Immersed ultrafiltration concentrated water treatment method and system

Abstract

The invention relates to the technical field of water treatment, and provides an immersed ultrafiltration concentrated water treatment method and system.The method comprises the steps that reclaimed water treated by a sewage plant is subjected to immersed ultrafiltration treatment, and concentrated water obtained after ultrafiltration is conveyed to a biochemical pool through an overflow tank to be subjected to aeration biochemical treatment; the ultrafiltration concentrated water subjected to ultrafiltration treatment overflows to the biochemical pool by adjusting the height of the flashboard; and the biochemical pool conveys the ultrafiltration concentrated water subjected to aeration biochemical treatment to an MBR membrane pool for solid-liquid separation, and if concentrated water is generated, the concentrated water is continuously conveyed to the biochemical pool for secondary treatment. According to the invention, the flashboard is additionally arranged in the overflow tank, so that the immersed ultrafiltration concentrated water directly enters the biochemical pool for biochemical treatment in an overflow manner without additionally arranging a drainage system, a water storage system and the like, and the operation energy consumption is reduced.

Description

Technical Field

[0001] The present application relates to the field of water treatment technology, and in particular to an immersion ultrafiltration concentrated water treatment method and system. Background Art

[0002] With the rapid development of urbanization, industrialization and economy in my country, the contradiction between water supply and demand and water pollution problems have become increasingly prominent. Relevant departments have successively issued relevant documents to clarify that water reuse is an important development direction for the industrial industry as a technically feasible and economically applicable comprehensive utilization technology of water resources. The "Action Plan for Water Pollution Prevention and Control" issued by my country clearly requires that power plants gradually increase the proportion of reclaimed water used. The "Guiding Opinions on Promoting the Resource Utilization of Wastewater" issued by the National Development and Reform Commission of the People's Republic of China and other departments clearly stated that if high-water-consuming industry projects have the conditions to use recycled water but have not effectively used it, new water withdrawal permits should be strictly controlled. The "Implementation Plan for the Recycling of Industrial Wastewater" clearly stated that by 2025, the reuse rate of industrial water above a certain scale should be strived to reach about 94%. Thermal power plants are large users of industrial water, and the use of reclaimed water as a water source has a positive effect on water conservation and wastewater treatment in thermal power plants.

[0003] At present, with the continuous improvement of ultrafiltration membrane performance and the continuous reduction of prices, ultrafiltration and other water treatment technologies have gradually been combined for urban water supply, industrial water, and power plant water treatment at home and abroad. Compared with other ultrafiltration systems, the submerged ultrafiltration system has low energy consumption and is easy to combine with traditional processes; in terms of system design, the ultrafiltration membrane of the submerged ultrafiltration system can be directly immersed in the water to be treated. Submerged ultrafiltration membrane components have been widely used in the field of wastewater treatment, especially in the treatment of high turbidity sewage, submerged ultrafiltration has received more and more attention. However, the submerged ultrafiltration system needs to discharge part of the concentrated water regularly during operation, so it is necessary to establish additional auxiliary systems such as concentrated water tanks to coagulate or directly discharge this part of the concentrated water, which increases the production cost of the enterprise and reduces the utilization rate of water resources.

[0004] In summary, there are at least the following technical problems in the prior art: during the operation of traditional immersion ultrafiltration, a portion of the brine must be discharged regularly through an emptying pump, and a separate brine storage tank needs to be established; the discharged brine is generally treated by coagulation and clarification and other technologies, and the equipment is bulky, occupies a large area, has many operating procedures, and is costly to treat; treating the brine by direct external discharge requires additional sewage fees, which also reduces the utilization of water resources. Summary of the invention

[0005] In response to the above problems, the present application provides an immersion ultrafiltration concentrated water treatment method and system to solve the technical problems raised in the background technology section of the present application.

[0006] To achieve the purpose of this application, this application provides the following technical solutions:

[0007] In a first aspect, the present application provides a submerged ultrafiltration concentrated water treatment method, the method comprising:

[0008] Submerged ultrafiltration is performed on the treated reclaimed water from the sewage treatment plant, and the ultrafiltration concentrate produced after the ultrafiltration treatment of the reclaimed water is transported to the aeration biochemical tank via an overflow tank for aeration biochemical treatment, wherein the overflow tank has a gate plate, and the ultrafiltration concentrate after the ultrafiltration treatment is overflowed to the aeration biochemical tank by adjusting the height of the gate plate;

[0009] The ultrafiltration concentrated water treated in the biochemical pool is transported to the MBR membrane pool, solid-liquid separation is performed on the ultrafiltration concentrated water through the MBR membrane pool, and the clean water obtained after the solid-liquid separation is input into the industrial water pool.

[0010] Furthermore, the submerged ultrafiltration treatment of the treated reclaimed water from the sewage treatment plant comprises:

[0011] The reclaimed water after treatment at the sewage treatment plant is pre-treated and then transported to the water storage biochemical pool, wherein the pre-treatment steps include filtering and heating;

[0012] The reclaimed water in the water storage biochemical pool is transported to an immersion ultrafiltration pool for immersion ultrafiltration treatment to obtain the ultrafiltration concentrated water.

[0013] Furthermore, the reclaimed water in the water storage biochemical pool is transported to the submerged ultrafiltration tank via a water distribution tank; wherein the water distribution tank includes a first baffle and a water inlet, the baffle is used to separate the ultrafiltration concentrated water from the reclaimed water, and the water inlet is connected to the submerged ultrafiltration tank.

[0014] Furthermore, the reclaimed water in the water storage biochemical pool is pumped into the water distribution tank by a submersible axial flow pump.

[0015] Furthermore, the overflow trough includes a second baffle and the gate plate, and the overflow trough is connected to the submerged ultrafiltration tank and the MBR membrane tank respectively; the second baffle is used to separate the ultrafiltration concentrate from the concentrate in the MBR membrane tank, and the gate plate is arranged on the outlet side of the ultrafiltration concentrate, and the height of the gate plate is adjustable.

[0016] Furthermore, the reclaimed water in the water storage biochemical pool is transported to an immersion ultrafiltration pool for immersion ultrafiltration treatment to obtain clean water and the ultrafiltration concentrated water. The clean water is transported to an industrial water pool, and the ultrafiltration concentrated water overflows to the overflow tank.

[0017] Furthermore, the solid-liquid separation of the ultrafiltration concentrated water by the MBR membrane pool also includes:

[0018] Obtaining clean water and concentrated water after solid-liquid separation;

[0019] The obtained clean water is transported to the industrial water pool, and the concentrated water is transported to the aerated biochemical pool for secondary treatment.

[0020] The second aspect of the present application provides an immersion ultrafiltration concentrated water treatment system, which is implemented based on the method described in the first aspect above, and includes:

[0021] Immersed ultrafiltration and treatment module, used for submersed ultrafiltration treatment of the treated water from the sewage plant;

[0022] A biochemical treatment module, used for conveying the ultrafiltration concentrated water generated after the ultrafiltration treatment of the reclaimed water to the aeration biochemical tank via an overflow tank for aeration biochemical treatment, wherein the overflow tank has a gate plate, and the ultrafiltration concentrated water after the ultrafiltration treatment is overflowed to the aeration biochemical tank by adjusting the height of the gate plate;

[0023] The output module is used to transport the ultrafiltration concentrated water after aeration and biochemical treatment to the MBR membrane pool, perform solid-liquid separation on the ultrafiltration concentrated water through the MBR membrane pool, and input the clean water obtained after solid-liquid separation into the industrial water pool.

[0024] The following technical effects are achieved by using an immersion ultrafiltration concentrated water treatment method provided in this application:

[0025] The immersed ultrafiltration concentrate treatment method does not require the construction of a separate drainage, water storage and treatment system; the immersed ultrafiltration concentrate flows into the aeration biochemical tank by overflowing through a gate, and does not require the use of a special pump to pump water, thereby reducing operating energy consumption; the immersed ultrafiltration concentrate is treated in an aeration biochemical tank to achieve the reuse of concentrate and improve water utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation on the present application.

[0027] Figure 1 A schematic diagram of an immersion ultrafiltration concentrated water treatment method provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of the water distribution tank structure provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of the overflow tank structure provided in an embodiment of the present application;

[0030] Reference numerals in the figure: 1, water distribution trough; 11, first baffle; 12, water inlet; 2, overflow trough; 21, second baffle; 22, gate. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of this application, unless otherwise specified, "plurality" means two or more.

[0033] The immersed ultrafiltration concentrate treatment method and system provided in this specific embodiment does not require the construction of a separate drainage, water storage and treatment system; the immersed ultrafiltration concentrate flows into the aeration biochemical tank by overflowing through the gate plate 22, and does not require the use of a special pump to pump water, thereby reducing operating energy consumption; the immersed ultrafiltration concentrate is treated in the aeration biochemical tank to achieve the reuse of the concentrate and improve water utilization.

[0034] according to Figure 1 As shown, the present application provides an immersion ultrafiltration concentrated water treatment method, which specifically includes:

[0035] Step S1, performing immersion ultrafiltration treatment on the treated reclaimed water of the sewage treatment plant, wherein the ultrafiltration concentrated water generated after the ultrafiltration treatment of the reclaimed water is transported to the aeration biochemical tank through the overflow tank 2 for aeration biochemical treatment, wherein the overflow tank 2 has a gate plate 22, and the height of the gate plate 22 is adjusted to allow the ultrafiltration concentrated water to overflow to the aeration biochemical tank;

[0036] Step S2, transporting the ultrafiltration concentrated water after treatment in the aeration biochemical pool to the MBR membrane pool, performing solid-liquid separation on the ultrafiltration concentrated water through the MBR membrane pool, and inputting the clean water obtained after the solid-liquid separation into the industrial water pool.

[0037] Specifically, according to Figure 1 As shown, in step S1, the treated grey water from the sewage treatment plant first enters the regulating water tank, and then is transported to the pretreatment room by the grey water lift pump, and then enters the 1# water storage biochemical tank after being filtered by the self-cleaning filter and heated by the raw water heater, wherein the 1# biochemical tank is the water storage biochemical tank, which is mainly used as a water storage tank; the 2# biochemical tank is an aerated biochemical tank.

[0038] Furthermore, the treated water in the sewage treatment plant is usually called recycled water or reused water, which refers to non-drinking water that has reached a certain water quality standard after being purified by the sewage treatment plant and can be reused within a certain range. The water quality of the water is between the upper water (tap water) and the lower water (sewage), so it is called "water". The water first enters the regulating pool. This step is mainly to balance the water quality and water quantity to reduce the impact load in the subsequent treatment process. The regulating pool can buffer the fluctuations in water quality and water quantity to ensure that the subsequent treatment units can operate stably. The water is transported from the regulating pool to the pretreatment room by the water lifting pump. The water is filtered by the self-cleaning filter in the pretreatment room to remove impurities such as suspended matter and particulate matter in the water. The self-cleaning filter can automatically remove impurities on the filter screen, maintain the filtration efficiency, and reduce manual maintenance; the filtered water is heated by the raw water heater. The purpose of heating is to increase the water temperature and provide suitable temperature conditions for subsequent biochemical reactions, because most microorganisms are more active at suitable temperatures and can decompose organic matter more effectively. The treated reclaimed water in the pretreatment room mainly enters the #1 water storage biochemical pool, is pumped to the water distribution tank 1 by the submersible axial flow pump, and then enters the #1 and #2 submerged ultrafiltration pools through the water inlet holes for submerged ultrafiltration treatment. Each submerged ultrafiltration pool is equipped with a suction pump. The clean water obtained after the submerged ultrafiltration pool treatment enters the industrial water pool for subsequent treatment, and the ultrafiltration concentrated water overflows to the overflow tank 2 and returns to the #2 biochemical pool for biochemical treatment.

[0039] Furthermore, in step S2, the #2 biochemical pool is an aerated biochemical pool, and the influent is mainly a small amount of reclaimed water, domestic sewage from the whole plant, and immersed ultrafiltration concentrated water. The ultrafiltration concentrated water after aeration and biochemical treatment is pumped to the water distribution tank 1 by a submersible axial flow pump, and then enters the #3 and #4 MBR membrane pools through the water inlet hole. The water in the MBR membrane pool is separated into solid and liquid by the matching suction pump, and the clean water is input into the industrial water pool, and the concentrated mud water overflows to the overflow tank 2 and returns to the 2# aerated biochemical pool for aeration and biochemical treatment again.

[0040] Specifically, the main function of the #2 biochemical pool is to aerate the incoming water (including a small amount of reclaimed water, domestic sewage from the entire plant, and concentrated water from submerged ultrafiltration) to further remove pollutants such as organic matter, nitrogen, and phosphorus, thereby improving water quality and meeting discharge standards or reuse requirements. The treatment steps of the aerated biochemical pool usually include the following stages: aeration mixing, aerobic biodegradation, nitrification, denitrification, phosphorus removal, mixing and circulation, sludge return, sludge treatment, effluent monitoring and adjustment, etc. The MBR (membrane bioreactor) membrane pool is a sewage treatment process that combines traditional activated sludge method and membrane separation technology. In the MBR system, the biochemically treated sewage is separated into solid and liquid through a membrane assembly to achieve separation of sludge and treated water. The membrane technology improves the solid-liquid separation efficiency of the sludge, while reducing the sludge output and improving the water quality.

[0041] Further, according to Figure 2 The water distribution tank 1 includes a first baffle 11 and a water inlet 12. The baffle is used to separate the ultrafiltration concentrate from the medium water. The water inlet 12 is connected to the submerged ultrafiltration tank. Preferably, the water distribution tank 1 is located higher than the submerged ultrafiltration tank and the MBR membrane tank. It is an integral water tank with four water inlet holes distributed at the bottom, corresponding to the #1 submerged ultrafiltration tank, the #2 submerged ultrafiltration tank, the #3MBR membrane tank, and the #4MBR membrane tank. By installing the first baffle 11 in the middle of the water distribution tank 1, the ultrafiltration concentrate and the medium water can be separated.

[0042] Further, according to Figure 3 , the overflow trough 2 includes a second baffle 21 and a gate 22, and the overflow trough 2 is connected to the submerged ultrafiltration tank and the MBR membrane tank respectively; the second baffle 21 is used to separate the ultrafiltration concentrate from the concentrate in the MBR membrane tank, and the gate 22 is arranged on the outlet side of the ultrafiltration concentrate, and the height of the gate 22 is adjustable. Preferably, the overflow trough 2 is located below the water distribution tank 1, connected to the submerged ultrafiltration tank and the MBR membrane tank cofferdam, and the ultrafiltration concentrate overflows to the overflow trough 2 during the operation of the system. In order to separate the submerged ultrafiltration concentrate from the MBR membrane tank concentrate, a second baffle 21 slightly lower than the cofferdam is installed in the middle of the overflow trough 2, and a gate 22 is installed at the end of the overflow trough 2 on the side where the submerged ultrafiltration concentrate flows in. By adjusting the height of the gate 22, the submerged ultrafiltration concentrate can turn over the middle gate 22 and overflow to the #2 aeration biochemical tank.

[0043] Optionally, the height adjustment methods of the gate plate 22 include drive device adjustment, manual adjustment, etc. When adjusting the height of the gate plate 22, remote operation can be achieved by leading the control model to the DCS system in the control room, thereby improving the convenience of operation and reducing human labor intensity.

[0044] Furthermore, the reclaimed water in the #1 water storage biochemical pool is transported to an immersed ultrafiltration pool for immersed ultrafiltration treatment to obtain clean water and ultrafiltration concentrate, the clean water is transported to an industrial water pool, and the ultrafiltration concentrate overflows to the overflow tank 2; the ultrafiltration concentrate from the #2 aeration biochemical pool is transported to the MBR membrane pool for solid-liquid separation to obtain clean water and concentrate after solid-liquid separation, wherein the clean water is transported to the industrial water pool, and the obtained ultrafiltration concentrate is transported to the #2 aeration biochemical pool for secondary biochemical treatment, thereby realizing the reuse of concentrate and improving water utilization.

[0045] This embodiment further provides an immersion ultrafiltration concentrated water treatment system, which is implemented based on the immersion ultrafiltration concentrated water treatment method described above in this embodiment, and the system includes:

[0046] The submerged ultrafiltration treatment module is used for submerged ultrafiltration treatment of the treated water in the sewage treatment plant;

[0047] A biochemical treatment module, used for conveying the ultrafiltration concentrated water generated after the ultrafiltration treatment of the reclaimed water to the biochemical pool via an overflow trough for aeration and biochemical treatment, wherein the overflow trough has a gate plate, and the ultrafiltration concentrated water after the ultrafiltration treatment is overflowed to the biochemical pool by adjusting the height of the gate plate;

[0048] The output module is used to transport the ultrafiltration concentrated water after aeration and biochemical treatment to the MBR membrane pool, perform solid-liquid separation on the ultrafiltration concentrated water through the MBR membrane pool, and input the clean water obtained after solid-liquid separation into the industrial water pool.

[0049] The beneficial effects of the embodiments of the present application are as follows:

[0050] 1. The combined operation of submerged ultrafiltration and MBR provides a guarantee for enterprises to use reclaimed water efficiently and achieves "zero discharge" in the reclaimed water pretreatment process;

[0051] 2. Gates and baffles are installed in the overflow trough. By adjusting the height of the gate, the concentrated water from the submerged ultrafiltration can overflow to the #2 biochemical pool for biochemical treatment and reuse, which solves the problem that the traditional process requires a separate concentrated water discharge system or external discharge. The destination of the concentrated water from the submerged ultrafiltration can be determined simply by adjusting the height of the gate, without the need for additional drainage, water storage and other systems, thereby reducing operating energy consumption.

[0052] In the several embodiments provided in the present application, it should be understood that the disclosed systems, modules and methods can be implemented in other ways. For example, the module embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, modules or units, which can be electrical, mechanical or other forms.

[0053] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it. The present application is not limited to the exact structure described above and illustrated in the accompanying drawings, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, various changes and modifications made without departing from the concept of the present application should be deemed to belong to the protection scope of the present application.

Claims

1. A method for treating concentrated water by submerged ultrafiltration, characterized in that: The method comprises: Submerged ultrafiltration is performed on the treated reclaimed water from the sewage treatment plant, and the ultrafiltration concentrate produced after the ultrafiltration treatment of the reclaimed water is transported to the aeration biochemical tank via an overflow tank for aeration biochemical treatment, wherein the overflow tank has a gate plate, and the ultrafiltration concentrate after the ultrafiltration treatment is overflowed to the aeration biochemical tank by adjusting the height of the gate plate; The ultrafiltration concentrated water treated in the aeration biochemical pool is transported to the MBR membrane pool, solid-liquid separation is performed on the ultrafiltration concentrated water through the MBR membrane pool, and the clean water obtained after the solid-liquid separation is input into the industrial water pool.

2. The method for treating concentrated water by submerged ultrafiltration according to claim 1, characterized in that: The submerged ultrafiltration treatment of the treated reclaimed water from the sewage treatment plant comprises: The reclaimed water after treatment at the sewage treatment plant is pre-treated and then transported to the water storage biochemical pool, wherein the pre-treatment steps include filtering and heating; The reclaimed water in the water storage biochemical pool is transported to an immersion ultrafiltration pool for immersion ultrafiltration treatment to obtain the ultrafiltration concentrated water.

3. The method for treating concentrated water by submerged ultrafiltration according to claim 2, characterized in that: The reclaimed water in the water storage biochemical pool is transported to the submerged ultrafiltration pool via a water distribution tank; wherein the water distribution tank comprises a first baffle and a water inlet, the baffle is used to separate the ultrafiltration concentrated water from the reclaimed water, and the water inlet is connected to the submerged ultrafiltration pool.

4. The method for treating concentrated water by submerged ultrafiltration according to claim 3, characterized in that: The reclaimed water in the water storage biochemical pool is pumped into the water distribution tank by a submersible axial flow pump.

5. The method for treating concentrated water by submerged ultrafiltration according to claim 1, characterized in that: The overflow trough includes a second baffle and the gate plate. The overflow trough is connected to the submerged ultrafiltration tank and the MBR membrane tank respectively. The second baffle is used to separate the ultrafiltration concentrate from the concentrate in the MBR membrane tank. The gate plate is arranged on the outlet side of the ultrafiltration concentrate, and the height of the gate plate is adjustable.

6. The method for treating concentrated water by submerged ultrafiltration according to claim 2, characterized in that: After the reclaimed water in the water storage biochemical pool is transported to the submerged ultrafiltration pool for submerged ultrafiltration treatment, clean water and the ultrafiltration concentrated water are obtained. The clean water is transported to the industrial water pool, and the ultrafiltration concentrated water overflows to the overflow tank.

7. The method for treating concentrated water by submerged ultrafiltration according to claim 1, characterized in that: The solid-liquid separation of the ultrafiltration concentrated water by the MBR membrane pool also includes: Obtaining clean water and concentrated water after solid-liquid separation; The obtained clean water is transported to the industrial water pool, and the concentrated water is transported to the aerated biochemical pool for secondary treatment.

8. An immersion ultrafiltration concentrated water treatment system, the system is implemented based on the method according to any one of claims 1 to 7, the system comprising: Immersed ultrafiltration treatment module, used for immersing ultrafiltration treatment of the treated water in the sewage plant; A biochemical treatment module, used for conveying the ultrafiltration concentrated water generated after the ultrafiltration treatment of the reclaimed water to the aeration biochemical pool via an overflow tank for aeration biochemical treatment, wherein the overflow tank has a gate plate, and the ultrafiltration concentrated water after the ultrafiltration treatment is overflowed to the biochemical pool by adjusting the height of the gate plate; The output module is used to transport the ultrafiltration concentrated water after aeration and biochemical treatment to the MBR membrane pool, perform solid-liquid separation on the ultrafiltration concentrated water through the MBR membrane pool, and input the clean water obtained after solid-liquid separation into the industrial water pool.

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