] The dewatering device is an integrated unit consisting of a mud inlet pump, a pressure pump, a plate and frame filter press, a cleaning device, and instruments.

[0019] The storage device is a square silo made of carbon steel. Below the square silo is a mud-receiving space for trucks to park. The mud cake can be disposed of by landfill or utilized as needed.

[0020] According to a preferred embodiment of the present invention, the sludge discharge tank, drainage tank, and balancing tank are prefabricated components made of stainless steel, and the dimensions of the sludge discharge tank, drainage tank, and balancing tank are designed and prefabricated according to the size of the site to be constructed; the membrane separation system and the sludge dewatering and temporary storage system are located in the equipment workshop and are constructed using steel structures.

[0021] The treatment process for sludge discharge from a water treatment plant using the above system includes:

[0022] S1. After homogenization, the water in the drainage tank is transported to the sludge discharge tank. After homogenization and adjustment, the sludge and water in the sludge discharge tank are transported to the membrane separation system for membrane separation. Membrane separation yields permeate and concentrate. The permeate is reused in the water plant. Part of the permeate is used to flush the membrane separation system, and the flushing water is returned to the sludge discharge tank.

[0023] S2. The concentrate produced by membrane separation is homogenized and conditioned in a balancing tank, and then transported to the sludge dewatering and temporary storage system. Conditioning agent PAC is added to the sludge dewatering and temporary storage system. The concentrate is treated by the sludge dewatering and temporary storage system to produce separated water and sludge cake. The separated water is circulated to the sludge discharge tank and is finally treated by the membrane separation system to obtain permeate water for reuse. The dewatered sludge cake is temporarily stored and then transported for disposal.

[0024] Preferably, the concentrate produced by the membrane separation system has a solids content of 3% or more; the dewatering device in the sludge dewatering and temporary storage system is a plate and frame filter press with a pressing pressure greater than 2.5 MPa, and the solids content of the filter cake after pressing is greater than 30%. The separated water produced by pressing is reused in the sludge discharge tank to homogenize and adjust the sludge discharge water in the sludge discharge tank.

[0025] Preferably, the balancing tank is further equipped with an online concentration meter for monitoring the solids content in the concentrate; the sludge dewatering and temporary storage system consists of a conditioning tank, an automated PAC dosing device, a dewatering device, and a storage device; an online electromagnetic flow meter is installed between the balancing tank and the conditioning tank; the automated PAC dosing device includes a PAC storage tank (preferably made of PE), a PAC metering pump, and a control system; an ultrasonic level gauge is installed in the PAC storage tank; the control system is a PLC control system; the online electromagnetic flow meter and the online concentration meter are signal-connected to the PLC control system, and the PLC control system is signal-connected to the PAC metering pump. Thus, the PLC control system calculates the required amount of PAC based on the amount of concentrate entering the conditioning tank detected by the online electromagnetic flow meter and the online concentration meter, and the solids content of the concentrate in the balancing tank, and accordingly controls the operating parameters of the PAC metering pump to automatically and quantitatively add PAC.

[0026] According to a preferred embodiment of the present invention, the PAC dosing metering pump is a variable frequency mechanical diaphragm pump, and is equipped with a safety valve, a back pressure valve and a pulse damper.

[0027] Preferably, the membrane separation system is flushed once a week, or when the permeate flow rate is detected to be less than 10%-15% of the design value; the flushing water source is the permeate of the membrane separation system, and the flushing water volume does not exceed 1 / 20 of the permeate of the membrane separation system (the flushing water volume for weekly flushing does not exceed 1 / 20 of the permeate of that week); the flushing water of the membrane separation system is discharged into the sludge discharge tank, where it is homogenized and then separated by the membrane separation system.

[0028] (III) Beneficial Effects

[0029] The beneficial effects of this utility model are:

[0030] This invention provides a short-process sludge treatment system for water treatment plants, cleverly utilizing membrane separation technology and placing it at an appropriate stage. On one hand, it replaces the thickening tank in traditional processes, achieving a concentration effect; on the other hand, it eliminates the need for any external chemicals, making the reclaimed water safer. This invention integrates the separation of chemical-free reclaimed water and concentrate into a single membrane separation system, completing the process simultaneously. Furthermore, the treatment process does not require the addition of flocculant PAM, further enhancing the safety of the reclaimed water. The membrane separation system effectively removes suspended solids (SS) from the water, achieving a removal rate of up to 99%, meeting the reuse standards of water treatment plants and allowing for direct reuse.

[0031] The sludge dewatering and temporary storage system of this invention only adds PAC conditioner permitted for use in water treatment plants. Considering that the SS concentration in the separated water in the sludge dewatering and temporary storage system is high and cannot be directly reused, the separated water will flow back to the sludge discharge tank and will eventually pass through the membrane separation system for safe reuse of the separated water. Water resources circulate within the system, achieving zero wastewater discharge and reducing water waste.

[0032] This invention features a highly integrated and automated membrane separation system and sludge dewatering and temporary storage system, saving floor space. The prefabricated design and construction of the tanks further reduces construction time and costs. Compared to existing technologies, this process is simpler, does not use flocculant polyacrylamide (PAM), and the permeate from the membrane separation system can be directly reused in water treatment plants. The entire system avoids external wastewater discharge. The high degree of integration between the membrane separation system and sludge dewatering and temporary storage system saves floor space, and the prefabricated design and construction of the tanks further reduces construction time and costs.

[0033] In summary, the system of this utility model has the advantages of simple process route, short process, ability to produce safe reclaimed water without PAM, zero water discharge, low construction cost, convenient operation and maintenance, and no waste of water resources. Attached Figure Description

[0034] Figure 1 Flow chart of sludge treatment process in a water supply plant;

[0035] Figure 2 Diagram of a membrane separation system;

[0036] [Explanation of Labels in the Attached Image]

[0037] 1: Product water pump; 2: Circulation pump; 3: Vacuum pump; 4: Membrane module; 5: Membrane tank; 6: Cleaning device; 61: Cleaning pump; 62: Cleaning tank; Detailed Implementation

[0038] To better explain and facilitate understanding of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] This invention proposes a short-process sludge treatment system for water treatment plants, comprising a drainage tank, a sludge discharge tank, a membrane separation system, a balancing tank, and a sludge dewatering and temporary storage system. Compared to existing technologies, this invention features a simpler process route and easier operation and maintenance. The membrane separation system replaces the thickening tank in traditional processes, integrating the separation of chemical-free reclaimed water and concentrate into a single system. Furthermore, no chemicals are required during membrane separation, making the reclaimed water safer to use. Although the system is simple in composition, it achieves zero water discharge by eliminating external drainage resources. The membrane separation system and sludge dewatering and temporary storage system are highly integrated, saving floor space. The prefabricated design and construction of the tanks reduce construction time and costs. Compared to existing systems with long process flows, numerous treatment units, long construction periods, high construction costs, and high operation and maintenance costs, this invention offers significant advantages.

[0040] Furthermore, this invention also collects data such as the solids content and flow rate of the concentrate entering the sludge dewatering and temporary storage system in real time through the control system, and automatically calculates the dosage of the dewatering conditioner PAC. This avoids problems such as high residue in the separated water and waste of PAC due to excessive dosage, and also avoids problems such as low sludge production efficiency due to insufficient dosage. It realizes the automated control of reagent dosing, saves reagent costs, and ensures the treatment effect of sludge discharge water from the water supply plant.

[0041] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0042] Example 1

[0043] This embodiment provides a short-process sludge treatment system for a water supply plant, such as... Figure 1As shown, it comprises a drainage tank, a sludge discharge tank, a membrane separation system, a balancing tank, and a sludge dewatering and temporary storage system connected in sequence; the drainage tank is used to collect and regulate the backwash water from the filter beds of the water supply plant; the sludge discharge tank is used to collect sludge from the sedimentation tank of the water supply plant and the drainage water from the drainage tank, and to homogenize and regulate it; the membrane separation system concentrates the sludge-water discharged from the sludge discharge tank to produce concentrated liquid and reusable permeate, which is reused in the water supply plant; the balancing tank is used to collect the concentrated liquid from the membrane separation system and to homogenize it; the sludge dewatering and temporary storage system is used to separate the sludge from the concentrated liquid from the balancing tank to obtain separated water and sludge cake; the separation... Water circulation is used to homogenize and regulate the sludge discharge water in the sludge discharge tank; the sludge water in the sludge discharge tank is transported into the membrane separation system, where it is treated to obtain concentrate and permeate. The permeate is connected to the cleaning device of the membrane separation system and the clear water tank or distribution well of the water supply plant; the concentrate is transported to the balancing tank; the homogenized concentrate in the balancing tank enters the sludge dewatering and temporary storage system for treatment, producing separated water and sludge cake. The sludge cake is temporarily stored in a sludge cake storage tank, and the separated water is returned to the sludge discharge tank through a connecting pipe; the permeate is connected to the cleaning device of the membrane separation system for rinsing the membrane separation system, and the rinsing water of the membrane separation system is connected to the sludge discharge tank through a water pipe.

[0044] In addition, the drainage pond and sludge discharge pond are existing structures in the water supply plant. The drainage pond connects to the sludge discharge pond, allowing the backwash water collected in the drainage pond to be transported there. The drainage pond is equipped with a stirring device to maintain the homogenization of the muddy water. Preferably, the drainage pond can be configured as two independent compartments, operating in parallel, with an effective water depth of 2-4 meters. Each compartment is equipped with a submersible stirring device, an ultrasonic level gauge, and a submersible pump. The ultrasonic level gauge and submersible pump are automatically interlocked, controlling the start and stop of the submersible pump based on the high / low water level in the compartment. The submersible pump transports water from the drainage pond to the sludge discharge pond.

[0045] Furthermore, the sludge discharge tank is configured as two independent compartments operating in parallel, with an effective water depth of 2-4m. Each compartment is equipped with a submersible agitator, an ultrasonic level gauge, and a submersible pump. The ultrasonic level gauge and submersible pump in the sludge discharge tank are automatically interlocked, controlling the pump's start and stop based on the sludge level. The submersible pump transports the sludge-discharged water from the sludge discharge tank to the membrane separation system. The submersible agitator ensures uniform mixing of materials within the tank. The balancing tank also has a similar structure, with an effective depth of 2-4m, and includes a submersible agitator, an ultrasonic level gauge, an online concentration meter, and a submersible pump. The ultrasonic level gauge and submersible pump in the balancing tank are automatically interlocked, controlling the pump's start and stop based on the sludge level. The submersible pump transports the concentrated liquid from the balancing tank to the sludge dewatering and temporary storage system. The submersible agitator maintains homogenization of the concentrated liquid in the balancing tank.

[0046] The sludge discharge tank, drainage tank, and balancing tank are prefabricated components made of stainless steel, and their dimensions are designed and prefabricated according to the size of the site to be constructed. The membrane separation system and sludge dewatering and temporary storage system are located in the equipment workshop and can be constructed using steel structures.

[0047] like Figure 2 As shown, in this embodiment, the membrane separation system is an integrated device. (See attached image) Figure 2 The system integrates a permeate pump 1, a circulation pump 2, a vacuum pump 3, a membrane module 4, a membrane tank 5, a cleaning device 6, and instruments. The cleaning device includes a cleaning pump 61 and a cleaning tank 62. The instruments include a flow meter, a pressure gauge, and a liquid filter meter. The membrane separation system uses an ultrafiltration membrane, made of PVDF organic membrane, PTFE organic membrane, or ceramic organic membrane. The pore size of the ultrafiltration membrane is ≤0.08μm. The vacuum pump 3 maintains a negative pressure in the permeate pipeline during the initial permeate production phase. Once the system is running stably, the permeate pump 1 maintains the negative pressure, and the vacuum pump 3 stops operating. The cleaning device 6 is used to flush the membrane module 4. The cleaning tank 62 stores the permeate from the membrane separation system and is used to flush the membrane module 4 to maintain its normal operation. Preferably, two or more membrane separation systems or membrane modules can be installed, allowing them to operate alternately, improving the continuity of sludge treatment and eliminating the need for frequent shutdowns of other equipment. The cleaning pump 61 delivers water from the cleaning tank 62 into the membrane tank 5 to rinse the membrane module 4. The circulation pump 2 circulates the initially generated concentrate for membrane separation and concentration. The membrane module 4 is a submerged membrane module, located within the membrane tank 5. The membrane flushing water is returned to the sludge discharge tank via pipelines to homogenize and regulate the sludge-water mixture in the sludge discharge tank.

[0048] The process for treating sludge discharge water from the water supply plant using the above system is as follows:

[0049] (1) The backwash water of the filter in the water supply plant enters the drainage pool through the pipeline. After being regulated by the drainage pool, the backwash water of the drainage pool is pumped to the sludge discharge pool.

[0050] (2) Sludge from the sedimentation tank of the water supply plant enters the sludge discharge tank through pipelines, physical flushing water from the membrane separation system enters the sludge discharge tank through pipelines, separation water from the sludge dewatering and temporary storage system enters the sludge discharge tank through pipelines, and backwash water from the drainage tank enters the sludge discharge tank through pipelines. After the above sludge-water mixture is homogenized and adjusted in the sludge discharge tank, it is pumped to the membrane separation system.

[0051] The sludge discharge tank has two independent compartments with an effective water depth of 2-4m; the sludge discharge tank includes a submersible stirring device, an ultrasonic level gauge and a submersible pump.

[0052] The submersible stirring device mixes the materials in the mixing tank; the ultrasonic level gauge monitors the liquid level in the sludge discharge tank; the submersible pump transports the mud-water mixture in the tank to the membrane separation system; the ultrasonic level gauge and the submersible pump are automatically interlocked, and the submersible pump is automatically turned on or off according to the liquid level in the tank.

[0053] (3) The membrane separation system plays a role in concentrating and separating the mud and water discharged from the sludge discharge tank. The separated water, i.e. the product water quality is good and meets the standards for reuse in the water supply plant. It is pumped to the water supply plant for reuse. The separated mud, i.e. the concentrated liquid has a high solids content, is pumped to the balance tank.

[0054] The membrane separation system is periodically flushed with water, and the flushing water is discharged into the sludge discharge tank. After being homogenized and adjusted with other materials in the sludge discharge tank, the water is then separated and reused by the membrane separation system. The flushing water is derived from the separated water, and the total amount of flushing water does not exceed 1 / 20 of the total water production.

[0055] The produced water is membrane-separated water with good quality and an SS removal rate of up to 99%, meeting the standards for reuse in water treatment plants; the concentrate is membrane-separated sludge with a high solids content, reaching over 3%.

[0056] (4) The homogenized concentrate from the balancing tank is pumped to the sludge dewatering system according to the operation of the dewatering machine.

[0057] The effective water depth of the balancing tank is 2-4m; the balancing tank includes a submersible stirring device, an ultrasonic level gauge, an online concentration meter, and a submersible pump.

[0058] The submersible stirring device mixes the materials in the mixing tank; the ultrasonic level gauge monitors the liquid level in the equilibration tank; the online concentration meter monitors the solids content of the liquid in the equilibration tank; and the submersible pump transports the concentrated liquid in the tank to the sludge dewatering and temporary storage system.

[0059] (5) The dewatering system receives the concentrate and dewaters it by pressure filtration. The dewatered sludge cake is temporarily stored and then transported for disposal. Considering that the SS of the dewatered water is high, it cannot be directly reused. It enters the sludge discharge tank through the pipeline. After being homogenized and adjusted with other materials in the sludge discharge tank, it is separated into water for reuse through the membrane separation system.

[0060] The sludge dewatering and temporary storage system includes a conditioning tank, an automated PAC dosing device, a dewatering device, and a storage device. The conditioning tank receives the concentrated liquid transported from the balancing tank. The automated PAC dosing device adds the conditioning agent PAC to the conditioning tank. After uniform mixing, the dewatering device performs pressure filtration dewatering. The separated water after dewatering enters the sludge discharge tank through a pipeline. The dewatered sludge cake is temporarily stored in the storage device.

[0061] The conditioning tank receives the concentrate from the balancing tank, and an online electromagnetic flow meter is installed on the delivery pipeline; the online electromagnetic flow meter monitors the amount of concentrate entering the conditioning tank; the conditioning tank includes a submerged stirring device and an ultrasonic level gauge; the submerged stirring device mixes the materials in the tank; the ultrasonic level gauge monitors the liquid level in the tank; the conditioning tank is modularly and prefabricated according to the site size, and the construction material is stainless steel.

[0062] In a preferred embodiment of this utility model, the PAC automated dosing device includes a PAC storage tank, a PAC dosing metering pump, and a control system. The PAC storage tank is equipped with an ultrasonic level gauge to monitor the liquid level within the tank. The PAC storage tank is made of PE. The PAC dosing metering pump is a variable frequency mechanical diaphragm pump, equipped with a safety valve, a back pressure valve, and a pulse damper. The control system is a PLC control system, using the solids content of the liquid in the balance tank monitored by an online concentration meter and the amount of concentrate entering the conditioning tank monitored by an online electromagnetic flow meter as input parameters. The amount of PAC to be added is calculated through simulation. The PAC is automatically added by the variable frequency metering pump. By calculating the addition amount, the concentration of residual PAC in the separated water can be lowered while ensuring the dehydration effect, preventing rapid fouling of the membrane separation system, and improving the quality of the membrane separation permeate.

[0063] The dewatering device is an integrated unit comprising a sludge pump, a pressurizing pump, a plate and frame filter press, a cleaning device, and instruments. The instruments include a flow meter, a pressure gauge, and a liquid filter meter. The plate and frame filter press performs dewatering to meet the required standards. The pressing pressure of the plate and frame filter press is greater than 2.5 MPa, and the solids content of the filtered cake is greater than 30%. The filtered cake is conveyed to the storage system for storage. The separated water generated during the filtration process has a high suspended solids (SS) content and cannot be directly reused. It enters the sludge discharge tank through a pipeline, where it is homogenized and adjusted with other materials before being separated and reused by the membrane separation system.

[0064] The storage device is a square silo made of carbon steel; the square silo has a mud-receiving space below it for trucks to park; the mud cake is disposed of by landfill or utilized as appropriate.

[0065] The drainage tank, the sludge discharge tank, and the balancing tank are designed and constructed in a modular, prefabricated manner according to the site size, and the construction material is stainless steel; the membrane separation system and the sludge dewatering and storage system are located in the equipment workshop and are designed and constructed using steel structures.

[0066] In summary, compared with the prior art, the main features of this utility model are: simple process route, fewer treatment units, shorter process, high safety of recycled water, high degree of automation, zero water discharge, low amount of reagent input, and lower construction and maintenance costs.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A short-process sludge treatment system for a water supply plant, characterized in that, The system comprises a drainage tank, a sludge discharge tank, a membrane separation system, a balancing tank, and a sludge dewatering and temporary storage system connected in sequence. The drainage tank is used to collect and regulate the backwash water from the filter beds of the water supply plant. The sludge discharge tank is used to collect and homogenize the sludge discharged from the sedimentation tank and the drainage water from the drainage tank. The membrane separation system concentrates the sludge-water discharged from the sludge discharge tank to produce concentrated liquid and reusable permeate. The balancing tank is used to collect the concentrated liquid from the membrane separation system and homogenize it. The sludge dewatering and temporary storage system separates the sludge from the concentrated liquid from the balancing tank to obtain separated water and sludge cake. The separated water is circulated to the sludge discharge tank to homogenize the sludge-water in the sludge discharge tank so that it can be treated and reused in the membrane separation system.

2. The short-process sludge treatment system for water supply plants according to claim 1, characterized in that, The flushing water of the membrane separation system is connected to the sludge discharge tank through a water pipe; the drainage tank is connected to the sludge discharge tank so that the filter backwash water collected in the drainage tank is transported to the sludge discharge tank, and the drainage tank is equipped with a stirring device.

3. The short-process sludge treatment system for water supply plants according to claim 2, characterized in that, The drainage pool is configured as two independent compartments that operate in parallel, with an effective water depth of 2-4m. Each compartment is equipped with a submersible stirring device, an ultrasonic level gauge, and a submersible pump. The ultrasonic level gauge and submersible pump are automatically interlocked, controlling the start and stop of the submersible pump according to the high / low water level in the pool. The submersible pump transports water from the drainage pool to the sludge discharge pool.

4. The short-process sludge treatment system for water supply plants according to claim 1, characterized in that, The sludge discharge tank is configured as two independent compartments that operate in parallel, with an effective water depth of 2-4m. Each compartment is equipped with a submersible stirring device, an ultrasonic level gauge, and a submersible pump. The ultrasonic level gauge and submersible pump in the sludge discharge tank are automatically interlocked, controlling the start and stop of the submersible pump according to the liquid level in the sludge discharge tank. The submersible pump transports the sludge discharge water from the sludge discharge tank to the membrane separation system. The effective depth of the balancing tank is 2-4m, and it includes a submersible stirring device, an ultrasonic level gauge, an online concentration meter, and a submersible pump; the ultrasonic level gauge and the submersible pump in the balancing tank are automatically interlocked, and the start and stop of the submersible pump are controlled according to the liquid level in the balancing tank; the submersible pump transports the concentrated liquid in the balancing tank to the sludge dewatering and temporary storage system.

5. The short-process sludge treatment system for water supply plants according to claim 1, characterized in that, The membrane separation system is an integrated device, which integrates a product water pump, a circulation pump, a membrane module, a membrane tank, a cleaning device, and instruments into one unit; the membrane module is an ultrafiltration membrane with a pore size of 0.01μm-0.08μm.

6. The short-process sludge treatment system for water supply plants according to claim 1, characterized in that, The sludge dewatering and temporary storage system consists of a conditioning tank, an automated PAC dosing device, a dewatering device, and a storage device. The conditioning tank receives the concentrate transported from the balancing tank, and the automated PAC dosing device adds the conditioner PAC to the conditioning tank. The dewatering device performs pressure filtration dewatering on the concentrate after adding the conditioner PAC, and the separated water after dewatering enters the sludge discharge tank. The dewatered sludge cake is temporarily stored in the storage device. The dewatering device is a plate and frame filter press.

7. The short-process sludge treatment system for water supply plants according to claim 6, characterized in that, The preparation tank includes an immersion stirring device and an ultrasonic level gauge; the preparation tank is modularly manufactured according to the size of the site and is made of stainless steel. The dewatering device is an integrated unit consisting of a mud inlet pump, a pressure pump, a plate and frame filter press, a cleaning device, and instruments. The storage device is a square silo made of carbon steel, and there is a mud-receiving space below the square silo for trucks to park.

8. The short-process sludge treatment system for water supply plants according to claim 1, characterized in that, The sludge discharge tank, drainage tank, and balancing tank are prefabricated components made of stainless steel, and their dimensions are designed and prefabricated according to the size of the site to be constructed. The membrane separation system and sludge dewatering and temporary storage system are located in the equipment workshop and are constructed using steel structures.

9. The short-process sludge treatment system for water supply plants according to claim 6, characterized in that, The balancing tank is also equipped with an online concentration meter to monitor the solids content in the concentrate; the sludge dewatering and temporary storage system consists of a conditioning tank, a PAC automatic dosing device, a dewatering device, and a storage device; an online electromagnetic flow meter is installed between the balancing tank and the conditioning tank; The PAC automated dosing device includes a PAC storage tank, a PAC dosing metering pump, and a control system; the PAC storage tank is equipped with an ultrasonic level gauge; the control system is a PLC control system; the online electromagnetic flow meter and the online concentration meter are connected to the PLC control system, and the PLC control system is connected to the PAC dosing metering pump.

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