System and method for improving acid production efficiency of organic wastewater hydrolysis acidification

Abstract

The application discloses a system and method for improving acid production efficiency of organic wastewater hydrolysis acidification, comprising a methanogen inhibition tank, a seeding sludge feeding pump, a hydrolysis acidification tank, an alkali adding device, an organic wastewater inlet pipeline and a temperature controller; an inhibition tank outlet on the bottom side of the methanogen inhibition tank is connected with a seeding sludge inlet on the top side of the hydrolysis acidification tank through the seeding sludge feeding pump; a dosing opening and an exhaust opening are arranged on the top of the hydrolysis acidification tank; the alkali adding device is connected with the dosing opening; the organic wastewater inlet pipeline is connected with a water inlet on the bottom of the hydrolysis acidification tank through the temperature controller; the system and method have higher acid production efficiency, and are not prone to produce poor carbon sources.

Description

Technical Field

[0001] This invention belongs to the field of organic wastewater treatment technology, and relates to a system and method for improving the efficiency of acid production from the hydrolysis and acidification of organic wastewater. Background Technology

[0002] Denitrification carbon sources are divided into three categories: the first category is rapidly biodegradable organic matter, the second category is slowly biodegradable organic matter, and the third category is endogenous respiration organic matter. Among them, the first category of substrates can be rapidly utilized by microorganisms and can obtain a relatively fast denitrification rate. These substrates are mainly small molecule acids such as volatile fatty acids such as acetic acid and propionic acid, and lactic acid.

[0003] As is well known, the hydrolysis and acidification process for organic wastewater can produce volatile fatty acids and lactic acid, which can provide carbon sources for the denitrification process in wastewater treatment. my country has a large volume of organic wastewater, and its resource utilization mainly involves anaerobic fermentation to produce biogas for power generation and heat production, or hydrolysis and acidification to produce small-molecule organic matter as an external carbon source for denitrification in wastewater treatment processes. Currently, the former technology is relatively mature, while technologies to improve the resource utilization rate of organic wastewater as a carbon source are still in their early stages. If low-quality carbon sources that are not easily utilized by microorganisms are generated during the hydrolysis and acidification process, it not only increases the transportation costs of the carbon source but also reduces the denitrification efficiency of wastewater treatment. Therefore, it is particularly necessary to develop a method for the hydrolysis and acidification of organic wastewater with high yields of high-quality carbon sources such as volatile fatty acids and lactic acid. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a system and method for improving the acid production efficiency of organic wastewater hydrolysis acidification. This system and method have high acid production efficiency and are less likely to produce inferior carbon sources.

[0005] To achieve the above objectives, the present invention discloses a system for improving the acid production efficiency of organic wastewater hydrolysis acidification, including a methanogen inhibition tank, an inoculated sludge dosing pump, a hydrolysis acidification tank, an alkali addition device, an organic wastewater inlet pipe, and a temperature controller. The outlet of the methanogen inhibition tank on the bottom side is connected to the inoculation sludge inlet on the top side of the hydrolysis acidification tank via an inoculation sludge dosing pump. The top of the hydrolysis acidification tank is equipped with a dosing port and an exhaust port. An alkali dosing device is connected to the dosing port. The organic wastewater inlet pipe is connected to the inlet at the bottom of the hydrolysis acidification tank via a temperature controller.

[0006] It also includes a methanogen inhibitor dosing device, wherein an inhibitor inlet is provided on the side of the top of the methanogen inhibitor tank, an inhibitor dosing port is provided on the top of the methanogen inhibitor tank, a mechanical stirrer is provided inside the methanogen inhibitor tank, and the outlet of the methanogen inhibitor dosing device is connected to the inhibitor dosing port.

[0007] It also includes a sedimentation tank and a sludge return pump. The outlet on the top side of the hydrolysis acidification tank is connected to the sedimentation tank inlet at the top of the sedimentation tank. The sedimentation tank sludge outlet at the bottom of the sedimentation tank is connected to the inlet at the bottom of the hydrolysis acidification tank via the sludge return pump.

[0008] The hydrolysis acidification tank is equipped with a gas stripping circulator, which includes a two-phase separation chamber and a liquid circulation pipe. The top opening of the liquid circulation pipe is inserted into the two-phase separation chamber, and the bottom opening of the liquid circulation pipe is provided on the side of the bottom of the two-phase separation chamber. It also includes a circulating exhaust port and a circulating exhaust pipe, with the circulating exhaust port connected to the exhaust port at the top of the two-phase separation chamber via the circulating exhaust pipe.

[0009] It also includes a nitrogen storage tank, a blower, a first inflation pipe, and a second inflation pipe. The nitrogen outlet at the top of the nitrogen storage tank is connected to an inflation port on the side of the liquid circulation pipe via the blower and the first inflation pipe. The nitrogen outlet is connected to a hydrolysis acidification tank via the second inflation pipe, and the outlet of the second inflation pipe is located inside the hydrolysis acidification tank. A first automatic valve is installed on the first inflation pipe, and a second automatic valve is installed on the second inflation pipe.

[0010] An online pH meter is installed inside the hydrolysis acidification tank.

[0011] It also includes a control platform, which is connected to the alkali addition device and the online pH meter.

[0012] It also includes a waste sludge pump and a sludge treatment system, wherein the inlet of the waste sludge pump is connected to the sludge outlet of the sedimentation tank, the outlet of the waste sludge pump is connected to the sludge treatment system, and the waste sludge pump is connected to the control platform.

[0013] This invention discloses a method for improving the efficiency of acid production from the hydrolysis and acidification of organic wastewater, comprising the following steps: Organic wastewater, after its temperature is regulated by a temperature controller, enters the hydrolysis acidification tank through the inlet. Methanogenic sludge, which inhibits methane activity, is pumped from the methanogen inhibition tank into the hydrolysis acidification tank via an inoculation sludge dosing pump. Alkali is added to the hydrolysis acidification tank via an alkali addition device to adjust the pH of the hydrolysis acidification reaction, ensuring the pH of the mixture inside the tank is 5-6. By adjusting the pH of the mixture and using the methane-inhibiting inoculation sludge, methanogenic bacteria in the tank are inhibited, thus blocking the methanogenesis process and ensuring the reaction in the hydrolysis acidification tank only reaches the acidification stage.

[0014] The present invention has the following beneficial effects: The system and method for improving the acid production efficiency of organic wastewater hydrolysis acidification, as described in this invention, involves using an inoculation sludge pump to deliver methanogenic sludge (containing inhibitors of methanogenic bacteria) from a methanogenic bacteria inhibition tank into a hydrolysis acidification tank. An alkali is then added to the tank via an alkali addition device to adjust the pH value of the hydrolysis acidification reaction. By adjusting the pH value of the mixture within the tank and using the methanogenic sludge, methanogenic bacteria are inhibited, thus blocking the methanogenesis process. This ensures the reaction in the tank remains only at the acid production stage, producing a small amount of methane and allowing small-molecule organic acids to accumulate, resulting in high acid production efficiency. Experiments show that this invention increases the acid production rate by approximately five times compared to the natural state, providing a high-quality carbon source for wastewater treatment systems and saving energy.

[0015] Furthermore, nitrogen gas is introduced into the hydrolysis acidification tank to ensure an anaerobic environment, and an air-lift circulation device is installed to ensure that the added sludge, reagents and the incoming organic wastewater are fully mixed, thereby improving the uniformity of the hydrolysis acidification reaction and thus improving the treatment effect of hydrolysis acidification. Attached Figure Description

[0016] Figure 1 This is a system diagram of the present invention.

[0017] Among them, 1 is the methanogen inhibition tank, 1-1 is the tank inlet, 1-2 is the tank outlet, 1-3 is the tank dosing port, 1-4 is the mechanical stirrer, 2 is the inoculated sludge dosing pump, 3 is the hydrolysis acidification tank, 3-1 is the water inlet, 3-2 is the water outlet, 3-3 is the dosing port, 3-4 is the inoculated sludge inlet, 3-5 is the air inlet, 3-6 is the exhaust port, 3-7 is the circulating exhaust port, 4 is the organic wastewater inlet pipe, 5 is the temperature controller, 6 is the air stripping circulator, 6-1 is the two-phase separation chamber, 6-2 is the liquid circulation port, 6-3 is the first air inlet pipe, and 6-4 is the liquid... 6-5 is the circulating pipe, 6-6 is the second air inlet pipe, 7 is the online pH meter, 8 is the sludge return pump, 9 is the sedimentation tank, 9-1 is the sedimentation tank inlet, 9-2 is the sedimentation tank sludge outlet, 9-3 is the sedimentation tank carbon source outlet, 10 is the blower, 11 is the nitrogen storage tank, 11-1 is the nitrogen storage tank outlet, 12 is the methanogen inhibitor dosing device, 13 is the alkali dosing device, 14 is the control platform, 15 is the first automatic valve, 16 is the second automatic valve, 17 is the excess sludge pump, 18 is the sludge treatment system, 19 is the carbon source transfer pump, and 20 is the carbon source dosing point. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0019] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0020] refer to Figure 1 The system for improving the acid production efficiency of organic wastewater hydrolysis acidification according to the present invention includes a methanogenic bacteria inhibition tank 1, an inhibition tank inlet 1-1, an inhibition tank outlet 1-2, an inhibition tank dosing port 1-3, a mechanical stirrer 1-4, an inoculated sludge dosing pump 2, a hydrolysis acidification tank 3, a water inlet 3-1, a water outlet 3-2, a dosing port 3-3, an inoculated sludge inlet 3-4, an air inlet 3-5, an exhaust port 3-6, a circulating exhaust port 3-7, an organic wastewater inlet pipe 4, a temperature controller 5, an air stripping circulator 6, a two-phase separation chamber 6-1, a liquid circulation port 6-2, and a first... 6-3 Aeration pipe, 6-4 Liquid circulation pipe, 6-5 Circulation exhaust pipe, 6-6 Second aeration pipe, 7 Online pH meter, 8 Sludge return pump, 9 Sedimentation tank, 9-1 Sedimentation tank inlet, 9-2 Sedimentation tank sludge outlet, 9-3 Sedimentation tank carbon source outlet, 10 Blower, 11 Nitrogen storage tank, 11-1 Nitrogen storage tank outlet, 12 Methanogen inhibitor dosing device, 13 Alkali dosing device, 14 Control platform, 15 First automatic valve, 16 Second automatic valve, 17 Residual sludge pump, 18 Sludge treatment system, 19 Carbon source transfer pump and 20 Carbon source dosing point; The methanogen inhibition tank 1 has an inhibition tank inlet 1-1 on its top side, an inhibition tank dosing port 1-3 on its top, a mechanical stirrer 1-4 inside the methanogen inhibition tank 1, an inhibition tank outlet 1-2 on its bottom side connected to the inoculation sludge inlet 3-4 on the top side of the hydrolysis acidification tank 3 via an inoculation sludge dosing pump 2, and an outlet of the methanogen inhibitor dosing device 12 connected to the inhibition tank dosing port 1-3.

[0021] The hydrolysis acidification tank 3 is equipped with a gas stripping circulator 6, which includes a two-phase separation chamber 6-1 and a liquid circulation pipe 6-4. The top opening of the liquid circulation pipe 6-4 is inserted into the two-phase separation chamber 6-1, and the bottom opening of the liquid circulation pipe 6-4 is provided. A liquid circulation port 6-2 is provided on the side of the bottom of the two-phase separation chamber 6-1.

[0022] The circulating exhaust port 3-7 is connected to the exhaust port at the top of the two-phase separation chamber 6-1 via the circulating exhaust pipe 6-5.

[0023] The outlet 3-2 on the top side of the hydrolysis acidification tank 3 is connected to the sedimentation tank inlet 9-1 at the top of the sedimentation tank 9. The sedimentation tank sludge outlet 9-2 at the bottom of the sedimentation tank 9 is connected to the inlet 3-1 at the bottom of the hydrolysis acidification tank 3 via the sludge return pump 8.

[0024] The nitrogen storage tank outlet 11-1 at the top of the nitrogen storage tank 11 is connected to the inflation port on the side of the liquid circulation pipe 6-4 via the blower 10 and the first inflation pipe 6-3. The nitrogen storage tank outlet 11-1 is connected to the hydrolysis acidification tank 3 via the first inflation pipe 6-6. The second inflation pipe is located inside the hydrolysis acidification tank 3. The first inflation pipe 6-3 is equipped with a first automatic valve 15, and the second inflation pipe 6-6 is equipped with a second automatic valve 16. The first inflation pipe 6-3 and the second inflation pipe 6-6 pass through the air inlet 3-5 on the side of the hydrolysis acidification tank 3.

[0025] The top of the hydrolysis acidification tank 3 is provided with a dosing port 3-3 and an exhaust port 3-6, and the alkali addition device 13 is connected to the dosing port 3-3.

[0026] The organic wastewater inlet pipe 4 is connected to the inlet 3-1 at the bottom of the hydrolysis acidification tank 3 via the temperature controller 5.

[0027] An online pH meter 7 is installed inside the hydrolysis acidification tank 3.

[0028] In this embodiment, the hydrolysis acidification tank 3 is a completely closed type.

[0029] In this embodiment, the methanogenic inhibitor is sodium 2-bromoethanesulfonate.

[0030] In this embodiment, a residual sludge pump 17 and a sludge treatment system 18 are also included. The inlet of the residual sludge pump 17 is connected to the sludge outlet 9-2 of the sedimentation tank, the outlet of the residual sludge pump 17 is connected to the sludge treatment system 18, and the residual sludge pump 17 is connected to the control platform 14.

[0031] In this embodiment, a carbon source dosing point 20 and a carbon source delivery pump 19 are also included. The carbon source dosing point 20 is connected to the sedimentation tank carbon source outlet 9-3 on the sedimentation tank via the carbon source delivery pump 19. The carbon source delivery pump 19 is connected to the control platform 14.

[0032] The methanogen inhibitor dosing device 12, alkali dosing device 13, mechanical stirrers 1-4, inoculated sludge dosing pump 2, first automatic valve 15, second automatic valve 16, sludge return pump 8, blower 10, excess sludge pump 17, and carbon source transfer pump 19 are controlled to start and stop via control platform 14. The online pH meter 7 uploads the monitoring data to control platform 14. Control platform 14, alkali dosing device 13, and online pH meter 7 jointly control the pH value in hydrolysis acidification tank 3.

[0033] refer to Figure 1 The method for improving the acid production efficiency of organic wastewater hydrolysis and acidification according to the present invention includes the following steps: The inoculated sludge used in the hydrolysis and acidification process enters the methanogen inhibition tank 1 through the inlet 1-1 of the inhibition tank, and methanogen inhibitor is added to the methanogen inhibition tank 1 through the methanogen inhibitor dosing device 12. The inhibitor is stirred evenly with the sludge by the mechanical stirrer 1-4, thereby inhibiting the activity of methanogens.

[0034] Organic wastewater enters the hydrolysis acidification tank 3 through the inlet 3-1 via the temperature controller 5. The temperature controller 5 provides a suitable temperature growth environment for the hydrolysis acidification bacteria, preventing the growth rate of microorganisms from being too slow and the enzyme activity from being too low, while many microorganisms will be inactivated when the temperature is too high. It is generally more suitable to set the temperature between 25-30℃.

[0035] Inoculating sludge, which inhibits methane activity, is added to the hydrolysis acidification tank 3 via inoculation sludge addition pump 2, and alkali is added to the hydrolysis acidification tank 3 via alkali addition device 13 to adjust the pH value of the hydrolysis acidification reaction. Related studies have shown that during the hydrolysis acidification process of organic wastewater, if the pH value of the reaction environment is not adjusted, the pH value of the acidified liquid quickly drops below 4. In a strongly acidic environment, the activity of acid-producing bacteria is inhibited, severely affecting the acid production rate. This invention monitors the pH value during the hydrolysis acidification process using an online pH meter 7, and adjusts the pH value in the hydrolysis acidification tank 3 every 24 hours via alkali addition device 13 to ensure that the pH value in the tank is at a suitable state, generally around 5-6, which can significantly improve the fermentation acid production efficiency. The optimal survival environment pH value for methanogens is 6.8-7.2. By controlling the pH value, methanogens can be further inhibited, completely blocking the methanogenesis process and only stopping at the acid production stage, allowing small molecule organic acids to accumulate, thereby improving the acid production efficiency.

[0036] The hydrolysis acidification tank 3 is equipped with two air-lift circulators 6 for circulating agitation, ensuring thorough mixing of the added sludge, reagents, and organic wastewater, thereby improving the uniformity of the hydrolysis acidification reaction and increasing the acid production efficiency. The nitrogen storage tank 11 uses a blower 10 to purge the liquid circulation pipe 6-4 in the air-lift circulator 6, lifting the wastewater to the two-phase separation chamber 6-1. The liquid is discharged into the hydrolysis acidification tank 3 through the liquid circulation port 6-2, achieving circulation and agitation. The air-lifted wastewater is transported to the outside of the tank through the air outlet and the circulating exhaust pipe 6-5.

[0037] The nitrogen gas charged into the hydrolysis acidification tank 3 and the gas charged into the gas lift circulation device 6 use the same gas charging equipment. When the blower 10 is turned on, the first automatic valve 15 is closed and the second automatic valve 16 is opened, and nitrogen gas is first charged into the hydrolysis acidification tank 3 for a preset time. The air in the upper layer of the hydrolysis acidification tank 3 is discharged through the exhaust port 3-6. The hydrolysis acidification tank 3 is completely sealed, so that the hydrolysis acidification tank 3 is completely oxygen-free. After the blower 10 has been turned on for a preset time, the second automatic valve 16 is closed and the first automatic valve 15 is opened to supply gas to the gas lift circulation device 6. The sealing performance of the gas lift circulation device 6 is higher than that of mechanical stirring and other stirring methods.

[0038] After the hydrolysis and acidification reaction is completed, the organic wastewater enters the sedimentation tank 9 through the outlet 3-2. Part of the sludge at the bottom of the sedimentation tank 9 is returned to the hydrolysis and acidification tank 3 through the sludge return pump 8. The acid-producing bacteria are returned with the bottom sludge to avoid loss of acid-producing bacteria and maintain the concentration of acid-producing bacteria in the tank. The remaining sludge at the bottom of the sedimentation tank 9 is transported to the sludge treatment system 18 for treatment through the remaining sludge pump 17. The supernatant of the sedimentation tank 9 is transported to the wastewater treatment plant as a high-quality carbon source for resource utilization, so as to achieve the purpose of saving energy.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A system for improving the efficiency of acid production from the hydrolysis and acidification of organic wastewater, characterized in that, It includes a methanogen inhibition tank (1), an inoculated sludge dosing pump (2), a hydrolysis acidification tank (3), an alkali addition device (13), an organic wastewater inlet pipe (4), and a temperature controller (5); The methanogen inhibition tank (1) has an outlet (1-2) on the bottom side of the inhibition tank connected to the inoculation sludge inlet (3-4) on the top side of the hydrolysis acidification tank (3) via the inoculation sludge dosing pump (2). The top of the hydrolysis acidification tank (3) is provided with a dosing port (3-3) and an exhaust port (3-6). The alkali dosing device (13) is connected to the dosing port (3-3). The organic wastewater inlet pipe (4) is connected to the inlet (3-1) at the bottom of the hydrolysis acidification tank (3) via the temperature controller (5). The hydrolysis acidification tank (3) is equipped with an air stripping circulator (6). The gas-lift circulator (6) includes a two-phase separation chamber (6-1) and a liquid circulation pipe (6-4), wherein the top opening of the liquid circulation pipe (6-4) is inserted into the two-phase separation chamber (6-1), the bottom opening of the liquid circulation pipe (6-4) is provided, and a liquid circulation port (6-2) is provided on the side of the bottom of the two-phase separation chamber (6-1). It also includes a recirculating exhaust port (3-7) and a recirculating exhaust pipe (6-5); The circulating exhaust port (3-7) is connected to the exhaust port at the top of the two-phase separation chamber (6-1) via the circulating exhaust pipe (6-5); It also includes a methanogen inhibitor dosing device (12), an inhibitor inlet (1-1) is provided on the side of the top of the methanogen inhibitor tank (1), an inhibitor dosing port (1-3) is provided on the top of the methanogen inhibitor tank (1), a mechanical stirrer (1-4) is provided inside the methanogen inhibitor tank (1), and the outlet of the methanogen inhibitor dosing device (12) is connected to the inhibitor dosing port (1-3); the methanogen inhibitor tank (1) is filled with sodium 2-bromoethanesulfonate; It also includes a nitrogen storage tank (11), a blower (10), a first inflation pipe (6-3) and a second inflation pipe (6-6). The nitrogen storage tank outlet (11-1) at the top of the nitrogen storage tank (11) is connected to the inflation port on the side of the liquid circulation pipe (6-4) via the blower (10) and the first inflation pipe (6-3). The nitrogen storage tank outlet (11-1) is connected to the hydrolysis acidification tank (3) via the second inflation pipe (6-6). A first automatic valve (15) is provided on the first inflation pipe (6-3), and a second automatic valve (16) is provided on the second inflation pipe (6-6). The outlet of the second inflation pipe (6-6) is located inside the hydrolysis acidification tank (3).

2. The system for improving the efficiency of acid production from the hydrolysis and acidification of organic wastewater according to claim 1, characterized in that, It also includes a sedimentation tank (9) and a sludge return pump (8). The outlet (3-2) on the top side of the hydrolysis acidification tank (3) is connected to the sedimentation tank inlet (9-1) at the top of the sedimentation tank (9). The sedimentation tank sludge outlet (9-2) at the bottom of the sedimentation tank (9) is connected to the inlet (3-1) at the bottom of the hydrolysis acidification tank (3) via the sludge return pump (8).

3. The system for improving the efficiency of acid production from the hydrolysis and acidification of organic wastewater according to claim 1, characterized in that, An online pH meter (7) is installed inside the hydrolysis acidification tank (3).

4. The system for improving the efficiency of acid production from the hydrolysis and acidification of organic wastewater according to claim 3, characterized in that, It also includes a control platform (14), which is connected to the alkali addition device (13) and the online pH meter (7).

5. The system for improving the efficiency of acid production from the hydrolysis and acidification of organic wastewater according to claim 4, characterized in that, It also includes a waste sludge pump (17) and a sludge treatment system (18), wherein the inlet of the waste sludge pump (17) is connected to the sludge outlet (9-2) of the sedimentation tank, the outlet of the waste sludge pump (17) is connected to the sludge treatment system (18), and the waste sludge pump (17) is connected to the control platform (14).

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