High-speed train excrement collector wastewater sludge reduction and resource utilization device, system and method

Abstract

The invention belongs to the field of sludge resource utilization, and particularly relates to a high-speed train excrement collector wastewater sludge reduction and resource utilization device, system and method. The device comprises a septic tank and a sludge fermentation tank which are sequentially connected, the interior of the septic tank is of a grid structure, a water inlet pipe and a water outlet pipe are arranged on the upper portion of the side wall of the septic tank, and a water ejector used for collecting sludge in different grids of the septic tank is further arranged above the septic tank; the bottom of the sludge fermentation tank is provided with an inclined bottom wall and a fermentation tank inner spray head used for spraying sludge upwards, the sludge fermentation tank is internally provided with a division baffle used for limiting the sludge from flowing along a turn-back type flowing path, and a sludge flowing and settling channel is formed between the division baffle and the inclined bottom wall. According to the method, resource utilization of the excrement collection type wastewater sludge is realized, the treatment cost of the sludge is saved, the potential risk of the sludge to the environment is reduced, sludge reduction and resource utilization are realized, the number of equipment is reduced, the operation cost is low, the operation is simple, and the raw materials are cheap.

Description

Technical Field

[0001] The present invention belongs to the field of sludge resource utilization, and specifically relates to a device, system and method for reducing and resource utilizing wastewater sludge from toilets in high-speed trains. Background Art

[0002] With the rapid development of the railway industry, the treatment of toilet wastewater has become a problem that relevant departments have paid more attention to recently. Since the wastewater from train toilets is collected by a vacuum toilet system, the mobile pollution source along the line is transformed into a centralized treatment and discharge method. Compared with conventional sewage, it has the characteristics of "four highs and one low", such as high organic matter (COD), high suspended solids concentration (SS), high ammonia nitrogen, high phosphorus, and low carbon ratio. With the promulgation of the "Water Quality Standard for Sewage Discharge into Urban Sewers" (GB / T 31962-2015), it is clearly limited to TN≤70mg / L and NH3-N≤45mg / L, and the problem of train toilet wastewater treatment faces more severe challenges.

[0003] In the absence of an external carbon source, the denitrification effect of treating low-carbon ratio high-speed train depot sewage using traditional biological treatment processes is poor. Therefore, in the actual treatment process, it is often necessary to add carbon sources such as sodium acetate to enhance the denitrification and phosphorus removal effect of sewage, which significantly increases the operating cost. In addition, a large amount of primary sludge precipitated in the septic tanks of train depots and stations needs to be transported out regularly, further increasing the treatment cost.

[0004] If the anaerobic fermentation products of primary sludge from septic tanks can replace sodium acetate as an external carbon source in the water treatment system to enhance the denitrification process in the biological treatment process, the amount of fecal wastewater sludge can be reduced and its resource utilization can be achieved, thereby achieving carbon emission reduction.

[0005] The hydrolysis and fermentation of sludge can achieve the purpose of sludge reduction. At the same time, a large amount of soluble organic matter (SCOD) and short-chain fatty acids (VFAs) in the fermentation liquid can be used as a carbon source for denitrification. It is known that fermentation temperature, hydraulic retention time and pH are the main factors affecting fermentation products. Appropriate pH and temperature are conducive to the dissolution of organic matter in sludge and the promotion of anaerobic acid production. Suitable SRT helps sludge hydrolysis and acidification, but too long SRT will reduce the production of VFAs. However, the existing patented technologies are mainly focused on increasing the production of SCOD in the fermentation liquid, and often ignore the problem of large amounts of N and P dissolving during the fermentation of septic tank sludge. At this time, using it as an external carbon source will further increase the denitrification load of subsequent sewage treatment processes. In addition, the existing methods for promoting anaerobic acid production in sludge have not fully considered the economic issues during the operation process, resulting in many difficulties in its actual engineering application. Summary of the invention

[0006] In order to overcome the related problems that an external carbon source is needed in the treatment of high-speed train depot sewage, and a large amount of N and P are dissolved during the fermentation of septic tank sludge, the present invention provides a high-speed train depot sewage sludge reduction and resource utilization device, system and method. First, it solves the problems of low organic matter yield and low VFAs yield in the hydrolysis and fermentation process of primary septic tank sludge, and large amount of N and P dissolution during the fermentation process; second, the fermentation liquid can be used as a carbon source for subsequent sewage treatment, which can achieve sludge reduction while reducing the addition of external carbon source in subsequent processes, thereby achieving carbon emission reduction; third, the fermentation liquid is alkaline, and the main process of reflux sewage treatment can balance the alkalinity consumed by nitrification reaction.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A high-speed train toilet wastewater sludge reduction and resource utilization device, comprising a septic tank and a sludge fermentation tank connected in sequence, wherein:

[0009] A septic tank having a compartment structure, wherein an inlet pipe and an outlet pipe are arranged on the upper part of the side wall of the septic tank, and a water ejector for collecting sludge in different compartments of the septic tank is also arranged above the septic tank;

[0010] A sludge fermentation tank is provided with an inclined bottom wall and an internal nozzle for spraying sludge upward at the bottom. A partition baffle is provided inside the sludge fermentation tank for limiting the flow of sludge along a return flow route, and a sludge flow and sedimentation channel is formed between the partition baffle and the inclined bottom wall.

[0011] In the above technical scheme, the wastewater from the high-speed train toilet enters the septic tank through the inlet pipe, the sludge is deposited at the bottom, and the supernatant enters the subsequent sewage treatment main process through the outlet pipe. The input end of the water ejector is located near the bottom of the septic tank, and the output end is connected to the nozzle in the fermentation tank at the bottom of the sludge fermentation tank through a pipeline. The power end is connected to the power water flow through a pipeline, and a pulse water distributor is arranged on the pipeline.

[0012] In the above technical solution, a plurality of partition plates are arranged in the septic tank, and the partition plates extend along the height direction of the septic tank, and a circulation channel is arranged near the middle of the partition plates.

[0013] In the above technical scheme, a carbon source supplement pipe and a sewage outlet are arranged on the upper part of the side wall of the sludge fermentation tank, a vent valve is arranged on the bottom of the side wall of the sludge fermentation tank, and an insulation layer is arranged on the outside. A part of the sludge fermentation product enters the main process anoxic zone through the carbon source supplement pipe, and the other part passes through the sewage outlet and the sewage pump as the motive water flow of the water ejector.

[0014] In the above technical solution, the number of the partition baffles is at least two, and the partition baffles extend along the height direction of the sludge fermentation tank, wherein the upper end of the partition baffle closest to the carbon source supplement pipe and the sewage outlet is fixedly connected to the top wall of the sludge fermentation tank, and the lower end is fixedly connected to the inclined intercepting plate, and the inclined intercepting plate is perpendicular to the inclined bottom wall; a fermentation product flow channel is formed between the upper ends of the remaining partition baffles and the top wall of the sludge fermentation tank.

[0015] The second invention object of the present invention is to provide a high-speed railway train toilet wastewater sludge reduction and resource utilization system, including the above-mentioned high-speed railway train toilet wastewater sludge reduction and resource utilization device and a control system that completes online monitoring and feedback during the sludge collection and fermentation process, the control system includes at least one computer processor, a memory, a pH and temperature monitor, and at least one pH and temperature detection probe electrically connected to it and arranged inside the sludge fermentation tank.

[0016] The above technical solution also includes an automatic dosing device connected to the sludge fermentation tank. The pH and temperature detection probes transmit the collected data to the computer processor and memory. The computer processor calculates the amount of dosing required to adjust to the set temperature and pH value through the computer program running on it, thereby achieving environmental stability in the sludge fermentation tank.

[0017] The third invention object of the present invention is to provide a method for reducing and recycling wastewater sludge from a high-speed train toilet, comprising the following steps:

[0018] Step 1: The wastewater from the high-speed train toilet enters the septic tank through the inlet pipe, the sludge is deposited at the bottom, and the supernatant enters the subsequent sewage treatment main process through the outlet pipe;

[0019] Step 2, using a water ejector to collect the bottom sludge in different compartments of the septic tank, connecting it to the bottom of the sludge fermentation tank, and spraying it upward in the fermentation tank through a nozzle in the fermentation tank. The sludge flows along a return flow path under the restriction of the compartment baffle. During this period, the septic tank sludge is anaerobically fermented under given fermentation temperature, pH, and sludge retention time to generate sludge fermentation products;

[0020] Step 3: a part of the sludge fermentation product enters the anoxic zone of the main process through the carbon source supplement pipe, and the sludge fermentation product is recycled to the sewage treatment system as a denitrification carbon source, and the other part is used as the motive water flow of the water ejector through the sewage pump.

[0021] In the above technical solution, the volatile solid content of the concentrated sludge obtained in step 1 is 12 to 22 g / L, and the natural sedimentation time of the primary sludge in the septic tank is 6 to 12 hours.

[0022] In the above technical solution, in step 2, the pH is set to 8.8-9.2, the temperature is set to 20-25°C, the sludge retention time is set to 48-72h, and the rising flow rate of the fermentation liquid is 0.25-0.30m / s.

[0023] The advantages and positive effects of the present invention are:

[0024] 1. By using the method proposed in the present invention, the resource utilization of sewage sludge (septic tank sludge) is realized, the disposal cost of sludge is saved, the potential risk to the environment is reduced, and the sludge is reduced and resourced.

[0025] 2. The fermentation liquid obtained after anaerobic fermentation and acid production in the present application has high organic matter content, high VFAs content, and high C / N, and can be directly reused in the anoxic zone in the sewage treatment process as a carbon source. While reducing the sludge, it also reduces the addition of carbon sources, effectively reducing carbon emissions.

[0026] 3. Taking into account the economic issues in the anaerobic fermentation process of sludge, the device and method applied for combine sludge collection, mixing and transportation together, reducing the number of equipment, low operating costs, simple operation, and cheap raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0028] Figure 1 It is a comparison chart of SCOD production during anaerobic fermentation of septic tank sludge under different treatments;

[0029] Figure 2 It is a comparison chart of C / N during anaerobic fermentation of septic tank sludge under different treatments;

[0030] Figure 3 It is a comparison chart of VFAs during anaerobic fermentation of septic tank sludge under different treatments;

[0031] Figure 4 It is a comparison chart of the comprehensive yield of VFAs in the anaerobic fermentation process of septic tank sludge under different treatments;

[0032] Figure 5 This is a schematic diagram of the structure of the device for reducing and recycling wastewater sludge from toilets in high-speed trains.

[0033] In the figure: 1. Septic tank; 1-1. Water inlet pipe; 1-2. Water outlet pipe; 1-3. Water ejector; 1-4. Partition plate; 2. Sludge fermentation tank; 2-1. Nozzle in the fermentation tank; 2-2. Vent valve; 2-3. Sewage pump; 2-4. Carbon source supplement pipe; 2-5. pH and temperature monitor; 2-6. Insulation layer; 2-7. Inclined bottom wall; 2-8. Partition baffle; 2-9. Sludge flow and sedimentation channel; 2-10. Inclined interception plate; 2-11. Fermentation product flow channel; 3. Pipeline; 3-1. Pulse water distributor. DETAILED DESCRIPTION

[0034] First of all, it should be noted that the specific structure, features and advantages of the present invention will be specifically described below by way of example, but all descriptions are only for illustration and should not be understood as limiting the present invention in any way. In addition, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature displayed or implied in the drawings, can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned in this document. In addition, in order to simplify the drawings, the same or similar technical features may be marked only in one place in the same drawing.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", "connection", "fixation", "screwing" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined, for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The present invention is described in detail below with reference to the accompanying drawings.

[0036] Embodiment 1:

[0037] A device for reducing and recycling wastewater sludge from toilets in high-speed trains, comprising a septic tank 1 and a sludge fermentation tank 2 connected in sequence, wherein:

[0038] A septic tank 1, which has a compartment structure, an inlet pipe 1-1 and an outlet pipe 1-2 are arranged on the upper part of the side wall of the septic tank 1, and a water ejector 1-3 for collecting sludge in different compartments of the septic tank 1 is also arranged above the septic tank 1;

[0039] The sludge fermentation tank 2 has an inclined bottom wall 2-7 and an internal fermentation tank nozzle 2-1 for spraying sludge upward at its bottom. The sludge fermentation tank 2 is provided with a partition baffle 2-8 for limiting the flow of sludge along a return flow route, and a sludge flow and sedimentation channel 2-9 is formed between the partition baffle 2-8 and the inclined bottom wall 2-7.

[0040] In this embodiment, the wastewater from the high-speed train toilet enters the septic tank 1 through the water inlet pipe 1-1. The septic tank is a compartment structure, and the sludge is deposited at the bottom. The supernatant enters the subsequent sewage treatment main process through the water outlet pipe 1-2; the sludge in different compartments of the septic tank 1 is collected by the water ejector 1-3, connected to the bottom of the sludge fermentation tank 2 through the pipeline 3, and sprayed to the top of the fermentation tank through the nozzle 2-1 in the fermentation tank. The fermentation tank is provided with a compartment baffle, and the sludge is stirred and the residence time is extended by the compartment baffle. The sludge fermentation tank is provided with a vent valve 2-2, the outer shell is provided with an insulation layer 2-6, and the interior is provided with a pH and temperature monitor 2-5; a part of the sludge fermentation product enters the anoxic zone of the main process through the carbon source supplement pipe 2-4, and the other part is used as the power water flow of the water ejector 1-3 through the sewage pump 2-3.

[0041] Furthermore, in this embodiment, it can also be considered that the wastewater from the high-speed rail train toilet enters the septic tank 1 through the inlet pipe 1-1, the sludge is deposited at the bottom, and the supernatant enters the subsequent sewage treatment main process through the outlet pipe 1-2. The input end of the water ejector 1-3 is located near the bottom of the septic tank 1, and the output end is connected to the nozzle 2-1 in the fermentation tank at the bottom of the sludge fermentation tank 2 through a pipeline. The power end is connected to the power water flow through the pipeline 3. A pulse water distributor 3-1 is provided on the pipeline 3 to increase the flow rate of the fluid in the pipeline.

[0042] In the device for reducing and recycling wastewater sludge from toilets in high-speed trains described in the present invention, water ejectors and valve pipelines are arranged so that sludge can be quantitatively absorbed in different compartments of the septic tank.

[0043] Furthermore, in the present embodiment, it can also be considered that a plurality of partition plates 1-4 are provided in the septic tank 1, the partition plates 1-4 extend along the height direction of the septic tank 1, and a circulation channel is provided near the middle of the partition plates 1-4.

[0044] Furthermore, in the present embodiment, a carbon source supplement pipe 2-4 and a sewage outlet are provided on the upper part of the side wall of the sludge fermentation tank 2, a vent valve 2-2 is provided on the bottom of the side wall of the sludge fermentation tank 2, and an insulation layer 2-6 is provided on the outside. A part of the sludge fermentation product enters the main process anoxic zone through the carbon source supplement pipe 2-4, and the other part passes through the sewage outlet and the sewage pump 2-3 as the motive water flow of the water ejector 1-3, which solves the problems of low organic matter production, low VFAs production, low C / N and difficulty in using the fermentation liquid as an external carbon source for sewage treatment during the hydrolysis and fermentation of primary sludge in high-speed railway train sections and septic tanks.

[0045] Furthermore, it can also be considered in this embodiment that the number of the partition baffles 2-8 is at least two, and the partition baffles 2-8 extend along the height direction of the sludge fermentation tank 2, wherein the upper end of the partition baffle 2-8 closest to the carbon source replenishment pipe 2-4 and the sewage outlet is fixedly connected to the top wall of the sludge fermentation tank 2, and the lower end is fixedly connected to the inclined interception plate 2-10, and the inclined interception plate 2-10 is perpendicular to the inclined bottom wall 2-7; the upper ends of the remaining partition baffles 2-8 and the top wall of the sludge fermentation tank 2 form a fermentation product flow channel 2-11. Figure 5 As shown, the sludge is sprayed upward in the fermentation tank through the nozzle 2-1 in the fermentation tank and fermented. Under the restriction of the partition baffle 2-8, the sludge first flows upward, passes through the fermentation product flow channel 2-11, and then flows downward under the action of gravity. In this way, it flows back and forth along the return flow route in the sludge fermentation tank 2. When it flows to the bottom of the sludge fermentation tank 2, the sludge with high density is deposited downward along the inclined bottom wall 2-7 through the sludge flow and sedimentation channel 2-9 on one side, and the sludge fermentation product with low density continues to flow forward through the sludge flow and sedimentation channel 2-9 on the other side. The sludge fermentation product continues to flow upward, and the inclined interception plate 2-10 plays an interception role. Finally, a part of the sludge fermentation product enters the main process anoxic zone through the carbon source supplement pipe 2-4, and the other part passes through the sewage pump 2-3 as the power water flow of the water ejector 1-3.

[0046] In the device for reducing and recycling wastewater sludge from toilets in high-speed trains described in the present invention, septic tank sludge is collected and sludge from a sludge fermentation tank is stirred and combined by a sewage pump and a water ejector.

[0047] In the device for reducing and recycling wastewater sludge from high-speed train toilets described in the present invention, the sludge enters the sludge fermentation tank from the bottom and is discharged from the top, and circulates in a directed manner in the tank body through the partition baffles, through the specific internal and external structures of the sludge fermentation tank.

[0048] Embodiment 2:

[0049] A high-speed train toilet wastewater sludge reduction and resource utilization system, including the high-speed train toilet wastewater sludge reduction and resource utilization device described in the above embodiment 1 and a control system that completes online monitoring and feedback during sludge collection and fermentation. The control system includes at least one computer processor, a memory, a pH and temperature monitor 2-5, and at least one pH and temperature detection probe electrically connected to the monitor and arranged inside the sludge fermentation tank 2.

[0050] Furthermore, in this embodiment, it is also possible to consider including an automatic dosing device connected to the sludge fermentation tank 2, and the pH and temperature detection probes transmit the collected data to the computer processor and memory. The computer processor calculates the amount of dosing required to adjust to the set temperature and pH value through the computer program running thereon, thereby achieving environmental stability in the sludge fermentation tank 2.

[0051] In this embodiment, the system includes at least one computer processor and memory, at least one pH and temperature detection probe, and a computer program that can run on the at least one processor. The probe can transmit the collected data to the processor and memory. The processor calculates the amount of medicine required to adjust to the set temperature and pH value through the program, thereby achieving environmental stability in the sludge fermentation tank.

[0052] The method of using the system includes the following steps:

[0053] Step 1, collecting the sludge in the septic tank of the high-speed train toilet wastewater into a sludge fermentation tank, wherein: the F wastewater is naturally settled in the primary sludge of the septic tank, and part of the supernatant is removed to obtain concentrated sludge;

[0054] Step 2, performing anaerobic fermentation on the septic tank sludge under given fermentation temperature, pH, and sludge retention time conditions;

[0055] Step 3, recycling the sludge fermentation product obtained in step 2 to the sewage treatment system for use as a denitrification carbon source, wherein: the sludge fermentation product is regulated to neutral (6.8-7.2) and can be directly recycled to the sewage treatment system for use as a denitrification carbon source.

[0056] Embodiment 3:

[0057] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0058] Embodiment 4:

[0059] An embodiment of the present invention further provides an information data processing terminal, which, when executed on an electronic device, provides a user input interface to implement the steps in the above method embodiments. The information data processing terminal is not limited to mobile phones, computers, and switches.

[0060] Embodiment 5:

[0061] A method for reducing and recycling wastewater sludge from toilets in high-speed trains, comprising the following steps:

[0062] Step 1: The wastewater from the high-speed train toilet enters the septic tank 1 through the inlet pipe 1-1, the sludge is deposited at the bottom, and the supernatant enters the subsequent sewage treatment main process through the outlet pipe 1-2;

[0063] Step 2, using the water ejector 1-3 to collect the bottom sludge in different compartments of the septic tank 1, connected to the bottom of the sludge fermentation tank 2, and sprayed upward in the fermentation tank through the nozzle 2-1 in the fermentation tank. The sludge flows along a return flow path under the restriction of the compartment baffle. During this period, the septic tank sludge is anaerobically fermented under the conditions of given fermentation temperature, pH, and sludge retention time to generate sludge fermentation products;

[0064] Step 3, part of the sludge fermentation product enters the main process anoxic zone through the carbon source supplement pipe 2-4, and the sludge fermentation product is recycled to the sewage treatment system as a denitrification carbon source, and the other part is used as the power water flow of the water ejector 1-3 through the sewage pump 2-3.

[0065] Furthermore, in this embodiment, it can also be considered that the volatile solid content of the concentrated sludge obtained in step 1 is 12 to 22 g / L, and the natural sedimentation time of the primary sludge in the septic tank is 6 to 12 hours.

[0066] Furthermore, in this embodiment, it can also be considered that in step 2, the pH is set to 8.8-9.2, the temperature is set to 20-25° C., the sludge retention time is set to 48-72 h, and the rising flow rate of the fermentation liquid is 0.25-0.30 m / s.

[0067] Embodiment 6:

[0068] The pH of the sludge fermentation tank is regulated to 9, which can take into account both high VFAs production and low operating costs. When the fermentation temperature is controlled at 20℃~25℃, the high output of SCOD, VFAs, and C / N in the sludge fermentation liquid is guaranteed, and the energy consumption caused by heating is saved. The sludge retention time is set to 2~3d, that is, 48h~72h, and can be flexibly set within this range according to the actual situation of the project.

[0069] Application Example 1:

[0070] (1) The primary sludge from the septic tank was allowed to settle naturally at room temperature for 12 hours, and the supernatant was removed to obtain concentrated sludge. The concentrated sludge had a volatile solid content of 20359 mg / L.

[0071] (2) 900 ml of concentrated sludge was placed in a 1000 ml anaerobic fermentation bottle, and the pH of the sludge was adjusted to 9 with a 2 mol / L NaOH solution, and the amount of NaOH used was recorded. Nitrogen was introduced into the fermentation bottle for 10 min, and then the fermentation bottle was sealed and placed in a water bath constant temperature oscillator with the temperature set at 20 °C and the oscillation rate at 100 rpm / min for anaerobic fermentation.

[0072] (3) During the fermentation process, sludge samples in the fermentation tank were taken at regular intervals and centrifuged to obtain the fermentation broth. The pH of the fermentation broth was adjusted to neutral (6.8-7.2) with 2 mol / L hydrogen chloride solution, and then the SCOD, TN, VFAs and other indicators of the fermentation broth were measured.

[0073] Application Example 2:

[0074] (1) The primary sludge from the septic tank was allowed to settle naturally at room temperature for 12 hours, and the supernatant was removed to obtain concentrated sludge. The concentrated sludge had a volatile solid content of 20359 mg / L.

[0075] (2) 900 ml of concentrated sludge was placed in a 1000 ml anaerobic fermentation bottle, and the pH of the sludge was adjusted to 9 with a 2 mol / L NaOH solution, and the amount of NaOH used was recorded. Nitrogen was introduced into the fermentation bottle for 10 min, and then the fermentation bottle was sealed and placed in a water bath constant temperature oscillator with the temperature set at 25 °C and the oscillation rate at 100 rpm / min for anaerobic fermentation.

[0076] (3) During the fermentation process, sludge samples in the fermentation tank were taken at regular intervals and centrifuged to obtain the fermentation broth. The pH of the fermentation broth was adjusted to neutral (6.8-7.2) with 2 mol / L hydrogen chloride solution, and then the SCOD, TN, VFAs and other indicators of the fermentation broth were measured.

[0077] Comparative Example 1 (low fermentation temperature):

[0078] (1) The primary sludge from the septic tank was allowed to settle naturally at room temperature for 12 hours, and the supernatant was removed to obtain concentrated sludge. The concentrated sludge had a volatile solid content of 20359 mg / L.

[0079] (2) 900 ml of concentrated sludge was placed in a 1000 ml anaerobic fermentation bottle, and the pH of the sludge was adjusted to 9 with a 2 mol / L NaOH solution, and the amount of NaOH used was recorded. Nitrogen was introduced into the fermentation bottle for 10 min, and then the fermentation bottle was sealed and placed in a water bath constant temperature oscillator with the temperature set at 15 °C and the oscillation rate at 100 rpm / min for anaerobic fermentation.

[0080] (3) During the fermentation process, sludge samples in the fermentation tank were taken at regular intervals and centrifuged to obtain the fermentation broth. The pH of the fermentation broth was adjusted to neutral (6.8-7.2) with 2 mol / L hydrogen chloride solution, and then the SCOD, TN, VFAs and other indicators of the fermentation broth were measured.

[0081] Comparative Example 2 (low fermentation pH):

[0082] (1) The primary sludge from the septic tank was allowed to settle naturally at room temperature for 12 hours, and the supernatant was removed to obtain concentrated sludge. The concentrated sludge had a volatile solid content of 20359 mg / L.

[0083] (2) 900 ml of concentrated sludge was placed in a 1000 ml anaerobic fermentation bottle, and the pH of the sludge was adjusted to 8 with a 2 mol / L NaOH solution, and the amount of NaOH used was recorded. Nitrogen was introduced into the fermentation bottle for 10 min, and then the fermentation bottle was sealed and placed in a water bath constant temperature oscillator with the temperature set at 20 °C and the oscillation rate at 100 rpm / min for anaerobic fermentation.

[0084] (3) During the fermentation process, sludge samples in the fermentation tank were taken at regular intervals and centrifuged to obtain the fermentation broth. The pH of the fermentation broth was adjusted to neutral (6.8-7.2) with 2 mol / L hydrogen chloride solution, and then the SCOD, TN, VFAs and other indicators of the fermentation broth were measured.

[0085] Comparative Example 3 (high fermentation pH):

[0086] (1) The primary sludge from the septic tank was allowed to settle naturally at room temperature for 12 hours, and the supernatant was removed to obtain concentrated sludge. The concentrated sludge had a volatile solid content of 20359 mg / L.

[0087] (2) 900 ml of concentrated sludge was placed in a 1000 ml anaerobic fermentation bottle, and the pH of the sludge was adjusted to 10 with a 2 mol / L NaOH solution, and the amount of NaOH used was recorded. Nitrogen was introduced into the fermentation bottle for 10 min, and then the fermentation bottle was sealed and placed in a water bath constant temperature oscillator with the temperature set at 20 °C and the oscillation rate at 100 rpm / min for anaerobic fermentation.

[0088] (3) During the fermentation process, sludge samples in the fermentation tank were taken at regular intervals and centrifuged to obtain the fermentation broth. The pH of the fermentation broth was adjusted to neutral (6.8-7.2) with 2 mol / L hydrogen chloride solution, and then the SCOD, TN, VFAs and other indicators of the fermentation broth were measured.

[0089] Comparative Example 4 (without pH adjustment):

[0090] (1) The primary sludge from the septic tank was allowed to settle naturally at room temperature for 12 hours, and the supernatant was removed to obtain concentrated sludge. The concentrated sludge had a volatile solid content of 12786 mg / L.

[0091] (2) 900 ml of concentrated sludge was placed in a 1000 ml anaerobic fermentation bottle. Nitrogen was introduced into the fermentation bottle for 10 min and then the fermentation bottle was sealed. The bottle was then placed in a water bath constant temperature oscillator with the temperature set at 20 °C and the oscillation rate set at 100 rpm / min for anaerobic fermentation.

[0092] (3) During the fermentation process, sludge samples in the fermentation tank are taken at regular intervals and centrifuged to obtain fermentation liquid. The pH of the fermentation liquid is adjusted to neutral (6.8-7.2), and then the SCOD, TN and other indicators of the fermentation liquid are measured.

[0093] like Figure 1 As shown, the SCOD content of the fermented liquid of each treatment group reached a peak value on the second day after the fermentation began, wherein the SCOD peak values ​​of Application Example 1 (pH = 9, 20°C) and Application Example 2 (pH = 9, 25°C) were 2487.17 mg / L and 2763.58 mg / L, respectively, and the SCOD peak values ​​of Comparative Example 1 (pH = 9, 15°C), Comparative Example 2 (pH = 8, 20°C), Comparative Example 3 (pH = 10, 25°C), and Comparative Example 4 (no pH adjustment, 20°C) were 2229.32 mg / L, 1389.83 mg / L, 3029.516 mg / L, and 796.68 mg / L, respectively. Each treatment group basically showed a rule that the higher the pH and the higher the temperature, the higher the organic matter dissolution within the experimental range. From the second day to the seventh day, the SCOD content of each treatment group began to slowly decrease over time. However, it is worth noting that the SCOD contents of Application Example 1 and Application Example 2 at the 5th day after the start of fermentation decreased to 1887.03 mg / L and 2179.92 mg / L, respectively, which were not much different from the peak values.

[0094] like Figure 2As shown, the C / N of the fermentation liquid of each treatment group reached a peak value on the second day after the start of fermentation, among which the C / N peak values ​​of Application Example 1 (pH = 9, 20°C) and Application Example 2 (pH = 9, 25°C) were 20.97 and 22.74 respectively, and the C / N peak values ​​of Comparative Example 1 (pH = 9, 15°C), Comparative Example 2 (pH = 8, 20°C), Comparative Example 3 (pH = 10, 25°C), and Comparative Example 4 (no pH adjustment, 20°C) were 23.88, 18.33, 23.40, and 8.22 respectively. Compared with the group without pH regulation, the treatment group with pH regulation had a higher C / N at the second day, which was more suitable as a denitrification carbon source in sewage treatment. From the second day to the seventh day, the C / N content of each treatment group began to slowly decrease over time.

[0095] like Figure 3 As shown, the content of VFAs in the fermentation liquid of each treatment group reached a peak value on the 5th day after the fermentation began, wherein the VFAs peak values ​​(in terms of COD content) of Application Example 1 (pH = 9, 20°C) and Application Example 2 (pH = 9, 25°C) were 1033.65 mg / L and 1003.3 mg / L, respectively, and the VFAs peak values ​​of Comparative Example 1 (pH = 9, 15°C), Comparative Example 2 (pH = 8, 20°C), and Comparative Example 3 (pH = 10, 25°C) were 931.13 mg / L, 512.89 mg / L, and 1376.21 mg / L, respectively. However, it is worth noting that the VFAs contents of Application Example 1 and Application Example 2 at the 2nd day after the fermentation began were 869.58 mg / L and 995.26 mg / L, respectively, which were not much different from the peak values. Each treatment group basically showed a rule that the higher the pH and the higher the temperature, the higher the VFAs yield in the experimental interval. From the 5th day to the 7th day, the VFAs content in each treatment group began to slowly decrease over time.

[0096] like Figure 4 As shown, on the 5th day of fermentation, the VFAs production of Comparative Example 3 was 1.38 times that of Example 1, but the amount of alkali used in Comparative Example 3 during the fermentation process was 2.43 times that of Example 1. At this time, the comprehensive yield of VFAs of Comparative Example 3 (VFAs production / (mass of volatile solids at the beginning of fermentation*mass of Na OH added for pH adjustment)) was 50.00 mg COD / (g VSS*g NaOH), and the comprehensive yield of VFAs of Example 1 was 88.00 mg COD / (g VSS*g NaOH). The pH of the primary sludge of the septic tank was adjusted to 10, the amount of alkali added was large, and the comprehensive yield of VFAs at this time was too low compared to that at pH=9, and the economic efficiency was poor.

[0097] In summary, adjusting the pH of the primary sludge in the septic tank to 9 can take into account both high VFAs production and low operating costs. When the fermentation temperature is controlled at 20℃~25℃, it ensures high SCOD, VFAs, and C / N output in the sludge fermentation liquid and saves energy consumption caused by heating. The SCOD peak and C / N peak appear on the 2nd day, and the VFAs peak and the peak of the comprehensive VFAs yield appear on the 5th day, but both on the 2nd and 5th days have high levels and small differences. In order to save operating costs, the fermentation time needs to be shortened as much as possible, so the sludge retention time is set to 2~3d, that is, 48h~72h, and it can be flexibly set within this range according to the actual situation of the project.

[0098] The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A device for reducing and recycling wastewater sludge from toilets in high-speed trains, characterized in that: The invention comprises a septic tank (1) and a sludge fermentation tank (2) which are connected in sequence, wherein: A septic tank (1) having a compartment structure therein, a water inlet pipe (1-1) and a water outlet pipe (1-2) being arranged on the upper part of the side wall of the septic tank (1), and a water ejector (1-3) for collecting sludge in different compartments of the septic tank (1) being arranged above the septic tank (1); A sludge fermentation tank (2) is provided with an inclined bottom wall (2-7) and a fermentation tank nozzle (2-1) for spraying sludge upward at its bottom. A partition baffle (2-8) for limiting the flow of sludge along a return flow path is provided in the sludge fermentation tank (2). A sludge flow and sedimentation channel (2-9) is formed between the partition baffle (2-8) and the inclined bottom wall (2-7).

2. The device for reducing and recycling wastewater sludge from toilets in high-speed trains according to claim 1 is characterized by: Wastewater from a high-speed train toilet enters a septic tank (1) through an inlet pipe (1-1), sludge is deposited at the bottom, and supernatant enters a subsequent sewage treatment main process through an outlet pipe (1-2). The input end of the water ejector (1-3) is located near the bottom of the septic tank (1), the output end is connected to a fermentation tank nozzle (2-1) at the bottom of a sludge fermentation tank (2) through a pipe (3), and the power end is connected to a power water flow through a pipe. A pulse water distributor (3-1) is provided on the pipe (3).

3. The device for reducing and recycling wastewater sludge from toilets in high-speed trains according to claim 2 is characterized by: A plurality of partition plates (1-4) are arranged in the septic tank (1), the partition plates (1-4) extending in the height direction of the septic tank (1), and a circulation channel is arranged near the middle of the partition plates (1-4).

4. The device for reducing and recycling wastewater sludge from toilets in high-speed trains according to claim 2 is characterized by: The upper part of the side wall of the sludge fermentation tank (2) is provided with a carbon source supplement pipe (2-4) and a sewage outlet, the bottom of the side wall of the sludge fermentation tank (2) is provided with a vent valve (2-2), and an insulation layer (2-6) is provided on the outside. A part of the sludge fermentation product enters the main process anoxic zone through the carbon source supplement pipe (2-4), and the other part passes through the sewage outlet and the sewage pump (2-3) as the power water flow of the water ejector (1-3).

5. The device for reducing and recycling wastewater sludge from toilets in high-speed trains according to claim 4 is characterized by: The number of the partition baffles (2-8) is at least two, and the partition baffles (2-8) extend along the height direction of the sludge fermentation tank (2), wherein the upper end of the partition baffle (2-8) closest to the carbon source replenishment pipe (2-4) and the sewage outlet is fixedly connected to the top wall of the sludge fermentation tank (2), and the lower end is fixedly connected to the inclined intercepting plate (2-10), and the inclined intercepting plate (2-10) is perpendicular to the inclined bottom wall (2-7); a fermentation product flow channel (2-11) is formed between the upper ends of the remaining partition baffles (2-8) and the top wall of the sludge fermentation tank (2).

6. A system for reducing and recycling wastewater sludge from toilets in high-speed trains, characterized by: It comprises a high-speed train toilet wastewater sludge reduction and resource utilization device as described in any one of claims 1 to 5, and a control system that performs online monitoring and feedback during sludge collection and fermentation, wherein the control system comprises at least one computer processor, a memory, a pH and temperature monitor (2-5), and at least one pH and temperature detection probe electrically connected thereto and arranged inside a sludge fermentation tank (2).

7. A high-speed train toilet wastewater sludge reduction and resource utilization system according to claim 6, characterized in that: It also includes automatic dosing equipment connected to the sludge fermentation tank (2), and the pH and temperature detection probes transmit the collected data to the computer processor and memory. The computer processor calculates the amount of dosing required to adjust to the set temperature and pH value through a computer program running on the computer processor, thereby achieving environmental stability in the sludge fermentation tank (2).

8. A method for reducing and recycling wastewater sludge from toilets in high-speed trains, characterized in that: The following steps are involved: Step 1, the wastewater from the high-speed train toilet enters the septic tank (1) through the inlet pipe (1-1), the sludge is deposited at the bottom, and the supernatant enters the subsequent sewage treatment main process through the outlet pipe (1-2); Step 2, using a water ejector (1-3) to collect the bottom sludge in different compartments of the septic tank (1), connecting it to the bottom of the sludge fermentation tank (2), and spraying it upward in the fermentation tank through a nozzle (2-1) in the fermentation tank. The sludge flows along a return flow path under the restriction of the compartment baffle (2-8). During this period, the septic tank sludge is anaerobically fermented under given fermentation temperature, pH, and sludge retention time conditions to generate sludge fermentation products; Step 3, part of the sludge fermentation product enters the anoxic zone of the main process through the carbon source supplement pipe (2-4), and the sludge fermentation product is recycled to the sewage treatment system as a denitrification carbon source, and the other part is used as the motive water flow of the water ejector (1-3) through the sewage pump (2-3).

9. A method for reducing and recycling wastewater sludge from toilets in high-speed trains according to claim 8, characterized in that: The volatile solid content of the concentrated sludge obtained in step 1 is 12-22 g / L, and the natural sedimentation time of the primary sludge in the septic tank is 6-12 h.

10. The method for reducing and recycling wastewater sludge from toilets in high-speed trains according to claim 8, characterized in that: In step 2, the pH is set to 8.8-9.2, the temperature is set to 20-25°C, the sludge retention time is set to 48-72h, and the rising flow rate of the fermentation liquid is 0.25-0.30m / s.

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