A wastewater treatment energy-saving and emission-reduction device and method

Abstract

This invention relates to an energy-saving and emission-reduction device and method for wastewater treatment. The device includes a non-aerated biological tank (1), an aerated biological tank (2), and a sealed air chamber (3). The non-aerated biological tank (1) is connected to a gas storage membrane (5) inside the sealed air chamber (3) via a drain pipe (4). The sealed air chamber (3) is connected to a blower pipe (6). The gas storage membrane (5) is connected to the aerated biological tank (2) via an aeration pipe (7). Compared with the prior art, this invention enables on-site monitoring, storage, and secondary utilization of odors and greenhouse gases generated by biochemical processes, reducing the waste of energy resources.

Description

Technical Field

[0001] This invention relates to the field of energy conservation and environmental protection technology, and in particular to an energy-saving and emission-reduction device and method for wastewater treatment. Background Technology

[0002] As a crucial pillar of green development, the energy conservation and environmental protection industry is ushering in a significant historical opportunity. Currently, wastewater treatment still primarily relies on biological treatment processes. These processes utilize microorganisms to degrade organic pollutants (such as BOD5 and TN) in wastewater, transforming them into harmless gaseous, liquid, and organic-rich solid products. Biological treatment offers advantages over physical and chemical treatment processes, with lower investment and better results. Biological treatment generally includes three processes: anaerobic, anoxic, and aerobic. Due to the complexity of biochemical processes, small amounts of toxic byproducts (such as H2S) and greenhouse gases may be generated during anaerobic and anoxic processes. Early wastewater treatment processes did not prioritize the small amounts of odor and greenhouse gases produced during anaerobic and anoxic processes. Later, a method of covering and suction was used to extract these gases to a centralized treatment center for treatment and discharge after meeting standards. However, because the concentration of odor and greenhouse gases produced during anaerobic and anoxic processes is low but the air volume is large, this method of centralized treatment after suction by fans results in a significant waste of resources and energy. Summary of the Invention

[0003] The purpose of this invention is to provide an energy-saving and emission-reduction device and method for wastewater treatment.

[0004] The objective of this invention can be achieved through the following technical solution: a wastewater treatment energy-saving and emission-reduction device, comprising a non-aerated biological tank, an aerated biological tank, and a sealed air chamber;

[0005] The non-aerated biological tank is connected to the air storage membrane in the sealed air chamber through a drain pipe. The sealed air chamber is connected to the blower pipe, and the air storage membrane is connected to the aerated biological tank through an aeration pipe.

[0006] Preferably, the top of the non-aerated biological tank is provided with a drainage chamber that extends above the tank top, and a drainage pipe connects the drainage chamber and the air storage membrane. A first valve is provided on the drainage pipe.

[0007] Preferably, the non-aerated biological tank is equipped with a stirrer, and a leak-proof water seal is provided between the stirrer and the top of the non-aerated biological tank.

[0008] Preferably, the top of the non-aerated biological tank is sealed, and a closed manhole and observation hole are provided on it.

[0009] Preferably, the non-aerated biological tank is connected to an inlet water and sludge inlet pipe, and an outlet slope wall is provided on the outlet side of the non-aerated biological tank, which is located between the non-aerated biological tank and the aerated biological tank. The outlet slope wall can serve as a guide and water seal, and can also prevent local backflow caused by local turbulence during the aeration process of the aerated biological tank.

[0010] More preferably, the end point of the outlet slope wall is higher than the bottom of the flow hole, so that if the liquid level in the non-aerated biological tank drops below the flow hole, the water in the aerated biological tank will not flow back into the non-aerated biological tank.

[0011] Preferably, the aeration pipe is provided with a second valve, and the blower pipe is provided with a third valve.

[0012] Preferably, a rangefinder for measuring the fullness or emptiness of the gas storage membrane is provided below the gas storage membrane, the gas storage membrane is connected to a nitrogen analyzer and a carbon dioxide analyzer, and a sampling valve is provided on the exhaust pipe.

[0013] Preferably, the bottom of the gas storage membrane is provided with a condensate drainage component.

[0014] Preferably, the blower pipe is connected to an aeration branch pipe, which is connected to the aerated biological tank.

[0015] An oxidized nitrogen return pipe is provided between the non-aerated biological tank and the aerated biological tank, and an oxidized nitrogen return pump is provided on the oxidized nitrogen return pipe.

[0016] Preferably, the gas storage membrane is made of a high-strength flame-retardant material that is resistant to biogas permeation, wear, wrinkles, and hydrogen sulfide corrosion, and operates at a pressure of 2-5 kPa.

[0017] Preferably, the effective volume of the gas storage membrane is not less than 10% of the average daily flow of sewage.

[0018] A wastewater treatment method for energy conservation and emission reduction, using the aforementioned apparatus, includes the following steps:

[0019] S1: Wastewater flows into the non-aerated biological tank through the inlet pipe. The odor and greenhouse gases produced by the anaerobic / anoxic reaction in the non-aerated biological tank enter the air storage membrane in the sealed air chamber through the drain pipe. At this time, the first valve is open and the second and third valves are closed.

[0020] S2: When the gas storage membrane is full, the first valve is closed and the second and third valves are opened, and the gas in the gas storage membrane is discharged to the aerated biological tank for synergistic aeration through the blower pipe and aeration pipe.

[0021] S3: When the gas volume in the gas storage membrane drops to the set value, the first valve opens and the second and third valves close, so that the odor and greenhouse gases produced by the reaction in the non-aerated biological tank continue to be discharged into the gas storage membrane.

[0022] After undergoing anaerobic / anoxic reactions in the non-aerated biological tank, the wastewater enters the aerated biological tank through the outlet slope wall.

[0023] Preferably, in step S3, when the gas volume in the gas storage membrane drops to 20% of the full gas volume of the gas storage membrane, the first valve opens and the second and third valves close.

[0024] Preferably, the first valve, the second valve, the third valve, and the rangefinder are all connected to the controller.

[0025] Preferably, the blower pressure is always greater than the pressure inside the gas storage membrane.

[0026] More preferably, the blower pressure is always greater than 0.6 MPa.

[0027] Preferably, both the non-aerated biological tank and the air chamber are sealed.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. This invention provides an energy-saving and emission-reduction device and method for wastewater treatment, which enables on-site monitoring, storage, and secondary utilization of odors and greenhouse gases generated by biochemical processes, thereby reducing the waste of energy resources;

[0030] 2. This invention, through the coordinated arrangement of a gas storage membrane, a guide pipe, a blower pipe, and an aeration pipe, can store the malodorous gases and greenhouse gases generated by anaerobic / anoxic reactions in a non-aerated biological tank within an empty gas storage membrane, thereby reducing gas emissions from the non-aerated biological tank. There is no need to install a separate deodorization device to collect the odorous gases in the non-aerated biological tank, reducing the investment in deodorization devices. The collected gases can be used to aerate the aerated biological tank, reducing the waste of energy resources.

[0031] 4. The non-aeration biological tank of the present invention can play the role of guiding flow and water sealing by setting the outlet slope wall, and can also avoid local backflow caused by local turbulence during the aeration process of the aerated biological tank;

[0032] 5. This invention can be used not only for the synergistic monitoring and on-site reduction of odorous gases and greenhouse gases in conventional non-aerated biological tanks such as anoxic tanks and anaerobic tanks, but also for places where similar gases are emitted, such as sludge storage tanks and sludge thickening tanks.

[0033] 6. The present invention features a sealed design for both the non-aerated biological tank and the air chamber, which can reduce the risk of odor and greenhouse gas leakage and ensure the safety of the non-aerated biological tank operation and production.

[0034] 7. The setting of the discharge chamber in the non-aerated biological tank of the present invention can initially collect the malodor and greenhouse gases produced by the biological reaction in the non-aerated biological tank, prevent the foam and scum in the non-aerated biological tank from clogging the discharge pipe, and facilitate the discharge of gas into the gas storage membrane.

[0035] 8. The valve and rangefinder are linked to achieve automated operation of odor collection and emission. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the wastewater treatment energy-saving and emission-reduction device of the present invention;

[0037] In the diagram: 1-Non-aerated biological tank, 2-Aerated biological tank, 3-Sealed air chamber, 4-Drainage pipe, 5-Air storage membrane, 6-Blower pipe, 7-Aeration pipe, 8-Drainage chamber, 9-Agitator, 10-Leak-proof water seal, 11-Manhole, 12-Observation hole, 13-Water and sludge inlet pipe, 14-Outlet slope wall, 15-Radarmeter, 16-Aeration branch pipe, 17-Oxidized nitrogen return pipe, 18-Oxidized nitrogen return pump, a-First valve, b-Second valve, c-Third valve, d-Sampling valve, e-Nitrogen analyzer and carbon dioxide analyzer, f-Pressure relief valve, g-Automatic drain valve. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0039] Example 1

[0040] A wastewater treatment energy-saving and emission-reduction device, such as Figure 1 As shown, it includes a non-aerated biological tank 1, an aerated biological tank 2, and a closed air chamber 3.

[0041] Among them, the non-aerated biological tank 1 is connected to the air storage membrane 5 in the sealed air chamber 3 through the drainage pipe 4, the air storage membrane 5 is connected to the aerated biological tank 2 through the aeration pipe 7, and the blower pipe 6 is connected to the sealed air chamber 3.

[0042] This device enables on-site monitoring, storage, and secondary utilization of odors and greenhouse gases generated by biochemical processes, reducing the waste of energy resources.

[0043] Example 2

[0044] An energy-saving and emission-reduction wastewater treatment device includes a non-aerated biological tank 1 with a drainage chamber 8 extending above the tank top. A drainage pipe 4 connects the drainage chamber 8 to an air storage membrane 5. The air storage membrane 5 is connected to an aerated biological tank 2 via an aeration pipe 7. A blower pipe 6 connects to a sealed air chamber 3. The top of the non-aerated biological tank 1 is sealed and equipped with a closed manhole 11 and an observation hole 12. An agitator 9 is installed inside the non-aerated biological tank 1, and a leak-proof water seal 10 is installed between the agitator 9 and the top of the non-aerated biological tank 1. The non-aerated biological tank 1 is connected to an inlet water and sludge inlet pipe 13, and an outlet slope wall 14 is provided between the non-aerated biological tank 1 and the aerated biological tank 2.

[0045] The guide pipe 4 is equipped with a first valve a, the aeration pipe 7 is equipped with a second valve b, and the blower pipe 6 is equipped with a third valve c.

[0046] A wastewater treatment method for energy conservation and emission reduction, using the aforementioned apparatus, includes the following steps:

[0047] S1: Wastewater flows into the non-aerated biological tank 1 through the inlet pipe 13. The odor and greenhouse gases produced by the anaerobic / anoxic reaction in the non-aerated biological tank 1 enter the air storage membrane 5 in the sealed air chamber 3 through the drain pipe. At this time, the first valve a is in the open state, and the second valve b and the third valve c are in the closed state.

[0048] S2: When the gas storage membrane 5 is full, the first valve a is closed, and the second valve b and the third valve c are opened. The gas in the gas storage membrane 5 is discharged to the aerated biological tank 2 for co-aeration through the blower pipe 6 and the aeration pipe 7.

[0049] S3: When the gas volume in the gas storage membrane 5 drops to the set value, the first valve a opens, and the second valve b and the third valve c close, so that the odor and greenhouse gases produced by the reaction in the unaerated biological tank 1 continue to be discharged into the gas storage membrane 5.

[0050] In the above process, after the sewage undergoes an anaerobic / anoxic reaction in the non-aerated biological tank 1, it enters the aerated biological tank 2 through the outlet slope wall 14.

[0051] Example 3

[0052] An energy-saving and emission-reduction wastewater treatment device includes a rangefinder 15 located below a gas storage membrane 5 to measure its full / empty state. The gas storage membrane 5 is connected to a nitrogen analyzer and a carbon dioxide analyzer e. A condensate discharge assembly is located at the bottom of the gas storage membrane 5. A sampling valve d is installed on the discharge pipe 4. The rest is the same as in Example 2.

[0053] Example 4

[0054] A wastewater treatment energy-saving and emission-reduction device includes a condensate discharge assembly at the bottom to prevent condensate accumulation within the gas storage membrane 5. The discharge assembly consists of a condensate collection pipe, a differential pressure level gauge, and a condensate pneumatic valve. Once a fixed liquid level is reached, the pneumatic valve is opened to discharge condensate to a certain level, after which the valve closes. This process is repeated. The rest is the same as in Example 3.

[0055] Example 5

[0056] An energy-saving and emission-reduction wastewater treatment device includes a blower pipe 6 connected to an aeration branch pipe 16, which connects to an aerated biological tank 2. An oxidized nitrogen return pipe 17 is provided between the non-aerated biological tank 1 and the aerated biological tank 2, connecting the two from the bottom of the tank. An oxidized nitrogen return pump 18 is installed on the oxidized nitrogen return pipe 17. The rest is the same as in Example 4.

[0057] The mixed liquor from the aerated biological tank 2 is returned to the non-aerated biological tank 1. To ensure the airtightness of the non-aerated biological tank 1, the oxidized nitrogen return pump 18 adopts a submerged effluent form instead of the conventional return pump to lift the mixed liquor to the return channel, and then the mixed liquor falls into the non-aerated biological tank 1.

[0058] Example 6

[0059] An energy-saving and emission-reduction wastewater treatment device includes a completely sealed non-aerated biological tank 1, with all manholes 11 and observation holes 12 sealed, and equipment installation holes such as the agitator 9 sealed with water seals. A sloping wall 14 at the outlet prevents oxygenated water from flowing back into the non-aerated biological tank 1 from the aerated biological tank 2. The non-aerated biological tank 1 has a drainage chamber 8 extending above the tank top to prevent foam and scum from clogging the drainage pipe 4. A sealed air chamber 3 contains an air-storage membrane 5, with a rangefinder 15 at the bottom to detect the air-storage volume. The sealed air chamber 3 is connected to a blower pipe 6; when pressurized by blowing air, the air-storage membrane 5 is discharged towards the end of the aerated biological tank 2.

[0060] The working principle of the device in this embodiment is as follows:

[0061] 1. Wastewater flows into a closed, non-aerated biological tank 1 through submerged pipes at both ends. After undergoing anaerobic / anoxic reactions within the non-aerated biological tank 1, it flows into an aerated biological tank 2 through the lower sloping wall. The odorous gases and greenhouse gases produced by the anaerobic / anoxic reactions in the non-aerated biological tank 1 enter a drainage chamber 8 above the tank top. These gases then gradually enter a vacuum gas storage membrane 5 within a sealed gas chamber 3 through a drainage pipe 4 connected to the drainage chamber 8. At this time, the first valve a is open, while the second valve b and the third valve c are closed. The odorous gases and greenhouse gases produced during the anaerobic and anoxic biological processes are collected by the gas storage membrane 5 without the need for a blower to extract them into a centralized odor treatment device. Calculations show that the air volume extracted by the deodorizing blower during the anaerobic / anoxic process is the water surface area × the air exchange rate per unit area (3m³). 3 / m 2 •h) + water surface area × freeboard × space ventilation rate (1-2 times / h). Example: A wastewater treatment plant with a capacity of 100,000 tons / day requires approximately 3200m². 2 The anaerobic-anoxic tank area and deodorization air volume are 14000 m³. 3 For each hour, a deodorizing fan of approximately 15 kW is required, which would result in energy savings of approximately 360 kWh / day.

[0062] 2. A rangefinder 15 is installed at the lower end of the gas storage membrane 5 to measure its full / empty state. When the gas storage membrane is fully saturated, the first valve a closes, and the second valve b and third valve c open. The gas inside the gas storage membrane 5 is then discharged to the aerated biological tank 2 for co-aeration by the blower pressure in the aeration tank, reducing the emission of odorous gases and greenhouse gases. The reduction in odorous gases and greenhouse gases can be calculated in real time using online analyzers for nitrogen, carbon dioxide, etc., connected to the gas storage membrane 5.

[0063] 3. When the gas volume in the gas storage membrane 5 drops to the set threshold, the second valve b and the third valve c are closed, and the first valve a is opened, so that the malodor and greenhouse gases generated in the unaerated biological tank 1 continue to be discharged into the gas storage membrane 5.

[0064] 4. When the pressure of the gas storage membrane 5 reaches the full-state critical value, the pressure relief valve f is temporarily opened to release the pressure. After the pressure reaches equilibrium, the pressure relief valve f is closed. The bottom of the gas storage membrane 5 is equipped with an automatic drain valve g and a differential pressure level gauge. When the bottom liquid level reaches the specified scale, the wastewater condensed in the gas storage membrane 5 is discharged.

[0065] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A sewage treatment energy-saving and emission-reducing method, characterized in that, The application relates to a sewage treatment energy-saving and emission-reducing device and a sewage treatment energy-saving and emission-reducing method. The device comprises a non-aeration biological tank (1), an aeration biological tank (2) and a closed air chamber (3). The non-aeration biological tank (1) is connected with a gas storage film (5) in the closed air chamber (3) through a guide pipe (4), the closed air chamber (3) is connected with a blowing pipe (6), and the gas storage film (5) is connected with the aeration biological tank (2) through an aeration pipe (7). The non-aeration biological tank (1) is provided with a guide chamber (8) which is higher than the top of the non-aeration biological tank (1), the guide pipe (4) is connected with the guide chamber (8) and the gas storage film (5), and a first valve (a) is arranged on the guide pipe (4). The non-aeration biological tank (1) is connected with a water and sludge inlet pipe (13), and a water outlet slope wall (14) is arranged on the water outlet side of the non-aeration biological tank (1). A second valve (b) is arranged on the aeration pipe (7), and a third valve (c) is arranged on the blowing pipe (6). The sewage treatment energy-saving and emission-reducing method comprises the following steps. S1: sewage flows into the non-aeration biological tank (1) through the water and sludge inlet pipe (13), and the odor and greenhouse gas generated by anaerobic reaction in the non-aeration biological tank (1) is discharged into the gas storage film (5) in the closed air chamber (3) through the guide pipe (4), wherein the first valve (a) is in an open state, and the second valve (b) and the third valve (c) are in a closed state; S2: when the gas storage film (5) is full, the first valve (a) is closed, the second valve (b) and the third valve (c) are opened, and the gas in the gas storage film (5) is discharged into the aeration biological tank (2) through the blowing pipe (6) and the aeration pipe (7) to realize aeration; S3: when the gas amount in the gas storage film (5) is reduced to a set value, the first valve (a) is opened, the second valve (b) and the third valve (c) are closed, and the odor and greenhouse gas generated by reaction in the non-aeration biological tank (1) is continuously discharged into the gas storage film (5); 2. The sewage treatment energy saving and emission reduction method according to claim 1, characterized in that, After the sewage is subjected to anaerobic reaction in the non-aeration biological tank (1), the sewage enters the aeration biological tank (2) through the water outlet slope wall (14).

3. The sewage treatment energy saving and emission reduction method according to claim 1, characterized in that, A stirrer (9) is arranged in the non-aeration biological tank (1), and an air leakage prevention water seal (10) is arranged between the stirrer (9) and the top of the non-aeration biological tank (1).

4. The sewage treatment energy saving and emission reduction method according to claim 1, characterized in that, The top of the non-aeration biological tank (1) is sealed, and a closed manhole (11) and an observation hole (12) are arranged on the top.

5. The sewage treatment energy saving and emission reduction method according to claim 1, characterized in that, A distance measuring instrument (15) for measuring the fullness of the gas storage film (5) is arranged below the gas storage film (5), the gas storage film (5) is connected with a nitrogen analyzer and a carbon dioxide analyzer, and a sampling valve (d) is arranged on the guide pipe (4).

6. The sewage treatment energy saving and emission reduction method according to claim 1, characterized in that, A condensate water discharge assembly is arranged at the bottom of the gas storage film (5). The blowing pipe (6) is connected with an aeration branch pipe (16), and the aeration branch pipe (16) is connected with the aeration biological tank (2). An oxidized nitrogen reflux pipe (17) is arranged between the non-aeration biological tank (1) and the aeration biological tank (2), and an oxidized nitrogen reflux pump (18) is arranged on the oxidized nitrogen reflux pipe (17).

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