Food high-COD (Chemical Oxygen Demand) degradation full-biomass integration system and method

Abstract

The invention provides a food high COD degradation full biomass integration system and method, and relates to the technical field of organic wastewater treatment.The food high COD degradation full biomass integration system comprises a core biological treatment medium and a special biochemical reactor, the core biological treatment medium is chitin living body gel for synthesizing microbial communities, and the special biochemical reactor is a biological reactor; the composition comprises a synthetic microbial community fixed in a chitin gel carrier, and the synthetic microbial community at least comprises rhizopus oryzae, pseudomonas putida, bacillus and yarrowia lipolytica; synthetic microbial communities with specific components are fixed in chitin gel through a synergistic cross-linking process to form living body gel with high biomass, high activity and strong adsorption capacity, microorganisms are firmly fixed and are not prone to loss, a system is rapidly started, fluctuation impact of water quality and water quantity can be effectively coped, and the biological activity of the chitin gel is improved. Chained deep degradation of pollutants is realized through the synergistic effect of microorganisms, and the treatment efficiency is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic wastewater treatment, and in particular to a food high-COD degradation full-biomass integrated system and method. BACKGROUND

[0002] In the food, fermentation and other industries, the treatment of high-concentration organic wastewater is a technical difficulty in the environmental protection field. The current mainstream activated sludge method and combined process based thereon have problems such as long process chain, numerous equipment, complex debugging, huge energy consumption, large sludge production, and possible secondary pollution caused by adding chemical agents when treating such wastewater. In order to strengthen the treatment effect, the prior art usually adopts the ways of adding special bacterial agents or optimizing the structure of the reactor, but the problems such as easy loss of microorganisms, slow start, weak resistance to impact load, etc. still exist, and subsequent chemical oxidation units are often still needed to ensure that the effluent meets the standards, and a truly green full-biological treatment cannot be achieved. The similar scheme in the prior art usually relies on free activated sludge for biological oxidation, and has inherent defects such as poor system stability caused by easy loss of microorganisms, long start-up and recovery period, and large sludge production. Its operation needs to accurately control the nutrients and dissolved oxygen, and the energy consumption and operation cost are high. In addition, this kind of scheme cannot make the high-COD wastewater stably meet the standards through biological treatment alone, and must be connected with a subsequent chemical deep oxidation unit, which not only increases the complexity and cost of the process flow, but also introduces chemical consumption and potential secondary pollution risk. The whole system process is long, the integration degree is low, and the land occupation area is large. Therefore, the present application proposes a food high-COD degradation full-biomass integrated system and method to solve the problems existing in the prior art. SUMMARY

[0003] In view of the above problems, the present application proposes a food high-COD degradation full-biomass integrated system and method, which fixes a synthetic microbial community with a specific composition in chitin gel through a synergistic cross-linking process to form a living gel with high biomass, high activity and strong adsorption capacity. The microorganisms are firmly fixed and not easy to lose, the system starts quickly, and can effectively cope with the fluctuation impact of water quality and quantity. The synergistic effect between microorganisms realizes chain deep degradation of pollutants, and the treatment efficiency is high.

[0004] To achieve the purpose of the present application, the present application realizes the following technical scheme: a food high-COD degradation full-biomass integrated system, comprising a core biological treatment medium and a special biochemical reactor, the core biological treatment medium is a chitin living gel of a synthetic microbial community, and contains a synthetic microbial community fixed in a chitin gel carrier, the synthetic microbial community at least includes Rhizopus oryzae, Pseudomonas putida, Bacillus and Yarrowia lipolytica. The special biochemical reactor is a gas-liquid-solid three-phase reaction container with an internal flow guide structure, and the special biochemical reactor is internally provided with a movable frame for modular loading, fixing and replacing the chitin living gel; and the water outlet end of the special biochemical reactor is integrated with a gas stripping reflux device for driving the wastewater circulation in the system and assisting oxygenation.

[0005] Further improvement lies in that in the synthetic microbial community, the volume ratio of Rhizopus oryzae, Pseudomonas putida, Yarrowia lipolytica and Bacillus is (3-5):(2-3):(1.5-2.5):(1-2).

[0006] Further improvement lies in that the chitin living gel is prepared by a synergistic process of chemical pre-crosslinking with glutaraldehyde and physical crosslinking through freeze-thaw cycles.

[0007] Further improvement lies in that the internal flow guide structure of the special biochemical reactor is an S-shaped baffle flow channel formed by a baffle.

[0008] Further improvement lies in that the gas stripping reflux device comprises an air blower, a riser and a reflux pipe; the bottom of the riser is arranged below the liquid level of the special biochemical reactor, the air blower introduces air into the bottom of the riser to form a low-density gas-liquid mixed phase, drives the mixed phase to rise and return to the water inlet end of the special biochemical reactor through the reflux pipe.

[0009] A food high-COD degradation whole-biomass integrated method, comprising the following steps: S1: preparing a synthetic microbial community suspension: culturing Rhizopus oryzae, Pseudomonas putida, Bacillus and Yarrowia lipolytica respectively, mixing the bacterial bodies in proportion after obtaining the bacterial bodies, and activating and domesticating to obtain a synthetic microbial community suspension; S2: mixing the synthetic microbial community suspension with a chitin dispersion liquid, adding a crosslinking agent for pre-crosslinking to obtain a mixed slurry; S3: freeze-thaw cycle crosslinking treatment is performed on the mixed slurry to form a chitin living gel; S4: loading the chitin living gel into a special biochemical reactor, introducing high-COD food wastewater to be treated, and starting the system for biodegradation treatment.

[0010] Further improvement lies in that in S2, the crosslinking agent is glutaraldehyde, and the final concentration of glutaraldehyde in the mixed system is 0.5%-4.0%(v / v); and in S2, the volume ratio of the synthetic microbial community suspension to the chitin dispersion liquid is 1:1 to 1:3.

[0011] Further improvement lies in that, in the S3, the freeze-thaw cycle cross-linking treatment comprises: freezing the mixed slurry at-20℃ to-80℃ for 12-24 hours, and then thawing at 4-25℃ for 4-8 hours, and the freezing-thawing process is repeated 2-4 times.

[0012] Further improvement lies in that, in the S4, the chitin living gel is one of rope type, granular type and block type; and the chitin living gel is fixed in a packed bed form or by a movable frame in a special biochemical reactor.

[0013] Further improvement lies in that, in the S4, the system realizes hydraulic internal circulation through a gas stripping reflux device, and the hydraulic retention time is 6-24 hours during the treatment process.

[0014] The beneficial effects of the present application are: 1. The present application fixes the synthetic microbial community with specific composition in the chitin gel through a synergistic cross-linking process to form a living gel with high biomass, high activity and strong adsorption capacity. The microorganisms are firmly fixed and are not easy to be lost. The system starts quickly and can effectively cope with the fluctuation impact of water quality and quantity. The synergistic effect between microorganisms realizes the chain-type deep degradation of pollutants, and the treatment efficiency is high.

[0015] 2. The present application takes the whole biomass material as the core, and does not need to add any chemical flocculant or oxidant during the treatment process, thereby fundamentally avoiding the generation of chemical sludge and secondary pollution. The special reactor realizes circulation and oxygenation through gas stripping reflux, which greatly reduces the energy consumption compared with traditional aeration. The gelatinized microbial community has strong environmental adaptability, reduces the harsh requirements for the nutrient ratio of the influent, and simplifies the operation and management.

[0016] 3. The present application integrates the efficient biological treatment medium and the optimized reactor structure into a compact unit, realizes the integration of biological oxidation and physical adsorption clarification functions, replaces the long process of traditional pretreatment+anaerobic+ aerobic+advanced treatment, and adopts modular design for the living gel, which is easy to load, replace and maintain. The whole system has small land occupation area, low investment and operation cost, and is especially suitable for dispersed or intermittent treatment scenes. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The figure is a schematic diagram of the special biochemical reactor of the present application. Figure 2 The figure is a flow chart of the present application. DETAILED DESCRIPTION

[0018] In order to deepen the understanding of the present application, the present application will be further described in combination with examples. The examples are only used to explain the present application and do not constitute a limitation on the protection scope of the present application.

[0019] Example one according to Figure 1 , 2 As shown, this embodiment proposes a fully biomass integrated system for the degradation of high COD in food. It utilizes a chitinous live gel based on a synthetic microbial community (Rhizopus oryzae, Pseudomonas putida, Bacillus, and Yersinia lipolyticis) as the core biological treatment medium. This system immobilizes highly efficient functional microbial communities within a high-strength, highly elastic biomass carrier, overcoming the drawback of easily lost free sludge. This forms a multifunctional microbial interaction network, with multiple microorganisms chain-treating high COD wastewater. Combined with specialized treatment equipment, it efficiently and thoroughly degrades high COD from food sources into carbon dioxide and water, avoiding the need for secondary treatment of large amounts of activated sludge. This integrated system aims to achieve rapid start-up (utilizing the initial high activity of the microbial community live gel) and maintain a stable biomass of high concentration and high activity within the reactor under fluctuating loads, thereby improving treatment efficiency and system robustness.

[0020] By leveraging the synergistic effects of synthetic microbial communities and the characteristics of the constructed gel ecosystem, the stringent requirements for the C / N / P ratio of wastewater can be reduced, and the dependence on external nutrient addition can be reduced or eliminated, thereby simplifying operation control parameters and reducing operational complexity and operating costs.

[0021] Through the synergistic biological treatment and deep degradation of a powerful synthetic microbial community, key indicators such as COD and turbidity of food wastewater can reach predetermined levels in a short time after treatment by this integrated system, thus completely eliminating the need for subsequent anaerobic treatment, deep oxidation, MBR, and other treatment units. This eliminates the cost, safety, and secondary pollution risks associated with multi-process unit series treatment, achieving truly environmentally friendly, fully biological treatment of high-COD food wastewater.

[0022] By integrating highly efficient microbial live gels with optimized biochemical treatment devices into a single integrated treatment unit, the overall process flow is shortened, the number of equipment and connection links are reduced, and a compact and highly modular treatment system is formed, which significantly reduces fixed asset investment costs, floor space and operating energy consumption.

[0023] A method for integrating biomass into the degradation of high COD in food: A core biological treatment medium—a chitin-based live gel based on a synthetic microbial community—is used. The synthetic microbial community includes *Rhizopus oryzae*, *Pseudomonas putida*, *Bacillus*, and *Yersinia lipolyticis*, and is obtained through the following preparation method. The highly active synthetic microbial community is firmly combined with a biocompatible chitin carrier to form a live gel with a three-dimensional network structure, high mechanical strength, high elasticity, and the ability to maintain microbial activity over a long period.

[0024] S1: Cultivation of synthetic microbial communities Preparation of Rhizopus oryzae fermentation broth Rhizopus oryzae ( Rhizopus oryzae Spores were inoculated into liquid fermentation medium and cultured with shaking at 28-32℃ and 150-200rpm for 24-48 hours to obtain Rhizopus oryzae fermentation broth rich in active mycelium.

[0025] The fermentation medium comprises: 10-40 g / L glucose, 0-1 g / L (NH4)2SO4, 0-1 g / L KH2PO4, 0-0.1 g / L FFeSO4, 0.1-1 g / L MgSO4, 0-0.1 g / L ZnSO4, 10-40 g / L CaCO3, and 1-7% v / v citrate buffer; preferably, the fermentation medium comprises: 40 g / L glucose, 0.71 g / L (NH4)2SO4, 0.6 g / L KH2PO4, 0.004 g / L FFeSO4·7H2O, 0.5 g / L MgSO4·7H2O, 0.01 g / L ZnSO4·7H2O, 30 g / L CaCO3, and 5% v / v citrate buffer.

[0026] The seed culture medium comprises: 10-40 g / L glucose, 2-5 g / L (NH4)2SO4, 0.2-1 g / L KH2PO4, 0-0.01 g / L FeSO4·7H2O, 0-1 g / L MgSO4·7H2O, and 0-0.2 g / L ZnSO4·7H2O; preferably, the seed culture medium comprises: 40 g / L glucose, 4.4 g / L (NH4)2SO4, 0.6 g / L KH2PO4, 0.005 g / L FeSO4·7H2O, 0.5 g / L MgSO4·7H2O, and 0.018 g / L ZnSO4·7H2O.

[0027] Pseudomonas putida Pseudomonas putida ( Pseudomonas putida Single colonies were inoculated into liquid seed culture medium and cultured with shaking at 30°C and 180-220 rpm for 12-16 hours to obtain a highly active seed culture. Subsequently, the culture was transferred to fermentation medium at an inoculation rate of 1-10% v / v and cultured with shaking at 28-30°C and 180-220 rpm for 18-36 hours to obtain a high-biomass *Pseudomonas putida* fermentation broth (cell suspension).

[0028] The fermentation medium comprises: 1-10 g / L carbon source (optionally glucose, sodium citrate, sodium benzoate, etc.), 1-5 g / L (NH4)2SO4, 1-6 g / L K2HPO4, 0.5-2 g / L KH2PO4, 0.1-1 g / L NaCl, 0-0.5 g / L MgSO4·7H2O, and 0.1-1 mL / L trace element solution, with a pH of 6.5-7.5; preferably, the fermentation medium comprises: 5 g / L sodium citrate, 2 g / L (NH4)2SO4, 4.8 g / L K2HPO4, 1.2 g / L KH2PO4, 0.5 g / L NaCl, 0.2 g / L MgSO4·7H2O, and 1 mL / L standard trace element solution SL-4, with a pH of 7.0.

[0029] The seed culture medium comprises: 5-15 g / L peptone, 2.5-10 g / L yeast extract, 5-15 g / L NaCl, and pH 6.5-7.5; preferably, the seed culture medium comprises: 10 g / L peptone, 5 g / L yeast extract, 10 g / L NaCl, and pH 7.0.

[0030] Bacillus Bacillus ( Bacillus spp. Single colonies or spore suspensions are inoculated into liquid seed culture medium and cultured with shaking at 35-37℃ and 150-200 rpm for 8-12 hours to obtain highly active seed culture. Subsequently, the culture is transferred to fermentation medium at an inoculation rate of 1-5% v / v and cultured with shaking at 35-37℃ and 150-200 rpm for 24-48 hours to obtain Bacillus fermentation broth rich in cells and extracellular products.

[0031] The fermentation medium comprises: 5-30 g / L carbon source (glucose, starch, sucrose, etc.), 1-10 g / L nitrogen source (peptone, yeast extract, (NH4)2SO4, beef extract, etc.), 0.1-2 g / L K2HPO4, 0.1-1 g / L KH2PO4, 0-0.5 g / L MgSO4·7H2O, 0-0.1 g / L CaCl2, 0-0.1 g / L MnSO4, pH 6.5-7.5; preferably, the fermentation medium comprises: 20 g / L glucose, 10 g / L peptone, 5 g / L yeast extract, 1 g / L K2HPO4, 0.5 g / L KH2PO4, 0.2 g / L MgSO4·7H2O, 0.02 g / L CaCl2, 0.01 g / L MnSO4, pH 7.0.

[0032] The culture medium for the seed liquid comprises: 5-15 g / L peptone, 3-10 g / L yeast extract, 5-15 g / L NaCl, pH 6.5-7.5; preferably, the culture medium for the seed liquid comprises: 10 g / L peptone, 5 g / L yeast extract, 10 g / L NaCl, pH 7.0.

[0033] Yarrowia lipolytica Yeast (Yersinia lipophila) Yarrowia lipolytica Single colonies were inoculated into liquid seed culture medium and cultured with shaking at 28-30℃ and 180-220 rpm for 18-24 hours to obtain a highly active seed culture. Subsequently, the culture was transferred to fermentation medium at an inoculation rate of 5-10% v / v and cultured with shaking at 28-30℃ and 180-220 rpm for 48-72 hours to obtain a high-biomass Yersinia lipolytica fermentation broth.

[0034] The fermentation medium comprises: 10-50 g / L carbon source (optionally glucose, glycerol, oleic acid, etc.), 1-5 g / L nitrogen source (optionally yeast extract, peptone, (NH4)2SO4, urea, etc.), 0.5-3 g / L KH2PO4, 0.5-2 g / L K2HPO4, 0.1-1 g / L MgSO4·7H2O, 0-0.1 g / L CaCl2, 0-0.1 g / L FeCl3, pH 5.5-6.8; preferably, the fermentation medium comprises: 30 g / L glucose, 5 g / L yeast extract, 3 g / L peptone, 2 g / L KH2PO4, 1 g / L K2HPO4, 0.5 g / L MgSO4·7H2O, 0.05 g / L CaCl2, pH 6.2.

[0035] The culture medium for the seed liquid comprises: 10-30 g / L glucose, 5-15 g / L peptone, 5-15 g / L yeast extract, and pH 5.5-6.5; preferably, the culture medium for the seed liquid comprises: 20 g / L glucose, 10 g / L peptone, 10 g / L yeast extract, and pH 6.0.

[0036] Preparation of synthetic microbial community suspension Independent high-density culture of each strain: Rhizopus oryzae: In a fermentation medium containing 40 g / L glucose, culture at 30°C and 180 rpm for 36-48 hours to obtain a concentrated mycelial fermentation broth. It can be used directly without filtration or by lightly homogenizing to break up excessively long mycelia.

[0037] *Pseudomonas putida*: Incubate in LB or inorganic salt medium at 30°C and 200 rpm for 16-18 hours (OD200). 600(≈2.0-3.0), to obtain a bacterial suspension. Centrifuge to collect the bacterial cells, and resuspend them in sterile physiological saline to the desired concentration.

[0038] Yeast extract: In YPD or optimized fermentation medium, culture at 28°C and 200 rpm for 48 hours (to reach the stationary phase) to obtain a yeast cell suspension. Collect by centrifugation and resuspend in sterile physiological saline.

[0039] Bacillus: Incubate in LB broth or nutrient broth at 37°C and 180 rpm for 12-16 hours (early stage of spore formation, when bacterial activity is high). Obtain a bacterial suspension. Collect by centrifugation and resuspend in sterile physiological saline.

[0040] Cell harvesting, washing and biomass standardization: Under aseptic conditions, the fermentation broths of the four strains were centrifuged (6000-8000 rpm, 10-15 minutes, 4℃) and the supernatant culture medium was discarded.

[0041] Wash the bacterial pellet with sterile physiological saline or phosphate-buffered saline (PBS) at pH 7.0, centrifuge, and repeat 1-2 times.

[0042] Each bacterial cell precipitate was resuspended separately with a small amount of sterile physiological saline or sterile filtrate of the target wastewater. The effective biomass concentration of each bacterial suspension was standardized to the same baseline (e.g., adjusted to 1.0 × 10^8–5.0 × 10^8 CFU / mL or equivalent biomass wet weight concentration) by measuring the wet weight of the bacterial cells or by counting with a hemocytometer.

[0043] Aseptic mixing according to functional proportions: The standardized strain suspensions were aseptically mixed in the following volume ratios to form the basic suspension for the synthetic microbial community: Rhizopus oryzae mycelial suspension: 30%~50%; Pseudomonas putida suspension: 20%~30%; Yersinia lipolytica suspension: 15%~25%; Bacillus suspension: 10%~20%. The preferred mixing volume ratio was: Rhizopus oryzae: Pseudomonas putida: Yersinia lipolytica: Bacillus = 4:2:2:2.

[0044] Community activation and acclimatization: The obtained basic suspension is transferred to a community activation medium at an inoculation rate of 5%-10%. The community activation medium is: sterilized raw food wastewater of the target food to be treated or its diluted solution, or a component simulation medium (containing 10-20 g / L glucose, 1-2 g / L peptone, 0.5-1 g / L yeast extract, pH 6.5-7.0).

[0045] Incubate at 28-30℃ and 150-180 rpm with shaking for 6-12 hours. This process allows different strains to establish initial physical contact and metabolic interactions, adapt to the complex environment, and activate their synergistic degradation potential against wastewater components. Continue incubation until the mixture becomes uniformly turbid and may be accompanied by the formation of tiny mycelial flocs. This mixture can then be used as the final synthetic microbial community suspension.

[0046] S2: Obtaining the chitin dispersion S3: Mixed with glutaraldehyde pre-crosslinking Under aseptic and gentle stirring conditions, the synthetic microbial community suspension prepared in step S1 and the chitin dispersion obtained in step S2 were uniformly mixed at a volume ratio of 1:1 to 1:3 to form a mixed slurry. Glutaraldehyde solution was slowly added dropwise to the mixed slurry until its final concentration in the mixture was 0.5-4.0% (v / v). The reaction was continued with gentle stirring at room temperature for 1-3 hours. Glutaraldehyde plays a crucial pre-crosslinking role in this process; its aldehyde groups react with the amino groups on the chitin molecular chain and the functional groups such as proteins on the surface of the mycelium through a Schiff base reaction, initially establishing a covalent crosslinking network. This anchors the microbial cells to the chitin backbone, significantly improving the initial structural stability and mechanical properties of the subsequent gel.

[0047] S4: Freeze-thaw cycle cross-linking molding The pre-crosslinked slurry is injected into a mold of a predetermined shape (such as a cylindrical cavity). Rope-type filler is placed in the cavity, ensuring it is completely submerged in the slurry. The mold is then frozen at -20°C to -80°C for 12-24 hours to allow the slurry to completely solidify. Subsequently, the frozen material is transferred to a 4-25°C environment for 4-8 hours to thaw completely into a gel state. This freeze-thaw process can be repeated 2-4 times. Freeze-thaw crosslinking is a physical crosslinking method: during freezing, water molecules form ice crystals, forcing chitin molecular chains and microbial cells to aggregate and converge, strengthening intermolecular hydrogen bonds and other forces; after thawing, the pores left by the melting ice crystals form the three-dimensional porous network structure of the gel. This process, synergistic with chemical crosslinking, further enhances the gel's porosity, water absorption and swelling properties, and structural toughness, providing a superior micro-habitat environment and mass transfer channels for microorganisms.

[0048] S5: Post-processing The formed rope-shaped live gel is removed from the mold and repeatedly rinsed with sterile water or buffer solution to remove unreacted glutaraldehyde and soluble impurities. After draining the water, a highly bioactive synthetic microbial community chitin live gel is obtained. This product can be stored for a long time under humid conditions at 4°C, or directly used in the wastewater treatment integrated system of this invention.

[0049] By employing a synergistic strategy of glutaraldehyde chemical crosslinking and freeze-thaw physical crosslinking, a biogel with excellent mechanical strength, a stable three-dimensional porous structure, and high microbial loading capacity was successfully constructed. This maximized the preservation of the bioactivity of various microorganisms, achieving a stable and efficient composite of functional microorganisms and natural carrier materials, and providing a reliable core functional material for subsequent wastewater treatment applications.

[0050] Design of dedicated biochemical reactors The bioreactor for live gel is essentially a gas-liquid-solid three-phase fluidized bed, where the solid phase is a rope-shaped live gel carrier. The reactor's structural design prioritizes facilitating sufficient contact between wastewater and the gel carrier. Its main body is typically a rectangular tank, with baffles evenly distributed within to guide the water flow in a continuous "S"-shaped path from the inlet to the outlet, thus forming multiple independent reaction zones connected in series. Movable frames are positioned at corresponding locations in each reaction zone to suspend and secure the rope-shaped live gel, enabling modular installation and disassembly of the carrier. An air-lift reflux device is integrated at the reactor's outlet. This device injects compressed air via a blower into the bottom of a submerged riser pipe, forming a gas-liquid mixture within the pipe. Because the density of the mixed phase is significantly lower than that of the liquid phase outside the pipe, the resulting pressure difference drives the mixed phase upwards, which is then transported back to the inlet via a reflux pipeline, thus achieving internal wastewater circulation within the system. This process achieves wastewater recirculation and improves treatment efficiency while simultaneously enabling air-liquid contact, thus providing auxiliary oxygenation and mixing. Once the wastewater reaches the set effluent standards after treatment by this bioreactor, it is discharged from the effluent outlet. The entire system has no underwater mechanical moving parts, making it less prone to clogging and with a low failure rate. Furthermore, its movable frame structure facilitates the loading, unloading, and maintenance of the live gel, ensuring stable treatment results while maintaining ease of operation and operational reliability.

[0051] S6: System Integration This integrated system utilizes a live gel as the core biological treatment medium, working in conjunction with a dedicated bioreactor. By suspending and fixing the rope-type live gel carrier within the bioreactor, modular assembly and replacement of the carrier are achieved. Simultaneously, an air-lift device integrates the air supply and circulation units, forming a compact and highly modular integrated treatment unit. During operation, it maintains minimal loss of microbial biomass, thus creating a stable and efficient biochemical reaction environment. It not only optimizes the contact conditions between water and the gel medium, improving the mass transfer efficiency between the gas, liquid, and solid phases, but also shortens the overall process flow through system integration, reducing the number of supporting equipment and piping connections, thereby lowering the system's operating costs, floor space, and energy consumption.

[0052] Example 2 according to Figure 1, 2 As shown, this embodiment proposes a whole biomass integrated system and method for the degradation of high COD food, including the following steps: Preparation of synthetic microbial community chitin live gel S1: Preparation of synthetic microbial community suspension Rhizopus oryzae, Pseudomonas putida, Yersinia lipolytica, and Bacillus were cultured at high densities separately. Specific culture conditions and preferred culture media are as described in the invention summary section.

[0053] Bacterial cell harvesting and standardization: Bacterial cells were collected by centrifugation under aseptic conditions, washed with sterile PBS, and resuspended. Counting was performed using a hemocytometer, and the concentration of each bacterial suspension was adjusted to approximately 2.0 × 10^8 CFU / mL.

[0054] Mixing and Activation: A basic suspension was prepared by mixing *Rhizopus oryzae*, *Pseudomonas putida*, *Yersinia lipophila*, and *Bacillus* at a volume ratio of 4:2:2:2. This suspension was then transferred at a 5% inoculum into sterilized simulated food wastewater (containing 15 g / L glucose, 1.5 g / L peptone, pH 7.0) and activated at 30°C and 160 rpm for 8 hours with shaking to obtain the activated synthetic microbial community suspension.

[0055] S2: Obtain a 2% (w / w) chitin acid dispersion.

[0056] S3: Mixing and Pre-crosslinking: In a sterile container, mix the suspension obtained in step S1 with the chitin dispersion from step S2 at a volume ratio of 1:2 and stir gently. Slowly add glutaraldehyde solution to a final concentration of 2.0% (v / v). Continue stirring at room temperature for 2 hours.

[0057] S4: Freeze-thaw crosslinking molding: Inject the pre-crosslinked slurry into a cylindrical mold, with rope-shaped filler pre-placed in the mold. Freeze at -40℃ for 16 hours, then transfer to 4℃ to thaw for 6 hours. Repeat this freeze-thaw cycle 3 times. S5: Post-treatment: Remove the molded gel, rinse thoroughly with sterile water, and drain to obtain the finished rope-shaped synthetic microbial community chitin live gel.

[0058] Construction of dedicated biochemical reactor The reactor body is a rectangular tank, internally divided by vertical baffles to create a continuous "S"-shaped flow of water from the inlet to the outlet. A movable frame is installed within each reaction zone to suspend and secure the prepared rope-shaped biogel. At the reactor outlet, an air-lift reflux device is installed: a blower introduces air into the bottom of a submerged riser pipe, causing the resulting gas-liquid mixture to rise within the pipe and be transported back to the inlet via the reflux pipe, achieving hydraulic circulation and auxiliary oxygenation.

[0059] Wastewater treatment operation The prepared live gel was modularly loaded into the reactor. Food processing wastewater (mainly containing starch, protein, and oil) with a COD concentration of 3500 mg / L and a turbidity of 200 NTU was pumped into the system, and the hydraulic retention time (HRT) was controlled at 12 hours. During system operation, circulation and a micro-aerobic environment were maintained solely through an airlift device; no nutrients or chemical agents were added.

[0060] Operational results show that the system starts up rapidly, with a COD removal rate exceeding 70% after 4 hours. After stable operation, the effluent COD remains below 150 mg / L, with a removal rate >95%; effluent turbidity drops below 5 NTU, achieving efficient simultaneous COD degradation and turbidity clarification. Throughout the entire operation cycle, no large-scale generation of activated sludge was observed in the reactor, and the gel biomass remained stable.

[0061] Example 3 according to Figure 1 , 2 As shown, this embodiment proposes a whole biomass integrated system and method for the degradation of high COD food, including the following steps: Strain and vector adjustment: In the synthetic microbial community, *Rhizopus oryzae* was replaced with *Aspergillus niger*, which has a similar function. Aspergillus niger The gel carrier is a blend of chitin and sodium alginate (mass ratio 7:3), and after pre-crosslinking, an ionic crosslinking step in 2% CaCl2 solution is added to further strengthen the gel network.

[0062] Reactor operation mode: Sequencing batch reactor (SBR) operation mode. The reactor is filled with granular living gel. Each operating cycle includes: influent (0.5h), reaction (10h), sedimentation (1h), and effluent (0.5h). During the reaction stage, jet aerators are used for stronger oxygenation and mixing to treat wastewater with higher COD concentrations (approximately 10,000 mg / L).

[0063] Gel regeneration: After one month of operation, some gel modules are removed from the reactor and placed in a nutrient-rich recovery solution for 24 hours to restore their microbial activity. They are then reassembled into the system to achieve offline gel regeneration.

[0064] When the system of this embodiment is used to treat high-concentration wastewater, the COD removal rate can still reach more than 92% within a total cycle of 14 hours, and the long-term operational stability of the system is guaranteed through gel regeneration.

[0065] Example 4 according to Figure 1 , 2 As shown, this embodiment proposes a whole biomass integrated system and method for the degradation of high COD food, including the following steps: Strain and vector adjustment: In the synthetic microbial community, *Rhizopus oryzae* was replaced with *Aspergillus niger*, which has a similar function. Aspergillus niger The gel carrier is a blend of chitin and sodium alginate (mass ratio 7:3), and after pre-crosslinking, an ionic crosslinking step in 2% CaCl2 solution is added to further strengthen the gel network.

[0066] Reactor operation mode: Sequencing batch reactor (SBR) operation mode. The reactor is filled with granular living gel. Each operating cycle includes: influent (0.5h), reaction (10h), sedimentation (1h), and effluent (0.5h). During the reaction stage, jet aerators are used for more powerful oxygenation and mixing to treat the more complex composition of landfill leachate.

[0067] After three days of operation, COD decreased from 9740 mg / L to 1282 mg / L, a reduction of 86.8%; ammonia nitrogen decreased from 1880 mg / L to 553 mg / L, a reduction of 70.6%; and total nitrogen decreased from 1900 mg / L to 495.5 mg / L, a reduction of 73.9%.

[0068] When the system of this embodiment is used to treat landfill leachate, the COD removal rate can still reach 86.8% within a total cycle of 72 hours, and the long-term operational stability of the system is guaranteed through gel regeneration.

[0069] This invention immobilizes a synthetic microbial community of a specific composition within a chitinous gel through a synergistic cross-linking process, forming a living gel with high biomass, high activity, and strong adsorption capacity. The microorganisms are firmly fixed and not easily lost, allowing for rapid system startup and effective response to fluctuations in water quality and quantity. The synergistic effect among the microorganisms achieves a chain-like deep degradation of pollutants, resulting in high treatment efficiency. Furthermore, this invention uses all-biomass materials as its core, eliminating the need for any chemical flocculants or oxidants during the treatment process, fundamentally avoiding the generation of chemical sludge and secondary pollution. The dedicated reactor employs airlift reflux for circulation and oxygenation, significantly reducing energy consumption compared to traditional aeration. The gelled microbial community exhibits strong environmental adaptability, reducing stringent requirements on influent nutrient ratios and simplifying operation and management. Meanwhile, this invention integrates a highly efficient biological treatment medium with an optimized reactor structure into a compact unit, realizing the integration of biological oxidation and physical adsorption clarification functions. It replaces the lengthy process of traditional pretreatment + anaerobic + aerobic + deep treatment. The live gel adopts a modular design, which is easy to load, replace and maintain, making the whole system occupy a small area and have low investment and operating costs, making it particularly suitable for decentralized or intermittent treatment scenarios.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A food high COD degradation whole biomass integrated system, comprising a core biological treatment medium, a special biochemical reactor, characterized in that: The core biological treatment medium is a chitin living gel of a synthetic microbial community, comprising a synthetic microbial community fixed in a chitin gel carrier, the synthetic microbial community at least including Rhizopus oryzae, Pseudomonas putida, Bacillus sp., and Yarrowia lipolytica; The special biochemical reactor is a gas-liquid-solid three-phase reaction container provided with an internal flow guide structure, and the internal part of the special biochemical reactor is provided with a movable frame for modular loading, fixing and replacing the chitin living gel; the water outlet end of the special biochemical reactor is integrated with a gas stripping reflux device for driving the circulation of wastewater in the system and assisting oxygenation.

2. The integrated system for COD degradation of food waste according to claim 1, wherein: In the synthetic microbial community, the volume ratio of Rhizopus oryzae, Pseudomonas putida, Yarrowia lipolytica and Bacillus sp. is (3-5):(2-3):(1.5-2.5):(1-2).

3. The integrated system for COD degradation of food waste according to claim 1, wherein: The chitin living gel is prepared by a synergistic process of glutaraldehyde chemical pre-crosslinking and freeze-thaw cycle physical crosslinking.

4. The integrated system for COD degradation of food waste according to claim 1, wherein: The internal flow guide structure of the special biochemical reactor is an S-shaped baffle channel formed by a baffle.

5. The integrated system for COD degradation of food waste according to claim 1, wherein: The gas stripping reflux device includes a blower, a riser and a reflux pipe; the bottom of the riser is located below the liquid level of the special biochemical reactor, the blower introduces air into the bottom of the riser to form a low-density gas-liquid mixture phase, which drives the mixture phase to rise and return to the water inlet end of the special biochemical reactor through the reflux pipe.

6. A food high COD degradation whole biomass integration method applied to the food high COD degradation whole biomass integration system of any one of claims 1-5, characterized in that, The method comprises the following steps: S1: preparing a synthetic microbial community suspension: culturing Rhizopus oryzae, Pseudomonas putida, Bacillus sp. and Yarrowia lipolytica respectively, mixing the bacterial bodies in proportion after obtaining them, and activating and domesticating to obtain a synthetic microbial community suspension; S2: mixing the synthetic microbial community suspension with a chitin dispersion liquid, adding a crosslinking agent for pre-crosslinking to obtain a mixed slurry; S3: freeze-thaw cycle crosslinking treatment of the mixed slurry to form a chitin living gel; S4: loading the chitin living gel into the special biochemical reactor, introducing high-COD food wastewater to be treated, and starting the system for biodegradation treatment.

7. The integrated process for the degradation of high COD food biomass according to claim 6, characterized in that: In S2, the crosslinking agent is glutaraldehyde, and the final concentration in the mixed system is 0.5%-4.0%(v / v); and in S2, the volume ratio of the synthetic microbial community suspension to the chitin dispersion liquid is 1:1 to 1:

3.

8. The integrated process for the degradation of high COD food biomass according to claim 6, characterized in that: In S3, the freeze-thaw cycle crosslinking treatment includes: freezing the mixed slurry at -20°C to -80°C for 12-24 hours, then thawing at 4-25°C for 4-8 hours, and repeating the freezing-thawing process 2-4 times.

9. The integrated process for the degradation of high COD food biomass according to claim 6, characterized in that: In S4, the chitin living gel is one of a rope type, a granular type and a block type; and the chitin living gel is fixed in a packed bed form or hung by a movable frame in the special biochemical reactor.

10. The integrated process for the degradation of high COD food biomass according to claim 6, characterized in that: In S4, the system runs through the gas stripping reflux device to realize hydraulic internal circulation, and the hydraulic retention time during the treatment process is 6-24 hours.

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