Sludge reduction and resource treatment process based on biological strain lysis dehydration

Abstract

The sludge reduction and resource treatment process based on biological strain lysis dehydration of the application comprises the following steps: the biochemical sludge of the municipal wastewater treatment plant is sent into a concentration tank for gravity concentration, the specific phagocytosis of the strain is used to destroy the sludge floc and the microbial cell membrane, the intracellular water and the interstitial water are synchronously released, and the antibiotics and the resistance genes in the sludge are reduced; the sludge after the biological lysis is sent into a plate frame dehydration system for mechanical dehydration, the sludge after the dehydration is sent into a low-temperature drying system, the crystallization carrier is filled in the Fenton fluidized bed, and the internal circulation reuse of the wastewater is realized; the sludge after the drying is sent into a sealed sludge bin for storage, and is used for preparing a sewage adsorbent or a garden organic fertilizer, and the resource utilization of the sludge is completed. The application does not add the chemical conditioning agents such as PAM and PAC in the whole process, the lysis strain is self-enriched and cultured from the excess sludge, no external nutrient substance is needed, no secondary chemical residue exists, and the reagent pollution is avoided from the source.

Description

Technical Field

[0001] This invention relates to the field of sludge treatment and disposal technology in environmental engineering, specifically to a sludge reduction and resource recovery process based on the lysis and dewatering of biological strains. Background Technology

[0002] With the full coverage of urban sewage treatment facilities, the output of biochemical waste sludge from sewage treatment plants is increasing year by year. Biochemical waste sludge is characterized by high water content, high organic matter content, and easy putrefaction and odor. It also commonly contains residual antibiotics, resistance genes, and other emerging pollutants. Improper treatment and disposal can lead to serious secondary pollution and ecological risks.

[0003] Currently, the mainstream sludge dewatering process mainly involves chemical conditioning combined with mechanical dewatering. This is achieved by adding chemical agents such as polyacrylamide (PAM), polyaluminum chloride (PAC), iron salts, and lime to improve the sludge's dewatering performance, followed by dewatering using plate and frame filter presses or belt filter presses to achieve a moisture content of approximately 80%. However, this process has the following inherent drawbacks: 1. High dependence on chemicals and high risk of secondary pollution: Chemical chemicals account for a high proportion of operating costs, and chemical residues can change the physicochemical properties of sludge, limiting subsequent resource utilization and easily causing secondary pollution of soil and water bodies. 2. Incomplete dehydration and limited volume reduction: It can only remove interstitial water between sludge flocs, but cannot destroy the cell membranes of microorganisms to release intracellular water and bound water. The dehydration limit is high, and the subsequent treatment pressure is great. 3. Insufficient degree of harmlessness: It is impossible to remove antibiotics and resistance genes from the sludge simultaneously. Conventional dewatering processes may even lead to the enrichment and spread of resistance genes, posing environmental safety hazards. 4. High energy consumption and no closed-loop reuse: Dehydrated filtrate and drying exhaust gas are mostly treated in a decentralized and independent manner, without forming a closed-loop reuse system, resulting in serious waste of water resources and heat energy, and high overall operating energy consumption; 5. Poor engineering adaptability: The treatment facilities mostly adopt concrete tank structures, which occupy a large area, have a long construction period, and low degree of automation, making it difficult to adapt to the upgrading and renovation needs of existing sewage treatment plants.

[0004] Existing technologies include single-function biolysis for waste reduction, fluidized bed Fenton oxidation, and waste heat recovery from sludge drying exhaust gas. However, these technologies suffer from limitations such as limited functionality and low system integration. Single-function biolysis technologies often employ batch-type stirred reactions, resulting in low mass transfer efficiency and long pyrolysis cycles. Furthermore, they still require the use of chemical conditioners to assist in dehydration during engineering applications. Fluidized bed Fenton technology is only applied independently to industrial wastewater treatment and is not coupled with sludge treatment systems. Exhaust gas and wastewater recovery are mostly performed using a single medium independently, without forming a dual-cycle system of gas-water interaction. Summary of the Invention

[0005] The present invention proposes a sludge reduction and resource utilization process based on the lysis and dewatering of biological strains, which can at least solve one of the technical problems in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A sludge reduction and resource recovery process based on biological strain lysis and dewatering includes the following steps: S1. The biochemical sludge from the urban sewage treatment plant is sent to a thickening tank for gravity thickening to obtain thickened sludge with a water content of 96% to 98%. S2. The concentrated sludge is fed into a vertical sludge pyrolysis fluidized bed, and a specific pyrolysis and dewatering bacteria cultured from the system's own surplus sludge is added. The bed is filled with a porous carrier for the bacteria to attach and grow. Fluidized mass transfer between the carrier and the sludge is achieved through a sludge return system. The biolysis reaction is carried out for 8 hours under controlled dissolved oxygen conditions. The specific phagocytic action of the bacteria destroys the sludge flocs and microbial cell membranes, simultaneously releasing intracellular water and interstitial water, and reducing antibiotics and resistance genes in the sludge. S3. The sludge after biodegradation is sent to a plate and frame dewatering system for mechanical dewatering. After dewatering, the sludge moisture content is reduced to ≤60%. The filtrate produced by dewatering is discharged into a Fenton fluidized bed for deep oxidation treatment. S4. After dewatering, the sludge is sent to a low-temperature drying system and dried at a constant temperature of 95℃ until the moisture content is ≤30%. The exhaust gas generated during the drying process and the exhaust gas generated in the subsequent sludge silo are sent to the exhaust gas treatment system together. After the exhaust gas meets the standards through two-stage spraying treatment, part of it is recycled back to the sludge pyrolysis fluidized bed as an oxygen source for the biological reaction, realizing the internal circulation and reuse of exhaust gas. S5. The Fenton fluidized bed is filled with a crystal-inducing support to facilitate the formation of crystals in the Fenton reaction. FeOOH heterogeneous catalytic layer is crystallized on the surface of the carrier to construct a homogeneous-heterogeneous synergistic catalytic system; the wastewater after Fenton oxidation treatment is partially recycled to the tail gas treatment system as spray water to realize the internal recycling of wastewater; S6. The dried sludge is sent to a closed sludge storage silo for use in the preparation of wastewater adsorbents or garden organic fertilizers, thus completing the resource utilization of sludge.

[0007] As a preferred embodiment of the sludge reduction and resource utilization process based on biological strain lysis and dewatering described in this invention, the specific lysis and dewatering strain is a specific phage bacterial community enriched and domesticated with residual sludge as the sole nutrient source; no chemical conditioners such as PAM and PAC are added throughout the process, and no exogenous nutrients are added.

[0008] As a preferred embodiment of the sludge reduction and resource utilization process based on biological strain lysis and dewatering described in this invention, the sludge lysis fluidized bed adopts a vertical tower structure with an internal porous ceramic or polyurethane porous carrier, and the carrier filling rate is 20% to 30% of the effective volume of the bed; a fluidized state is formed by the combined action of bottom aeration and side sludge recirculation, which enhances the gas-liquid-solid three-phase mass transfer, and the dissolved oxygen concentration is controlled at 1.5 to 2.5 mg / L during the reaction process.

[0009] As a preferred embodiment of the sludge reduction and resource recovery process based on biological strain lysis and dewatering described in this invention, the crystal-inducing carrier of the Fenton fluidized bed is quartz sand or activated carbon particles. FeOOH crystals generated in situ on the support surface possess heterogeneous catalytic activity.

[0010] As a preferred embodiment of the sludge reduction and resource utilization treatment process based on biological strain lysis and dewatering described in this invention, the exhaust gas treatment system employs a two-stage series process of an alkaline scrubbing tower and a water scrubbing tower to sequentially remove impurities from the exhaust gas. , Dust and other pollutants; the proportion of exhaust gas reused after treatment is 40% to 50%, and the reused exhaust gas is sent to the bottom aeration system of the pyrolysis fluidized bed after the air volume is adjusted.

[0011] As a preferred embodiment of the sludge reduction and resource utilization process based on biological strain lysis and dehydration described in this invention, the selected sludge in step S1 has a water content of 97%; in step S4, the drying system adopts closed-loop low-temperature hot air drying, the drying temperature is constantly controlled at 95℃, and the organic matter retention rate of the dried sludge is ≥85%.

[0012] As a preferred embodiment of the sludge reduction and resource recovery process based on biological strain lysis and dewatering described in this invention, the process is configured with an intelligent automatic control unit, including: 1) An online sludge concentration meter is installed in the thickening tank to automatically adjust the addition ratio of lysing bacteria based on the sludge concentration signal; 2) The sludge pyrolysis fluidized bed is equipped with online monitoring instruments for DO, temperature, and ORP, which are used to adjust the aeration flow rate and sludge return flow rate in a coordinated manner to maintain a stable fluidization and pyrolysis reaction state. 3) The drying system is equipped with online instruments for feed moisture content, discharge moisture content and temperature, and automatically adjusts the steam supply and hot air circulation to maintain a constant temperature of 95℃ for drying.

[0013] As a preferred embodiment of the sludge reduction and resource recovery process based on biological strain lysis and dewatering described in this invention, the following features are achieved: an overall sludge reduction rate ≥75%, a total antibiotic removal rate ≥90% in the sludge, and a reduction in resistance gene abundance of 2.8–3.9 orders of magnitude; the sludge specific resistance is reduced from the initial 3.82 × 10⁻⁶. m / kg decreased to 3.26× m / kg.

[0014] A sludge reduction and resource utilization system based on biological strain pyrolysis and dewatering includes a sludge thickening tank, a sludge pyrolysis fluidized bed, a sludge plate and frame dewatering system, a sludge drying system, and a sludge silo connected in sequence, as well as an exhaust gas treatment system, a Fenton fluidized bed, and an intelligent automatic control system. The tail gas outlet of the sludge drying system and the tail gas outlet of the sludge silo are both connected to the air inlet of the tail gas treatment system, and the air outlet of the tail gas treatment system is connected to the aeration air inlet of the sludge pyrolysis fluidized bed, forming an internal tail gas circulation loop. The filtrate outlet of the sludge plate and frame dewatering system and the wastewater outlet of the tail gas treatment system are both connected to the inlet of the Fenton fluidized bed, and the outlet of the Fenton fluidized bed is connected to the spray water inlet of the tail gas treatment system, forming an internal wastewater circulation loop. The intelligent automatic control system is electrically connected to the sludge thickening tank, the sludge pyrolysis fluidized bed, and the sludge drying system, respectively, to realize automatic control of parameters throughout the entire process.

[0015] As a preferred embodiment of the sludge reduction and resource utilization treatment system based on biological strain lysis and dewatering described in this invention, both the sludge lysis fluidized bed and the Fenton fluidized bed adopt a vertical tower modular skid-mounted structure, and the single tower processing capacity can be spliced ​​and combined as needed.

[0016] The beneficial effects of this invention are: This invention does not add chemical conditioners such as PAM and PAC throughout the entire process. The lysing bacteria are self-enriched and cultured from the remaining sludge, requiring no external nutrients and leaving no secondary chemical residues, thus avoiding chemical pollution from the source. This invention simultaneously degrades antibiotics and destroys resistance gene structures during the main biolysis reaction, achieving a total antibiotic removal rate of ≥90%, solving the problem that traditional processes cannot remove emerging pollutants and significantly reducing environmental risks. This invention enables the reuse of treated exhaust gas for oxygen supply and the reuse of treated wastewater for spraying, forming a dual-media interactive cycle of air and water. The overall operating cost is lower than that of traditional processes, achieving energy conservation, consumption reduction and maximum resource utilization. Attached Figure Description

[0017] Figure 1 This is a process flow diagram of the sludge reduction and resource utilization process based on the lysis and dewatering of biological strains according to the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Example

[0019] like Figure 1 As shown, a sludge reduction and resource recovery process based on biological strain lysis and dewatering includes the following steps: S1. The biochemical sludge from the urban sewage treatment plant is sent to a thickening tank for gravity thickening to obtain thickened sludge with a water content of 96% to 98%. S2. The concentrated sludge is fed into a vertical sludge pyrolysis fluidized bed, and a specific pyrolysis and dewatering bacteria cultured from the system's own surplus sludge is added. The bed is filled with a porous carrier for the bacteria to attach and grow. Fluidized mass transfer between the carrier and the sludge is achieved through a sludge return system. The biolysis reaction is carried out for 8 hours under controlled dissolved oxygen conditions. The specific phagocytic action of the bacteria destroys the sludge flocs and microbial cell membranes, simultaneously releasing intracellular water and interstitial water, and reducing antibiotics and resistance genes in the sludge. S3. The sludge after biodegradation is sent to a plate and frame dewatering system for mechanical dewatering. After dewatering, the sludge moisture content is reduced to ≤60%. The filtrate produced by dewatering is discharged into a Fenton fluidized bed for deep oxidation treatment. S4. After dewatering, the sludge is sent to a low-temperature drying system and dried at a constant temperature of 95℃ until the moisture content is ≤30%. The exhaust gas generated during the drying process and the exhaust gas generated in the subsequent sludge silo are sent to the exhaust gas treatment system together. After the exhaust gas meets the standards through two-stage spraying treatment, part of it is recycled back to the sludge pyrolysis fluidized bed as an oxygen source for the biological reaction, realizing the internal circulation and reuse of exhaust gas. S5. The Fenton fluidized bed is filled with a crystal-inducing support to facilitate the formation of crystals in the Fenton reaction. FeOOH heterogeneous catalytic layer is crystallized on the surface of the carrier to construct a homogeneous-heterogeneous synergistic catalytic system; the wastewater after Fenton oxidation treatment is partially recycled to the tail gas treatment system as spray water to realize the internal recycling of wastewater; S6. The dried sludge is sent to a closed sludge storage silo for use in the preparation of wastewater adsorbents or garden organic fertilizers, thus completing the resource utilization of sludge.

[0020] Furthermore, the enrichment and cultivation method for the specific lysis and dehydration bacteria is as follows: the residual sludge from the secondary sedimentation tank of the sewage treatment plant is used as the inoculum source, and the organic matter in the original residual sludge is used as the sole carbon and nutrient source, without adding any exogenous nutrients; the dissolved oxygen is controlled at 1.5~2.5 mg / L and the temperature is controlled at 25~30℃, 50% of the volume of fresh residual sludge is replaced every 24 hours, and the culture is continuously subcultured for 15~20 days to enrich a complex lysis bacteria community with Bacillus, Pseudomonas, and Bdellovibrio as the core.

[0021] Furthermore, the process is equipped with an intelligent automatic control unit, and the core control logic includes: The thickening tank is equipped with an online sludge concentration meter, which automatically adjusts the dosage ratio of lysing bacteria according to the sludge concentration. The pyrolysis fluidized bed is equipped with online instruments for DO, temperature, and ORP, which are linked to adjust the aeration flow rate and sludge return flow rate. The drying system is equipped with online instruments for feed / discharge moisture content and temperature, and automatically adjusts the steam supply through a PID algorithm to maintain a constant temperature of 95℃ for drying.

[0022] Furthermore, a sludge reduction and resource recovery system based on biological strain lysis and dewatering: The system includes a sludge thickening tank, a sludge pyrolysis fluidized bed, a sludge plate and frame dewatering system, a sludge drying system, and a sludge silo, all connected in sequence. It also includes an exhaust gas treatment system, a Fenton fluidized bed, and an intelligent automatic control system.

[0023] The connection relationships of each unit are as follows: Sludge production line: thickening tank, pyrolysis fluidized bed, plate and frame dewatering system, drying system, silo; Tail gas internal circulation loop: tail gas outlet of drying system, tail gas outlet of silo, air inlet of tail gas treatment system, air inlet of pyrolysis fluidized bed aeration; Wastewater internal circulation loop: filtrate outlet of plate and frame dewatering system, wastewater outlet of tail gas treatment system, water inlet of Fenton fluidized bed, and water inlet of spray water of tail gas treatment system; Automatic control link: The intelligent automatic control system is electrically connected to the detection instruments and actuators of the thickener, pyrolysis fluidized bed and drying system to realize automatic control of the whole process.

[0024] Specifically, both the sludge pyrolysis fluidized bed and the Fenton fluidized bed adopt a vertical tower-type modular skid-mounted structure, and the single tower processing capacity can be spliced ​​and combined as needed.

[0025] The key performance calculation and control algorithms involved in this invention are disclosed as follows: 1. Calculation formula for sludge specific resistance: The sludge dewatering performance is determined using the Buchner funnel vacuum filtration method. The calculation formula for sludge specific resistance is as follows: ; In the formula: This indicates the specific resistance of the sludge, measured in m / kg. The higher the value, the worse the dewatering performance. Filtration pressure difference, unit Pa, standard measurement condition is 50 kPa; Indicates the filtration area, in units of ; The slope of the fitted line t / V is expressed in units. , where t is the filtration time and V is the cumulative filtrate volume; This indicates the dynamic viscosity of the filtrate, in Pa. s, take 1.005 at room temperature Pa s; This indicates the mass of dry sludge corresponding to a unit volume of filtrate, in units of... It is calculated from the weight of the filter cake and the volume of the filtrate.

[0026] 2. Formula for calculating the total sludge reduction rate: The reduction rate includes two parts: moisture removal and organic matter biodegradation. The calculation formula is: ; In the formula: Indicates the total sludge reduction rate; Indicates the wet weight of the original sludge before treatment; This indicates the final wet weight of the dried sludge after treatment. 3. Formula for calculating intracellular water release rate: The free water and bound water content was determined using differential centrifugation. The formula for calculating the intracellular water release rate is as follows: ; In the formula: Indicates the rate of intracellular water release; This indicates the percentage of free interstitial water mass before pyrolysis; This indicates the percentage of total mass of free water after pyrolysis; This indicates the percentage of total mass of intracellular bound water in the original sludge; 4. Formula for antibiotic resistance gene removal effect: Total antibiotic removal rate: ; In the formula, , These represent the total antibiotic concentrations in the sludge before and after treatment, in units of... Dry sludge; Decrease in abundance of resistance genes: ; In the formula, , The figures represent the abundance of resistance genes before and after treatment, in copies / g of dry sludge. 5. Pseudo-first-order kinetics of the Fenton reaction: The COD degradation process during Fenton oxidation follows pseudo-first-order reaction kinetics. ; In the formula: Indicates the COD concentration of the influent; This represents the COD concentration at time t during the reaction. This represents the rate constant of the reaction. Indicates reaction time; 6. Core algorithm for intelligent self-control: 1) Formula for linkage control of inoculum addition: Automatic dosage adjustment based on sludge concentration in the thickener: ; In the formula: Indicates the inoculum dosage flow rate; This represents the dosage ratio coefficient, ranging from 0.02 to 0.05, and is calibrated periodically based on the bacterial community activity. This indicates the mass concentration of the concentrated sludge. This indicates the sludge inlet flow rate of the pyrolysis fluidized bed; 2) PID control formula for drying temperature: A proportional-integral-differential algorithm is used to maintain a constant drying temperature. ; In the formula: This indicates the output signal indicating the opening degree of the steam regulating valve; This indicates the deviation between the set drying temperature and the measured value; Indicates the proportionality coefficient; Indicates the integration time; This represents the derivative time, which is a preset control parameter.

[0027] Specific examples are as follows: This embodiment uses the residual biochemical sludge from a municipal wastewater treatment plant as the treatment target, and conducts a pilot-scale treatment using the process of this invention. The specific process is as follows: Raw sludge characteristics: The raw sludge had a moisture content of 99.2%, an organic matter content of 58.3%, an initial total antibiotic content of 216 μg / kg dry sludge, and an initial sludge specific resistance. .

[0028] Sludge thickening: The raw sludge enters the radial flow thickening tank and is concentrated by gravity for 18 hours. After thickening, the water content is stabilized at 97%, and the supernatant is returned to the front end of the fine screen in the plant.

[0029] Biolysis: Concentrated sludge is pumped into a vertical sludge pyrolysis fluidized bed via a screw pump. The effective volume of a single tower is 5 m³, with a height-to-diameter ratio of 5:1. The bed is filled with a porous ceramic carrier with a particle size of 8 mm and a filling rate of 25%. Self-cultivated specific pyrolysis bacteria are added at a ratio of 3% of the sludge inlet volume. The sludge return ratio is controlled at 150%, the DO in the bed is 1.5~2.5 mg / L, the ORP is 150~250 mV, and the reaction is carried out at room temperature for 8 hours.

[0030] Plate and frame dewatering: The pyrolysis sludge is fed into a 10m² plate and frame filter press with a filtration pressure of 0.7MPa and a pressing time of 45min. The average moisture content of the sludge after dewatering is 56.8%, and no chemical conditioning agents are added throughout the process.

[0031] Low-temperature drying: The dewatered sludge is fed into a mesh belt low-temperature dryer and dried with constant temperature hot air at 95℃. The average moisture content of the dried sludge is 28.7%.

[0032] Tail gas treatment and reuse: After being collected, the dried tail gas and the silo tail gas enter a two-stage scrubbing tower. The first-stage alkaline scrubbing tower uses an 8% NaOH solution with the pH controlled at 10-12, and the second-stage water scrubbing tower uses clean water. After treatment, the NH3 removal rate in the tail gas is 96.2%, and the H2S removal rate is 98.7%. 45% of the qualified tail gas is sent to the bottom gas distribution device of the pyrolysis fluidized bed through a reflux fan for oxygen supply, and the rest is discharged at high altitude in compliance with standards.

[0033] Fenton oxidation and wastewater reuse: The plate and frame dewatering filtrate and tail gas washing wastewater are mixed and then fed into the Fenton fluidized bed. The average COD concentration of the influent is 2340 mg / L. The pH of the influent is adjusted to 3.5, the Fe²⁺ dosage is 1.2 mmol / L, and the H₂O₂ dosage is 1.2:1 based on the COD mass ratio. The bed is filled with quartz sand crystal carrier with a filling rate of 35% and a reaction time of 80 min. The average COD concentration of the effluent is 505 mg / L, and the COD removal rate is 78.4%. 50% of the effluent is reused in the tail gas treatment system as spray makeup water, and the remainder is discharged into the plant's biological treatment tank.

[0034] Resource utilization: The dried sludge is conveyed into a closed silo via a screw conveyor. The organic matter retention rate is 87.2%, and it is directly used as a supplementary adsorbent for the biological filter in the plant. The treatment effect is shown in Table 1 below. Table 1

[0035] Comparative Example 1: Traditional chemical conditioning + plate and frame dehydration process: The same batch of raw sludge as in Example 1 was used and treated with the mainstream traditional process in China: chemical conditioning was performed by adding 200 mg / L of PAC and 3 mg / L of anionic PAM, and the sludge was dewatered using the same plate and frame filter press without biodegradation or drying.

[0036] The results showed that the moisture content of the dewatered sludge was 81.2%, and the specific resistance of the sludge was 9.75 × 10⁻⁶. m / kg, total reduction rate 41.6%, total antibiotic removal rate only 12.3%; the cost of the agent is 11.6 times that of Example 1, and the sludge has high aluminum salt and PAM residue levels, making it unsuitable for direct land use.

[0037] Comparative Example 2: Conventional stirred biolysis process: Using the same batch of raw sludge and the same bacterial strain as in Example 1, the mixture was reacted in a conventional mechanically stirred aeration tank for 8 hours. The subsequent plate and frame dewatering conditions were the same as in Example 1.

[0038] The results showed that the intracellular water release rate was only 47.5%, and the sludge specific resistance was 8.92 × 10⁻⁶. m / kg, the moisture content after dehydration is 68.3%, and the total antibiotic removal rate is 56.7%. Due to low mass transfer efficiency and insufficient contact between bacteria and mud, the pyrolysis effect is far lower than that of fluidized bed process, and deep dehydration cannot be achieved.

[0039] Comparative Example 3: Traditional Homogeneous Fenton Process: Using the same mixed wastewater quality as in Example 1, the conventional homogeneous Fenton process was employed for treatment, with the same target COD removal rate controlled.

[0040] The results showed that in order to achieve a COD removal rate of 78%, the Fe²⁺ dosage needed to reach 2.5 mmol / L, which was 2.1 times that of Example 1; the iron sludge production was 2.6 times that of Example 1, the operating reagent cost was significantly increased, and there was no long-term stability of crystallization catalysis.

[0041] As can be seen from the comparison of the embodiments and comparative examples, the present invention is not a simple combination of existing single technologies, but rather a system that achieves synergistic effect through "self-cultivated bacterial lysis + dual fluidized bed coupling + dual internal circulation closed loop", which produces unexpected technical effects in terms of dehydration performance, harmlessness effect and operating cost.

[0042] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sludge reduction and resource utilization process based on biological strain lysis and dewatering, characterized in that, Includes the following steps: S1. The biochemical sludge from the urban sewage treatment plant is sent to a thickening tank for gravity thickening to obtain thickened sludge with a water content of 96% to 98%. S2. The concentrated sludge is fed into a vertical sludge pyrolysis fluidized bed, and a specific pyrolysis and dewatering bacterial strain enriched and cultured from the system's own residual sludge is added. The bed is filled with a porous carrier for the bacterial strain to attach and grow. Fluidized mass transfer between the carrier and the sludge is achieved through a sludge return system. The biolysis reaction is carried out for 8 hours under controlled dissolved oxygen conditions. The specific phage action of the bacterial strain destroys the sludge flocs and microbial cell membranes, simultaneously releasing intracellular water and intercellular water, and reducing antibiotics and resistance genes in the sludge. The specific pyrolysis and dewatering bacterial strain is a specific phage bacterial community enriched and domesticated using residual sludge as the sole nutrient source. No PAM or PAC chemical conditioners are added throughout the process, and no exogenous nutrients are added. S3. The sludge after biodegradation is sent to a plate and frame dewatering system for mechanical dewatering. After dewatering, the sludge moisture content is reduced to ≤60%. The filtrate produced by dewatering is discharged into a Fenton fluidized bed for deep oxidation treatment. S4. After dewatering, the sludge is sent to a low-temperature drying system and dried at a constant temperature of 95℃ until the moisture content is ≤30%. The exhaust gas generated during the drying process and the exhaust gas generated in the subsequent sludge silo are sent to the exhaust gas treatment system together. After the exhaust gas has been treated by two stages of spraying to meet the standards, part of it is recycled back to the sludge pyrolysis fluidized bed as an oxygen source for the biological reaction, realizing the internal circulation and reuse of exhaust gas. S5. The Fenton fluidized bed is filled with a crystal-inducing support, so that the Fe generated by the Fenton reaction... 3+ FeOOH heterogeneous catalytic layer is crystallized on the support surface to construct a homogeneous-heterogeneous synergistic catalytic system; The wastewater treated by Fenton oxidation is partially recycled back to the tail gas treatment system as spray water, realizing the internal recycling of wastewater. S6. The dried sludge is sent to a closed sludge storage silo for use in the preparation of wastewater adsorbents or garden organic fertilizers, thus completing the resource utilization of sludge.

2. The sludge reduction and resource utilization process based on biological strain lysis and dewatering according to claim 1, characterized in that: The sludge pyrolysis fluidized bed adopts a vertical tower structure with an internal porous ceramic or polyurethane porous carrier. The carrier filling rate is 20% to 30% of the effective volume of the bed. The fluidized state is formed by the combined action of bottom aeration and side sludge recirculation, which enhances the gas-liquid-solid three-phase mass transfer. The dissolved oxygen concentration is controlled at 1.5 to 2.5 mg / L during the reaction process.

3. The sludge reduction and resource utilization process based on biological strain lysis and dewatering according to claim 1, characterized in that: The crystal-inducing carrier of the Fenton fluidized bed is quartz sand or activated carbon particles, Fe 3+ FeOOH crystals generated in situ on the support surface possess heterogeneous catalytic activity.

4. The sludge reduction and resource utilization process based on biological strain lysis and dewatering according to claim 1, characterized in that: The exhaust gas treatment system adopts a two-stage series process of alkaline scrubbing and water scrubbing to remove H2S, NH3 and dust from the exhaust gas in sequence. The proportion of exhaust gas reused after treatment is 40% to 50%. The reused exhaust gas is sent to the bottom aeration system of the pyrolysis fluidized bed after the air volume is regulated.

5. The sludge reduction and resource recovery process based on biological strain lysis and dewatering according to claim 1, characterized in that: In step S1, the selected concentrated sludge has a moisture content of 97%; in step S4, the drying system adopts closed-loop low-temperature hot air drying, and the drying temperature is constantly controlled at 95℃. After drying, the organic matter retention rate of the sludge is ≥85%.

6. The sludge reduction and resource utilization process based on biological strain lysis and dewatering according to claim 1, characterized in that: The process is configured with an intelligent automatic control unit, including: 1) An online sludge concentration meter is installed in the thickening tank to automatically adjust the addition ratio of lysing bacteria based on the sludge concentration signal; 2) The sludge pyrolysis fluidized bed is equipped with online monitoring instruments for DO, temperature, and ORP, which are used to adjust the aeration flow rate and sludge return flow rate in a coordinated manner to maintain a stable fluidization and pyrolysis reaction state. 3) The drying system is equipped with online instruments for feed moisture content, discharge moisture content and temperature, and automatically adjusts the steam supply and hot air circulation to maintain a constant temperature of 95℃ for drying.

7. The sludge reduction and resource utilization process based on biological strain lysis and dewatering according to claim 1, characterized in that: The overall sludge reduction rate after treatment was ≥75%, the total antibiotic removal rate in the sludge was ≥90%, and the abundance of resistance genes decreased by 2.8–3.9 orders of magnitude; the specific drag of the sludge decreased from the initial 3.82 × 10⁻⁶. 12 m / kg decreased to 3.26×10 11 m / kg.

8. The sludge reduction and resource recovery process based on biological strain lysis and dewatering according to any one of claims 1-7, characterized in that, The sludge reduction and resource utilization system based on biological strain pyrolysis and dewatering includes a sludge thickening tank, a sludge pyrolysis fluidized bed, a sludge plate and frame dewatering system, a sludge drying system, and a sludge silo, which are connected in sequence. It also includes an exhaust gas treatment system, a Fenton fluidized bed, and an intelligent automatic control system. The tail gas outlet of the sludge drying system and the tail gas outlet of the sludge silo are both connected to the air inlet of the tail gas treatment system, and the air outlet of the tail gas treatment system is connected to the aeration air inlet of the sludge pyrolysis fluidized bed, forming an internal tail gas circulation loop. The filtrate outlet of the sludge plate and frame dewatering system and the wastewater outlet of the tail gas treatment system are both connected to the inlet of the Fenton fluidized bed, and the outlet of the Fenton fluidized bed is connected to the spray water inlet of the tail gas treatment system, forming an internal wastewater circulation loop. The intelligent automatic control system is electrically connected to the sludge thickening tank, the sludge pyrolysis fluidized bed, and the sludge drying system, respectively, to realize automatic control of parameters throughout the entire process.

9. The sludge reduction and resource recovery system based on biological strain lysis and dewatering according to claim 8, characterized in that, Both the sludge pyrolysis fluidized bed and the Fenton fluidized bed adopt a vertical tower modular skid-mounted structure, and the single tower processing capacity can be spliced ​​and combined as needed.

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