Device and method for preparing composite carbon source from high-concentration organic wastewater

Abstract

The invention relates to the technical field of organic wastewater resource utilization, in particular to a device and method for preparing a composite carbon source from high-concentration organic wastewater, and the device comprises a hydrolysis device, an acidification device, a separation device and a concentration device which are connected in sequence; the hydrolysis device and the acidification device are respectively provided with an up-flow type hydraulic circulation stirring system, and are provided with a labyrinth inclined plate and an effluent weir in a matched manner, so that low-consumption and high-efficiency mud-water separation can be realized; through an intelligent adjusting system, the temperature and pH value in the hydrolysis and acidification process can be automatically controlled, the fermentation efficiency of the material can be improved, the preparation period of the carbon source can be shortened, and the stability of the product can be improved; the quality of the carbon source is further improved through physical processes such as membrane separation and membrane concentration; the high-concentration organic wastewater generated in the processing process of organic garbage and agricultural products is converted into a high-added-value recycling product, and the high-concentration organic wastewater is applied to the denitrification process of a sewage treatment plant, so that the denitrification performance is improved, and the recycling utilization of the high-concentration organic wastewater is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of resource utilization of organic wastewater, and particularly to a device and method for preparing a composite carbon source from high-concentration organic wastewater. Background Art

[0002] In China, sewage treatment plants generally have problems such as low C / N in the influent and reduced microbial activity in the biochemical pool in winter, resulting in C / N imbalance. Most sewage treatment plants basically need to reserve carbon sources for a long time to adjust C / N to achieve stable sewage treatment effects. At present, the main commercial carbon sources are methanol, acetic acid, sodium acetate, glucose, etc. Although they have good denitrification effects, they have problems such as poor safety (methanol) and high prices (acetic acid, glucose), which greatly increase the sewage treatment cost. Therefore, a composite carbon source with good quality and low cost is needed.

[0003] A composite carbon source refers to a product composed of two or more small-molecule organic acids (such as acetic acid, propionic acid, butyric acid, etc.) or alcohols (such as methanol, ethanol, propanol, etc.), which can provide nutrients for the growth and metabolism of microorganisms in the sewage biochemical treatment system. In recent years, researchers have done certain research on the preparation of composite carbon sources. For example, the system and method for preparing a new biomass carbon source by enhanced anaerobic fermentation of organic waste disclosed in Chinese Patent CN202110709179.8 perform extrusion, impurity removal, three-phase separation, fermentation, and separation and purification on organic waste to obtain a biomass carbon source product, and the effective equivalent of COD of the carbon source product is not high. The equipment and method for preparing a kitchen waste high-efficiency fermentation carbon source disclosed in Chinese Patent CN202311585638.1 improve the fermentation acid production efficiency through pneumatic internal circulation stirring, but there are problems such as poor system stability and incomplete biological reactions. Summary of the Invention

[0004] The purpose of the present invention is to provide a device and method for preparing a composite carbon source from high-concentration organic wastewater that can improve the quality of the produced carbon source and has low production costs.

[0005] Based on the above purpose, the present invention adopts the following technical solutions:

[0006] A device for preparing a composite carbon source from high-concentration organic wastewater includes a hydrolysis device, an acidification device, a separation device, and a concentration device connected in sequence. The hydrolysis device includes a hydrolysis tank, and the acidification device includes an acidification tank; circulation pumps are provided on both the hydrolysis tank and the acidification tank, and the circulation pumps are connected to a water supply system; a hydraulic circulation stirring system is provided inside both the hydrolysis tank and the acidification tank, and the hydraulic circulation stirring system is arranged at the bottom of the hydrolysis tank and the acidification tank; a labyrinth inclined plate is provided inside both the hydrolysis tank and the acidification tank, an effluent weir is provided above the labyrinth inclined plate, and the outlets of the hydrolysis tank and the acidification tank are arranged inside the effluent weir; both the hydrolysis device and the acidification device include an intelligent adjustment system, and the intelligent adjustment system includes a dosing device and a temperature adjustment device.

[0007] The labyrinth inclined plate is composed of a complex channel network structure formed by multiple layers of arranged inclined plates or corrugated plates, which is similar to the circuitous path in a labyrinth. Its principle is similar to that of an inclined plate sedimentation tank, and solid particles can settle naturally during the flow process through the inclination angle to reduce the sludge loss in the hydrolysis tank and acidification tank.

[0008] Preferably, the hydraulic circulation stirring system includes a main water distribution pipe, on which a circulating water connection port is provided and is connected to a circulating pump; the main water distribution pipe is connected with a plurality of water distribution pipes through valves, and each water distribution pipe extends into the hydrolysis tank or acidification tank and is connected with a hydraulic stirrer at the end.

[0009] Preferably, the hydraulic stirrer is a straight pipe structure with a water outlet on the side. A plurality of hydraulic stirrers in the same hydrolysis tank or acidification tank are evenly arranged around the vertical central axis in a rotating manner, and the water outlet directions of the plurality of hydraulic stirrers are the same.

[0010] Preferably, the intelligent regulation system includes a pH / T meter, which is arranged on the side walls of the hydrolysis tank and acidification tank; a chemical dosing device is provided with a chemical dosing port, and a stirring device is arranged inside the chemical dosing device; the chemical dosing device is connected to the hydrolysis tank and acidification tank through a metering pump.

[0011] Preferably, the temperature regulation device includes a heating device and a heat preservation device arranged in the hydrolysis tank and acidification tank. The heating device is an electric heating rod or a steam coil; the temperature regulation device includes a PLC connected to the pH / T meter, and the PLC is connected to the heating device and the heat preservation device through a data communication module.

[0012] Preferably, the labyrinth inclined plate includes a plurality of inclined plate-like structures arranged in parallel at equal intervals. The inclination angle of the labyrinth inclined plate with respect to the horizontal plane is 30 - 80°; the effluent weir is arranged in a ring shape around the inner side surface of the hydrolysis tank and acidification tank, and the top of the effluent weir plate of the effluent weir is set as a triangular tooth-like structure.

[0013] A method for preparing a composite carbon source includes the following steps:

[0014] S1. Wastewater pretreatment: Pretreat the high-concentration organic wastewater; the pretreatment process includes grid / screen filtration, sedimentation, and flotation; grid / screen filtration is used to remove larger solid particles (such as fruit peels, fibers, residues, etc.) in the wastewater, and sedimentation and flotation are used to remove suspended solids and oils (such as oils in food waste) by using a sedimentation tank or a flotation device;

[0015] S2. Stirring hydrolysis: Feed the wastewater obtained in step S1 into the hydrolysis device and stir it through the hydraulic circulation stirring system, and hydrolyze for 1 - 2 days under the action of amylase; the hydrolysis temperature is 35 - 45°C, and the pH value is 4 - 6;

[0016] S3. Stirring acidification: The wastewater treated in step S2 is introduced into an acidification device and acidified for 2 - 4 days under the action of a hydraulic circulation stirring system at an acidification temperature of 35 - 45°C and a pH value of 5 - 7.

[0017] S4. Solid - liquid separation: The wastewater treated in step S3 is transported to a centrifugal separation device, and the solid residues and grease in the wastewater are removed by centrifugal separation to obtain liquid - phase organic acids.

[0018] S5. Membrane separation: The liquid - phase organic acids treated in step S4 are separated and purified through a ceramic membrane separation device to remove suspended solids in the liquid phase to obtain a clear liquid.

[0019] S6. Membrane concentration: The clear liquid treated in step S5 is concentrated through a concentration device to obtain a composite carbon source.

[0020] Preferably, in step S4, the rotational speed range of the centrifugal separation device is 3000 - 5000 rpm; in step S5, the membrane pore size range of the ceramic membrane separation device is 50 - 150 nm; in step S6, the concentration device uses a nanofiltration membrane or an RO membrane.

[0021] Preferably, in step S3, two acidification tanks are arranged in series in the acidification device. After staying in the first acidification tank for 1 - 2 days, it stays in the second acidification tank for 1 - 2 days. Series connection means connecting the two acidification tanks in sequence, and the effluent of acidification tank 1 serves as the influent of acidification tank 2.

[0022] Preferably, in step S3, two acidification tanks are arranged in parallel in the acidification device to acidify the hydrolyzed wastewater, and it stays in the two acidification tanks for 2 - 4 days. Parallel connection means that the two acidification tanks simultaneously treat the same stream of wastewater. Acidification tank 1 and acidification tank 2 operate independently but jointly undertake the treatment task; whether the two acidification tanks are connected in parallel or in series, the overall residence time of the material in them is the same, totaling 2 - 4 days. The beneficial effects of the present invention are as follows:

[0023] The present invention can treat high - concentration organic wastewater of different properties singly or synergistically, including wastewater generated during the treatment of organic garbage such as kitchen waste and food waste, as well as wastewater generated during processes such as agricultural product and food processing. It has a wide range of applications and can be widely used in the treatment of organic wastewater in various industries.

[0024] The present invention separately arranges the devices for hydrolysis and acidification reactions, which is conducive to achieving full contact of materials and accurate distinction of the metabolic process; both the hydrolysis and acidification devices adopt up - flow hydraulic stirring, which can effectively reduce the energy consumption of the equipment; by setting two acidification tanks and using valves to adjust the connection relationship between the two acidification tanks, the two acidification tanks can be connected in "series" or "parallel" respectively; when connected in parallel, the treatment efficiency can be improved, and when connected in series, the treatment effect can be gradually optimized.

[0025] Compared with the traditional process of preparing carbon source by hydrolysis and acidification, the present invention can add specific enzymes in the hydrolysis stage to promote the degradation of macromolecular substances, and then adjust parameters such as temperature and pH to achieve directional acid production (mainly acetic acid), thereby improving the biodegradability of organic wastewater, shortening the fermentation cycle and improving the treatment efficiency; and adopting the method of physical separation and purification to further improve the COD equivalent and C / N of the obtained carbon source, so as to obtain a composite carbon source with high quality and good stability. Description of the Drawings

[0026] Figure 1 is the flow chart of the present invention;

[0027] Figure 2 is the top view of the hydrolysis device and acidification device in Embodiment 1 of the present invention;

[0028] Figure 3 is the front view of the hydrolysis device and acidification device in Embodiment 1 of the present invention;

[0029] Figure 4 is the schematic diagram of the internal structure of the hydrolysis tank and acidification tank in Embodiment 1 of the present invention;

[0030] Figure 5 is the schematic diagram of the structure of the hydraulic circulation stirring system in Embodiment 1 of the present invention;

[0031] Figure 6 is the schematic diagram of the lower layer support and upper fixing structure of the labyrinth inclined plate in Embodiment 1 of the present invention;

[0032] Figure 7 is the top view of the structure of the effluent weir in Embodiment 1 of the present invention;

[0033] Figure 8 is the schematic diagram of the structure of the effluent weir plate in Embodiment 1 of the present invention.

[0034] In the figure: chemical dosing device 1; pH / T meter 11; metering pump 2; hydrolysis tank 3; inlet of hydrolysis circulation pump 31; acidification tank 4; inlet of acidification circulation pump 41; valve 42; hydrolysis circulation pump 5; hydrolysis circulation pipe 51; acidification circulation pump 6; acidification circulation pipe 61; hydraulic stirrer 7; circulating water connection port 71; distribution main pipe 72; water distribution pipe 73; butterfly valve 74; labyrinth inclined plate 8; effluent weir 9. Detailed Embodiments

[0035] Embodiment 1

[0036] The following is a further explanatory description of the present invention in combination with specific embodiments, such as Figure 1As shown in the figure, this embodiment is a device for preparing composite carbon source from high-concentration organic wastewater, which mainly includes a hydrolysis device, an acidification device, a separation device and a concentration device connected in sequence, for hydrolyzing, acidifying, solid-liquid separating, membrane separating and membrane concentrating the high-concentration organic wastewater in sequence to finally obtain composite carbon source and low-concentration clear liquid.

[0037] As Figure 2 and Figure 3 shown, the hydrolysis device includes a hydrolysis tank 3, and the acidification device includes two acidification tanks 4; both the hydrolysis tank 3 and the acidification tank 4 are connected with circulation pumps, namely a hydrolysis circulation pump 5 and an acidification circulation pump 6 respectively; the hydrolysis circulation pump 5 is connected with the hydrolysis tank 3 through a hydrolysis circulation pipe 51, and the acidification circulation pump 6 is connected with the acidification tank 4 through an acidification circulation pipe 61; the two circulation pumps are also respectively connected with an external water supply system, which can supply water to the hydrolysis tank 3 and the acidification tank 4, or recycle the water therein; a hydrolysis circulation pump inlet 31 is arranged on the hydrolysis tank 3, and an acidification circulation pump inlet 41 is arranged on the acidification tank 4, which are respectively connected with the hydrolysis circulation pump 5 and the acidification circulation pump 6 to discharge the water in the tank for recycling.

[0038] As Figure 4 and Figure 5 shown, at the inner bottom of both the hydrolysis tank 3 and the acidification tank 4, a hydraulic circulation stirring system is arranged, including a hydraulic stirrer 7; the hydraulic stirrer 7 is a straight pipe structure with a water outlet on one side, which is connected to a water distribution main pipe 72 through a water distribution pipe 73, and the water distribution main pipe 72 is further connected with the circulation pump through a circulating water connection port 71; in this embodiment, four hydraulic stirrers 7 are arranged in each of the hydrolysis tank 3 and the acidification tank 4, and the four hydraulic stirrers 7 are evenly distributed around the vertical central axis of the hydrolysis tank 3 or the acidification tank 4 and rotate, and at the same time, the water outlet directions of each hydraulic stirrer 7 are the same, which is set counterclockwise; thus when the circulating water sprays out from the water outlet of the hydraulic stirrer 7, a directional vortex water flow can be formed in the tank, so as to stir the materials; a butterfly valve 74 is arranged on the part of the water distribution pipe 73 outside the tank to control the operation of the hydraulic stirrer 7.

[0039] As Figure 4 shown, a labyrinth inclined plate 8 is arranged in the upper middle part of the hydrolysis tank 3 and the acidification tank 4. The labyrinth inclined plate 8 is composed of multiple parallel and equally spaced inclined plates. In this embodiment, the inclination angle of the inclined plate is 60°; when the materials in the tank are stirred by the hydraulic stirrer 7, under the action of the circulating centrifugal force, the particulate matters in the materials will precipitate while being thrown towards the four walls of the labyrinth inclined plate, and the precipitates in the materials can be effectively precipitated under the action of the low-speed circulating flow; as Figure 6 shown, the labyrinth inclined plate 8 is fixedly arranged in the tank by angle steel up and down, and its fixation is firm and reliable.

[0040] As Figure 3 ,Figure 4 and Figure 7 As shown in Figure 7 , water outlet weirs 9 are provided at the tops of both the hydrolysis tank 3 and the acidification tank 4. The water outlet weirs 9 are arranged annularly on the inner wall of the tank, and their cross-sections are L-shaped; as Figure 8 shown in Figure 8 , one side of the water outlet weir plate of the water outlet weir 9 is a triangular tooth-shaped structure, which can effectively intercept the sludge in the material, prevent the outlet from being blocked, and ensure uniform water flow distribution; the triangular tooth-shaped weir plate structure has good stability for water flow fluctuations; the water outlets of the hydrolysis tank 3 and the acidification tank 4 are both arranged in the water outlet weir 9. By setting the water outlet weir 9, the situation of the outlet being blocked can be effectively avoided.

[0041] The hydrolysis device and the acidification device are also provided with an intelligent adjustment system, which respectively includes a temperature adjustment system and a pH value adjustment system; pH / T meters 11 are provided on both the hydrolysis tank 3 and the acidification tank 4. Through the pH / T meters 11, the pH value and temperature of the material in the tank can be monitored in real time; the intelligent adjustment system includes a PLC connected to the pH / T meters 11. After the PLC obtains the data of the pH / T meters 11, it controls the heating device, the heat preservation device and the dosing device 1 through the data communication module; among them, the heating device includes an electric heating rod or a steam coil, which can heat the material in the tank; a chemical agent feeding port is provided on the dosing device 1, and acids, alkalis and enzyme preparations can be put in; the dosing device 1 is connected to the hydrolysis tank 3 and the acidification tank 4 through a metering pump 2, and can respectively put in acid or alkali solution under the control of the PLC to control the pH value in the tank; the dosing device 1 also puts enzyme preparations into the hydrolysis tank 3 to improve the hydrolysis efficiency.

[0042] As Figure 3 shown in Figure 3 , three outlets and three inlets are respectively arranged between the two acidification tanks 4; among them, the outlet at the top of the first acidification tank 4 is respectively connected to the inlets at the top and bottom of the second acidification tank 4, the middle outlet of the first acidification tank 4 is connected to the middle inlet of the second acidification tank 4, and the bottom outlet of the first acidification tank 4 is connected to the bottom inlet of the second acidification tank 4; and four valves 42 are respectively arranged at the three outlets of the first acidification tank 4 and on the pipeline between the top outlet and the bottom inlet. By controlling the opening and closing of the four valves 42, the connection relationship between the two acidification tanks 4 can be controlled, so that they are respectively connected in a "parallel" or "series" manner to meet different usage requirements.

[0043] Example 2

[0044] Taking the treatment of high-concentration wastewater generated from the treatment of kitchen waste in a certain project as an example, where COD is 9×104 mg / L, SS (suspended solids) is 6.5×104 mg / L, pH is 4, TN is 2000 mg / L, and B / C = 0.4.

[0045] A method for preparing a composite carbon source from high-concentration organic wastewater using the device in Example 1 includes the following steps:

[0046] S1. Wastewater pretreatment: Pretreat the high-concentration organic wastewater;

[0047] S2. Stirring hydrolysis: Pump the wastewater obtained in step S1 into the hydrolysis device, add amylase using dosing device 1 to promote hydrolysis, and convert macromolecular substances into small-molecule soluble substances; The residence time of the slurry in the device is 2 days, adjust the pH value to about 5 and the temperature to 35°C, and the hydraulic stirring is intermittent stirring with a working frequency of 30 min / h

[0048] S3. Stirring acidification: Then pump the slurry into the acidification device, adjust the pH to about 6 and the temperature to 35°C for acidification reaction, with a residence time of 3 days, and the hydraulic stirring is intermittent stirring with a working frequency of 30 min / h;

[0049] S4. Solid-liquid separation: Transport the wastewater treated in step S3 to the centrifugal separation device, remove the solid residues and grease in the wastewater by centrifugal separation to obtain liquid-phase organic acids; The rotational speed range of the centrifugal separation device is 3500 rpm;

[0050] S5. Membrane separation: Separate and purify the liquid-phase organic acids treated in step S4 through a ceramic membrane separation device of about 100 nm to remove the suspended solids in the liquid phase to obtain a clear liquid; After removing the suspended solids, the SS concentration is lower than 100 mg / L;

[0051] S6. Membrane concentration: Concentrate the clear liquid treated in step S5 through the RO membrane concentration device to obtain composite carbon source 1; The remaining clear liquid after concentration is low-concentration wastewater, which can directly meet the discharge standard.

[0052] In this embodiment, the two acidification tanks in the acidification device in step S3 are connected in series. Open the top valve and the connection valve between the top outlet and the bottom inlet, close the other two valves, and sequentially perform acidification treatment on the hydrolyzed wastewater; After staying in the first acidification tank for 2 days, stay in the second acidification tank for 2 days; During hydrolysis and acidification, the hydraulic stirrer uses intermittent stirring with a working frequency of 30 min / h;

[0053] Example 3

[0054] The difference between this embodiment and Example 2 is that in this embodiment, the two acidification tanks in the acidification device in step S3 are connected in parallel, and the opening and closing mode of valve 42 is opposite to that in Example 2; And uniformly perform acidification treatment on the hydrolyzed wastewater, and stay in the two acidification tanks for 2 - 4 days at the same time.

[0055] Example 4

[0056] The difference between this embodiment and Embodiment 2 is that the temperature in the hydrolysis and acidification stages in this embodiment is 45 °C. After separation and purification, the resulting carbon source is the composite carbon source 2.

[0057] Embodiment 5

[0058] The difference between this embodiment and Embodiment 2 is that the pH value in the hydrolysis stage in this embodiment is 6. After separation and purification, the resulting carbon source is the composite carbon source 3.

[0059] Embodiment 6

[0060] The difference between this embodiment and Embodiment 2 is that the pH value in the acidification stage in this embodiment is 7. After separation and purification, the resulting carbon source is the composite carbon source 4.

[0061] Embodiment 7

[0062] The difference between this embodiment and Embodiment 2 is that the residence time in the hydrolysis stage in this embodiment is set to 1 day. After separation and purification, the resulting carbon source is the composite carbon source 5.

[0063] Embodiment 8

[0064] The difference between this embodiment and Embodiment 2 is that the residence time in the acidification stage in this embodiment is set to 4 days. After separation and purification, the resulting carbon source is the composite carbon source 6.

[0065] Control Example 1:

[0066] Compared with Embodiment 2, the difference is that the liquid phase after solid-liquid separation is not physically separated and purified, and the remaining steps refer to Embodiment 2. The liquid phase formed under this condition is the composite carbon source 7.

[0067] Control Example 2:

[0068] Compared with Embodiment 2, the difference is that the temperature in the hydrolysis and acidification stages is not controlled, and the carbon source is prepared at room temperature. The liquid phase formed under this condition is the composite carbon source 8.

[0069] Control Example 3:

[0070] Compared with Embodiment 2, the difference is that the pH in the hydrolysis and acidification stages is not adjusted. The liquid phase formed under this condition is the composite carbon source 9.

[0071] Control Example 4:

[0072] Compared with Embodiment 2, the difference is that the residence time in the hydrolysis stage is 1 day and the residence time in the acidification stage is 5 days. The liquid phase formed under this condition is the composite carbon source 10.

[0073] Control Example 5:

[0074] Compared with Example 2, the difference lies in that the intermittent hydraulic stirring frequency in the hydrolysis and acidification stages is 15 min / h. The liquid phase formed under this condition is composite carbon source 11.

[0075] The above examples and control examples were compared as shown in Table 1:

[0076] Table 1. Results of preparing carbon source

[0077]

[0078] In the table, B / C, i.e., the BOD5 / COD ratio, is the core parameter for evaluating the biodegradability of organic matter in sewage. When B / C > 0.45, the biodegradability is excellent and it can be directly used as a carbon source.

[0079] It can be seen from Table 1 that based on multiple indicators such as the obtained COD value, B / C, and the proportion of acetic acid in VFA, the optimal process conditions for preparing the carbon source are as follows: In the hydrolysis stage, the residence time is 1 - 3 days, the pH value is 4 - 6, the temperature is 35 - 45 °C, and the hydraulic stirring is intermittent stirring with a working frequency of 30 min / h. In the acidification stage, the residence time is 2 - 4 days, the pH value is 5 - 7, the temperature is 35 - 45 °C, and the hydraulic stirring is intermittent stirring with a working frequency of 30 min / h. The COD value in the obtained carbon source is ≥ 2.0×105 mg / L, B / C ≥ 0.6, and acetic acid accounts for more than 50% of VFA.

[0080] It can be seen from Table 1 that when the residence time is fixed, 35 °C is the optimal hydrolysis and acidification temperature. When it is higher or lower than 35 °C, the proportion of acetic acid in VFA both decreases. This is because high temperature may induce thermophilic bacteria to dominate, generating products such as propionic acid and butyric acid, reducing the proportion of acetic acid; while low temperature will reduce the metabolic rate of the hydrolysis and acidification flora, slow down the decomposition rate of organic matter, and affect the generation of acetic acid.

[0081] When the hydrolysis and acidification temperature is fixed, the acetic acid production effect is the best when the slurry stays in the hydrolysis tank for 2 days and in the acidification tank for 3 days. If the hydrolysis and acidification residence time is too long or too short, the proportion of acetic acid in VFA both decreases. This is mainly because when the residence time is too short, the hydrolysis and acidification bacteria fail to fully complete the decomposition of macromolecular organic matter and the acidification process, resulting in some macromolecular substances (such as cellulose and protein) not being completely converted into VFA, reducing the proportion of acetic acid in VFA; too long residence time may enhance the activity of methanogens, consuming acetic acid and leading to a decrease in its proportion.

[0082] When the temperature and residence time are constant, when the pH value in the hydrolysis stage is 5 and the pH value in the acidification stage is 6, the proportion of acetic acid in VFA is relatively high. Since the hydrolysis bacteria (such as cellulose-decomposing bacteria) have higher activity at pH = 5, the hydrolysis process can be strengthened, and the acid-producing bacteria (such as acetic acid bacteria) have higher metabolic efficiency at pH = 6, which can increase the proportion of acetic acid. Therefore, regulating the pH values of the hydrolysis and acidification stages in stages is beneficial to increasing the acetic acid yield.

[0083] Through the comparison between Example 2 and Comparative Example 1, it can be seen that physical separation and purification of the liquid phase after solid-liquid separation can increase the COD value in the composite carbon source, increase the proportion of acetic acid, increase the B / C value, and improve the biodegradability of the composite carbon source, so as to be better used for sewage treatment.

[0084] As described above, it is only a further explanatory description of the present invention in combination with specific embodiments. All the descriptions made do not represent a limitation on the protection scope of the present invention. Any changes or alternative solutions that can be easily thought of by any person skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An apparatus for preparing a composite carbon source from high-concentration organic wastewater, comprising a hydrolysis device, an acidification device, a separation device and a concentration device connected in sequence, characterized in that: The hydrolysis device includes a hydrolysis tank, and the acidification device includes an acidification tank; circulating pumps are provided on both the hydrolysis tank and the acidification tank, and the circulating pumps are connected to a water supply system; a hydraulic circulation stirring system is provided inside both the hydrolysis tank and the acidification tank, and the hydraulic circulation stirring system is arranged at the bottom of the hydrolysis tank and the acidification tank; labyrinth inclined plates are provided inside both the hydrolysis tank and the acidification tank, a water outlet weir is arranged above the labyrinth inclined plates, and the outlets of the hydrolysis tank and the acidification tank are arranged inside the water outlet weir; both the hydrolysis device and the acidification device include an intelligent regulation system, and the intelligent regulation system includes a chemical dosing device and a temperature regulation device.

2. The device for preparing a composite carbon source from high-concentration organic wastewater according to claim 1, wherein: The hydraulic circulation stirring system includes a water distribution main pipe, a circulating water connection port is arranged on the water distribution main pipe, and the circulating water connection port is connected to the circulating pump; the water distribution main pipe is connected with a plurality of water distribution pipes through valves, and each water distribution pipe extends into the hydrolysis tank or the acidification tank and is connected with a hydraulic stirrer at the end.

3. The device for preparing the composite carbon source from high-concentration organic wastewater according to claim 2, wherein: The hydraulic stirrer is a straight pipe structure with a water outlet arranged on the side, and a plurality of hydraulic stirrers in the same hydrolysis tank or acidification tank are evenly arranged around the vertical central axis in a rotating manner, and the water outlet directions of the plurality of hydraulic stirrers are the same.

4. The device for preparing composite carbon source from high-concentration organic wastewater according to claim 1, characterized in that: The intelligent regulation system includes a pH / T meter, and the pH / T meter is arranged on the side walls of the hydrolysis tank and the acidification tank; a chemical dosing port is arranged on the chemical dosing device, and a stirring device is arranged inside the chemical dosing device; the chemical dosing device is connected to the hydrolysis tank and the acidification tank through a metering pump.

5. The device for preparing composite carbon source from high-concentration organic wastewater according to claim 4, characterized in that: The temperature regulation device includes a heating device and a heat preservation device arranged inside the hydrolysis tank and the acidification tank, and the heating device is an electric heating rod or a steam coil; the temperature regulation device includes a PLC connected to the pH / T meter, and the PLC is connected to the heating device and the heat preservation device through a data communication module.

6. The device for preparing composite carbon source from high-concentration organic wastewater according to claim 1, characterized in that: The labyrinth inclined plate includes a plurality of inclined plate-like structures arranged in parallel at equal intervals, and the inclination angle of the labyrinth inclined plate with the horizontal plane is 30-80°; the water outlet weir is arranged in a ring shape around the inner side surface of the hydrolysis tank and the acidification tank, and the top of the water outlet weir plate of the water outlet weir is arranged in a triangular tooth-like structure.

7. A method for preparing a composite carbon source by using the device according to any one of claims 1-6, comprising the following steps: S1. Wastewater pretreatment: Pretreat high-concentration organic wastewater. S2. Stirring hydrolysis: Feed the wastewater obtained in step S1 into the hydrolysis device, stir through the hydraulic circulation stirring system, and hydrolyze for 1-2 days under the action of amylase; the hydrolysis temperature is 35-45°C, and the pH value is 4-6. S3. Stirring acidification: Feed the wastewater treated in step S2 into the acidification device, and acidify for 2-4 days under the action of the hydraulic circulation stirring system; the acidification temperature is 35-45°C, and the pH value is 5-7. S4. Solid-liquid separation: Transport the wastewater treated in step S3 to a centrifugal separation device, and remove the solid residues and oils in the wastewater through centrifugal separation to obtain liquid-phase organic acids. S5. Membrane separation: Separate and purify the liquid-phase organic acids treated in step S4 through a ceramic membrane separation device, and remove the suspended substances in the liquid phase to obtain a clear liquid. S6. Membrane concentration: Concentrate the supernatant after the treatment in step S5 through a concentration device to obtain a composite carbon source.

8. The method according to claim 7, wherein: In the step S4, the rotation speed range of the centrifugal separation device is 3000 - 5000 rpm; in the step S5, the membrane pore size range of the ceramic membrane separation device is 50 - 150 nm; in the step S6, the concentration device uses a nanofiltration membrane or an RO membrane.

9. The method according to claim 8, characterized in that: In the acidification device in the step S3, there are two acidification tanks connected in series. After staying in the first acidification tank for 1 - 2 days, it stays in the second acidification tank for 1 - 2 days.

10. The method according to claim 8, wherein: In the acidification device in the step S3, there are two acidification tanks connected in parallel to acidify the hydrolyzed wastewater, and it stays in the two acidification tanks for 2 - 4 days.

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