A method for recycling sludge resources

Abstract

The present invention discloses a method for recycling and reusing sludge as a resource, relating to the field of sludge recycling and environmentally friendly treatment technology. The method comprises the following steps: collecting and pre-treating raw sludge; obtaining a sludge digestion nutrient solution and a solid sludge residue from the pre-treated raw sludge through a high-efficiency anaerobic digestion method; propagating microalgae from the sludge digestion nutrient solution through an intelligent photobioreactor to obtain high-value-added dried algae; and obtaining a high-efficiency dehydrated solid residue from the solid sludge residue after anaerobic digestion through magnetic nanomaterial-assisted separation combined with a plate-and-frame filter press. The method then combines the high-efficiency dehydrated solid residue with multifunctional auxiliary materials to prepare high-performance multifunctional building materials. By combining high-efficiency anaerobic digestion with an intelligent photobioreactor, and high-efficiency dehydration with multifunctional auxiliary materials, the present invention increases the growth rate and added value of microalgae, achieving comprehensive recycling of sludge.

Description

Technical Field

[0001] The present invention relates to the technical field of sludge resource utilization and environmental protection treatment, in particular to a method for sludge resource reuse. Background Art

[0002] With the acceleration of urbanization, sewage treatment and solid waste management have become key areas of environmental protection and resource recycling. Sludge, an inevitable byproduct of wastewater treatment, faces increasingly severe challenges in its treatment and resource recovery. Traditional sludge treatment methods, such as incineration and landfilling, not only cause environmental pollution and waste resources, but also increase disposal costs. Therefore, the search for efficient, environmentally friendly, and economically viable sludge resource recovery technologies has become a research hotspot. Among the many sludge treatment technologies, anaerobic digestion is widely used in sludge treatment due to its efficient organic matter degradation, low energy consumption, and renewable energy (biogas) recovery. Simultaneously, the cultivation and application of microalgae have also attracted attention from both academia and industry. Microalgae, through photosynthesis, not only effectively absorb nutrients from sludge but also achieve rapid growth in a short period of time, resulting in high economic added value. Therefore, microalgae-based sludge resource recovery methods are becoming an innovative direction for future sludge treatment.

[0003] However, existing technologies still have some limitations in terms of sludge resource utilization. First, the traditional sludge anaerobic digestion process has the problems of long treatment cycle and unstable treatment effect, especially when the sludge concentration is high, which often leads to poor digestion effect and even affects the subsequent resource recovery link. Secondly, although the microalgae breeding process can effectively improve the conversion rate of nutrients in sludge, the current technology is mostly focused on a single photobioreactor design and microalgae screening, and lacks precise control of the microalgae growth environment. This makes the efficiency of microalgae reproduction low, and it is difficult to achieve stable and efficient algae production under different environmental conditions. Therefore, the existing sludge resource technology still faces problems such as low treatment efficiency, difficulty in resource recovery, and unclear economic benefits in practical applications. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a method for recycling sludge resources to solve the problems of long treatment cycle in traditional anaerobic digestion process and lack of precise environmental control in microalgae breeding process.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for recycling sludge resources, which includes collecting raw sludge and pre-treating the raw sludge; obtaining sludge digestion nutrient solution and anaerobic digestion sludge solid residue based on the pretreated raw sludge through a high-efficiency anaerobic digestion method; propagating microalgae based on the sludge digestion nutrient solution through an intelligent photobioreactor to obtain high-value-added dried algae; obtaining high-efficiency dehydrated solid residue based on the anaerobic digestion sludge solid residue through magnetic nanomaterial-assisted separation combined with a plate and frame filter press; and preparing high-performance multifunctional building materials based on the high-efficiency dehydrated solid residue and multifunctional auxiliary materials.

[0008] As a preferred embodiment of the method for recycling sludge as a resource of the present invention, the steps of collecting the original sludge and pre-treating the original sludge are as follows:

[0009] Raw sludge is collected from wastewater treatment plants and industrial outfalls;

[0010] The pretreatment of the raw sludge includes removing large particle impurities, crushing and homogenizing.

[0011] As a preferred embodiment of the method for recycling sludge resources of the present invention, the sludge digestion nutrient solution and the sludge solid residue after anaerobic digestion are obtained by a high-efficiency anaerobic digestion method based on the pretreated raw sludge. The specific steps are as follows:

[0012] Based on the pretreated raw sludge, it is fed into a large anaerobic reactor through a screw pump to mix with anaerobic bacteria;

[0013] The large anaerobic reactor is heated by indirect steam heating, and the reaction temperature of anaerobic bacteria and pretreated raw sludge is adjusted in real time using PID. The expression is:

[0014]

[0015] Among them, T r (t+Δt) is the reaction temperature after adjustment at time step t+Δt, T m is the target temperature, T a (t) is the actual temperature at time step t, T a (τ) is the actual temperature at the time point τ of the integral variable, K p is the proportional control coefficient of PID, K i is the integral control coefficient of PID, K d is the differential control coefficient of PID, dτ is the small increment of the integral variable at the time point τ, d(T m -T a(t)) is the instantaneous change in temperature difference, dt is the small increment of time step t, τ is the index variable of the integration variable time point, t is the index variable of the time step, and Δt is the time increment;

[0016] The pH value of the reaction between anaerobic bacteria and pretreated raw sludge is adjusted by lime water and sodium bicarbonate, and the expression is:

[0017]

[0018] Where pH(t+Δt) is the pH value after adjustment at time step t+Δt, [H + ]0 is the initial hydrogen ion concentration, k s is the proportional constant of the effect of alkaline substances on hydrogen ion concentration, ΔV l (t) is the volume of lime water that needs to be added at time step t, ΔV n (t) is the volume of sodium bicarbonate that needs to be added at time step t, V e is the volume of the large anaerobic reactor;

[0019] The VFA concentration was measured by gas chromatography, and the operating parameters of the large-scale anaerobic reactor were optimized based on the VFA concentration measurement results;

[0020] Based on the adjusted reaction temperature, adjusted pH value and optimized large-scale anaerobic reactor operating parameters, anaerobic bacteria gradually decompose the organic matter in the pretreated raw sludge to obtain digestion products;

[0021] The digestion products are separated by sedimentation separation and mechanical dehydration to obtain sludge digestion nutrient solution and sludge solid residue after anaerobic digestion.

[0022] As a preferred embodiment of the method for recycling sludge resources described in the present invention, the digestion products are separated by sedimentation separation and mechanical dehydration to obtain sludge digestion nutrient solution and sludge solid residue after anaerobic digestion. The specific steps are as follows:

[0023] The digested product is stirred by a mechanical stirrer to obtain a homogenized product;

[0024] The homogenized product is settled to the bottom by gravity in a sedimentation tank to form a solid waste residue and a clear liquid rich in nutrient solution that are initially separated;

[0025] The solid waste residue that is initially separated is initially dehydrated by high-speed rotation of a centrifugal dehydrator;

[0026] After sedimentation separation and mechanical dehydration, the sludge digestion nutrient solution and the sludge solid residue after anaerobic digestion are finally obtained.

[0027] As a preferred embodiment of the method for recycling sludge resources described in the present invention, the method comprises the following steps: based on the sludge digestion nutrient solution, microalgae are propagated through an intelligent photobioreactor to obtain high-value-added dried algae.

[0028] The nutrient components in the sludge digestion nutrient solution were adjusted by the linear regulation method to optimize the sludge digestion nutrient solution in the intelligent photobioreactor. The expression is:

[0029] N(t)=N0+s1·W+s2·(Y-Y0);

[0030] Wherein, N(t) is the nutrient concentration in the sludge digestion nutrient solution after optimization at time step t, N0 is the nutrient concentration in the initial sludge digestion nutrient solution, s1 is the proportional constant for adjusting the nutrient concentration in the sludge digestion nutrient solution, s2 is the proportional constant for temperature influence, W is the effective nutrient volume in the sludge digestion nutrient solution, Y is the real-time temperature in the intelligent photobioreactor, and Y0 is the starting temperature in the intelligent photobioreactor;

[0031] Based on the optimized sludge digestion nutrient solution, microalgae with the best growth rate are screened from the microalgae library through biological screening methods;

[0032] The optimal growth rate microalgae and the optimized sludge digestion nutrient solution were inoculated, and the growth status of the optimal growth rate microalgae was evaluated in real time through the sensor in the intelligent photobioreactor. The calculation expression is:

[0033]

[0034] Among them, F(t) is the growth optimization score of the optimal growth rate microalgae at time step t, I(t) is the light intensity at time step t, α is the temperature sensitivity coefficient, and Y u is the optimal temperature in the intelligent photobioreactor, β is the light cycle adjustment coefficient, 2πt is the position of time step t in the periodic change, G is the light cycle, δ is the pH sensitivity coefficient, γ is a constant term, pH ′ (t) is the current pH value, pH z ′ is the optimal pH value, η is the dissolved oxygen regulation coefficient, D(t) is the dissolved oxygen concentration at time step t, D x is the target dissolved oxygen concentration, θ is the dissolved oxygen impact index;

[0035] Based on the growth optimization score, the growth status of microalgae with the best growth rate was evaluated;

[0036] Based on the growth status evaluation results of microalgae with the optimal growth rate, the microalgae are collected using membrane separation technology, and the collected microalgae are subjected to low-temperature drying technology to remove moisture, ultimately obtaining high-value-added dried algae.

[0037] As a preferred embodiment of the method for recycling sludge as a resource of the present invention, the growth state of microalgae with the best growth rate is evaluated based on the growth optimization score. The specific steps are as follows:

[0038] Based on the historical growth optimization score, the ideal growth threshold Б is set by analyzing the microalgae growth performance corresponding to different score intervals;

[0039] Evaluate the growth status of microalgae with optimal growth rate based on growth optimization score and ideal growth threshold;

[0040] When F(t)≥Б, it indicates that the growth state of the microalgae with the current optimal growth rate is very ideal;

[0041] When F(t)<Б, it means that the growth state of the microalgae with the current optimal growth rate is not ideal, and the environmental parameters need to be adjusted until F(t)≥Б.

[0042] As a preferred embodiment of the method for recycling sludge resources described in the present invention, the solid residue of sludge after anaerobic digestion is separated by magnetic nanomaterials and combined with a plate and frame filter press to obtain a highly efficient dehydrated solid residue. The specific steps are as follows:

[0043] preparing the magnetic nanomaterial into magnetic nanomaterial particles by a ball milling method;

[0044] The magnetic nanomaterial particles are mixed with the solid residue of sludge after anaerobic digestion in an organic liquid by a liquid dispersion method to obtain a magnetic nano suspension;

[0045] The strong magnetic field in the magnetic field separation is used to separate the solid residue of the sludge after anaerobic digestion that adsorbs the magnetic nanomaterial from the magnetic nano suspension to obtain the magnetic nano sludge solid residue;

[0046] The magnetic nano-sludge solid residue is dehydrated by mechanical pressure using a plate and frame filter press to obtain a dehydrated solid residue;

[0047] The moisture content of the dehydrated solid residue is further reduced by hot air drying to obtain a highly efficient dehydrated solid residue.

[0048] As a preferred embodiment of the method for recycling sludge resources described in the present invention, the method of preparing high-performance multifunctional building materials based on the highly efficient dehydrated solid residue and multifunctional auxiliary materials comprises the following specific steps:

[0049] The composition of the solid residue from high-efficiency dehydration was analyzed by X-ray fluorescence spectrometry;

[0050] Based on the analysis results, a highly efficient dehydrated solid residue with a high proportion of minerals is screened out;

[0051] Use comprehensive performance testing and material screening methods to select multifunctional auxiliary materials with excellent performance from the candidate material library;

[0052] The high-performance dehydrated solid residue with a high proportion of minerals and the multifunctional auxiliary materials with good performance are mixed in a mass ratio by high-speed stirring;

[0053] The mixed high-proportion mineral efficient dehydration solid residue and high-quality multifunctional auxiliary materials are formed using prefabricated molds and hydraulic pressure;

[0054] The formed building materials are cured at room temperature to produce high-performance multifunctional building materials.

[0055] In a second aspect, the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program is executed by the processor, any step of the method for sludge resource reuse as described in the first aspect of the present invention is implemented.

[0056] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the method for sludge resource reuse as described in the first aspect of the present invention is implemented.

[0057] The beneficial effects of the present invention are as follows: through the combination of efficient anaerobic digestion and intelligent photobioreactors, efficient treatment and resource utilization of sludge are achieved. First, the organic matter in the sludge is efficiently decomposed to generate biogas and nutrient solution through optimized anaerobic digestion methods, and the treatment efficiency is improved by precisely controlling the reaction temperature and pH value. Secondly, based on the sludge digestion nutrient solution, the intelligent photobioreactor is used to precisely control the growth environment of microalgae, thereby increasing the growth rate and added value of microalgae. Finally, through the combination of efficient dehydration treatment and multifunctional auxiliary materials, the solid residue is converted into high-performance building materials, realizing the comprehensive resource utilization of sludge, which not only reduces the environmental burden, but also has significant economic benefits and market application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0059] Figure 1 This is a flow chart of a method for sludge resource recycling in Example 1.

[0060] Figure 2 This is a flow chart for obtaining highly efficient dehydrated solid residue in Example 1. DETAILED DESCRIPTION

[0061] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0062] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0063] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0064] Example 1, reference Figure 1 and Figure 2 , which is the first embodiment of the present invention, provides a method for recycling sludge resources, comprising the following steps:

[0065] S1. Collect the original sludge and pre-treat it.

[0066] S1.1. Collect raw sludge from sewage treatment plants and industrial outfalls.

[0067] S1.2. Pretreatment of raw sludge includes removal of large particle impurities, crushing and homogenization.

[0068] It should be noted that the original sludge is pretreated by removing large particles of impurities, crushing and homogenizing. The specific process is as follows:

[0069] Removal of large particles: Through a series of screening equipment, such as coarse screens (for intercepting larger floating objects and suspended solids) and fine screens (for capturing smaller particulate matter), these devices are usually composed of metal bars or mesh structures. They screen out objects with a diameter larger than the set value according to the predetermined aperture size. In addition, rotary screens or vibrating screens can also be used to effectively separate large particles;

[0070] Crushing: After removing large particles of impurities, the sludge is sent to a specially designed crusher, which is equipped with high-speed rotating blades or shearing devices. When the sludge passes through, these mechanical components will exert strong shearing and impact forces on larger sludge clumps, breaking them into smaller and more uniform particles.

[0071] Homogenization: The crushed sludge is then introduced into a mixing tank or agitator equipped with a high-efficiency stirring device, such as a paddle agitator or turbine agitator. Through continuous and uniform stirring action, the sludge of different properties and concentrations is fully mixed.

[0072] S2. Based on the pretreated original sludge, a high-efficiency anaerobic digestion method is used to obtain sludge digestion nutrient solution and sludge solid residue after anaerobic digestion.

[0073] S2.1. Based on the pretreated raw sludge, it is input into the large anaerobic reactor through a screw pump to mix with anaerobic bacteria.

[0074] S2.2. The large anaerobic reactor is heated by indirect steam heating, and the reaction temperature of the anaerobic bacteria and the pretreated raw sludge is adjusted in real time using PID. The expression is:

[0075]

[0076] Among them, T r (t+Δt) is the reaction temperature after adjustment at time step t+Δt, T m is the target temperature, T a (t) is the actual temperature at time step t, T a (τ) is the actual temperature at the time point τ of the integral variable, K p is the proportional control coefficient of PID, K i is the integral control coefficient of PID, K d is the differential control coefficient of PID, dτ is the small increment of the integral variable at the time point τ, d(T m -T a (t)) is the instantaneous change in temperature difference, dt is the small increment of time step t, τ is the index variable of the integration variable time point, t is the index variable of the time step, and Δt is the time increment.

[0077] It should be noted that by referring to the best practice temperature range for anaerobic digestion, combined with factors such as sludge characteristics, reactor design and operating costs, one of the medium temperature (35-38°C) or high temperature (50-55°C) digestion ranges is selected as the target. Engineers will evaluate the impact of different temperatures on the activity of anaerobic bacteria, consider local climatic conditions, energy consumption and economic benefits, and ultimately determine a target temperature that can ensure efficient and economical sludge treatment.

[0078] S2.3. Adjust the pH value of the reaction between anaerobic bacteria and pretreated raw sludge using lime water and sodium bicarbonate. The expression is:

[0079]

[0080] Where pH(t+Δt) is the pH value after adjustment at time step t+Δt, [H + ]0 is the initial hydrogen ion concentration, k s is the proportional constant of the effect of alkaline substances on hydrogen ion concentration, ΔV l (t) is the volume of lime water that needs to be added at time step t, ΔV n (t) is the volume of sodium bicarbonate that needs to be added at time step t, V e is the volume of the large anaerobic reactor.

[0081] S2.4. Measure the VFA concentration by gas chromatography and optimize the operating parameters of the large-scale anaerobic reactor based on the VFA concentration measurement results.

[0082] Furthermore, representative samples are first collected from different locations within the large-scale anaerobic reactor and immediately pretreated to remove solid particles and substances that may interfere with analysis. Next, the pretreated samples are injected into a calibrated gas chromatograph set to specific separation conditions (such as column temperature and carrier gas flow rate). The automated sampling process is initiated, and the peak areas or heights in the chromatogram are compared with the standard curve to accurately calculate the concentrations of each VFA component. Subsequently, the measured VFA concentration data are compared with the pre-set optimal operating range to assess whether operating parameters such as organic loading rate, pH value, and temperature deviate from their ideal state. For example, an abnormally high VFA concentration may indicate excessive organic loading or inappropriate pH and temperature. In this case, measures should be taken to reduce the feed rate, adjust the pH to the ideal range of 6.5-7.5, and ensure that the temperature remains stable within the range of 35-38°C (medium temperature) or 50-55°C (high temperature). Finally, based on the evaluation results, these operating parameters are continuously monitored and adjusted accordingly to ensure that the anaerobic reactor maintains efficient and stable operation.

[0083] S2.5. Based on the adjusted reaction temperature, the adjusted pH value and the optimized operating parameters of the large-scale anaerobic reactor, the anaerobic bacteria gradually decompose the organic matter in the pretreated raw sludge to obtain digestion products.

[0084] Furthermore, by adjusting the reaction temperature and pH value of the anaerobic reactor and optimizing the operating parameters of the reactor, environmental conditions suitable for the growth and metabolism of anaerobic bacteria are created. Then, under this optimized environment, anaerobic bacteria gradually decompose the organic matter in the pretreated raw sludge. The process goes through multiple stages, including hydrolysis, acidification, hydrogen production, acetogenesis, and methane production. In the hydrolysis stage, complex organic matter (such as proteins, fats, carbohydrates, etc.) is broken down into simple soluble organic matter; in the acidification stage, some hydrolysis products are converted into short-chain fatty acids, hydrogen, and carbon dioxide; then, hydrogen-producing bacteria and acetogens further convert hydrogen and organic acids to produce acetic acid and other intermediate metabolites; finally, in the methanogenesis stage, methanogens convert intermediate products such as acetic acid and hydrogen into methane and carbon dioxide. After this series of biochemical reactions, the other substances in the reactor (the part that has not been converted into gas) are ultimately converted into digestion products.

[0085] Furthermore, the generated methane and carbon dioxide gases are typically collected by gas collection devices and sent to a biogas purification system for processing. First, the methane and carbon dioxide gases are separated. Methane, as a renewable energy source, can be used for power generation, heating, or converted into other forms of energy, while the carbon dioxide can be processed through adsorption or other technologies, some of which can be used for industrial applications or safely discharged. Through this treatment method, methane gas is effectively utilized and carbon dioxide is managed through appropriate means, thereby maximizing resource utilization and sustainable environmental protection.

[0086] S2.6. Separate the digestion products by sedimentation separation and mechanical dehydration to obtain sludge digestion nutrient solution and sludge solid residue after anaerobic digestion.

[0087] S3. Separate the digestion products by sedimentation separation and mechanical dehydration to obtain sludge digestion nutrient solution and sludge solid residue after anaerobic digestion.

[0088] S3.1. Stir the digestion product using a mechanical stirrer to obtain a homogenized product.

[0089] S3.2. The homogenized product is settled to the bottom of the sedimentation tank by gravity, forming a preliminarily separated solid waste residue and a clear liquid rich in nutrient solution.

[0090] It should be noted that the homogenized mixture is introduced into a sedimentation tank, where gravity causes the heavier solid particles to gradually settle to the bottom of the tank, forming a preliminarily separated solid waste layer. Meanwhile, the lighter liquid portion, i.e., the nutrient-rich clear liquid, remains on top. After a period of stagnant standing and sufficient separation of the solid and liquid phases, the solid waste at the bottom can be regularly removed using sludge removal equipment, while the clear liquid on top is discharged via an overflow weir or suction device.

[0091] S3.3. The solid waste residue that is initially separated is initially dehydrated by high-speed rotation of a centrifugal dehydrator.

[0092] It should be noted that the initially separated water-containing solid waste residue is continuously or intermittently input into the centrifugal dehydrator, and the strong centrifugal force generated by the high-speed rotation of the machine is used to quickly separate the solid matter and water; the heavier solid particles are thrown to the inner wall of the centrifuge shell and accumulate to form a solid residue layer, while the lighter water is discharged through the filter or sieve holes, realizing effective separation of solid and liquid; finally, the dehydrated solid residue is discharged from the specific outlet of the centrifuge.

[0093] S3.4. After sedimentation separation and mechanical dehydration, the sludge digestion nutrient solution and the sludge solid residue after anaerobic digestion are finally obtained.

[0094] S4. Based on the nutrient solution from sludge digestion, microalgae are propagated through intelligent photobioreactors to obtain high-value-added dried algae.

[0095] S4.1. The nutrient composition of the sludge digestion nutrient solution is adjusted by a linear adjustment method to optimize the sludge digestion nutrient solution in the intelligent photobioreactor. The expression is:

[0096] N(t)=N0+s1·W+s2·(Y-Y0);

[0097] Among them, N(t) is the nutrient concentration in the sludge digestion nutrient solution after optimization at time step t, N0 is the nutrient concentration in the initial sludge digestion nutrient solution, s1 is the proportional constant for adjusting the nutrient concentration in the sludge digestion nutrient solution, s2 is the proportional constant for temperature influence, W is the effective nutrient volume in the sludge digestion nutrient solution, Y is the real-time temperature in the intelligent photobioreactor, and Y0 is the starting temperature in the intelligent photobioreactor.

[0098] It should be noted that nutrients mainly include nitrogen (N), phosphorus (P), potassium (K) and trace elements such as iron (Fe), manganese (Mn), zinc (Zn);

[0099] It should also be noted that the inorganic and small-molecule organic compounds produced by the microbial decomposition of raw sludge during anaerobic digestion. When complex organic matter, including proteins, nucleic acids, carbohydrates, and lipids, is gradually degraded by anaerobic bacteria in an anaerobic environment, ammonia nitrogen (from proteins), phosphates (from nucleic acids and phospholipids), and other mineral elements are released. These components dissolve into the digestive fluid as the organic matter decomposes, forming a nutrient solution rich in various nutrients.

[0100] S4.2. Based on the optimized sludge digestion nutrient solution, microalgae with the best growth rate are screened from the microalgae library using a biological screening method.

[0101] It should be noted that, first, different types of microalgae samples were inoculated into a culture medium containing the optimized sludge digestion nutrient solution and cultured in parallel in a laboratory environment with controlled light, temperature, pH and other conditions; then, the growth rate, biomass yield and nutrient absorption efficiency of each microalgae sample in the nutrient solution were regularly monitored; based on the experimental data, those microalgae strains that showed the fastest growth rate and the highest nutrient utilization efficiency under the specified nutrient solution conditions were selected, and finally the microalgae with the optimal growth rate that was most suitable for the nutrient solution was determined.

[0102] S4.3. Inoculate the microalgae with the optimal growth rate and the optimized sludge digestion nutrient solution. Use the sensor in the intelligent photobioreactor to evaluate the growth status of the microalgae with the optimal growth rate in real time. The calculation expression is:

[0103]

[0104] Among them, F(t) is the growth optimization score of the optimal growth rate microalgae at time step t, I(t) is the light intensity at time step t, α is the temperature sensitivity coefficient, and Y u is the optimal temperature in the intelligent photobioreactor, β is the light cycle adjustment coefficient, 2πt is the position of time step t in the periodic change, G is the light cycle, δ is the pH sensitivity coefficient, γ is a constant term, pH ′ (t) is the current pH value, pH z ′ is the optimal pH value, η is the dissolved oxygen regulation coefficient, D(t) is the dissolved oxygen concentration at time step t, D x is the target dissolved oxygen concentration, and θ is the dissolved oxygen impact index.

[0105] It should be noted that the light intensity is monitored in real time by a light sensor installed in the intelligent photobioreactor;

[0106] The photoperiod refers to the time pattern of alternating light and dark, which simulates the day and night changes in nature to adapt to the physiological rhythm of microalgae. It is obtained by a set of time parameters of alternating light and dark executed by the automated control system of the intelligent photobioreactor.

[0107] The dissolved oxygen concentration is continuously measured inside the intelligent photobioreactor using a dissolved oxygen probe or electrode;

[0108] It should also be noted that the optimal temperature in the intelligent photobioreactor is obtained by experimentally studying the growth rate and biomass yield of microalgae at different temperatures to find the temperature range that promotes the most efficient photosynthesis and cell division, usually mesophilic (35-38°C) or hyperthermic (50-55°C);

[0109] Optimal pH value: Through experimental evaluation of the effects of different pH values on microalgae growth rate, nutrient absorption, and metabolic activity, a pH range that maximizes microalgae productivity and maintains system stability is determined, generally between 6.5 and 7.5. This is then monitored in real time using an online pH sensor and adjusted using an automatic regulator (such as sodium bicarbonate or lime water) to ultimately achieve the optimal pH value.

[0110] The target dissolved oxygen concentration is determined by experimentally measuring the growth performance and health status of microalgae under different dissolved oxygen levels. A concentration is selected that can support normal respiration of microalgae while avoiding excessive oxygen inhibition of their growth. It is usually close to saturation but not exceeding 100%. The target dissolved oxygen concentration is finally obtained through feedback control of the aeration system and dissolved oxygen sensor.

[0111] S4.4. Evaluate the growth status of microalgae with the optimal growth rate based on the growth optimization score.

[0112] S4.5. Based on the growth status evaluation results of the microalgae with the optimal growth rate, the microalgae are collected using membrane separation technology, and the collected microalgae are subjected to low-temperature drying technology to remove moisture, ultimately obtaining high-value-added dried algae.

[0113] It should be noted that membrane separation technology involves pumping a culture solution containing microalgae into a membrane filtration system equipped with a suitable pore size (usually 0.1 to 0.45 microns). By applying a moderate pressure difference, liquids and small molecules are allowed to pass through the membrane, while larger microalgae cells are retained on the membrane surface or in the concentration zone, thereby obtaining concentrated microalgae.

[0114] The concentrated microalgae collected by the above-mentioned membrane separation technology are first frozen to an extremely low temperature (usually below -40°C). At this temperature, the water inside the microalgae is completely frozen into ice crystals. Next, it enters the sublimation stage under a vacuum environment. The ice crystals are directly sublimated from a solid state to gaseous water vapor through decompression. In order to ensure drying efficiency and product quality, the entire freeze-drying process requires precise control of temperature, pressure and time parameters. In addition, in some cases, a staged heating method is used to gradually increase the temperature to accelerate the sublimation of water while avoiding damage to the cell structure of the microalgae. In the end, what is obtained is a high-value-added dried algae that retains the original nutrients and bioactive substances.

[0115] S5. Based on the growth optimization score, the growth status of the microalgae with the optimal growth rate is evaluated.

[0116] S5.1. Based on the historical growth optimization score, set the ideal growth threshold Б by analyzing the microalgae growth performance corresponding to different score intervals.

[0117] It should be noted that the historical growth optimization score is first divided into multiple intervals, and then the average values and changing trends of key indicators such as microalgae growth rate, biomass yield and environmental adaptability in each interval are statistically analyzed; then, statistical methods (such as correlation analysis or regression analysis) are used to evaluate the relationship between these indicators and the scores, and the score interval corresponding to the optimal growth conditions is identified. Based on these analysis results, by comparing the performance of key indicators such as microalgae growth rate, biomass yield and environmental adaptability in different score intervals, the score interval with the best performance is identified, and the lower limit value of the optimal score interval is selected as the ideal growth threshold, or the average value of all scores in the interval is calculated as the threshold.

[0118] S5.2. Evaluate the growth status of microalgae with optimal growth rate based on the growth optimization score and ideal growth threshold;

[0119] When F(t)≥Б, it indicates that the growth state of the microalgae with the current optimal growth rate is very ideal;

[0120] When F(t)<Б, it means that the growth state of the microalgae with the current optimal growth rate is not ideal, and the environmental parameters need to be adjusted until F(t)≥Б.

[0121] S6. Based on the solid residue of sludge after anaerobic digestion, magnetic nanomaterial-assisted separation is combined with a plate and frame filter press to obtain highly efficient dehydrated solid residue.

[0122] S6.1. Prepare magnetic nanomaterials into magnetic nanomaterial particles by ball milling.

[0123] Specifically, the initial magnetic material powder and an appropriate amount of hard grinding balls (such as stainless steel or zirconia balls) are added to a ball mill in a certain proportion, and then an appropriate process control agent (such as a surfactant or solvent) is added. The ball mill is then sealed and placed on a ball mill for mechanical ball milling at a set speed and time. During the ball milling process, the high-energy collision and friction between the grinding balls cause the magnetic material to be continuously refined, eventually forming uniformly dispersed magnetic nanomaterial particles.

[0124] S6.2. Mix the magnetic nanomaterial particles with the solid residue of sludge after anaerobic digestion in an organic liquid by a liquid dispersion method to obtain a magnetic nano suspension.

[0125] Specifically, the pre-prepared magnetic nanomaterial particles and the solid sludge residue after anaerobic digestion are added to the selected organic solvent respectively; then, the liquid dispersion method (ultrasonic treatment or mechanical stirring, etc.) is used to fully disperse and evenly mix the two in the organic liquid to ensure that the magnetic nanoparticles are evenly attached to the surface of the sludge particles; finally, unbound impurities are removed through filtration or centrifugation to obtain a stable and evenly distributed magnetic nanosuspension.

[0126] S6.3. Separate the solid sludge residue after anaerobic digestion that has adsorbed magnetic nanomaterials from the magnetic nano suspension through a strong magnetic field in magnetic field separation to obtain magnetic nano sludge solid residue.

[0127] Specifically, the magnetic nanosuspension is introduced into the area of action of a strong magnetic field, and the responsiveness of the magnetic nanomaterial to the magnetic field is utilized to make the solid sludge residue adsorbed with the magnetic nanomaterial move rapidly toward the magnetic pole and gather; then, by physically removing or collecting these solid particles attracted by the magnetic field, effective separation from the liquid is achieved, and finally the magnetic nanosludge solid residue is obtained.

[0128] S6.4. Dewater the magnetic nano-sludge solid residue by mechanical pressure using a plate and frame filter press to obtain a dehydrated solid residue.

[0129] Specifically, the magnetic nano-sludge solid residue is evenly distributed in the filter chamber of the plate and frame filter press. By applying mechanical pressure, the liquid is squeezed out of the filter cloth and discharged, while the solid particles are retained in the filter chamber to form a cake. After a period of high-pressure pressing, the water is removed to the greatest extent possible, and finally a dry and stable dehydrated solid residue is obtained.

[0130] S6.5. Further reduce the moisture content of the dehydrated solid residue by hot air drying to obtain a highly efficient dehydrated solid residue.

[0131] Specifically, the dehydrated solid residue after being processed by the plate and frame filter press is evenly spread in the drying equipment, and then an appropriate amount of hot air is introduced to accelerate the evaporation of water by utilizing the high temperature and airflow of the hot air; during the hot air drying process, the temperature and humidity are continuously monitored to ensure uniform heating and efficient dehydration; finally, an efficient dehydrated solid residue with extremely low moisture content, dry and stable texture is obtained.

[0132] S7. Prepare high-performance multifunctional building materials based on highly efficient dehydrated solid residues and multifunctional auxiliary materials.

[0133] S7.1. Analyze the composition of the high-efficiency dehydration solid residue by X-ray fluorescence spectrometry.

[0134] Specifically, the dehydrated solid residue sample is ground into a fine powder and pressed into tablets or directly prepared into a form suitable for testing; then, the sample is placed on the sample stage of the XRF spectrometer, and the instrument emits X-rays to irradiate the sample, stimulating the characteristic fluorescent X-rays of the elements in the sample; by detecting the energy and intensity of these characteristic X-rays, the XRF spectrometer can quickly and non-destructively determine the type and content of each element in the sample.

[0135] S7.2. Based on the analysis results, select a highly efficient dehydrated solid residue with a high proportion of minerals.

[0136] Specifically, based on the elemental composition data provided by XRF, samples containing a higher proportion of minerals (such as silicon, calcium, iron, etc.) are identified; then, a threshold standard for mineral content is set, and by comparing the analysis results of each sample, high-efficiency dehydrated solid residues that meet or exceed this standard are selected.

[0137] S7.3. Use comprehensive performance testing and material screening methods to select multifunctional auxiliary materials with excellent performance from the candidate material library.

[0138] Specifically, key performance indicators are determined based on application requirements (such as the required mechanical strength, thermal stability, chemical durability or specific functional requirements), and physical, chemical and mechanical property tests are conducted on candidate materials to evaluate their performance under different conditions; combining the test results with cost-benefit analysis, the material screening method is used to compare the comprehensive performance of each candidate material, and finally those materials that perform well in all key indicators and are cost-effective are selected as multifunctional auxiliary materials.

[0139] S7.4. High-performance dehydrated solid residue with a high proportion of minerals and multifunctional auxiliary materials with good performance are mixed in a mass ratio by high-speed stirring.

[0140] Specifically, the optimal ratio is determined based on the desired final product performance, such as mechanical strength, chemical stability, or specific functionality, and through preliminary testing and analysis. For example, if the mechanical strength of the composite material is to be enhanced, a higher proportion of auxiliary materials may be selected; while if cost control is important, a higher proportion of solid residue may be adjusted.

[0141] Accurately weigh the two materials according to the predetermined mass ratio, add them to the high-speed mixer, and continue stirring for a certain period of time at the set speed to ensure that the two are fully and evenly mixed, and finally obtain a composite material with stable performance.

[0142] S7.5. The mixed high-proportion mineral efficient dehydrated solid residue and high-quality multifunctional auxiliary materials are molded using a prefabricated mold and hydraulic pressure.

[0143] Specifically, first, the uniformly mixed material is filled into a pre-designed mold; then, the mold filled with the material is placed in a hydraulic press and compression-molded using a set pressure and holding time; finally, after a certain curing or cooling process, the stability and strength of the molded part are ensured, thereby obtaining a finished component with a fixed shape and excellent performance.

[0144] S7.6. The formed building materials are cured at room temperature to produce high-performance multifunctional building materials.

[0145] Specifically, the formed material is placed in a humidity-controlled and well-ventilated environment and naturally cured at room temperature for a certain period of time. During this period, chemical cross-linking reactions or physical changes occur inside the material, gradually enhancing its structural stability and mechanical properties. After curing is completed, a universal testing machine is used to test its compressive, tensile and flexural strength to ensure that it meets the design standards. Durability is evaluated through accelerated aging tests, such as weather resistance, freeze-thaw cycle resistance and chemical corrosion resistance. Functional requirements, such as thermal conductivity, water absorption and fire resistance, are checked, and comprehensive testing is carried out using professional instruments and standardized testing methods to ensure that it meets the expected strength, durability and functional requirements, thereby obtaining high-performance multifunctional building materials.

[0146] This embodiment also provides a computer device suitable for a method of sludge resource reuse, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement a method of sludge resource reuse as proposed in the above embodiment.

[0147] The computer device may be a terminal, comprising a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a button, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse.

[0148] This embodiment also provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for realizing a sludge resource reuse as proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0149] In summary, the present invention achieves efficient treatment and resource utilization of sludge through: the combination of efficient anaerobic digestion and intelligent photobioreactor. First, the organic matter in the sludge is efficiently decomposed to generate biogas and nutrient solution through optimized anaerobic digestion methods, and the treatment efficiency is improved by precisely controlling the reaction temperature and pH value. Secondly, based on the sludge digestion nutrient solution, the intelligent photobioreactor is used to precisely control the growth environment of microalgae, thereby increasing the growth rate and added value of microalgae. Finally, through the combination of efficient dehydration treatment and multifunctional auxiliary materials, the solid residue is converted into high-performance building materials, realizing the comprehensive resource utilization of sludge, which not only reduces the environmental burden, but also has significant economic benefits and market application potential.

[0150] Example 2, referring to Table 1, is the second example of the present invention. In order to further verify the technical solution of the present invention, experimental simulation data of a method for recycling sludge resources is provided.

[0151] To demonstrate the innovative nature and advantages of the present invention in sludge resource reuse, a series of experiments were designed to compare the effectiveness of existing technologies with the present invention at different treatment stages. The experiments were conducted using raw sludge collected from sewage treatment plants and industrial outfalls. Pretreatment, anaerobic digestion, solid residue separation, microalgae propagation, and subsequent solid residue treatment were performed according to the present invention's procedures. These experiments focused on comparing the differences between conventional sludge treatment methods and the optimized scheme proposed in the present invention in terms of digestion efficiency, nutrient solution utilization, microalgae growth rate, and solid residue dehydration rate.

[0152] The experiment began by collecting raw sludge from sewage treatment plants and industrial outfalls and pre-treating it. During pre-treatment, the sludge was screened through coarse and fine screens to remove large particles. It was then mechanically crushed in a crusher and homogenized using a high-efficiency mixing device, ensuring uniform mixing for subsequent processing.

[0153] Next, the pretreated sludge is pumped into a large anaerobic reactor using a screw pump, where it mixes with anaerobic bacteria for anaerobic digestion. A PID temperature control system regulates the reactor's temperature in real time, while limewater and sodium bicarbonate are used to adjust the pH of the reaction system to optimize the reaction environment. Under these conditions, the anaerobic bacteria begin to break down the organic matter in the sludge, producing digestion products including gases such as methane and carbon dioxide.

[0154] The digestion products are then separated in a sedimentation tank and centrifugal dehydrator, yielding a nutrient-rich supernatant and a solid sludge residue after anaerobic digestion. Membrane separation technology is used to collect high-quality microalgae, and their growth conditions are optimized in an intelligent photobioreactor. By real-time monitoring and adjustment of parameters such as light, temperature, and pH, microalgae with the optimal growth rate are selected. Finally, low-temperature drying technology is used to remove moisture, resulting in high-value dried algae.

[0155] Finally, after magnetic nanomaterial-assisted separation and plate-and-frame filter press dehydration, the sludge solid residue is further dehydrated, resulting in a highly efficient dehydrated solid residue. Based on this dehydrated solid residue and multifunctional auxiliary materials, high-performance multifunctional building materials are prepared through component analysis, performance screening, and mixing, providing a sustainable solution for sludge resource reuse.

[0156] The existing technology specifically refers to traditional sludge treatment methods, such as conventional anaerobic digestion and physical and chemical treatment technologies.

[0157] The details are shown in Table 1 below:

[0158] Table 1 Sludge treatment comparison data

[0159]

[0160]

[0161] The present invention is superior to the existing technology in many key indicators. Compared with the traditional sludge treatment method, the pretreatment effect (large particle impurity removal rate) of the existing technology is 72.3%, while the present invention is increased to 85.7%. The digestion efficiency (COD removal rate) is also significantly improved, from 78.5% to 90.1%. In addition, the present invention also shows better effects in VFA concentration and microalgae growth rate. The VFA concentration is increased from 1050.4 mg / L to 1287.6 mg / L, and the microalgae growth rate is increased from 0.42 g / L·d to 0.58 g / L·d, indicating that the present invention has a higher promoting effect on the cultivation and biodegradation process of microalgae. The solid residue dehydration rate is also increased from 61.7% to 74.3%, reflecting the advantages of the present invention in resource recovery.

[0162] By optimizing the coupled process of anaerobic digestion and microalgae cultivation, this method significantly improves sludge treatment efficiency and resource utilization. Compared to existing technologies, it effectively removes large impurities, increases COD removal rates, increases VFA concentrations, and promotes the rapid growth of microalgae, thereby enhancing sludge degradation efficiency and energy recovery. Furthermore, this method improves the dehydration rate of solid residues, achieving efficient sludge dehydration and resource utilization, reducing treatment costs and providing excellent environmental and economic benefits.

[0163] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for recycling sludge resources, characterized by: include, Collecting raw sludge and pre-treating it; Based on the pre-treated raw sludge, a high-efficiency anaerobic digestion method is used to obtain sludge digestion nutrient solution and sludge solid residue after anaerobic digestion; Based on the nutrient solution digested by sludge, microalgae are propagated through intelligent photobioreactors to obtain high-value-added dried algae. The specific steps are as follows: The nutrient components in the sludge digestion nutrient solution were adjusted by the linear regulation method to optimize the sludge digestion nutrient solution in the intelligent photobioreactor. The expression is: ； in, is in the time step The nutrient concentration in the optimized sludge digestion nutrient solution is is the nutrient concentration in the initial sludge digestion nutrient solution, is the proportional constant for regulating the nutrient concentration in the sludge digestion nutrient solution, is the proportionality constant of the temperature effect, is the volume of effective nutrients in the nutrient solution from sludge digestion, It is the real-time temperature in the intelligent photobioreactor. is the starting temperature in the intelligent photobioreactor; Based on the optimized sludge digestion nutrient solution, microalgae with the best growth rate are screened from the microalgae library through biological screening methods; The optimal growth rate microalgae and the optimized sludge digestion nutrient solution were inoculated, and the growth status of the optimal growth rate microalgae was evaluated in real time through the sensor in the intelligent photobioreactor. The calculation expression is: ； in, is the optimal growth rate of microalgae at time step Growth optimization score, is the time step The light intensity, is the temperature sensitivity coefficient, It is the optimal temperature in the intelligent photobioreactor. is the photoperiod regulation coefficient, is the time step The position in the cyclical change, is the photoperiod, yes Value sensitivity coefficient, is a constant term, is currently value, is the best value, is the dissolved oxygen regulation coefficient, is in the time step The dissolved oxygen concentration, is the target dissolved oxygen concentration, is the dissolved oxygen impact index; Based on the growth optimization score, the growth status of microalgae with the best growth rate was evaluated; Based on the growth status assessment results of the microalgae with the best growth rate, the microalgae are collected using membrane separation technology, and the collected microalgae are then dried using low-temperature drying technology to remove moisture, ultimately obtaining high-value-added dried algae. Based on the solid residue of sludge after anaerobic digestion, the magnetic nanomaterial-assisted separation is combined with a plate and frame filter press to obtain highly efficient dehydrated solid residue; High-performance multifunctional building materials are prepared based on highly efficient dehydrated solid residues and multifunctional auxiliary materials.

2. The method for recycling sludge as claimed in claim 1, wherein: The raw sludge is collected and pre-treated, and the specific steps are as follows: Raw sludge is collected from wastewater treatment plants and industrial outfalls; The pretreatment of the raw sludge includes removing large particle impurities, crushing and homogenizing.

3. The method for recycling sludge as claimed in claim 2, characterized in that: The method is based on the pre-treated raw sludge, and obtains the sludge digestion nutrient solution and the sludge solid residue after anaerobic digestion through a high-efficiency anaerobic digestion method. The specific steps are as follows: Based on the pretreated raw sludge, it is fed into a large anaerobic reactor through a screw pump to mix with anaerobic bacteria; The large anaerobic reactor is heated by indirect steam heating, and the reaction temperature of anaerobic bacteria and pretreated raw sludge is adjusted in real time using PID. The expression is: ； in, is in the time step After adjusting the reaction temperature, is the target temperature, is the time step The actual temperature, is the integration variable time point The actual temperature, is the proportional control coefficient of PID, is the integral control coefficient of PID, is the differential control coefficient of PID, is the integration variable time point A small increment of is the instantaneous change in temperature difference, is the time step A small increment of is the index variable of the time point of the integration variable, is the index variable of the time step, is the time increment; Adjust the reaction between anaerobic bacteria and pretreated raw sludge by lime water and sodium bicarbonate Value, the expression is: ； in, is in the time step Adjusted value, is the initial hydrogen ion concentration, is the proportional constant of the effect of alkaline substances on the hydrogen ion concentration, is in the time step The volume of lime water to be added, is in the time step The volume of sodium bicarbonate to be added, is the volume of the large anaerobic reactor; The VFA concentration was measured by gas chromatography, and the operating parameters of the large-scale anaerobic reactor were optimized based on the VFA concentration measurement results; Based on the adjusted reaction temperature, The anaerobic bacteria gradually decompose the organic matter in the pretreated raw sludge to obtain digestion products. The digestion products are separated by sedimentation separation and mechanical dehydration to obtain sludge digestion nutrient solution and sludge solid residue after anaerobic digestion.

4. The method for recycling sludge as claimed in claim 3, wherein: The digestion products are separated by sedimentation separation and mechanical dehydration to obtain sludge digestion nutrient solution and sludge solid residue after anaerobic digestion. The specific steps are as follows: The digested product is stirred by a mechanical stirrer to obtain a homogenized product; The homogenized product is settled to the bottom by gravity in a sedimentation tank to form a solid waste residue and a clear liquid rich in nutrient solution that are initially separated; The solid waste residue that is initially separated is initially dehydrated by high-speed rotation of a centrifugal dehydrator; After sedimentation separation and mechanical dehydration, the sludge digestion nutrient solution and the sludge solid residue after anaerobic digestion are finally obtained.

5. The method for recycling sludge as claimed in claim 1, wherein: Based on the growth optimization score, the growth status of the microalgae with the best growth rate is evaluated. The specific steps are as follows: Based on the historical growth optimization score, the ideal growth threshold is set by analyzing the microalgae growth performance corresponding to different score intervals. ; Evaluate the growth status of microalgae with optimal growth rate based on growth optimization score and ideal growth threshold; when When , it means the current optimal growth rate and the growth state of microalgae are very ideal; when When the optimal growth rate is reached, it indicates that the growth state of the microalgae is not ideal and the environmental parameters need to be adjusted until .

6. The method for recycling sludge as claimed in claim 4, characterized in that: The solid residue of sludge after anaerobic digestion is separated by magnetic nanomaterials and combined with a plate and frame filter press to obtain a highly efficient dehydrated solid residue. The specific steps are as follows: preparing the magnetic nanomaterial into magnetic nanomaterial particles by a ball milling method; The magnetic nanomaterial particles are mixed with the solid residue of sludge after anaerobic digestion in an organic liquid by a liquid dispersion method to obtain a magnetic nano suspension; The strong magnetic field in the magnetic field separation is used to separate the solid residue of the sludge after anaerobic digestion that adsorbs the magnetic nanomaterial from the magnetic nano suspension to obtain the magnetic nano sludge solid residue; The magnetic nano-sludge solid residue is dehydrated by mechanical pressure using a plate and frame filter press to obtain a dehydrated solid residue; The moisture content of the dehydrated solid residue is further reduced by hot air drying to obtain a highly efficient dehydrated solid residue.

7. The method for recycling sludge as claimed in claim 6, characterized in that: The method of preparing high-performance multifunctional building materials based on efficient dehydrated solid residue and multifunctional auxiliary materials comprises the following specific steps: The composition of the solid residue from high-efficiency dehydration was analyzed by X-ray fluorescence spectrometry; Based on the analysis results, a highly efficient dehydrated solid residue with a high proportion of minerals is selected; Use comprehensive performance testing and material screening methods to select multifunctional auxiliary materials with excellent performance from the candidate material library; The high-performance dehydrated solid residue with a high proportion of minerals and the multifunctional auxiliary materials with good performance are mixed in a mass ratio by high-speed stirring; The mixed high-proportion mineral efficient dehydration solid residue and high-quality multifunctional auxiliary materials are formed using prefabricated molds and hydraulic pressure; The formed building materials are cured at room temperature to produce high-performance multifunctional building materials.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for resource recycling of sludge according to any one of claims 1 to 7 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for resource recycling of sludge according to any one of claims 1 to 7 are implemented.

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