Apparatus and method for treating sludge by coupling hydrolytic acidification with biological drying

Abstract

Disclosed in the present invention are an apparatus and method for treating sludge by coupling hydrolytic acidification with biological drying, the method comprising: dewatering sludge, mixing same with wood chips, which are an auxiliary material, so as to regulate the water content, and then enabling the mixture to enter a hydrolytic acidification area through a sludge inlet of a reactor, the pH of the hydrolytic acidification area being controlled to be 3-4, and the hydrolytic acidification area being rapidly started up by inoculating hydrolytic acidification bacteria; enabling the sludge to stay in the hydrolytic acidification area for 3-5 days, and then enabling the sludge to enter a biological drying area and stay therein for 5-8 days; and after the biological drying, discharging the sludge from a sludge outlet, wherein the biological drying area works under continuous or intermittent aeration to keep the oxygen concentration thereof at 2-8 vt%, the remainder being nitrogen, and carbon dioxide and other gas generated in the hydrolytic acidification and biological drying processes are discharged from vent holes in the top of the reactor. In the present invention, the hydrolytic acidification area and the biological drying area are provided in the reactor, such that the hydrolytic acidification area is fully utilized to degrade the macromolecular refractory organic matter in sludge, and then the degraded organic matter can be fully utilized by means of the biological drying area, thereby improving biological drying efficiency.

Description

A device and method for treating sludge by hydrolysis and acidification coupled with biological drying Technical field:

[0001] The present invention relates to the technical field of sludge resource utilization, and in particular to a device and method for treating sludge by hydrolysis and acidification coupled with biological drying. Background technology:

[0002] Sludge biological drying technology utilizes the bioheat generated by aerobic microbial respiration during the degradation of organic matter in sludge, combined with forced ventilation to promote water evaporation, to achieve rapid and efficient sludge drying without the addition of external heat. The drying process minimizes organic matter and calorific value loss, offering advantages such as low energy consumption, stable equipment operation, and flexible product applications. However, current sludge biological drying technology still faces bottlenecks such as low microbial oxygen utilization and a short duration of the high-temperature period, resulting in a long process and large footprint, hindering its widespread application.

[0003] The high temperature period is the most important part of biological drying, as it allows for a large amount of water to be removed. Maintaining the high temperature period is not only for better water removal, but also to provide a favorable growth environment for thermophilic microorganisms and maintain their activity.

[0004] Organic matter in sludge is primarily composed of proteins and polysaccharides. Studies have shown that the utilization rate of organic matter in the biodrying process is approximately 15%. To further improve this utilization, a hydrolysis-acidification coupled biodrying process has been developed to achieve rapid degradation of large, recalcitrant organic matter, providing more effective organic matter for the biodrying system and improving its efficiency. Summary of the invention:

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a device and method for treating sludge by coupling hydrolysis and acidification with biological drying. The hydrolysis and acidification zone in the reactor is used to rapidly degrade the sludge, converting large molecular weight, difficult-to-degrade organic matter into easily degradable substances. The biological drying system is then used to fully utilize the small molecular weight substances produced after hydrolysis and acidification, thereby improving the biological drying efficiency.

[0006] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0007] A device for treating sludge by coupling hydrolysis and acidification with biological drying, the main body of which is a reactor, the top of the reactor is provided with an air vent, the bottom of the reactor is provided with a support, a first baffle is provided in the reactor, the bottom of the first baffle is mounted on the bottom of the reactor, and a gap is left between the top and the top of the reactor, the first baffle divides the interior of the reactor into a hydrolysis and acidification zone and a biological drying zone, the bottom of the biological drying zone is provided with a mud inlet, and the top is formed with an opening through the first baffle, a second baffle is provided in the hydrolysis and acidification zone, the second baffle divides the biological drying zone into a descending zone and an ascending zone, the descending zone is adjacent to the biological drying zone, aeration devices are provided at the bottom of the descending zone and the ascending zone, the top and bottom of the second baffle leave a flow gap with the inner wall of the reactor, and the top surface of the second baffle is higher than the top surface of the first baffle, and the outer wall of the reactor is provided with a mud outlet and a feeding port.

[0008] Further technology of the present invention:

[0009] Preferably, the pH of the hydrolysis and acidification zone is controlled at 3-4.

[0010] Preferably, the biological drying zone is aerated continuously or intermittently to maintain an oxygen concentration of 2-8vt% in the zone, with the remainder being nitrogen.

[0011] Preferably, the hydrolysis and acidification zone is quickly started by inoculating hydrolysis and acidification bacteria, including but not limited to the following various facultative and obligate anaerobic bacteria, including Clostridium, anaerobic peptococcus, Bifidobacterium, Desulfovibrio, Corynebacterium, Lactobacillus, Actinomyces, Staphylococcus and Escherichia coli.

[0012] Preferably, a first auger is provided in the hydrolysis and acidification zone, and the first auger drives the sludge in the hydrolysis and acidification zone to move upward; a second auger is provided in the descending zone of the biological drying zone, and the second auger drives the sludge in the descending zone to move downward; a third auger is provided in the ascending zone of the biological drying zone, and the second auger drives the sludge in the ascending zone to move upward; and the driving motors of the first auger, the second auger and the third auger are all provided at the bottom of the reactor.

[0013] Preferably, the mud outlet is located above the side wall of the reactor and communicates with the upward zone, and is located below the feeding port.

[0014] Preferably, gates are provided at both the mud outlet and the feeding port, and a gate is also provided in the upward area between the mud outlet and the feeding port.

[0015] Preferably, the method of utilizing the device is as follows:

[0016] The sludge is dehydrated and mixed with sawdust auxiliary materials in a ratio of 3:1, and the moisture content is adjusted to 50%-60%. The sludge enters the hydrolysis and acidification zone from the mud inlet of the reactor. The pH of the hydrolysis and acidification zone is controlled at 3-4. The hydrolysis and acidification zone is quickly started by inoculating hydrolysis and acidification bacteria. The sludge stays in the hydrolysis and acidification zone for 3-5 days. The drive motor is turned on and the first auger is started to drive the sludge in the hydrolysis and acidification zone upward to the opening and enter the biological drying zone. The biological drying agent is added from the feeding port and enters the biological drying zone. Due to the obstruction of the second partition, the second auger is opened in conjunction with the opening. The sludge first enters the descending zone of the biological drying zone from the hydrolysis and acidification zone, and then the third auger is opened. The sludge enters the ascending zone from the flow gap at the bottom of the second partition. The third auger is closed and the sludge stays for 5-8 days.

[0017] After biological drying, continue to open the third auger, and the sludge is discharged from the mud outlet. The biological drying area is aerated continuously or intermittently to maintain the oxygen concentration in the area at 2-8vt%, and the rest is nitrogen. The carbon dioxide and other gases generated by the hydrolysis, acidification and biological drying process are discharged from the vents on the upper part of the reactor.

[0018] Preferably, the sludge after the first biological drying is discharged from the mud outlet, and 10%-20% remains. The mud outlet gate is closed, and the gate between the mud outlet and the feeding port is opened. The sludge returns through the top flow gap of the second partition and is mixed with the subsequent acidified sludge and enters the biological drying area.

[0019] The beneficial effects of the present invention are:

[0020] Good comprehensive treatment effect: By coupling hydrolysis acidification and biological drying, sludge can be comprehensively treated in an integrated reactor, reducing the complexity of the treatment process.

[0021] Low energy consumption: The optimized reactor design reduces the energy consumption of the entire treatment process.

[0022] Efficient degradation of organic matter: Through the synergistic effect of hydrolysis and acidification and biological drying, organic matter can be effectively degraded and treatment efficiency can be improved.

[0023] Environmentally friendly and sustainable: The use of chemical agents is reduced, and the utilization of waste heat meets the requirements of environmental protection and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] FIG1 is a schematic diagram of the structure of a device for treating sludge by hydrolysis and acidification coupled with biological drying;

[0026] Figure 2 is a schematic diagram of sludge flow in the device;

[0027] The serial numbers in the above figure are: 1-reactor, 2-vent, 3-support, 4-first baffle, 5-hydrolysis and acidification zone, 6-biological drying zone, 7-mud inlet, 8-second baffle, 9-downstream zone, 10-upstream zone, 11-aeration device, 12-mud outlet, 13-feeding port, 14-first auger, 15-second auger, 16-third auger, 17-drive motor, 18-gate. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0029] As shown in Figure 1 , this embodiment provides a device for treating sludge by hydrolysis and acidification coupled with biological drying. The main body comprises a reactor 1. A vent 2 is provided at the top of the reactor 1 to facilitate the discharge of carbon dioxide and other gases generated during the hydrolysis and acidification and biological drying processes. A support 3 is provided at the bottom.

[0030] The reactor 1 is provided with a first baffle 4, the bottom of which is mounted on the bottom of the reactor 1, and a gap is left between the top and the top of the reactor 1. The first baffle 4 divides the interior of the reactor 1 into a hydrolysis and acidification zone 5 and a biological drying zone 6. The biological drying zone 6 is provided with a mud inlet 7 at the bottom, and an opening is formed at the top through the first baffle 4. The hydrolysis and acidification zone 5 is provided with a second baffle 8, which divides the biological drying zone 6 into a descending zone 9 and an ascending zone 10. The descending zone 9 is adjacent to the biological drying zone 6. The temperature of the hydrolysis and acidification zone 5 will increase with the increase of the temperature of the biological drying zone 6. High temperature is conducive to further accelerating the efficiency of hydrolysis and acidification. An aeration device 11 is provided at the bottom of the descending zone 9 and the ascending zone 10. The top and bottom of the second baffle 8 leave a flow gap with the inner wall of the reactor 1, and the top surface of the second baffle 8 is higher than the top surface of the first baffle 4. The outer wall of the reactor 1 is provided with a mud outlet 12 and a feeding port 13.

[0031] In this embodiment, a hydrolysis and acidification zone 5 and a biological drying zone 6 are respectively set inside the reactor 1, and the hydrolysis and acidification zone 5 is fully utilized to degrade the large molecular difficult-to-degrade organic matter in the sludge, and the degraded organic matter is fully utilized through the biological drying zone 6 to improve the biological drying efficiency.

[0032] The pH of the hydrolysis and acidification zone 5 is controlled at 3-4. This helps decompose organic matter and produce acidic metabolites. Too low a pH will affect the efficiency of the biological drying system, while too high a pH indicates poor hydrolysis and acidification results.

[0033] The biological drying zone 6 is aerated continuously or intermittently to maintain an oxygen concentration of 2-8vt% in the zone, with the remainder being nitrogen.

[0034] The hydrolysis and acidification zone 5 is quickly started by inoculating hydrolysis and acidification bacteria, including but not limited to the following facultative and obligate anaerobic bacteria, including Clostridium, anaerobic peptococcus, Bifidobacterium, Desulfovibrio, Corynebacterium, Lactobacillus, Actinomyces, Staphylococcus and Escherichia coli.

[0035] In order to increase the sludge movement efficiency in the above structure, a first auger 14 is provided in the hydrolysis and acidification zone 5, and the first auger 14 drives the sludge in the hydrolysis and acidification zone 5 to move upward. A second auger 15 is provided in the descending zone 9 of the biological drying zone 6, and the second auger 15 drives the sludge in the descending zone 9 to move downward. A third auger 16 is provided in the ascending zone 10 of the biological drying zone 6, and the second auger 15 drives the sludge in the ascending zone 10 to move upward. The driving motors 17 of the first auger 14, the second auger 15 and the third auger 16 are all provided at the bottom of the reactor 1.

[0036] The mud outlet 12 is located above the side wall of the reactor 1 and communicates with the upward zone 10 , and is located below the feeding port 13 .

[0037] Both the mud outlet 12 and the feeding port 13 are provided with gates, and a gate 18 is also provided in the upward area 10 between the mud outlet 12 and the feeding port 13 .

[0038] This embodiment also provides a method for utilizing the device, as follows:

[0039] As shown in Figure 2, sludge is taken for dehydration, and wood chips are mixed with auxiliary materials in a ratio of 3:1 to adjust the moisture content to 50%-60%. The sludge enters the hydrolysis and acidification zone 5 from the mud inlet 7 of the reactor 1. The pH of the hydrolysis and acidification zone 5 is controlled at 3-4. The hydrolysis and acidification zone 5 is quickly started by inoculating hydrolysis and acidification bacteria. The sludge stays in the hydrolysis and acidification zone 5 for 3-5 days. The drive motor 17 is turned on and the first auger 14 is started to drive the sludge in the hydrolysis and acidification zone 5 upward to the opening and enter the biological drying zone 6. The biological drying agent is added from the feeding port 13 and enters the biological drying zone 6. Due to the obstruction of the second partition 8, the second auger 15 is opened in conjunction with the opening. The sludge first enters the descending zone 9 of the biological drying zone 6 from the hydrolysis and acidification zone 5, and then the third auger 16 is opened. The sludge enters the ascending zone 10 through the flow gap at the bottom of the second partition 8. The third auger 16 is closed and the sludge stays for 5-8 days.

[0040] After biological drying, the third auger 16 is continued to be turned on, and the sludge is discharged from the mud outlet 12. The biological drying zone 6 is aerated continuously or intermittently to maintain the oxygen concentration in the area at 2-8vt%, and the rest is nitrogen. The carbon dioxide and other gases generated by the hydrolysis, acidification and biological drying process are discharged from the vent 2 at the top of the reactor 1.

[0041] The sludge after the first biological drying is discharged from the mud outlet 12, and 10%-20% remains. The gate of the mud outlet 12 is closed, and the gate 18 between the mud outlet 12 and the feeding port 13 is opened. The sludge returns through the top flow gap of the second partition 8 and is mixed with the sludge that has been subsequently acidified and enters the biological drying area 6.

[0042] The above description is merely a preferred embodiment of the present invention. Anyone skilled in the art may utilize the above-described technical solutions to modify the present invention or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent replacement based on the technical solution of the present invention falls within the scope of protection claimed by the present invention.

Claims

1. A device for treating sludge by hydrolysis and acidification coupled with biological drying, characterized in that: The main body is a reactor, which has an air vent on the top and a support at the bottom. A first partition is provided in the reactor, and the bottom of the first partition is mounted on the bottom of the reactor, with a gap between the top and the top of the reactor. The first partition divides the interior of the reactor into a hydrolysis and acidification zone and a biological drying zone. The bottom of the biological drying zone is provided with a mud inlet, and the top is formed with an opening through the first partition. A second partition is provided in the hydrolysis and acidification zone, and the second partition divides the biological drying zone into a descending zone and an ascending zone. The descending zone is adjacent to the biological drying zone, and aeration devices are provided at the bottom of the descending zone and the ascending zone. The top and bottom of the second partition leave a flow gap with the inner wall of the reactor, and the top surface of the second partition is higher than the top surface of the first partition. The outer wall of the reactor is provided with a mud outlet and a feeding port.

2. The device for treating sludge by hydrolysis and acidification coupled with biological drying according to claim 1, characterized in that: The pH of the hydrolysis and acidification zone is controlled at 3-4.

3. The device for treating sludge by hydrolysis and acidification coupled with biological drying according to claim 1, characterized in that: The biological drying zone is aerated continuously or intermittently to maintain an oxygen concentration of 2-8vt% in the zone, with the remainder being nitrogen.

4. The device for treating sludge by hydrolysis and acidification coupled with biological drying according to claim 1, characterized in that: The hydrolysis and acidification zone is quickly started by inoculating hydrolysis and acidification bacteria, including but not limited to the following facultative and obligate anaerobic bacteria, including Clostridium, anaerobic peptococcus, Bifidobacterium, Desulfovibrio, Corynebacterium, Lactobacillus, Actinomyces, Staphylococcus and Escherichia coli.

5. The device for treating sludge by hydrolysis and acidification coupled with biological drying according to claim 1, characterized in that: A first auger is provided in the hydrolysis and acidification zone, which drives the sludge in the hydrolysis and acidification zone to move upward. A second auger is provided in the descending zone of the biological drying zone, which drives the sludge in the descending zone to move downward. A third auger is provided in the ascending zone of the biological drying zone, which drives the sludge in the ascending zone to move upward. The driving motors of the first auger, the second auger and the third auger are all provided at the bottom of the reactor.

6. The device for treating sludge by hydrolysis and acidification coupled with biological drying according to claim 5, characterized in that: The mud outlet is located above the side wall of the reactor and is communicated with the upward zone, and is located below the feeding port.

7. The device for treating sludge by hydrolysis and acidification coupled with biological drying according to claim 6, characterized in that: The mud outlet and the feeding port are both provided with gates, and the upward area between the mud outlet and the feeding port is also provided with a gate.

8. The device for treating sludge by hydrolysis and acidification coupled with biological drying according to claim 7, characterized in that: The method of using the device is as follows: The sludge is dehydrated and mixed with sawdust auxiliary materials in a ratio of 3:1, and the moisture content is adjusted to 50%-60%. The sludge enters the hydrolysis and acidification zone from the mud inlet of the reactor. The pH of the hydrolysis and acidification zone is controlled at 3-4. The hydrolysis and acidification zone is quickly started by inoculating hydrolysis and acidification bacteria. The sludge stays in the hydrolysis and acidification zone for 3-5 days. The drive motor is turned on and the first auger is started to drive the sludge in the hydrolysis and acidification zone upward to the opening and enter the biological drying zone. The biological drying agent is added from the feeding port and enters the biological drying zone. Due to the obstruction of the second partition, the second auger is opened in conjunction with the opening. The sludge first enters the descending zone of the biological drying zone from the hydrolysis and acidification zone, and then the third auger is opened. The sludge enters the ascending zone from the flow gap at the bottom of the second partition. The third auger is closed and the sludge stays for 5-8 days. After biological drying, continue to open the third auger, and the sludge is discharged from the mud outlet. The biological drying area is aerated continuously or intermittently to maintain the oxygen concentration in the area at 2-8vt%, and the rest is nitrogen. The carbon dioxide and other gases generated by the hydrolysis, acidification and biological drying process are discharged from the vents on the upper part of the reactor.

9. The device for treating sludge by hydrolysis and acidification coupled with biological drying according to claim 8, characterized in that: After the first biological drying, part of the sludge is discharged from the mud outlet, and 10%-20% remains. The mud outlet gate is closed, and the gate between the mud outlet and the feeding port is opened. The sludge returns through the top flow gap of the second partition and is mixed with the subsequent acidified sludge and enters the biological drying area.

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