System and process for preparing organic fertilizer from biochemical sludge of Maotai-flavor liquor wastewater

Abstract

This invention discloses a system and process for preparing organic fertilizer from biochemical sludge of Maotai-flavor liquor wastewater, belonging to the field of solid waste resource utilization technology. The system includes a pretreatment unit, a mixing unit, a two-stage fermentation unit, a post-processing unit, and a waste gas biofiltration unit. It also integrates an intelligent decision server, a multispectral online detection device, a microbial community online monitoring module, and a waste heat recovery system. The process includes a pretreatment unit for sludge dewatering and enzymatic separation of the liquor residue; a two-stage fermentation unit that couples material composting with initial waste gas filtration; a waste gas biofiltration unit for deep purification of pollutants; a post-processing unit for organic fertilizer granulation; and a waste heat system for graded recovery and utilization of fermentation waste heat. This invention features a continuous process, low energy consumption, and excellent environmental benefits. The prepared organic fertilizer is thoroughly composted and meets nutrient standards, effectively solving the problems of solid waste disposal and waste gas pollution associated with Maotai-flavor liquor, and is suitable for large-scale application.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization technology, specifically to a system and process for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater. Background Technology

[0002] The brewing industry of Maotai-flavor liquor is a water-intensive and waste-generating industry. During the production process, a large amount of wastewater is generated, with extremely high concentrations of organic matter. After biochemical treatment, a large amount of biochemical sludge is generated. This sludge is rich in organic matter and nutrients such as nitrogen and phosphorus, but it also has a high water content and a viscous structure. If not handled properly, it can easily cause secondary pollution. At the same time, the brewing process also generates a large amount of liquor lees, which are rich in crude fiber, rice husks and organic nutrients. Traditional disposal methods are mostly incineration and landfill, which not only have low resource utilization rates, but also have problems such as high costs and secondary pollution.

[0003] Composting this type of biochemical sludge is an ideal resource utilization method. However, existing composting technologies face several challenges: First, the sludge dewatering effect is poor, and high moisture content easily leads to anaerobic fermentation and incomplete decomposition. Second, sludge from Maotai-flavor liquor contains 25%-30% rice husks with high crude fiber content. When composted alone, its dense structure and poor aeration easily create an anaerobic environment, producing odors and resulting in a long decomposition period. When untreated liquor lees are directly mixed into the compost, the crude fiber is difficult to degrade, and the separation of rice husks from organic components is insufficient, reducing the utilization rate of nutrients. Third, the fermentation process is mostly a single aerobic fermentation, resulting in poor controllability of decomposition degree. Furthermore, the ammonia and VOCs waste gases produced during fermentation are directly emitted, polluting the surrounding environment and causing significant nitrogen volatilization losses, severely reducing the fertilizer efficiency of the final product. Fourth, the fermentation process lacks intelligent control. The abundance of functional microorganisms cannot be monitored in real time, and operations such as aeration, turning, and adding microbial agents rely on manual experience, resulting in poor stability of organic fertilizer quality.

[0004] Therefore, developing an organic fertilizer preparation system and method that can achieve the co-processing of biochemical sludge from Maotai-flavor liquor wastewater and other wastes from the distillery, as well as intelligent control of the fermentation process, has become an urgent technical problem to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a system and process for preparing organic fertilizer from biochemical sludge of Maotai-flavor liquor wastewater, in order to solve the technical problems of difficult disposal of solid waste such as biochemical sludge and liquor lees from Maotai-flavor liquor, low efficiency of organic fertilizer preparation, pollution of fermentation exhaust gas, and high energy consumption. Through integrated design, it realizes the efficient resource utilization of solid waste from Maotai-flavor liquor, and the prepared organic fertilizer meets the nutrient standards and is thoroughly decomposed.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A system for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater includes a pretreatment unit, a batching and mixing unit, a two-stage fermentation unit, and a post-treatment processing unit connected sequentially along a material conveying path. It also includes a waste gas biofiltration unit, an online microbial community monitoring module, and an intelligent decision server connected to the two-stage fermentation unit via a gas pipeline.

[0007] The pretreatment unit includes a sludge dewatering module and a liquor lees enzymatic hydrolysis module. The two modules work together to solve the problems of excessive water content in biochemical sludge and the difficulty in degrading coarse fiber in liquor lees, laying the foundation for subsequent fermentation. Furthermore, the sludge dewatering module includes a plate and frame filter press or a belt filter press, adapted to the characteristics of the high viscosity and easy clogging of the biochemical sludge of Maotai-flavor liquor, to stably reduce the moisture content of the biochemical sludge to 75%~85%. The feed end of the sludge dewatering module is connected to the wastewater biochemical treatment system of the winery, and the dewatered filtrate is returned to the wastewater treatment system for treatment. The discharge end of the sludge dewatering module is connected to the feed end of the batching and mixing unit through a screw conveyor. Furthermore, the enzymatic hydrolysis module for discarded baijiu lees includes a pulverizer, an enzymatic hydrolysis reaction tank, and a solid-liquid separator connected in sequence. The pulverizer includes a hammer mill, which pulverizes the discarded baijiu lees to a particle size ≤10mm, refining the particle size, increasing the contact area for enzymatic hydrolysis, and improving reaction efficiency. The enzymatic hydrolysis reaction tank is equipped with a hot water inlet, and can also be optionally equipped with a constant temperature control component and a variable frequency stirring component to control the reaction temperature at 45~55℃, which is close to the optimal activity temperature of the compound enzyme preparation, avoiding enzymatic failure due to temperature fluctuations. The variable frequency stirring ensures uniform mixing of materials and enzyme preparations. The solid-liquid separator includes a closed screw extrusion solid-liquid separator. The liquid phase outlet outputs high-nutrient discarded lees organic components to the feed end of the ingredient mixing unit, and the solid phase outlet transports rice husks to the rice husk silo of the ingredient mixing unit, realizing full utilization of the discarded baijiu lees components and eliminating solid waste disposal.

[0008] The batching and mixing unit includes a mixer; the mixer includes a twin-shaft paddle mixer or a horizontal ribbon mixer. The feed end of the batching and mixing unit is connected to the discharge end of the sludge dewatering module, the liquid phase outlet of the solid-liquid separator, the waste sludge metering hopper, the functional microbial agent metering hopper, and the rice husk silo. Each feed inlet can be optionally equipped with a variable frequency quantitative feeding device. The variable frequency quantitative feeding device includes a metering hopper, a weighing sensor, a variable frequency motor, and a variable frequency controller to achieve precise proportioning of dewatered sludge, discarded organic components, waste sludge, rice husk, and functional microbial agent, with the batching error controlled within ±2%. The discharge end of the batching and mixing unit is connected to the feed end of the two-stage fermentation unit. Furthermore, the mixing unit is equipped with a multispectral online detection device, which includes a near-infrared spectral probe located in the discharge pipe of the mixer. This device performs real-time, non-destructive detection of the carbon-nitrogen ratio and moisture content of the materials, ensuring that the moisture content of the mixed materials is 55%~65% and the carbon-nitrogen ratio is 20:1~30:1, thus adapting to the optimal conditions for the next step of aerobic fermentation and guaranteeing fermentation efficiency and organic fertilizer quality from the source. The multispectral online detection device is electrically connected to the input end of the intelligent decision server.

[0009] The two-stage fermentation unit includes a first-stage high-temperature aerobic fermentation device and a second-stage aging biological filtration device connected in series, so as to realize the simultaneous fermentation of materials and the preliminary purification of waste gas. Furthermore, the primary high-temperature aerobic fermentation device includes a fermentation tank, which may be a trough-type turning fermentation chamber equipped with a turning machine or a horizontal drum fermentation tank. The bottom of the fermentation tank is equipped with an aeration network connected to an aeration fan, allowing for real-time adjustment of the aeration rate according to the fermentation process. The fermentation tank is equipped with monitoring sensors, including a temperature sensor, an oxygen concentration sensor, and a pH sensor, to collect key fermentation parameters in real time. The online microbial community monitoring module uses a high-throughput sequencer, with its sampling port connected to the inside of the fermentation tank via an automatic sampling pipeline. It collects material samples periodically and quantitatively, accurately monitoring the abundance of functional bacteria such as Bacillus subtilis and nitrifying bacteria. The sensors and the online microbial community monitoring module are electrically connected to the input of the intelligent decision server. The output of the intelligent decision server is electrically connected to the aeration fan, the turning machine, and the microbial agent replenishment device. The discharge end of the microbial agent replenishment device is connected to the feed end of the primary high-temperature aerobic fermentation device. The intelligent decision server incorporates a machine learning-based digital twin model of the composting process, enabling fully automated and intelligent closed-loop control of the entire fermentation process. Furthermore, the secondary aging biological filtration device includes an aging chamber with a waste gas distribution network at the bottom. The first exhaust port of the fermentation tank is connected to the waste gas distribution network via an induced draft fan to transport the primary fermentation waste gas. The aging chamber is equipped with a humidity control component, which includes a water distribution network, multiple nozzles, and a humidity sensor. This component can automatically maintain the moisture content of the aging material at 45% to 55%, ensuring material maturation and microbial degradation activity. The secondary aging biological filtration device has the dual functions of material maturation and primary waste gas purification. It utilizes the aging compost material to adsorb and degrade ammonia in the primary fermentation waste gas, converting ammonia nitrogen into nitrate nitrogen and enriching it within the material. This reduces the pollutant load in the waste gas and increases the total nitrogen content of the organic fertilizer. The two-stage fermentation unit is equipped with a multispectral online detection device, which includes a hyperspectral imaging system installed inside the fermentation tank and aging chamber to monitor the material maturity distribution; the multispectral online detection device also includes an electronic nose sensor array installed at the first exhaust port of the fermentation tank and the second exhaust port of the aging chamber to detect the concentrations of ammonia, hydrogen sulfide and VOCs; the multispectral online detection device is electrically connected to the input terminal of the intelligent decision server.

[0010] The waste gas biofiltration unit includes a biofiltration tower, which is filled from bottom to top with a modified biofilter layer and an ultraviolet photocatalytic component. The filter medium of the biofilter tower is aged compost material output after aging in a two-stage aging biofiltration device. The modified biofilter layer is aged compost material loaded with 5%~10% manganese oxide. As a catalytically active component, manganese oxide can significantly improve the catalytic degradation efficiency of the filter material for VOCs, and has the triple purification effects of physical adsorption, biodegradation, and catalytic oxidation. The ultraviolet photocatalytic component uses an ultraviolet catalytic module with a wavelength of 254~365nm, which works synergistically with the modified biofilter layer to deeply decompose residual trace pollutants. The air inlet of the waste gas biofiltration unit is connected to the second exhaust port of the aging chamber. The waste gas stays in the modified biofilter layer for 15~30 seconds to ensure full contact between the gas and the material. The removal rate of pollutants such as ammonia, VOCs, and hydrogen sulfide reaches more than 95%. The purified waste gas is odorless and meets emission standards, completely solving the problem of fermentation waste gas pollution.

[0011] The post-processing unit includes a screening machine, a crusher, a mixer, and a granulator. The inlet of the screening machine is connected to the outlet of the secondary aging biological filter device, using a 3-5mm mesh screen. The undersize outlet of the screening machine is connected to the inlet of the mixer, and the oversize outlet is connected to the inlet of the crusher. The outlet of the crusher is connected to the inlet of the mixer, achieving full utilization of materials with no waste generation. The inlet of the mixer is also connected to an inorganic nutrient element metering hopper, which can accurately add inorganic nutrients such as urea, superphosphate, and potassium sulfate according to the crop's nutrient requirements, adjusting the total nutrient content of the organic fertilizer. The outlet of the mixer is connected to the inlet of the granulator to produce uniform granular organic fertilizer. Subsequently, it undergoes low-temperature drying (≤60℃), cooling, quality inspection, and metering and packaging to obtain a finished product with a moisture content of ≤15%. Low-temperature drying avoids nutrient loss caused by high temperature and retains the active nutrients of the organic fertilizer to the greatest extent.

[0012] Preferably, the two-stage fermentation unit also integrates a waste heat recovery system, which includes a heat exchanger and a heat pump unit. The heat exchanger includes a shell-and-tube heat exchanger or a plate heat exchanger, installed on the pipeline between the first exhaust port of the fermenter and the waste gas distribution network. The cold water inlet of the heat exchanger is connected to a water source, and the hot water outlet of the heat exchanger is connected to the hot water inlet of the enzymatic hydrolysis reactor. This recovers the waste heat from the high-temperature waste gas of the first-stage fermentation, preheats the ambient temperature water to 40-50°C, and directly supplies it to the enzymatic hydrolysis reactor, reducing the external heating energy consumption of the enzymatic hydrolysis process. The heat pump unit is for low-temperature waste heat recovery. The heat pump unit comprises a wall-mounted heat exchange coil, an evaporator, a variable frequency compressor, a condenser, a throttling valve, and a circulating water pump. The heat-absorbing end of the heat pump unit, the wall-mounted heat exchange coil, is installed on the outer wall of the fermentation tank to efficiently recover low-grade waste heat lost from the tank wall and convert it into a suitable low-temperature heat source. The heat-releasing end of the heat pump unit is connected to the humidity control component of the secondary aging biological filtration device for heat preservation of the aging chamber and heating of the spray water, maintaining a stable temperature in the aging chamber without the need for additional energy consumption for heating, achieving efficient recovery and utilization of waste heat, and reducing overall production energy consumption by 20% to 30%.

[0013] This invention also provides a process for preparing organic fertilizer based on the above system, comprising the following steps: S1. Pretreatment: The residual sludge after the biochemical treatment of the soy sauce-flavored liquor wastewater is dewatered by a sludge dewatering module to reduce the sludge moisture content to 75%~85%, thereby reducing the sludge volume. The liquor lees are crushed to a particle size ≤10mm by a pulverizer and sent to an enzymatic hydrolysis tank. A compound enzyme preparation composed of acidic protease, high-temperature amylase and cellulase in a certain proportion is added. The total amount of the compound enzyme preparation added is 0.3%~0.8% of the dry weight of the liquor lees. Water is added to adjust the solid-liquid ratio to 1:2~1:3. Enzymatic hydrolysis is carried out at 45~55℃ for 4~6 hours to fully degrade the coarse fiber of the lees. The liquid phase of the lees organic components and the solid phase of rice husks are obtained by a solid-liquid separator, thereby achieving the quality improvement and component separation of the lees. S2. Co-mixing: Dehydrated sludge, discarded organic components, crushed waste silage, functional microbial agents, and rice husks are fed into a mixer according to a preset ratio. The amount of rice husks added is 5%~15% of the total dry weight of the mixture, and the initial porosity of the mixture is controlled to be 35%~45% to ensure fermentation aeration. The functional microbial agents are a compound microbial system composed of Bacillus subtilis, Bacillus stearothermophilus, and nitrifying bacteria in a live bacteria ratio of (3~5):(2~4):(1~2). The amount of functional microbial agents added is 0.5%~1.2% of the total dry weight of the mixture, which is suitable for high-temperature fermentation and nitrogen conversion requirements. After mixing, the mixture is monitored in real time by a multi-spectral online detection device to control the moisture content of the mixed material to be 55%~65% and the carbon-nitrogen ratio to be 20:1~30:1. After passing the test, the mixture is sent to the two-stage fermentation unit. Unqualified materials are automatically returned and remixed. S3. Two-stage fermentation: The mixed materials are fed into the fermentation tank of the first-stage high-temperature aerobic fermentation device and fermented at 55~70℃ for 7~15 days. This temperature range can effectively kill harmful pathogens such as roundworm eggs and E. coli, ensuring that the organic fertilizer meets hygiene standards. During fermentation, the monitoring sensors and the microbial community online monitoring module collect parameter data in real time and transmit it to the intelligent decision server. The intelligent decision server automatically controls turning, aeration, and addition of microbial agents. The specific control method of the intelligent decision server is as follows: when the temperature exceeds 65℃, the aeration rate is automatically increased and the pile is turned to quickly dissipate heat and control the temperature; when the temperature is below 50℃, the aeration rate is reduced and 10%~20% of the initial dose of functional microbial agents is added through the microbial agent addition device; when the pH value is below 6.5, waste pit mud is automatically added to adjust it to 6.5~8.0; the pile is turned 2~4 times during the entire 7~15-day first-stage fermentation cycle to ensure uniform fermentation of the material; the abundance of cellulose-degrading bacteria is below 10. 6 When CFU / g, supplement with Bacillus subtilis; nitrifying bacteria abundance is below 10. 5 Nitrifying bacteria are added when the concentration of CFU / g is 10% to 20% of the initial dose to maintain the microbial balance of the fermentation system. The waste heat recovery system is started simultaneously during the fermentation process to recover waste gas and waste heat from the tank wall, thus achieving energy-saving production.

[0014] After high-temperature fermentation, the material is transferred to the aging chamber of the secondary aging biological filtration device and aged at below 40℃ for 15-25 days to further improve the maturity of the material and eliminate the risk of root burn from organic fertilizer. During the aging process, the exhaust gas generated by the primary fermentation is introduced into the bottom of the aging chamber through an exhaust fan and exhaust gas distribution network. The exhaust gas passes through the aged compost material from bottom to top, and ammonia is adsorbed and degraded, achieving preliminary purification of the exhaust gas. The humidity control component automatically maintains the moisture content of the material in the chamber at 45%-55% to ensure the activity of microbial degradation and simultaneously complete the material aging and exhaust gas denitrification. S4. Waste Gas Purification: Incompletely purified waste gas in the aging chamber is sent to the biofiltration tower of the waste gas biofiltration unit by an induced draft fan. It is then subjected to preliminary adsorption by the aged compost material, catalytic degradation by the modified biological filter layer, and deep oxidation by the ultraviolet photocatalytic component. The residence time of the waste gas in the modified biological filter layer is 15-30 seconds, and pollutants such as ammonia, VOCs, and hydrogen sulfide are efficiently removed. After purification, the waste gas is discharged in compliance with standards through a high-altitude exhaust stack. S5. Post-processing and formulation: After aging, the decomposed material is screened by a screener with a mesh size of 3-5mm. The fine material undersizes enters the mixer, while the coarse material oversizes is crushed by a crusher and returned to the mixer, achieving full utilization of the material. Inorganic nutrients such as urea, superphosphate, and potassium sulfate are added to adjust the total nutrient content (N+P2O5+K2O) of the granular fertilizer to 5.0%~8.0%. After being mixed evenly, the mixture is sent to a granulator for granulation. Low-temperature drying at ≤60℃ is used to control the moisture content of the finished product to ≤15%, thus obtaining organic fertilizer. The granular fertilizer is tested, and after passing the test, it is weighed and packaged. Beneficial effects

[0015] Due to the adoption of the above technical solution, the technical progress achieved by this invention compared to the prior art is as follows: 1. The waste gas treatment effect meets the standards and is stable: The secondary aging process is coupled with the primary waste gas purification process. The aged compost material in the secondary aging biological filter device is used as biological filter material to perform in-situ adsorption and biodegradation of ammonia-containing waste gas generated by the primary high-temperature aerobic fermentation. This achieves simultaneous deodorization and purification of waste gas and enrichment of nitrogen nutrients. The two-stage synergistic treatment process of "secondary aging primary purification + biological filter tower deep purification" is adopted. The removal rate of pollutants such as ammonia, VOCs, and hydrogen sulfide in the fermentation waste gas is not less than 95%. The purified waste gas meets the relevant standards for atmospheric pollutant emissions.

[0016] 2. Significantly reduced production energy consumption and costs: The waste heat of different grades generated during primary fermentation is graded, recovered, and utilized. High-temperature waste heat is recovered through heat exchangers for preheating water in the enzymatic hydrolysis process, and low-grade heat dissipation from the fermentation tank walls is recovered through heat pump units for insulation of the secondary aging chamber and temperature regulation of the spray water. This achieves resource utilization of low-grade waste heat, which can reduce the overall production energy consumption of the system by 20% to 30% and reduce the consumption of energy such as steam and electricity.

[0017] 3. Innovative Intelligent Closed-Loop Management and Control: An intelligent management and control system is constructed, linking multi-sensor monitoring, online detection of microbial communities, and machine learning digital twin models. This system enables real-time monitoring of temperature, oxygen, pH, and microbial abundance during fermentation, as well as automated and precise control of aeration, turning, and inoculant replenishment. This ensures complete material decomposition, achieving a 100% kill rate for harmful pathogens such as roundworm eggs and E. coli, eliminating the problem of root and seedling burn after organic fertilizer application. Ammonia nitrogen in fermentation waste gas is biologically converted into nitrate nitrogen and enriched in the material, increasing the total nitrogen content of the finished organic fertilizer by 15%~30%, with an organic matter content ≥43%, meeting total nutrient standards and conforming to the NY / T 525-2021 organic fertilizer standard, resulting in stable and excellent fertilizer efficacy.

[0018] 4. Maximize the utilization rate of all resources by treating waste with waste: Using biochemical sludge, baijiu lees, waste cellar mud, and rice husks, which are byproducts of the production of Maotai-flavor baijiu, as raw materials, the entire amount is utilized in a synergistic manner, without the need for landfill or incineration of solid waste; the aged compost material is also used as biological filter material for waste gas, eliminating the need to purchase special filter material from outside, realizing the full resource utilization of baijiu solid waste and the harmless treatment of fermentation waste gas, without the generation of secondary solid waste, forming a closed-loop resource utilization system.

[0019] 5. High degree of process adaptability and scalability: The system equipment and process parameters are adapted to the characteristics of high moisture content, high organic matter and high viscosity of solid waste of Maotai-flavor liquor. It can be flexibly adjusted according to the production scale and is suitable for various large and medium-sized Maotai-flavor liquor production enterprises, realizing continuous and large-scale production and solving the problems of poor adaptability and difficulty in industrialization of traditional processes. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the system structure of the present invention; Figure 2 This is a schematic diagram of the material handling process of the present invention; Figure 3 This is a schematic diagram of the waste gas treatment process of the present invention; Figure 4 This is a flowchart of the process flow of the present invention.

[0021] In the diagram: 100 - Pretreatment unit; 110 - Sludge dewatering module; 120 - Baijiu (Chinese liquor) lees enzymatic hydrolysis module; 121 - Crusher; 122 - Enzymatic hydrolysis reaction tank; 123 - Solid-liquid separator; 124 - Constant temperature control component; 125 - Variable frequency stirring component; 200 - Batching and mixing unit; 210 - Mixer; 211 - Waste pit mud metering hopper; 212 - Functional microbial agent metering hopper; 213 - Rice husk bin; 300-Two-stage fermentation unit; 310-Fermentation tank; 311-Aeration pipeline network; 312-Aeration blower; 313-Monitoring sensor; 314-Inoculant replenishment device; 315-First exhaust port; 320-Aging chamber; 321-Waste gas distribution pipeline network; 322-Humidity control component; 323-Second exhaust port; 400 - Post-processing unit; 410 - Screening machine; 420 - Crusher; 430 - Mixer; 440 - Granulator; 450 - Inorganic nutrient element metering hopper; 500 - Waste gas biological filtration unit; 510 - Biological filtration tower; 511 - Modified biological filter media layer; 512 - Ultraviolet photocatalytic component; 600 - Multispectral online detection device; 610 - Near-infrared spectral probe; 620 - Hyperspectral imaging system; 630 - Electronic nose sensor array; 700-Microbial Community Online Monitoring Module; 800 - Waste heat recovery system; 810 - Heat exchanger; 820 - Heat pump unit; 900-Intelligent Decision Server. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to embodiments: Example 1

[0023] like Figures 1-4 As shown, a system for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater includes a pretreatment unit 100, a batching and mixing unit 200, a two-stage fermentation unit 300, and a post-treatment processing unit 400 connected sequentially along a material conveying path. It also includes a waste gas biofiltration unit 500 connected to the two-stage fermentation unit 300 via a gas pipeline, a multispectral online detection device 600, a microbial community online monitoring module 700, and an intelligent decision server 900.

[0024] The pretreatment unit 100 includes a sludge dewatering module 110 and a liquor lees disposal enzymatic hydrolysis module 120; In this embodiment, the sludge dewatering module 110 adopts a plate and frame filter press, and the baijiu lees enzymatic hydrolysis module 120 adopts a hammer mill 121, an enzymatic hydrolysis reaction tank 122 and a closed screw extrusion solid-liquid separator 123 connected in sequence. The enzymatic hydrolysis reaction tank 122 is provided with a hot water inlet. The tank is equipped with a constant temperature control component 124 and a variable frequency stirring component 125. The constant temperature control component 124 includes a tank wall jacket, an internal heat exchange coil, a temperature sensor and a constant temperature controller. The variable frequency stirring component 125 includes a variable frequency motor, a stirring shaft, a stirring paddle and a variable frequency controller. The batching and mixing unit 200 adopts a twin-shaft paddle mixer 210. The feed end is connected to the discharge end of the plate and frame filter press, the liquid phase outlet of the solid-liquid separator 123, the waste sludge metering hopper 211, the functional microbial agent metering hopper 212, and the rice husk silo 213. Each feed inlet is equipped with a variable frequency quantitative feeding device, which includes a metering hopper, a weighing sensor, a variable frequency motor, and a variable frequency controller. A multispectral online detection device 600 is installed in the discharge end pipe of the mixer 210. The multispectral online detection device 600 includes a near-infrared spectral probe 610, which is electrically connected to the input end of the intelligent decision server 900.

[0025] The two-stage fermentation unit 300 includes a primary high-temperature aerobic fermentation device and a secondary aging biological filtration device connected in series. The primary high-temperature aerobic fermentation device includes a fermentation tank 310, which adopts a trough-type turning fermentation chamber with a turning machine. The bottom of the fermentation tank 310 is equipped with an aeration pipe network 311, which is connected to an aeration blower 312. The fermentation tank 310 is equipped with monitoring sensors 313, including a temperature sensor, an oxygen concentration sensor, and a pH sensor. The secondary aging biological filtration device includes an aging chamber 320, with a waste gas distribution network 321 at the bottom of the aging chamber 320. The first exhaust port 315 of the fermentation tank 310 is connected to the waste gas distribution network 321 via an induced draft fan. The aging chamber 320 is equipped with a humidity control component 322, which includes a water distribution network, multiple nozzles, and a humidity sensor. The two-stage fermentation unit 300 is also equipped with an online microbial community monitoring module 700 and a multispectral online detection device 600. The online microbial community monitoring module 700 uses a high-throughput sequencer, and the sampling port is connected to the inside of the fermenter 310 through an automatic sampling pipeline. The multispectral online detection device 600 includes a hyperspectral imaging system 620 installed inside the fermenter 310 and the aging chamber 320, and an electronic nose sensor array 630 installed at the first exhaust port 315 of the fermenter 310 and the second exhaust port 323 of the aging chamber 320. The monitoring sensor 313, the online microbial community monitoring module 700, and the multispectral online detection device 600 are electrically connected to the input end of the intelligent decision server 900. The output end of the intelligent decision server 900 is electrically connected to the aeration blower 312, the turner, and the microbial agent replenishment device 314, respectively. The discharge end of the microbial agent replenishment device 314 is connected to the feed end of the first-stage high-temperature aerobic fermentation device. The intelligent decision server 900 has a built-in digital twin model of the composting process based on machine learning.

[0026] The exhaust gas biofiltration unit 500 includes a biofiltration tower 510, which is filled from bottom to top with a modified biofilter layer 511 and an ultraviolet photocatalytic component 512. The filter medium of the biofiltration tower 510 is the aged compost material output after aging in the aging chamber 320. The modified biofilter layer 511 is the aged compost material loaded with 8% manganese oxide. The ultraviolet photocatalytic component 512 is an ultraviolet catalytic module with a wavelength of 254~365nm. The air inlet of the biofiltration tower 510 is connected to the second exhaust port 323 of the aging chamber 320.

[0027] The post-processing unit 400 includes a screening machine 410, a crusher 420, a mixer 430, and a granulator 440. The inlet of the screening machine 410 is connected to the outlet of the aging silo 320, and a 5mm aperture screen is used. The undersize outlet of the screening machine 410 is connected to the inlet of the mixer 430, and the oversize outlet of the screening machine 410 is connected to the inlet of the crusher 420. The outlet of the crusher 420 is connected to the inlet of the mixer 430. The inlet of the mixer 430 is also connected to an inorganic nutrient element metering hopper 450. The outlet of the mixer 430 is connected to the inlet of the granulator 440.

[0028] The two-stage fermentation unit 300 also integrates a waste heat cascade recovery system 800, which includes a heat exchanger 810 and a heat pump unit 820. The heat exchanger 810 is a shell-and-tube heat exchanger, installed on the pipeline between the first exhaust port 315 of the fermenter 310 and the waste gas distribution network 321. The cold water inlet of the heat exchanger 810 is connected to a water source, and the hot water outlet of the heat exchanger 810 is connected to the hot water inlet of the enzymatic reaction tank 122. The heat pump unit 820 is a low-temperature waste heat recovery type heat pump unit, including a wall-mounted heat exchange coil, an evaporator, a variable frequency compressor, a condenser, a throttling valve, and a circulating water pump. The wall-mounted heat exchange coil is installed on the outer wall of the fermenter 310, and the condenser is connected to the water distribution network of the humidity control component 322 of the aging chamber 320.

[0029] A process for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater based on the above system includes the following steps: S1. Pretreatment: The residual sludge after the biochemical treatment of the soy sauce-flavored liquor wastewater is dewatered by a plate and frame filter press to reduce the moisture content of the sludge to 80%; the liquor lees are crushed to a particle size of 10mm by a pulverizer 121 and sent to an enzymatic hydrolysis tank 122. A compound enzyme preparation composed of acidic protease, high-temperature amylase and cellulase in a ratio of 4:4:1 is added. The total amount of the compound enzyme preparation added is 0.5% of the dry weight of the liquor lees. Water is added to adjust the solid-liquid ratio to 1:2.5, and enzymatic hydrolysis is carried out at 50℃ for 5 hours. S2. Co-mixing: Dewatered sludge, discarded organic components, crushed waste sludge, functional microbial agents, and rice husks are fed into mixer 210 according to the specified ratio. The amount of rice husks added is 10% of the total dry weight of the mixture, and the initial porosity of the mixture is controlled to be 40%. The functional microbial agent is a compound microbial system composed of Bacillus subtilis, Bacillus stearothermophilus, and nitrifying bacteria in a viable count ratio of 3:4:1. The amount of functional microbial agent added is 1% of the total dry weight of the mixture. After mixing, the mixture is monitored in real time by a multispectral online detection device 600 to control the moisture content of the mixed material to be 60% and the carbon-nitrogen ratio to be 25:1. S3. Two-stage fermentation: The mixed materials are fed into the fermenter 310 of the first-stage high-temperature aerobic fermentation device and fermented at 60℃ for 11 days. During the fermentation, the parameters are collected in real time by the monitoring sensor 313 and the microbial community online monitoring module 700 and transmitted to the intelligent decision server 900. The intelligent decision server 900 automatically controls turning, aeration and addition of microbial agents. The material is turned 3 times during the entire 11-day first-stage fermentation cycle. When the temperature is below 50℃, 15% of the dosage of microbial agents is added. The waste heat recovery system 800 is started simultaneously during the fermentation process. The material after high-temperature fermentation is transferred to the aging chamber 320 of the secondary aging biological filtration device and aged at 35°C for 20 days. During the aging period, the waste gas generated by the primary fermentation is introduced into the bottom of the aging chamber 320 through an induced draft fan and waste gas distribution pipe network 321. The humidity adjustment component 322 automatically maintains the moisture content of the material in the chamber at 50%. S4. Waste gas purification: The waste gas that is not completely purified in the aging chamber 320 is sent into the biological filter tower 510 of the waste gas biological filter unit 500 by the induced draft fan. It is then subjected to preliminary adsorption by the aging compost material filter layer, catalytic degradation by the modified biological filter material layer 511, and deep oxidation by the ultraviolet photocatalytic component 512. The residence time of the waste gas in the modified biological filter material layer 511 is 22 seconds. After purification, the waste gas is discharged in compliance with standards through the high-altitude exhaust stack. S5. Post-processing and formulation: After aging, the decomposed material is screened by a 4mm mesh screener 410. The undersize fine material enters the mixer 430, while the oversize coarse material is crushed by a crusher 420 and then returned to the mixer 430. Inorganic nutrients such as urea, superphosphate, and potassium sulfate are added to adjust the total nutrient content (N+P2O5+K2O) of the granular fertilizer to 6.7%. After being mixed evenly, the mixture is sent to a granulator 440 for granulation and dried at a low temperature of 60℃ to obtain organic fertilizer with a moisture content of 13% and an organic matter content of ≥45%. The granular fertilizer is tested and packaged after passing the test.

[0030] The total nitrogen content of the organic fertilizer produced in this embodiment is 22% higher than that of conventional processes. It is odorless, thoroughly decomposed, meets the NY / T525-2021 organic fertilizer standard, and the fermentation exhaust gas emission meets the standards. The production energy consumption is reduced by 25% compared with traditional processes. Example 2

[0031] System configuration: The sludge dewatering module 110 adopts a belt filter press, the primary high-temperature aerobic fermentation device adopts a horizontal drum fermenter 310, and the rest of the equipment is the same as in Example 1; the modified biological filter media layer 511 has a manganese oxide loading of 5%.

[0032] Process parameters: In S1, sludge is dewatered to a moisture content of 75%, and the liquor lees are discarded and enzymatically hydrolyzed at 45℃ for 6 hours. The amount of compound enzyme preparation added is 0.3%, the ratio of compound enzyme preparation is 3:5:2, and the solid-liquid ratio is 1:2. In S2, rice husk is added at 5%, the initial porosity of the mixture is adjusted to 35%, functional bacteria agent is added at 0.5%, the ratio of live bacteria is 3:2:1, and the moisture content of the material is adjusted to 55% and the carbon-nitrogen ratio is 20:1. In S3, primary fermentation is carried out at 55℃ for 15 days, with two turnings, and aging is carried out at 40℃ for 15 days. In S4, the waste gas residence time is 15 seconds. In S5, the total nutrients are adjusted to 5.0%, and the material is dried at a low temperature of 60℃ with a screen mesh size of 3mm.

[0033] Product specifications: The finished organic fertilizer has a moisture content of 14%, total nutrients of 5.1%, organic matter content ≥43%, total nitrogen content 15% higher than conventional processes, all indicators are qualified, waste gas purification efficiency ≥95%, and production energy consumption is reduced by 20% compared with traditional processes. Example 3

[0034] System configuration: The equipment is the same as in Example 1; the modified biological filter media layer has a manganese oxide loading of 10%.

[0035] Process parameters: In S1, sludge is dewatered to a moisture content of 85%, and the liquor lees are discarded and enzymatically hydrolyzed at 55℃ for 4 hours. The amount of compound enzyme preparation added is 0.8%, the ratio of compound enzyme preparation is 2:3:1, and the solid-liquid ratio is 1:3. In S2, rice husk is added at 15%, the initial porosity of the mixture is adjusted to 45%, functional bacteria agent is added at 1.2%, the ratio of live bacteria is 5:4:2, and the moisture content of the material is adjusted to 65% and the carbon-nitrogen ratio is 30:1. In S3, primary fermentation is carried out at 70℃ for 7 days, with 4 turnings, and aging is carried out at 30℃ for 25 days. In S4, the waste gas residence time is 30 seconds. In S5, the total nutrients are adjusted to 8.0%, and the material is dried at 50℃ with a screen mesh size of 5mm.

[0036] Product specifications: The finished organic fertilizer has a moisture content of 12%, total nutrients of 7.9%, organic matter content ≥46%, total nitrogen content is 30% higher than that of conventional processes, all indicators are qualified, waste gas purification efficiency is ≥95%, and production energy consumption is 31% lower than that of traditional processes.

[0037] It should be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0038] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A system for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater, characterized in that, The system includes a pretreatment unit, a mixing unit, a two-stage fermentation unit, and a post-treatment processing unit connected in sequence. The system also includes a waste gas biofiltration unit connected to the two-stage fermentation unit via a gas pipeline. The pretreatment unit includes a sludge dewatering module and a baijiu (Chinese liquor) lees enzymatic hydrolysis module. The sludge dewatering module includes a plate and frame filter press or a belt filter press. The feed end of the sludge dewatering module is connected to the wastewater biochemical treatment system of the winery, and the discharge end of the sludge dewatering module is connected to the feed end of the ingredient mixing unit. The baijiu lees enzymatic hydrolysis module includes a pulverizer, an enzymatic hydrolysis reaction tank, and a solid-liquid separator connected in sequence. The liquid phase outlet of the solid-liquid separator is connected to the feed end of the ingredient mixing unit, and the solid phase outlet of the solid-liquid separator is connected to the rice husk silo of the ingredient mixing unit. The batching and mixing unit includes a mixer; the feed end of the batching and mixing unit is connected to the discharge end of the sludge dewatering module, the liquid phase outlet of the solid-liquid separator, the waste sludge metering hopper, the functional microbial agent metering hopper, and the rice husk silo; the discharge end of the batching and mixing unit is connected to the feed end of the two-stage fermentation unit. The two-stage fermentation unit includes a primary high-temperature aerobic fermentation device and a secondary aging biological filtration device connected in series. The primary high-temperature aerobic fermentation device includes a fermentation tank with an aeration pipe network at the bottom, which is connected to an aeration blower. The secondary aging biological filtration device includes an aging chamber with an exhaust gas distribution pipe network at the bottom, and the first exhaust port of the fermentation tank is connected to the exhaust gas distribution pipe network. The aging chamber is equipped with a humidity control component, which includes a water distribution pipe network, multiple nozzles, and a humidity sensor. The waste gas biological filtration unit includes a biological filtration tower, which is filled with a modified biological filter media layer and an ultraviolet photocatalytic component from bottom to top. The air inlet of the waste gas biological filtration unit is connected to the second exhaust port of the secondary aging biological filtration device. The filter medium of the biological filtration tower is aged compost material. The post-processing unit includes a screening machine, a crusher, a mixer, and a granulator. The inlet of the screening machine is connected to the outlet of the secondary aging biological filtration device. The undersize outlet of the screening machine is connected to the inlet of the mixer. The oversize outlet of the screening machine is connected to the inlet of the crusher. The outlet of the crusher is connected to the inlet of the mixer. The inlet of the mixer is also connected to an inorganic nutrient element metering hopper. The outlet of the mixer is connected to the inlet of the granulator.

2. The system for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater according to claim 1, characterized in that, The system also includes an online microbial community monitoring module and an intelligent decision-making server; the fermentation tank includes a trough-type turning fermentation chamber with a turning machine or a horizontal drum fermentation tank, and the fermentation tank is equipped with monitoring sensors, including a temperature sensor, an oxygen concentration sensor, and a pH sensor; the monitoring sensors and the online microbial community monitoring module are electrically connected to the input end of the intelligent decision-making server; the output end of the intelligent decision-making server is electrically connected to the aeration fan, the turning machine, and the microbial agent supplementation device, respectively; the online microbial community monitoring module uses a high-throughput sequencer, and the sampling port is connected to the inside of the fermentation tank through an automatic sampling pipeline; the intelligent decision-making server has a built-in digital twin model of the composting process based on machine learning; the discharge end of the microbial agent supplementation device is connected to the feed end of the primary high-temperature aerobic fermentation device.

3. The system for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater according to claim 2, characterized in that, The system also includes a multispectral online detection device; the multispectral online detection device includes a near-infrared spectral probe, a hyperspectral imaging system, and an electronic nose sensor array; the near-infrared spectral probe is installed at the discharge end of the batching and mixing unit to detect the carbon-nitrogen ratio and moisture content of the material; the hyperspectral imaging system is installed inside the fermentation tank and aging chamber to monitor the material's maturity distribution; the electronic nose sensor array is installed at the first exhaust port of the fermentation tank and the second exhaust port of the aging chamber to detect the concentrations of ammonia, hydrogen sulfide, and VOCs; the multispectral online detection device is electrically connected to the input end of the intelligent decision server.

4. The system for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater according to claim 1, characterized in that, The two-stage fermentation unit also integrates a waste heat recovery system, which includes a heat exchanger and a heat pump unit. The heat exchanger includes a shell-and-tube heat exchanger or a plate heat exchanger, and the heat pump unit includes a low-temperature waste heat recovery type heat pump unit. The heat exchanger is installed on the pipeline between the first exhaust port of the fermenter and the waste gas distribution network. The cold water inlet of the heat exchanger is connected to a water source, and the hot water outlet of the heat exchanger is connected to the hot water inlet of the enzymatic reaction tank. The heat absorption end of the heat pump unit is installed on the outer wall of the fermenter, and the heat release end of the heat pump unit is connected to the humidity control component of the secondary aging biological filtration device.

5. The system for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater according to claim 1, characterized in that, The aged compost material is the material output after aging through a two-stage aging biological filtration device; the modified biological filter layer is aged compost material loaded with manganese oxides, with a manganese oxide loading of 5% to 10%.

6. A process for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater based on the system described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Pretreatment: The residual sludge after the biochemical treatment of the soy sauce-flavored liquor wastewater is dewatered by the sludge dewatering module to reduce the sludge moisture content to 75%~85%; the liquor lees are crushed to a particle size ≤10mm by a pulverizer and sent to an enzymatic hydrolysis tank. Compound enzyme preparation and water are added, and the solid-liquid ratio is adjusted to 1:2~1:

3. Enzymatic hydrolysis is carried out at 45~55℃ for 4~6h. The liquid phase of the lees organic components and the solid phase of rice husks are obtained by a solid-liquid separator. S2. Co-processing: Dewatered sludge, discarded organic components, crushed waste sludge, functional microbial agents and rice husks are fed into a mixer. The moisture content of the mixed material is controlled to be 55%~65% and the carbon-nitrogen ratio is 20:1~30:

1. S3, Two-stage fermentation: The mixed materials are fed into the fermentation tank of the first-stage high-temperature aerobic fermentation device and fermented at 55~70℃ for 7~15 days. During the fermentation, data is fed back through monitoring sensors and the microbial community online monitoring module. The intelligent decision server automatically controls turning, aeration and addition of microbial agents. At the same time, the waste heat of fermentation is recovered synchronously through the waste heat cascade recovery system. The material after high-temperature fermentation is transferred to the aging chamber of the second-stage aging biological filtration device and aged at below 40℃ for 15~25 days. During the aging period, the waste gas generated by the first-stage fermentation is introduced into the bottom of the aging chamber for preliminary purification through the exhaust fan and waste gas distribution pipeline network. S4. Exhaust gas purification: Incompletely purified exhaust gas in the aging chamber is sent to the exhaust gas biological filtration unit. After being treated by the aged compost material, the modified biological filter layer and the ultraviolet photocatalytic component, it meets the emission standards. The residence time of the exhaust gas in the modified biological filter layer is 15~30 seconds. S5. Post-processing and formulation: After aging, the material is screened by a screening machine. The undersize material enters the mixer, and the oversize material is crushed by a crusher and returned to the mixer. Inorganic nutrients are added, and after being mixed evenly, the mixture is sent to a granulator to granulate and produce organic fertilizer. The granulated fertilizer is tested, and after passing the test, it is weighed and packaged.

7. The process for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater according to claim 6, characterized in that, The compound enzyme preparation mentioned in step S1 includes acidic protease, high-temperature amylase and cellulase, and the total amount of the compound enzyme preparation added is 0.3% to 0.8% of the dry weight of the discarded lees of the liquor.

8. The process for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater according to claim 6, characterized in that, In step S2, the amount of rice husk added is 5% to 15% of the total dry weight of the mixture, so that the initial porosity of the mixture reaches 35% to 45%; the functional microbial agent is a compound microbial system composed of Bacillus subtilis, Bacillus stearothermophilus and nitrifying bacteria in a viable count ratio of (3 to 5): (2 to 4): (1 to 2), and the amount of functional microbial agent added is 0.5% to 1.2% of the total dry weight of the mixture.

9. The process for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater according to claim 6, characterized in that, The specific control method of the intelligent decision server in step S3 is as follows: when the temperature inside the fermenter exceeds 65℃, the aeration volume of the aeration fan is automatically increased and the compost is turned; when the temperature is below 50℃, the aeration volume is reduced and 10%~20% of the initial dosage of Bacillus subtilis and nitrifying bacteria is added through the microbial agent replenishment device; when the pH value is below 6.5, it is adjusted to 6.5~8.0 by adding waste pit mud; the compost is turned 2~4 times during the primary fermentation cycle; when the abundance of cellulose-degrading bacteria is detected to be below 10... 6 When CFU / g, Bacillus subtilis is added; when the abundance of nitrifying bacteria is below 10... 5 When the concentration of CFU / g is reached, nitrifying bacteria are added; the moisture content of the material in the aging chamber is maintained at 45%~55% using a humidity control component.

10. The process for preparing organic fertilizer from biochemical sludge of soy sauce-flavored liquor wastewater according to claim 6, characterized in that, In step S5, the inorganic nutrients include urea, superphosphate, and potassium sulfate, which are added to make the total nutrient content of the granular fertilizer reach 5.0%~8.0%; after granulation, a low-temperature drying method is used, with a drying temperature ≤60℃, to ensure that the moisture content of the finished product is ≤15%; the screen mesh size is 3~5mm during sieving.

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