Short-process water supply plant sludge water treatment system and process

Abstract

The invention relates to a short-process water supply plant sludge water treatment system and method. The short-process water supply plant 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 drain tank is used for collecting and adjusting filter backwashing water of a water supply plant; the sludge discharge tank is used for collecting discharged sludge of the sedimentation tank of the water supply plant and discharged water of the drainage tank and homogenizing and adjusting; the membrane separation system is used for concentrating muddy water discharged from the sludge discharge tank and generating a concentrated solution and recyclable produced water; the balance tank is used for collecting a concentrated solution from the membrane separation system and homogenizing the concentrated solution; the sludge dewatering and temporary storage system is used for carrying out mud-water separation on the concentrated solution from the balance tank to obtain separated water and a mud cake; and the separated water is circulated to the sludge discharge tank to homogenize and adjust the sludge water in the sludge discharge tank so as to enter the membrane separation system to be treated and recycled. The process route is simple, the flow is short, recycled water without PAM can be produced, zero discharge of water in the whole process is achieved, the investment and construction cost is low, and no water resource is wasted.

Description

Technical Field

[0001] The invention relates to the technical field of sludge water treatment, and in particular to a short-process sludge water treatment system and process for a water supply plant. Background Art

[0002] The conventional treatment process of water treatment plants is raw water-coagulation sedimentation or clarification-filtration-disinfection, and a large amount of sludge water will be generated during the treatment process. Sludge water mainly includes sludge water from sedimentation tanks or clarification tanks and filtered backwash water, which contains a large amount of suspended solids (SS) and a certain amount of organic pollutants, microorganisms and heavy metals. The total solid content is generally 0.1%-2%. If it is discharged directly into natural water bodies without treatment, it will cause pollution risks. At the same time, the SS content in sludge water far exceeds the relevant provisions of the national standard "Comprehensive Sewage Discharge Standard". Direct reuse will pose a higher water quality safety risk and may have an impact on water plant production. In order to ensure the water quality safety of sludge water reuse water, many large water plants have considered sludge water reuse measures during design, but most of them adopt direct recycling after adjustment and sedimentation.

[0003] In the prior art, water supply plants use the traditional process of "regulation-concentration-balance-dehydration" to treat the supernatant of sludge water to meet the standards and then discharge or reuse it. For example, Chinese patent application CN116514368A discloses a sludge treatment system and sludge treatment process for a water treatment plant, including a sludge water tank, a reuse water tank and a sludge concentration and dehydration workshop; although the sludge concentration and dehydration workshop is built above the sludge water tank and the reuse water tank, which saves floor space compared with the traditional process, the foundation of the sludge concentration and dehydration workshop uses the reinforced concrete box structure of the sludge water tank and the reuse water tank as the building foundation, and adopts a multi-layer structure above the ground and underground, which makes the civil construction difficult and has a long period. In addition, since the process tank body is constructed with a steel concrete structure and the equipment room is constructed with a reinforced concrete frame structure, the construction period is long, the investment is high, and the floor space is large. Chinese patent application CN110448940A discloses a water treatment plant sludge water treatment system and treatment method. Although most of the civil engineering tanks are changed to steel tanks, compared with the traditional process, the floor space is saved and the construction period is shortened, but the dehydrated liquid of the dehydration system in the treatment process is discharged, resulting in waste of water resources and the economic value brought by its reuse is not realized; and a dosing mechanism is set in the concentration stage, and the supernatant (including the agent) produced by the concentration is returned to the water inlet of the water treatment plant, which has a potential safety hazard for reuse. The above-mentioned prior art all adds PAM in the concentration process. Since the PAM monomer has a biological toxic effect (the standards in some areas stipulate that the front-end treatment of the reused supernatant prohibits the addition of organic coagulants, such as PAM, etc.), it is difficult to reuse the concentrated supernatant and the dehydrator dehydrated liquid. Direct discharge will cause waste of water resources and it is difficult to realize the economic value brought by its reuse.

[0004] Chinese patent application CN118598393A discloses a system and method for safe reuse of sludge water discharged from a water supply plant, wherein an ultrafiltration membrane system is arranged at the outlet of the supernatant of the concentration tank, and a dehydration regulating tank, an ultrafiltration membrane system and a biological activated carbon filter are arranged downstream of the sludge dehydration workshop. Although the supernatant of the concentration tank and the sludge dehydration liquid are treated and reused respectively, the overall process is lengthy, there are many processing units, a long construction period, complex repair and maintenance, and high investment. There are many dosing points for units such as flotation and sludge dehydration, and the activated carbon filter material of the biological carbon filter should be replaced regularly and properly disposed of, resulting in high operating costs. Chinese patent application CN105396335A discloses a process for treating sludge water discharged from a small and medium-sized water purification plant. Although the process has few components, the supernatant of the concentration tank is only discharged in compliance with the standards and is not reused, thus causing a waste of water resources. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a short-process sludge water treatment system and process for a water supply plant, which solves the technical problems of the prior art sludge water treatment process for water supply plants being lengthy, long construction period, high investment cost, large footprint, high operating cost, chemicals in recycled water affecting safety, and waste of water resources caused by dehydration and discharge of some technical sludge.

[0007] (II) Technical solution

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] The present invention 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 dehydration and temporary storage system connected in sequence; the drainage tank is used to collect and adjust the filter tank backwash water of the water supply plant; the sludge tank is used to collect the sludge from the sedimentation tank of the water supply plant and the drainage from the drainage tank and homogenize and adjust; the membrane separation system concentrates the sludge water discharged from the sludge tank and produces a concentrated liquid and reusable produced water; the balancing tank is used to collect the concentrated liquid from the membrane separation system and homogenize the concentrated liquid; the sludge dehydration and temporary storage system is used to separate the concentrated liquid from the balancing tank from the sludge water to obtain separated water and a sludge cake; the separated water is circulated to the sludge tank to homogenize and adjust the sludge water in the sludge tank so as to enter the membrane separation system for treatment and reuse;

[0010] The muddy water in the sludge discharge tank enters the membrane separation system, and is processed by the membrane separation system to obtain concentrated liquid and produced water. The produced water is connected to the cleaning device of the membrane separation system and the clear water tank or water distribution well of the water supply plant, and the concentrated liquid is transported to the balancing tank; the concentrated liquid in the balancing tank that has been homogenized and adjusted enters the sludge dehydration and temporary storage system for treatment to produce separated water and mud cake. The mud cake is temporarily stored in the mud cake storage bin, and the separated water flows back to the sludge discharge tank through the connecting pipe.

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

[0012] According to a preferred embodiment of the present invention, the drainage tank is configured as two independent tank bodies, the two tank bodies operate in parallel, the effective water depth is 2-4m, and the two tank bodies are respectively provided with an immersion stirring device, an ultrasonic level meter and a submersible pump; the ultrasonic level meter and the submersible pump are automatically interlocked to control the start and stop of the submersible pump according to the high / low liquid level in the tank body; the submersible pump transports the water in the drainage tank to the mud discharge tank.

[0013] According to a preferred embodiment of the present invention, the mud discharge pool is configured as two independent pool bodies, the two pool bodies are operated in parallel, the effective water depth is 2-4m, and the two pool bodies are respectively provided with an immersion stirring device, an ultrasonic level gauge and a submersible pump; the ultrasonic level gauge and the submersible pump in the mud discharge pool are automatically interlocked to control the start and stop of the submersible pump according to the liquid level in the mud discharge pool; the submersible pump transports the mud discharge water in the mud discharge pool to the membrane separation system. The two pool bodies can improve the continuity of the 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 a preferred embodiment of the present invention, the effective depth of the balancing tank is 2-4m, and it includes an immersion stirring device, an ultrasonic level meter, an online concentration meter and a submersible pump; the ultrasonic level meter and the submersible pump in the balancing tank are automatically interlocked to control the start and stop of the submersible pump according to the liquid level in the balancing tank; the submersible pump transports the concentrated liquid in the balancing tank to the sludge dehydration and temporary storage system.

[0015] According to a preferred embodiment of the present invention, the membrane separation system is an integrated device, which is integrated with a water production pump, a circulation pump, a membrane assembly, a membrane tank, a cleaning device and instruments; the membrane assembly is an ultrafiltration membrane, and the pore size of the ultrafiltration membrane is 0.01μm-0.08μm. Preferably, the membrane material of the membrane assembly is a PVDF organic membrane, a PTFE organic membrane or a ceramic organic membrane.

[0016] According to a preferred embodiment of the present invention, the sludge dewatering and temporary storage system consists of a conditioning tank, a PAC automatic dosing device, a dewatering device and a storage device; the conditioning tank receives the concentrated liquid transported by the balancing tank, and the PAC automatic dosing device adds the conditioning agent PAC to the conditioning tank; the dewatering device performs filter pressing and dewatering on the concentrated liquid to which the conditioning agent PAC is added, and the separated water after dehydration enters the sludge discharge tank, and the dehydrated mud 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 conditioning tank includes an immersion stirring device and an ultrasonic level meter; the conditioning tank is modularly manufactured according to the size of the site and is made of stainless steel;

[0018] The dehydration device is an integrated device, which is composed of a mud feed 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. A mud receiving space is provided below the square silo for parking trucks. The mud cake can be landfilled or utilized as appropriate.

[0020] According to a preferred embodiment of the present invention, the sludge discharge tank, drainage tank and balancing tank are assembled components made of stainless steel, and the sizes 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 sludge dehydration and temporary storage system are located in the equipment workshop and are constructed of steel structures.

[0021] In a second aspect, the present invention provides a short-process method for treating sludge water discharged from a water supply plant, which uses the above-mentioned system to treat sludge water discharged from a water supply plant; the method comprises:

[0022] S1. After the water in the drainage pool is homogenized, it is transported to the sludge pool. After the sludge water in the sludge pool is homogenized, it is transported to the membrane separation system for membrane separation. The membrane separation obtains produced water and concentrated liquid, and the produced water is reused in the water supply plant; part of the produced water is used to flush the membrane separation system, and the flushing water returns to the sludge pool;

[0023] S2. The concentrated liquid produced by membrane separation is homogenized and adjusted in the balancing tank, and then transported to the sludge dewatering and temporary storage system. The conditioning agent PAC is added to the sludge dewatering and temporary storage system. The concentrated liquid is treated by the sludge dewatering and temporary storage system to produce separation water and mud cake; the separation water is circulated to the sludge discharge tank, and finally treated by the membrane separation system to obtain produced water and be reused; the dehydrated mud cake is temporarily stored and then transported for disposal.

[0024] According to a preferred embodiment of the present invention, the solid content of the concentrated liquid produced by the membrane separation system reaches 3-5%; the dehydration device in the sludge dehydration and temporary storage system is a plate and frame filter press, the pressing pressure of the plate and frame filter press is greater than 2.5MPa, the solid content of the mud cake after filtration is greater than 30%, and the separation water produced by filtration is recycled to the sludge discharge pool to homogenize the sludge water in the sludge discharge pool.

[0025] According to a preferred embodiment of the present invention, an online concentration meter for monitoring the solid content in the concentrate is also provided in the balancing tank; the sludge dehydration and temporary storage system is composed of a conditioning tank, a PAC automatic dosing device, a dehydration device and a storage device; an online electromagnetic flowmeter is provided between the balancing tank and the conditioning tank;

[0026] The PAC automatic dosing device includes a PAC storage tank (preferably made of PE), a PAC dosing metering pump and a control system; an ultrasonic level meter is arranged in the PAC storage tank; the control system is a PLC control system; the online electromagnetic flowmeter and the online concentration meter are connected to the PLC control system by signal, and the PLC control system is connected to the PAC dosing metering pump by signal; the PLC control system calculates the demand for the conditioning agent PAC based on the amount of concentrated liquid entering the conditioning tank detected by the online electromagnetic flowmeter and the online concentration meter and the solid content of the concentrated liquid in the balancing tank, and controls the working parameters of the PAC dosing metering pump accordingly to perform automatic quantitative dosing of PAC.

[0027] According to a preferred embodiment of the present invention, the PAC dosing metering pump adopts a variable frequency mechanical diaphragm pump and is equipped with a safety valve, a back pressure valve and a pulse damper.

[0028] According to a preferred embodiment of the present invention, the membrane separation system is flushed regularly once a week, or is flushed when it is detected that the water production flow rate is 10%-15% less than the design value; the flushing water source is the water produced by the membrane separation system, and the flushing water volume does not exceed 1 / 20 of the water production of the membrane separation system (the flushing water volume of weekly flushing does not exceed 1 / 20 of the water production of that week); the flushing water of the membrane separation system is discharged into the sludge discharge tank, is homogenized in the sludge discharge tank, and then separated by the membrane separation system.

[0029] (III) Beneficial effects

[0030] The beneficial effects of the present invention are:

[0031] The present invention provides a short-process water treatment system for sludge water discharged from a water plant, which cleverly uses membrane separation technology and sets membrane separation in an appropriate process. On the one hand, it replaces the concentration tank in the traditional process to achieve a concentration effect, and on the other hand, no external agent is required to be added, making the recycled water safer; the present invention integrates the separation of recycled water and concentrated liquid without chemicals into the membrane separation system for simultaneous completion, and no flocculant PAM is required to be added during the treatment process, making the recycled water safer. The membrane separation system effectively removes SS in the water, with a removal rate of up to 99%, which meets the reuse standards of the water plant and can be directly reused in the water plant.

[0032] Only PAC conditioning agents permitted for use by water plants are added to the sludge dewatering and temporary storage system of the present invention. Considering that the SS concentration in the separated water in the sludge dewatering and temporary storage system is relatively high and cannot be directly reused, the separated water will flow back to the sludge discharge pool and will eventually pass through the membrane separation system for separated water production for safe reuse. Water resources circulate within the system, achieving zero wastewater discharge and reducing water resource waste.

[0033] The membrane separation system and sludge dehydration and temporary storage system of the present invention are highly integrated and automated, saving floor space. Since the tank body is designed and constructed in an assembled manner, the construction period and construction cost can be saved. Compared with the prior art, the process route is simple, no flocculant polyacrylamide (PAM) is added in the treatment process, the water produced by the membrane separation system can be directly reused in the water plant, and there is no waste of external drainage resources in the entire process system. The membrane separation system and sludge dehydration and temporary storage system are highly integrated and save floor space. The tank body is designed and constructed in an assembled manner, saving construction period and construction cost.

[0034] In summary, the system of the present invention has the advantages of simple process route, short process, can produce safe recycled water without PAM, achieves zero water discharge, low investment and construction cost, convenient operation and maintenance, no waste of water resources, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the process flow chart of sludge water treatment in water supply plant;

[0036] Figure 2 This is a diagram of the membrane separation system device;

[0037] [Description of Reference Numerals]

[0038] 1: water production pump; 2: circulation pump; 3: vacuum pump; 4: membrane assembly; 5: membrane tank; 6: cleaning device; 61: cleaning pump; 62: cleaning tank; DETAILED DESCRIPTION

[0039] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0040] The present invention proposes a short-process water treatment system for a water supply plant, which is composed of a drainage tank, a sludge tank, a membrane separation system, a balancing tank, and a sludge dehydration and temporary storage system. Compared with the prior art, the process route of the present invention is simple, and the operation and maintenance are convenient. The membrane separation system in the treatment process replaces the concentration tank in the traditional process, and the separation of the recycled water and the concentrated liquid without the reagent is integrated into the membrane separation system. No reagent is required to be added during the membrane separation process, making the use of the recycled water safer. Although the system of the present invention is simple in composition, the entire process system has no external drainage resources, and realizes zero discharge of water resources. The membrane separation system and the sludge dehydration and temporary storage system equipment are highly integrated, saving floor space. The tank body adopts prefabricated design and construction, which can save construction period and construction cost. Compared with the systems with long process flow, numerous treatment units, long construction period, high construction cost, high operation and maintenance cost in the prior art, the scheme of the present invention has obvious advantages.

[0041] In addition, the present invention also collects data such as the solid content and flow rate of the concentrated liquid entering the sludge dehydration and temporary storage system in real time through the control system, and automatically calculates the dosage of the dehydration conditioning agent PAC, thereby avoiding problems such as high residue in the separated water and PAC waste due to excessive dosage, and also avoiding problems such as low sludge production efficiency due to insufficient dosage, thereby realizing automatic control of the dosage of the reagent, saving the reagent cost, and ensuring the treatment effect of the sludge water discharged from the water supply plant.

[0042] In order to better understand the above technical solution, 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 accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0043] Example 1

[0044] This embodiment provides a short-process water treatment system for a water supply plant. Figure 1As shown, it comprises a drainage tank, a sludge tank, a membrane separation system, a balancing tank and a sludge dehydration and temporary storage system connected in sequence; the drainage tank is used to collect and regulate the filter tank backwash water of the water supply plant; the sludge tank is used to collect the sludge from the sedimentation tank of the water supply plant and the drainage from the drainage tank and regulate them homogenously; the membrane separation system concentrates the muddy water discharged from the sludge tank and produces a concentrated liquid and reusable produced water, and the produced water is recycled to the water supply plant; the balancing tank is used to collect the concentrated liquid from the membrane separation system and homogenize the concentrated liquid; the sludge dehydration and temporary storage system is used to separate the mud and water from the concentrated liquid from the balancing tank to obtain separated water and mud cake; The water circulation is used to homogenize and adjust the sludge water in the sludge tank; the sludge water in the sludge tank is transported to the membrane separation system, and concentrated liquid and produced water are obtained after being processed by the membrane separation system. The produced water is connected to the cleaning device of the membrane separation system and the clear water tank or water distribution well of the water supply plant; the concentrated liquid is transported to the balancing tank; the concentrated liquid in the balancing tank that has been homogenized and adjusted enters the sludge dehydration and temporary storage system for treatment to produce separation water and mud cake, which is temporarily stored in the mud cake storage tank, and the separation water is returned to the sludge tank through the connecting pipe; the produced water is connected to the cleaning device of the membrane separation system for flushing the membrane separation system, and the flushing water of the membrane separation system is connected to the sludge tank through a water pipe.

[0045] In addition, the drainage pool and the mud discharge pool are the pools originally equipped in the water supply plant. The drainage pool is connected to the mud discharge pool so that the filter tank backwash water collected in the drainage pool is transported to the mud discharge pool. A stirring device is provided in the drainage pool to keep the muddy water in the drainage pool homogenized. Preferably, the drainage pool can be set up into two independent compartments, and the two compartments of the pool body are operated in parallel, with an effective water depth of 2-4m. The two compartments of the pool body are respectively provided with an immersion stirring device, an ultrasonic level meter and a submersible pump; the ultrasonic level meter and the submersible pump are automatically interlocked to control the start and stop of the submersible pump according to the high / low liquid level in the pool body; the submersible pump transports the water in the drainage pool to the mud discharge pool.

[0046] Furthermore, the sludge discharge pool is configured as two independent pool bodies, which are operated in parallel with an effective water depth of 2-4m. The two pool bodies are respectively provided with an immersion stirring device, an ultrasonic level gauge and a submersible pump; the ultrasonic level gauge and the submersible pump in the sludge discharge pool are automatically interlocked to control the start and stop of the submersible pump according to the liquid level in the sludge discharge pool; the submersible pump transports the sludge water in the sludge discharge pool to the membrane separation system. The immersion stirring device plays a role in mixing the materials in the pool evenly. Among them, the balancing pool also has a similar structure with an effective depth of 2-4m, and it includes an immersion 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 pool are automatically interlocked to control the start and stop of the submersible pump according to the liquid level in the balancing pool; the submersible pump transports the concentrated liquid in the balancing pool to the sludge dehydration and temporary storage system. The immersion stirring device is used to keep the concentrated liquid in the balancing pool homogenized.

[0047] Among them, the sludge tank, drainage tank and balancing tank are assembled components made of stainless steel, and the sizes of the sludge 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 sludge dehydration and temporary storage system are located in the equipment workshop and can be constructed with steel structure.

[0048] like Figure 2 As shown, the membrane separation system in this embodiment is an integrated device. Figure 2 , which is integrated with a water production pump 1, a circulation pump 2, a vacuum pump 3, a membrane assembly 4, a membrane pool 5, a cleaning device 6 and instruments; the cleaning device includes a cleaning pump 61 and a cleaning box 62; the instruments include a flow meter, a pressure gauge and a liquid filter; the membrane separation system uses an ultrafiltration membrane, which is made of a PVDF organic membrane, a PTFE organic membrane or a ceramic organic membrane; the pore size of the ultrafiltration membrane is ≤0.08μm. The vacuum pump 3 is used to maintain the negative pressure state of the water production pipeline in the early stage of water production of the membrane assembly. After the system runs stably, the water production pump 1 maintains the negative pressure state of the pipeline and stops the operation of the vacuum pump 3. The cleaning device 6 is used to flush the membrane assembly 4, and the cleaning box 62 stores the water produced by the membrane separation system, which is used to flush the membrane assembly 4 to maintain the normal operation of the membrane assembly 4. Preferably, two or more membrane separation systems or two or more membrane assemblies can be set up, so that the two or more membrane separation systems or two or more membrane assemblies can be operated alternately, so as to improve the continuity of mud water treatment and do not need to frequently shut down other equipment. The cleaning pump 61 delivers water from the cleaning tank 62 into the membrane pool 5 to rinse the membrane assembly 4. The circulation pump 2 can circulate the concentrated liquid produced initially for membrane separation and concentration. The membrane assembly 4 is an immersed membrane assembly, which is arranged in the membrane pool 5. The membrane flushing water is returned to the mud discharge pool through the pipeline to homogenize the mud water in the mud discharge pool.

[0049] The process of using the above system to treat the sludge water discharged from the water supply plant is as follows:

[0050] (1) The backwash water from the filter tank of the water supply plant enters the drainage tank through the pipeline. After being regulated in the drainage tank, the backwash water from the drainage tank is transported to the sludge tank by a pump.

[0051] (2) The sludge from the sedimentation tank of the water supply plant enters the sludge discharge tank through a pipeline, the physical flushing water of the membrane separation system enters the sludge discharge tank through a pipeline, and the separation water of the sludge dehydration and temporary storage system enters the sludge discharge tank through a pipeline; the backwash water from the drainage tank enters the sludge discharge tank through a pipeline. The above sludge-water mixture is homogenized and adjusted in the sludge discharge tank and then transported to the membrane separation system through a pump.

[0052] The mud discharge pool has two independent compartments with an effective water depth of 2-4m; the mud discharge pool includes an immersion stirring device, an ultrasonic level meter and a submersible pump;

[0053] The submerged stirring device mixes the materials in the pool; the ultrasonic level meter monitors the liquid level in the mud discharge pool; the submersible pump transports the mud-water mixture in the pool to the membrane separation system; the ultrasonic level meter and the submersible pump are automatically interlocked to automatically start or stop the submersible pump according to the liquid level in the pool.

[0054] (3) The membrane separation system concentrates and separates the mud and water discharged from the mud pool, and separates the mud and water. The separated water, i.e., the produced water, has good water quality and meets the reuse standards of 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 solid content and is pumped to the balancing tank.

[0055] The membrane separation system is regularly flushed with water, and the flushing water is discharged into the sludge pool. After being homogenized with other materials in the sludge pool, it is separated and reused by the membrane separation system; the flushing water comes from the separated produced water, and the total amount of flushing water does not exceed 1 / 20 of the total produced water.

[0056] The produced water is membrane separated water with good water quality and SS removal rate of up to 99%, which meets the reuse standard of water supply plants; the concentrated liquid is membrane separated mud with high solid content of more than 3%.

[0057] (4) The concentrated liquid is homogenized and adjusted in the balancing tank and transported to the sludge dewatering system through a pump according to the operation of the dewatering machine.

[0058] The effective water depth of the balancing tank is 2-4m; the balancing tank includes an immersion stirring device, an ultrasonic level meter, an online concentration meter and a submersible pump;

[0059] The submerged stirring device mixes the materials in the tank; the ultrasonic level meter monitors the liquid level in the balancing tank; the online concentration meter monitors the solid content of the liquid in the balancing tank; and the submersible pump transports the concentrated liquid in the tank to the sludge dehydration and temporary storage system.

[0060] (5) The dehydration system receives the concentrated liquid and performs pressure filtration to dehydrate it. The dehydrated mud cake is temporarily stored and then transported for disposal. The separated water after dehydration cannot be directly reused due to its high SS. It enters the mud discharge pool through a pipeline, and after being homogenized with other materials in the mud discharge pool, it is separated and reused by the membrane separation system.

[0061] The sludge dehydration and temporary storage system includes a conditioning tank, a PAC automatic dosing device, a dehydration device and a storage device; the conditioning tank receives the concentrated liquid transported by the balancing tank, the PAC automatic dosing device adds the conditioning agent PAC to the conditioning tank, and after uniform mixing, the dehydration device performs filter pressing and dehydration, and the dehydrated separated water enters the sludge discharge tank through a pipeline, and the dehydrated mud cake is temporarily stored in the storage device;

[0062] The conditioning tank receives the concentrated liquid transported by the balancing tank, and an online electromagnetic flowmeter is provided on the transport pipeline; the online electromagnetic flowmeter monitors the amount of concentrated liquid entering the conditioning tank; the conditioning tank includes an immersion stirring device and an ultrasonic level meter; the immersion stirring device mixes the materials in the tank; the ultrasonic level meter monitors the liquid level in the tank; the conditioning tank is modularly and prefabricatedly designed and constructed according to the size of the site, and the construction material is stainless steel.

[0063] In a preferred embodiment of the present invention, the PAC automatic dosing device includes a PAC drug storage tank, a PAC dosing metering pump and a control system; an ultrasonic level meter is provided in the PAC drug storage tank; the ultrasonic level meter monitors the liquid level in the tank; the PAC drug storage tank is made of PE; 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; the control system is a PLC control system, and the solid content of the balancing tank liquid monitored by the online concentration meter in the balancing tank and the amount of concentrated liquid entering the conditioning tank monitored by the online electromagnetic flowmeter are used as input parameters, and the amount of the conditioning agent PAC added is obtained through simulation calculation; the conditioning agent PAC is automatically added by the variable frequency metering pump. By calculating and adding, the concentration of residual PAC in the separated water can be lowered, while ensuring the dehydration effect, avoiding the membrane separation system from being quickly blocked by dirt, and improving the quality of the membrane separation water.

[0064] The dehydration device is an integrated device, which is integrated with a mud feed pump, a pressure 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 filter pressing and dehydration, which can meet the dehydration standard; the pressing pressure of the plate and frame filter press is greater than 2.5MPa, and the solid content of the mud cake after filter pressing is greater than 30%; the mud cake after filter pressing is conveyed by a conveyor to the storage system for storage, and the separated water generated during the filter pressing process has a high SS content and cannot be directly reused, and enters the mud discharge pool through a pipeline, and after being homogenized with other materials in the mud discharge pool, it is separated and produced water is reused through the membrane separation system;

[0065] The storage device is a square silo made of carbon steel; a mud receiving space for trucks to park is provided below the square silo; the mud cake can be landfilled or utilized as appropriate.

[0066] The drainage tank, the sludge tank and the balance tank are designed and constructed in a modular and assembled manner according to the size of the site, and the construction material is stainless steel; the membrane separation system and the sludge dehydration and storage system are located in the equipment workshop and are designed and constructed using steel structures.

[0067] In summary, compared with the prior art, the main features of the present invention are: simple process route, fewer processing units, short process, high safety of recycled water, high degree of automation, zero discharge of water resources, low chemical input, and low investment, construction and maintenance costs.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A short-process water treatment system for a water supply plant, characterized in that: It comprises a drainage tank, a sludge tank, a membrane separation system, a balancing tank and a sludge dehydration and temporary storage system connected in sequence; the drainage tank is used to collect and regulate the filter tank backwash water of the water supply plant; the sludge tank is used to collect the sludge from the sedimentation tank of the water supply plant and the drainage from the drainage tank and regulate them homogenously; the membrane separation system concentrates the muddy water discharged from the sludge tank and produces a concentrated liquid and reusable produced water; the balancing tank is used to collect the concentrated liquid from the membrane separation system and homogenize the concentrated liquid; the sludge dehydration and temporary storage system is used to separate the concentrated liquid from the balancing tank from mud and water to obtain separated water and mud cake; the separated water is circulated to the sludge tank to homogenize the muddy water in the sludge tank so that it can enter the membrane separation system for treatment and reuse; The muddy water in the sludge discharge tank enters the membrane separation system, and is processed by the membrane separation system to obtain concentrated liquid and produced water. The produced water is connected to the cleaning device of the membrane separation system and the clear water tank or water distribution well of the water supply plant, and the concentrated liquid is transported to the balancing tank; the concentrated liquid in the balancing tank that has been homogenized and adjusted enters the sludge dehydration and temporary storage system for treatment to produce separated water and mud cake, which is temporarily stored in the mud cake storage bin, and the separated water flows back to the sludge discharge tank through the connecting pipe; the flushing water of the membrane separation system is connected to the sludge discharge tank through a water pipe.

2. The short-process sludge water treatment system of a water supply plant according to claim 1 is characterized in that: The drainage tank is connected to the sludge discharge tank, so that the filter tank backwash water collected in the drainage tank is transported to the sludge discharge tank; the drainage tank is configured as two independent tank bodies, the two tank bodies operate in parallel, the effective water depth is 2-4m, and the two tank bodies are respectively provided with an immersion stirring device, an ultrasonic level meter and a submersible pump; the ultrasonic level meter and the submersible pump are automatically interlocked to control the start and stop of the submersible pump according to the high / low liquid level in the tank body; the submersible pump transports the water in the drainage tank to the sludge discharge tank.

3. The short-process sludge water treatment system of a water supply plant according to claim 1 is characterized in that: The mud discharge pool is configured as two independent pool bodies, which are operated in parallel, with an effective water depth of 2-4m. The two pool bodies are respectively provided with an immersion stirring device, an ultrasonic level gauge and a submersible pump; the ultrasonic level gauge and the submersible pump in the mud discharge pool are automatically interlocked to control the start and stop of the submersible pump according to the liquid level in the mud discharge pool; the submersible pump transports the mud discharge water in the mud discharge pool to the membrane separation system; The effective depth of the balancing tank is 2-4m, and it includes an immersion stirring device, an ultrasonic level meter, an online concentration meter and a submersible pump; the ultrasonic level meter and the submersible pump in the balancing tank are automatically interlocked to control the start and stop of the submersible pump according to the liquid level in the balancing tank; the submersible pump transports the concentrated liquid in the balancing tank to the sludge dehydration and temporary storage system.

4. The short-process sludge water treatment system of a water supply plant according to claim 1 is characterized in that: The membrane separation system is an integrated device, which is composed of a water production pump, a circulation pump, a membrane component, a membrane pool, a cleaning device and instruments and meters; the membrane component is an ultrafiltration membrane, and the pore size of the ultrafiltration membrane is 0.01μm-0.08μm.

5. The short-process sludge water treatment system of a water supply plant according to claim 1 is characterized in that: The sludge dehydration and temporary storage system is composed of a conditioning tank, a PAC automatic dosing device, a dehydration device and a storage device; the conditioning tank receives the concentrated liquid transported by the balancing tank, and the PAC automatic dosing device adds the conditioning agent PAC to the conditioning tank; the dehydration device performs filter pressing and dehydration on the concentrated liquid to which the conditioning agent PAC is added, and the separated water after dehydration enters the sludge discharge tank, and the dehydrated mud cake is temporarily stored in the storage device; The dehydration device is a plate and frame filter press.

6. The short-process water supply plant sludge water treatment system according to claim 5 is characterized in that: The conditioning tank includes an immersion stirring device and an ultrasonic level meter; the conditioning tank is modularly manufactured according to the size of the site and is made of stainless steel; The dehydration device is an integrated device, which is composed of a mud feed 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 a mud receiving space for parking trucks is provided below the square silo.

7. The short-process sludge water treatment system of a water supply plant according to claim 1 is characterized in that: The sludge discharge tank, drainage tank and balancing tank are assembled components made of stainless steel, and the sizes 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 sludge dehydration and temporary storage system are located in the equipment workshop and are constructed of steel structures.

8. A short-process method for treating sludge water discharged from a water supply plant, which uses the system according to any one of claims 1 to 7 to treat sludge water discharged from a water supply plant; the method comprises: S1. After the water in the drainage pool is homogenized, it is transported to the sludge pool. After the sludge water in the sludge pool is homogenized, it is transported to the membrane separation system for membrane separation. The membrane separation obtains produced water and concentrated liquid, and the produced water is reused in the water supply plant; S2. The concentrated liquid produced by membrane separation is homogenized and adjusted in the balancing tank, and then transported to the sludge dewatering and temporary storage system. The conditioning agent PAC is added to the sludge dewatering and temporary storage system. The concentrated liquid is treated by the sludge dewatering and temporary storage system to produce separation water and mud cake; the separation water is circulated to the sludge discharge tank, and finally treated by the membrane separation system to obtain produced water and be reused; the dehydrated mud cake is temporarily stored and then transported for disposal.

9. The short-process water treatment method for water supply plant sludge water according to claim 8, characterized in that: The solid content of the concentrated liquid produced by the membrane separation system is 3-5%; the dehydration device in the sludge dehydration and temporary storage system is a plate-frame filter press, the pressing pressure of the plate-frame filter press is greater than 2.5MPa, and the solid content of the mud cake after filtration is greater than 30%; The balancing tank is also provided with an online concentration meter for monitoring the solid content in the concentrate; the sludge dehydration and temporary storage system consists of a conditioning tank, a PAC automatic dosing device, a dehydration device and a storage device; an online electromagnetic flowmeter is provided between the balancing tank and the conditioning tank; The PAC automatic dosing device includes a PAC drug storage tank, a PAC dosing metering pump and a control system; an ultrasonic liquid level meter is arranged in the PAC drug storage tank; the control system is a PLC control system; the online electromagnetic flowmeter and the online concentration meter are connected to the PLC control system by signal, and the PLC control system is connected to the PAC dosing metering pump by signal; the PLC control system calculates the demand for the conditioning agent PAC according to the amount of concentrated liquid entering the conditioning tank detected by the online electromagnetic flowmeter and the online concentration meter and the solid content of the concentrated liquid in the balancing tank, and controls the working parameters of the PAC dosing metering pump accordingly to perform automatic quantitative dosing of PAC.

10. The short-process water treatment method for water supply plant according to claim 8, characterized in that: The membrane separation system is flushed regularly once a week, or when it is detected that the water production flow rate is 10%-15% less than the design value; the flushing water source comes from the water produced by the membrane separation system, and the flushing water volume does not exceed 1 / 20 of the water produced by the membrane separation system; the flushing water of the membrane separation system is discharged into the sludge discharge pool, homogenized in the sludge discharge pool, and then separated by the membrane separation system.

Images