A sewage treatment apparatus combining membrane filtration and membrane concentrate regeneration

Abstract

The application relates to the technical field of sewage treatment, in particular to a sewage treatment device combining membrane filtration and membrane concentrated liquid regeneration, which comprises a front coagulation unit, a hydrolysis aerobic unit, a membrane filtration unit and a membrane concentrated water oxidation unit; sewage inflow water sequentially passes through the front coagulation unit and the hydrolysis aerobic unit and then reaches the membrane filtration unit; the membrane concentrated liquid concentrated by the membrane filtration unit is used for entering the membrane concentrated water oxidation unit; and the effluent of the membrane concentrated water oxidation unit is used for backflowing to the front coagulation unit. The application has the following effects: the combination of biochemical treatment and advanced oxidation can realize strong decomposition capacity, reduce sewage treatment cost and realize high-standard effluent indexes; the orderly combination and cyclic treatment of the units can utilize the low-cost advantage of biochemical treatment and exert the decomposition effect of advanced oxidation on organic pollutants, and the substances generated in the oxidation process can be secondarily utilized in the coagulation stage, so that the consumption of reagents is reduced.

Description

Technical Field

[0001] This application relates to the technical field of wastewater treatment, and in particular to a wastewater treatment apparatus that combines membrane filtration and membrane concentrate regeneration. Background Technology

[0002] In the field of water treatment technology, wastewater treatment has always been a crucial and highly concerned issue. With rapid industrial development and continuous population growth, wastewater discharge is increasing daily, posing a serious threat to water resources and the ecological environment. Effective wastewater treatment technologies can not only protect water resources but also promote their recycling, which is of vital importance to achieving sustainable development. Good wastewater treatment processes can remove harmful substances from wastewater, bringing it up to discharge standards or reusable water quality requirements, thereby reducing environmental pollution and ensuring the safety of drinking water for people.

[0003] In traditional wastewater treatment processes, various methods are typically employed to address wastewater purification issues, including coagulation, biological treatment, and membrane filtration technologies. Coagulation involves adding coagulants to wastewater, causing pollutants to settle before discharge. Biological treatment utilizes activated sludge microorganisms to decompose decomposable pollutants in wastewater under aeration conditions. Membrane filtration technology uses specific membranes to selectively allow certain substances to permeate, thereby purifying wastewater.

[0004] However, traditional wastewater treatment methods have obvious drawbacks. Single coagulation, biological treatment, or membrane filtration technologies often fail to achieve high effluent standards. Furthermore, further improving treatment efficiency can lead to a significant increase in operating costs and construction investment, which imposes a substantial economic burden on wastewater treatment in practical applications. Utility Model Content

[0005] In order to achieve high effluent standards while reducing economic burden, this application provides a wastewater treatment device that combines membrane filtration and membrane concentrate regeneration.

[0006] This application provides a wastewater treatment device combining membrane filtration and membrane concentrate regeneration, which adopts the following technical solution: it includes a pre-coagulation unit, a hydrolysis aerobic unit, a membrane filtration unit, and a membrane concentrate oxidation unit. Wastewater influent passes through the pre-coagulation unit and the hydrolysis aerobic unit in sequence before reaching the membrane filtration unit. The membrane concentrate from the membrane filtration unit is used to enter the membrane concentrate oxidation unit, and the effluent from the membrane concentrate oxidation unit is used to return to the pre-coagulation unit.

[0007] By adopting the above technical solutions, the cost of wastewater treatment is reduced and high-standard effluent indicators are achieved by combining the low cost of biochemical treatment with the strong decomposition capabilities of advanced oxidation. The orderly combination and cyclical treatment of each unit not only utilizes the low-cost advantage of biochemical treatment, but also leverages the decomposition effect of advanced oxidation on organic pollutants. At the same time, the substances generated during the oxidation process can be reused in the coagulation stage, reducing the consumption of reagents.

[0008] Preferably, the pre-coagulation unit includes a pre-coagulation inlet and a pre-coagulation outlet. The pre-coagulation inlet is used to supply wastewater, the pre-coagulation unit is used for the addition of coagulant, and the pre-coagulation outlet is used to connect with the hydrolysis aerobic unit.

[0009] By adopting the above technical solution, the clear liquid after coagulation treatment to remove suspended solids can flow to the hydrolysis aerobic unit.

[0010] Preferably, the hydrolysis aerobic unit includes a hydrolysis zone agitator and an aerobic zone aerator. The hydrolysis zone agitator is used to agitate the coagulated wastewater, and the aerobic zone aerator is used to perform biochemical treatment on the agitated wastewater.

[0011] By adopting the above technical solution, the wastewater after stirring and coagulation is brought into full contact with the activated sludge microorganisms, which promotes the hydrolysis reaction. The microorganisms can fully decompose the decomposable pollutants in the wastewater under aerobic conditions.

[0012] Preferably, the membrane filtration unit includes a pretreatment zone, which removes insoluble substances from the water through mechanical filtration.

[0013] By adopting the above technical solution, the pretreatment zone removes insoluble substances from the water through mechanical filtration, thus protecting the nanofiltration membrane.

[0014] Preferably, the membrane filtration unit further includes a nanofiltration membrane, which has a permeate outlet and a concentrate outlet. The effluent from the permeate outlet is used for direct discharge in compliance with standards, and the concentrate outlet is used to connect to the concentrate oxidation unit.

[0015] By adopting the above technical solution, the effluent from the membrane permeate discharge outlet, having undergone membrane filtration and having most of the organic pollutants removed, can be directly discharged in compliance with standards. The membrane concentrate outlet is used to connect to the membrane concentrate oxidation unit, transporting the membrane concentrate containing a large amount of organic molecular pollutants to the membrane concentrate oxidation unit for treatment.

[0016] Preferably, the nanofiltration membrane is used to selectively allow monovalent and divalent salt ions such as sodium, potassium, chloride, and sulfate to pass through while intercepting large organic molecules.

[0017] Preferably, an RO membrane is provided between the pretreatment zone and the nanofiltration membrane. The RO membrane is used for wastewater reuse, and the concentrate from the RO membrane enters the nanofiltration membrane for further treatment.

[0018] By adopting the above technical solution, the RO membrane further separates salt ions and organic molecules, realizing water reuse.

[0019] Preferably, the membrane concentrate oxidation unit is used to add oxidant to oxidize and decompose organic pollutants in the water entering the membrane concentrate oxidation unit.

[0020] By adopting the above technical solution, organic pollutants in the membrane concentrate oxidation unit do not need to be completely degraded, but only partially degraded and modified. Therefore, the amount of oxidant used can be significantly less than that used for complete degradation, thus reducing the cost of wastewater treatment.

[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. It achieves alternating treatment of advanced oxidation and biochemical processes, combining the low cost of biochemical treatment with the strong decomposition capability of advanced oxidation, thus significantly reducing the cost of wastewater treatment; 2. Nanofiltration membranes separate salt ions and organic molecules, enabling the interception and recycling of organic molecules as well as the normal discharge of inorganic ions. Therefore, it can achieve high-standard wastewater discharge, high water reuse rate, and stable system operation. 3. It can achieve high-standard effluent indicators while saving on operating chemicals. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of this application.

[0023] Explanation of reference numerals in the attached diagram: 1. Pre-coagulation unit; 1-1. Pre-coagulation inlet; 1-2. Pre-coagulation outlet; 2. Hydrolysis aerobic unit; 2-1. Hydrolysis zone agitator; 2-2. Aerobic zone aerator; 2-3. Hydrolysis aerobic unit outlet; 3. Membrane filtration unit; 3-1. Membrane pretreatment; 3-2. Nanofiltration membrane; 3-3. Membrane permeate discharge outlet; 3-4. Membrane concentrate outlet; 4. Membrane concentrate oxidation unit; 4-1. Oxidation unit effluent return pipe. Detailed Implementation

[0024] The present application will be further described in detail below with reference to the accompanying drawings.

[0025] This application discloses a wastewater treatment device that combines membrane filtration and membrane concentrate regeneration, which aims to achieve high effluent standards while reducing economic burden.

[0026] A wastewater treatment device combining membrane filtration and membrane concentrate regeneration includes a pre-coagulation unit 1, a hydrolysis aerobic unit 2, a membrane filtration unit 3, and a membrane concentrate oxidation unit 4. Wastewater influent sequentially passes through the pre-coagulation unit 1 and the hydrolysis aerobic unit 2 before reaching the membrane filtration unit 3. The membrane concentrate discharged from the membrane filtration unit 3 enters the membrane concentrate oxidation unit 4, and the effluent from the membrane concentrate oxidation unit 4 is returned to the pre-coagulation unit 1. This achieves the effect of combining low-cost biological treatment with the strong decomposition capabilities of advanced oxidation, reducing wastewater treatment costs and achieving high-standard effluent indicators. Through the orderly combination and cyclical treatment of each unit, the low-cost advantage of biological treatment is utilized, while the decomposition effect of advanced oxidation on organic pollutants is leveraged. Simultaneously, substances generated during the oxidation process can be reused in the coagulation stage, reducing reagent consumption.

[0027] Specifically, the pre-coagulation unit 1 includes a pre-coagulation inlet 1-1 and a pre-coagulation outlet 1-2. The pre-coagulation inlet 1-1 is usually a pipe structure, which allows the wastewater to be treated to enter the pre-coagulation unit 1. The pre-coagulation unit 1 is used to add coagulants, such as common polyaluminum chloride and aluminum sulfate. The addition method can be a metering pump to accurately add the agent to the wastewater in a certain proportion. The pre-coagulation outlet 1-2 is a channel connecting the pre-coagulation unit 1 and the hydrolysis aerobic unit 2. Its shape is generally circular or square. The clear liquid after the suspended solids are removed by coagulation can flow to the hydrolysis aerobic unit 2 through the pre-coagulation outlet 1-2.

[0028] The hydrolysis aerobic unit 2 includes a hydrolysis zone agitator 2-1 and an aerobic zone aerator 2-2. The hydrolysis zone agitator 2-1 generally consists of a motor, a stirring shaft, and stirring blades. The motor can be a three-phase asynchronous motor to provide power for stirring. The stirring shaft is usually made of metal with an anti-corrosion treatment. The stirring blades stir the coagulated wastewater, ensuring sufficient contact between the wastewater and activated sludge microorganisms, promoting the hydrolysis reaction. The aerobic zone aerator 2-2 can be an aeration disc or aeration head, which introduces air into the wastewater to provide sufficient oxygen for the activated sludge microorganisms, enabling them to fully decompose decomposable pollutants in the wastewater under aerobic conditions. The biochemically treated water then flows through the outlet of the hydrolysis aerobic unit 2 to the membrane filtration unit 3.

[0029] The membrane filtration unit 3 includes a pretreatment zone and a nanofiltration membrane 3-2. The pretreatment zone removes insoluble matter from the water through mechanical filtration. As a protection for the nanofiltration membrane 3-2, the pretreatment zone can be equipped with a filter screen, filter cloth, or ultrafiltration membrane. The pore size of the filter screen is selected according to the size of the insoluble matter in the wastewater. The material of the filter cloth or ultrafiltration membrane can be polyester, polypropylene, or PVDF. The nanofiltration membrane 3-2 has a permeate discharge port 3-3 and a concentrate port 3-4. The nanofiltration membrane 3-2 is a semi-permeable membrane that can selectively allow the passage of monovalent and divalent salt ions such as sodium, potassium, chloride, and sulfate, while intercepting large organic molecules. The effluent from the permeate discharge port 3-3 has undergone membrane filtration, removing most of the organic pollutants, and can be directly discharged in compliance with standards. The concentrate port 3-4 is used to connect to the concentrate oxidation unit 4, transporting the concentrate containing more organic molecular pollutants to the concentrate oxidation unit 4 for treatment.

[0030] In addition, an RO membrane can be installed between the pretreatment zone and the nanofiltration membrane 3-2 for wastewater reuse. RO membranes are typically spiral wound structures. The permeate from the RO membrane can be reused in production, while the concentrate from the RO membrane enters the nanofiltration membrane 3-2 for further treatment.

[0031] The membrane concentrate oxidation unit 4 is used to add oxidants to oxidize and decompose organic pollutants in the incoming water. The oxidant can be ozone or hydrogen peroxide, and ozone catalysts or ferrous ions can also be added to achieve ozone catalytic oxidation or Fenton oxidation. The membrane concentrate oxidation unit 4 can be a catalytic oxidizer. In this unit, organic pollutants do not need to be completely degraded, only partially degraded and modified. Therefore, the amount of oxidant used can be significantly less than that used for complete degradation. The partially oxidized wastewater returns to the pre-coagulation unit 1 through the oxidation unit effluent return pipe 4-1 for further treatment.

[0032] The implementation principle of a wastewater treatment device combining membrane filtration and membrane concentrate regeneration according to an embodiment of this application is as follows: Multiple treatment units, including coagulation, aerobic hydrolysis, membrane filtration, and membrane concentrate oxidation, are organically combined. The pre-coagulation unit 1 removes suspended solids from the wastewater, reducing the burden on subsequent treatments. The aerobic hydrolysis unit 2 utilizes microorganisms to decompose decomposable pollutants. The membrane filtration unit 3 further separates salt ions and organic molecules through nanofiltration membranes 3-2 and, if possible, RO membranes, achieving water reuse and compliant discharge. The membrane concentrate oxidation unit 4 partially oxidizes organic pollutants in the membrane concentrate, and the oxidized effluent is returned to the pre-coagulation unit 1, allowing substances such as iron salts produced during oxidation to be reused during coagulation. This combined approach avoids the problems of traditional single-treatment methods failing to achieve high-standard effluent indicators and incurring high costs. It combines the low cost of biochemical treatment with the strong decomposition capabilities of advanced oxidation, reducing wastewater treatment costs and achieving high-standard wastewater discharge, high water reuse rates, and stable system operation.

[0033] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A wastewater treatment device combining membrane filtration and membrane concentrate regeneration, characterized in that: The system includes a pre-coagulation unit (1), a hydrolysis aerobic unit (2), a membrane filtration unit (3), and a membrane concentrate oxidation unit (4). Wastewater influent passes through the pre-coagulation unit (1) and the hydrolysis aerobic unit (2) in sequence before reaching the membrane filtration unit (3). The membrane concentrate from the membrane filtration unit (3) is used to enter the membrane concentrate oxidation unit (4), and the membrane permeate is discharged as qualified water from the entire treatment device. The effluent from the membrane concentrate oxidation unit (4) is used to return to the pre-coagulation unit (1).

2. The wastewater treatment device combining membrane filtration and membrane concentrate regeneration according to claim 1, characterized in that: The pre-coagulation unit (1) includes a pre-coagulation inlet (1-1) and a pre-coagulation outlet (1-2). The pre-coagulation inlet (1-1) is used to supply sewage inlet water, and the pre-coagulation unit (1) is used to supply coagulant. The pre-coagulation outlet (1-2) is used to connect with the hydrolysis aerobic unit (2).

3. The wastewater treatment device combining membrane filtration and membrane concentrate regeneration according to claim 1, characterized in that: The hydrolysis aerobic unit (2) includes a hydrolysis zone stirrer (2-1) and an aerobic zone aerator (2-2). The hydrolysis zone stirrer (2-1) is used to stir the coagulated wastewater, and the aerobic zone aerator (2-2) is used to perform biochemical treatment on the stirred wastewater.

4. A wastewater treatment device combining membrane filtration and membrane concentrate regeneration according to claim 1, characterized in that: The membrane filtration unit (3) includes a pretreatment zone, which removes insoluble substances from the water through mechanical filtration.

5. A wastewater treatment device combining membrane filtration and membrane concentrate regeneration according to claim 4, characterized in that: The membrane filtration unit (3) further includes a nanofiltration membrane (3-2), which has a membrane permeate discharge port (3-3) and a membrane concentrate port (3-4). The water discharged from the membrane permeate discharge port (3-3) is used for direct discharge in compliance with standards, and the membrane concentrate port (3-4) is used to connect with the membrane concentrate oxidation unit (4).

6. A wastewater treatment device combining membrane filtration and membrane concentrate regeneration according to claim 5, characterized in that: The nanofiltration membrane (3-2) is used to selectively permeate monovalent and divalent salt ions such as sodium, potassium, chloride, and sulfate while intercepting large organic molecules.

7. A wastewater treatment device combining membrane filtration and membrane concentrate regeneration according to claim 5, characterized in that: An RO membrane is provided between the pretreatment zone and the nanofiltration membrane (3-2). The RO membrane is used for water reuse, and the concentrate from the RO membrane enters the nanofiltration membrane (3-2) for further treatment.

8. A wastewater treatment device combining membrane filtration and membrane concentrate regeneration according to claim 1, characterized in that: The membrane concentrate oxidation unit (4) is used to add oxidant to oxidize and decompose organic pollutants in the water entering the membrane concentrate oxidation unit (4).

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