Method and system for improving solid waste recycling through low-carbon intelligent addition of rhamnolipid

Abstract

The invention discloses a method and system for improving solid waste recycling through low-carbon intelligent addition of rhamnolipid. An intelligent control system of the system is connected with an addition system 1, a reaction system 2 and a monitoring system 3 at the same time; the monitoring system 3 is connected with the feeding system 1 and the reaction system 2; the method comprises the following steps: respectively pretreating solid wastes and rhamnolipid, carrying out anaerobic reaction in an anaerobic environment of a reaction system to generate methane gas, and conveying the gas into a gas collecting barrel; in the reaction process, the monitoring system 3 monitors the states of the feeding system and the reaction system in real time and transmits the states to the intelligent control system 4 through electric signals, the intelligent control system 4 reacts on the feeding system 1 and the reaction system 2 through analysis and fitting, and an instruction is input to control the motor power and the valve opening degree at the far end. Meanwhile, the initial addition amount of the rhamnolipid in the next time is corrected. The system has the advantages of intelligence and automation, and solves the problem of low rate of methane production by sludge fermentation in the prior art.

Description

Technical Field

[0001] The invention belongs to the field of anaerobic digestion of excess sludge from organic wastewater, and in particular relates to a system and method for increasing methane production from anaerobic digestion of excess sludge by adding rhamnolipid. Background Art

[0002] A large amount of sludge is generated during the water treatment process, and the treatment and disposal of sludge has become an important issue that cannot be avoided. Under the background of sludge reduction, harmlessness and resource utilization, anaerobic digestion technology has become a research hotspot. On the one hand, anaerobic digestion of sludge can reduce the organic content in sludge and promote sludge stability. On the other hand, the biogas produced by digestion can realize energy recovery in sludge through cogeneration of heat and power. The residual sludge is rich in a large amount of organic matter (protein: 40-60%; polysaccharides: 10-20%; fat: 10%). The residual sludge is considered to be a huge renewable resource library and should be reused to recycle resources and energy and reduce the operating costs of sewage treatment plants. On the one hand, anaerobic digestion can convert various organic matter in the residual sludge into renewable bioenergy methane, and at the same time recycle it to replace fossil fuels and reduce carbon emissions. Compared with drying and incineration, anaerobic digestion can reduce 82.69kg CO2 carbon emissions for processing 1 ton of organic solid residue, realizing the resource utilization of residual sludge. On the other hand, anaerobic digestion can reduce the volume and weight of residual sludge and achieve residual sludge reduction.

[0003] However, due to the poor hydrolysis of activated sludge, the methane production of anaerobic digestion of activated sludge is usually unsatisfactory. Surfactants have solubilizing properties, which can change the tension and properties of the mud-water interface, promote the dissociation of excess sludge flocs and the hydrolysis of organic matter. Rhamnolipids are an eco-friendly biosurfactant. Compared with chemical surfactants, they have the advantages of lower toxicity and better biodegradability. Rhamnolipids have a significant solubilizing effect on particulate organic matter in excess sludge flocs. For the release of extracellular polymers induced by rhamnolipids, bacteria can use these dissolved substances to efficiently produce volatile fatty acids.

[0004] Chinese patent application No. 202410518668.9 discloses a method for pretreating excess sludge with pyrosulfite and promoting anaerobic digestion and hydrolysis of excess sludge. The method requires the excess sludge to settle naturally for 4-36 hours, requires a pH range of 8.8-9.2, and a temperature requirement of 20°C-25°C, which is more suitable for excess sludge with a volatile solid concentration of 4.0g / L-12g / L. However, the increase in the sludge pretreatment process will increase the operational complexity of the entire sludge treatment process and increase the operating cost of the sludge treatment process. Chinese patent No. 202410448609.9 discloses a method for promoting methanogenesis by anaerobic digestion of sludge using β-cyclodextrin, which uses β-cyclodextrin to enhance the production of biomethane during anaerobic digestion of excess sludge. The method first requires the anaerobic sludge to be rinsed and resuspended with a PBS buffer solution, and the excess sludge treated with PBS solution and the excess sludge to which β-cyclodextrin is added are configured in a ratio of 1:10. The method has relatively complex processing steps, large engineering workload, and is time-consuming. Frequent use of chemical agents in the process may cause secondary pollution. Therefore, it is of great significance to provide a low-energy, high-load, environmentally friendly, and easy-to-operate sludge anaerobic digestion method. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to overcome the problems existing in the prior art and to provide a method and system for improving the resource utilization of solid waste by adding rhamnolipids with low carbon, which solves the problem of low rate of methane production by sludge fermentation in the prior art, simplifies the process, enhances the automatic control effect, and can realize industrial and intelligent promotion.

[0006] Technical solution: The purpose of the present invention is achieved by the following technical solution.

[0007] A low-carbon intelligent system for adding rhamnolipid to improve the resource utilization of solid waste, comprising an adding system (1), a reaction system (2), a monitoring system (3), and an intelligent control system (4). The intelligent control system (4) is connected to the adding system (1), the reaction system (2), and the monitoring system (3) at the same time; the monitoring system (3) is connected to the adding system (1) and the reaction system (2); the monitoring system (3) monitors the status of the adding system and the reaction system in real time, and transmits the status to the intelligent control system (4) through electrical signals; the intelligent control system (4) reacts to the adding system (1) and the reaction system (2) through analysis and fitting, and inputs commands to remotely control the motor power and valve opening.

[0008] The dosing system is provided with an external drive device A (1-1); a motor A (1-5), a connecting shaft A (1-6), a rotating shaft A (1-7), and a stirring paddle (1-8) are provided therein; the motor A (1-5) is connected to the drive device A (1-1); the motor A (1-5) serves as a power source, and its power is controlled by an intelligent controller of the drive device A (1-1); the motor A (1-5) transmits power to the rotating shaft A (1-7) through the connecting shaft A (1-6), thereby driving the stirring paddle (1-8) to perform stirring, and the dosing system is used for pretreatment of rhamnose; a sampling port A (1-2) and a discharge port connected to a reaction system (2) are provided on the side wall of the dosing system; a valve (1-3) and a flow pump (1-4) are provided on the connecting channel; an observation port (1-5) is provided on the side wall of the device; and a dosing height indicator (1-9) and a dosing amount indicator (1-10) are provided on the side.

[0009] The reaction system (2) comprises an anaerobic fermentation device and a gas collecting device. The top of the anaerobic fermentation device is provided with a driving device B (2-2), a feeding port (2-1), and a feed filter port (2-3); the upper part of the side wall is provided with a vent hole (2-4), the lower part of the side wall is provided with a sampling hole B (2-5), and the bottom is provided with a heating device (2-6); the feed filter port (2-3) is used to pass pre-treated activated sludge, and the feeding port (2-1) is used to add a reagent; the gas produced by the anaerobic fermentation device is connected to the lower side of the gas collecting device through a blower (2-7); the gas collecting device comprises: a gas collecting barrel (5), the barrel body is provided with a sampling hole C (5-2), and a check valve (5-1) is provided on the connecting pipeline with the anaerobic fermentation device.

[0010] The internal structure of the anaerobic fermentation device includes: a motor B (2-8), a connecting shaft B (2-9), a rotating shaft B (2-10), a fixing frame (2-11), a lifting pipe (2-12), a spiral stirring blade (2-13), a feeding hole (2-14), and a slope (2-15); wherein the motor B (2-8) is used as a power source, and the power thereof is controlled by an intelligent controller connected to the driving device B (2-2); the motor B is connected to the rotating shaft B (2-10) via the connecting shaft B (2-9), A spiral stirring blade (2-13) is provided on the rotating shaft B; the spiral stirring blade is arranged in the lifting pipe (2-12); the mixed raw material is stirred by the spiral stirring blade (2-13), lifted in the lifting pipe (2-12), and flows out from the top of the lifting pipe; the sludge outside the lifting pipe enters the lifting pipe (2-12) again from the feeding hole (2-14) at the bottom of the lifting pipe due to the stirring action of the blade and the conveying of the bottom slope (2-15) to be stirred and lifted, thereby repeatedly generating an oscillating effect;

[0011] The monitoring system comprises: a temperature sensor, an air pressure sensor, and a liquid level sensor; wherein a temperature sensor is arranged on the dosing system (1), a temperature sensor and a liquid level sensor are arranged on the reaction system (2), and an air pressure sensor is arranged on the gas collecting barrel (5); the parameters detected by the monitoring system are transmitted to the input module (4-1) of the intelligent control system via electrical signals, and after fitting and analysis, are output to the output module (4-2) and the early warning module (4-3), remotely controlling valves and devices, and further guiding the dosing and reaction progress, thereby ensuring the safe and efficient operation of the reaction.

[0012] A method for improving the resource utilization of solid waste by adding rhamnolipid in a low-carbon and intelligent manner. The raw material rhamnolipid is pretreated and then sent to a reaction system (2) by a dosing system (1). It is mixed with the pretreated residual sludge for fermentation to produce gas. The gas is collected by a gas collection device (5). The process is reacted by a monitoring system (3). The intelligent control system analyzes and outputs correct program instructions, and the dosing and reaction stages are completed efficiently and safely. The specific steps are as follows:

[0013] Step 1: solid waste is taken, and after pretreatment, it is mixed according to the best ratio to obtain anaerobic fermentation raw materials; rhamnolipid raw materials from a pharmaceutical company are taken and introduced into the automatic dosing device (1). In the dosing device, the raw materials are reflected by the data collection of the temperature sensor and the sampling port A (1-2) and input into the module (4-1). The system judges whether the requirements for entering the reaction system are met according to the temperature and fluidity of the raw materials. If the temperature is lower than 25°C and the fluidity of the raw materials is poor, the signal is input into the output module (4-2), and the driving device A (1-1) is turned on for stirring to increase the fluidity of the rhamnolipid raw materials for easy addition; in order to control the strict anaerobic environment and protect the reactants from oxidation, the intelligent control system (4) introduces nitrogen into the vent (2-4) to remove the air in the reactor, prevent moisture and impurities in the air from entering the reactor, thereby ensuring the purity and stability of the reaction, and opens the sampling port C (5-2) to perform nitrogen purge pretreatment of the reaction system for 3-5 minutes.

[0014] Step 2: Reaction stage: the pre-treated anaerobic fermentation raw materials are fed into the reaction system (2) from the feed filter port (2-3), rhamnolipid is fed from the feed port (2-1), and a pH regulator is fed from the feed port (2-1), and an anaerobic reaction occurs in the reaction system to generate methane gas, which is then transported to a gas collection tank; the pH concentration of the reactor is maintained at 6.5-7.2, the temperature of the reactor is maintained at 32-36°C, and the reactor is stirred at a rotation speed of 150-200 rpm every 4-6 hours, and each stirring lasts for 60-90 minutes.

[0015] Step 3: During the control phase, based on the sensor information and sampling analysis information, the control system performs data analysis and inputs the electrical signal to the input module (4-1), and then inputs the signal to the output module (4-2) remote control device to re-optimize the dosage.

[0016] The height indicator (1-9) on the side wall of the dosing system shows the real-time height of rhamnolipid in the dosing system. t The flow rate Q1 delivered by the flow pump is calculated and displayed on the dosage indicator (1-10).

[0017]

[0018] Among them, Q1 is the flow rate delivered by the flow pump, the unit is m 3 / h;

[0019] S1 is the bottom area of ​​the dosing system (1), in m 2 ;

[0020] t1 is the opening time of the pneumatic valve (1-3), in seconds;

[0021] Solid waste includes residual sludge from urban sewage treatment plants, kitchen waste, and livestock and poultry manure from livestock and poultry farms. The pretreatment methods and requirements are as follows:

[0022] Residual sludge: Before use, filter the sludge with a 2.0mm stainless steel mesh to remove large particles, then naturally settle at 4°C for 24 hours, remove the supernatant for concentration, and use a pH regulator to adjust the pH value. The residual sludge after pretreatment should meet the following requirements: total suspended solids (TSS) ≤ 30.00g / L, volatile suspended solids (VSS) ≤ 15.00g / L; pH concentration 6.5-7.2;

[0023] Food waste: Use a filter press to crush it into slurry, and use a pH adjuster to adjust the pH value. The pretreated food waste should meet the following requirements: total suspended solids (TSS) concentration is 15.00-20.00g / L, volatile suspended solids (VSS) concentration is 10.00-15.00g / L; pH concentration is 6.0-6.5;

[0024] Livestock and poultry manure: Use a stainless steel screen to filter the sludge to remove large particles, and use a pH regulator to adjust the pH value. The pretreated kitchen waste should meet the following requirements: the volatile suspended solids (VSS) concentration is 25-35g / L, and the pH concentration is 7.0-8.0.

[0025] Before the formal operation, the optimal addition ratio of the three solid wastes is first determined through pre-operation. The specific steps are as follows:

[0026] The addition ratio of excess sludge is m1, the addition ratio of food waste is m2, and the addition ratio of livestock and poultry manure is m3. The three satisfy m1+m2+m3=1. The central composite design (CCD) is used to determine the optimal ratio of m1, m2 and m3. The five levels of m1, m2 and m3 addition are set to 0, 0.2, 0.4, 0.6 and 0.8 respectively. The addition ratio matrix used in the pre-run is shown in the following table:

[0027]

[0028] Among them, batches 1-3 are vertex experiments, batches 4-6 are edge midpoint experiments, batch 7 is center point experiments, and batches 8-12 are other experimental points.

[0029] Each batch of experiments was run for 10 days, and the monitoring system (3) recorded the cumulative methane production from the start of the reaction to the 10th day. …, The modified Gompertz equation was used to simulate the maximum methane production potential P of each batch of experiments. m The maximum methane production potential P of each batch of experiments m The response value was the response surface model established using R software to determine the optimal addition ratio of excess sludge, kitchen waste and livestock and poultry manure, which was and

[0030] In step 1, during the rhamnolipid pretreatment process, when the temperature monitored by the temperature sensor A (3-1) is lower than 25°C, the intelligent control system (4) turns on the driving device A (1-1) for stirring, thereby increasing the fluidity of the rhamnolipid raw material for easy addition; the method for maintaining the anaerobic environment of the fermentation reactor is to introduce nitrogen into the fermentation reactor for 10 to 20 minutes.

[0031] In step 2, the dosage of rhamnolipid in the reaction stage is adjusted in real time according to the methane production, and the specific adjustment method is:

[0032] 1) From the beginning of the reaction, the monitoring system (3) monitors the gas production and methane concentration in the gas collection barrel (5) in real time every day. On the tth day, the hourly gas production is obtained by monitoring Among them, t is the number of days of reaction; at the same time, the concentration of methane in the gas is monitored every hour. Calculate the gas production G on day t t :

[0033]

[0034] The actual cumulative gas production on the tth day is obtained by statistics.

[0035]

[0036] 2) Simultaneously monitor the system (3) for the cumulative gas production from the start of the reaction to day t-1 The modified Gompertz equation was used to simulate the methane production.

[0037]

[0038] The maximum methanogenesis rate on day t-1 is obtained by fitting and maximum methane production potential And calculate the estimated cumulative gas production on day t based on the fitting results Calculate the ratio of actual cumulative gas production to expected cumulative gas production In addition, the cumulative gas production from the start of the reaction to the tth day The modified Gompertz equation was also used to simulate the maximum methanogenesis rate on day t. and maximum methane production potential

[0039] 3) The dosing system corrects the dosage of rhamnolipid on day t-1 to obtain the dosage on day t

[0040]

[0041] Where, X t , X t-1 are the dosages of rhamnolipid on day t and day t-1, respectively;

[0042] k1 is the gas production fitting correction coefficient, k2 is the methane rate correction coefficient, and k3 is the methane production potential correction coefficient; where the value of k1 satisfies:

[0043]

[0044] The reaction system (2) modifies the amount of rhamnolipid added from the feed port (2-1) according to the calculation results. Intelligent control system simulates methane production Y X Relationship between different rhamnolipid dosages and days:

[0045] Y X =∫0 T A X T 2 +B X T+C X

[0046] Wherein, X is the dosage of rhamnolipid.

[0047] Preferably, the fermentation days T should satisfy 32d≤T≤36d;

[0048] The intelligent control system simulates the relationship between hydrogen production Y2 and rhamnolipid dosage X:

[0049] Y2=∫0 T B2X+C2

[0050] The fermentation days T should satisfy 2d≤T≤14d; the coefficient is 1.5≤B2≤2.0.

[0051] The gas content is detected by using an Agilent 7820A gas chromatograph, and the intelligent control system selects the optimal yield and controls the optimal dosage of rhamnolipid through data simulation.

[0052] In particular, to maintain system safety, the detection control procedures are as follows:

[0053]

[0054] When P ≥ 0.85P m When P≥0.95Pm, the intelligent control system early warning module (4-3) remotely closes the pneumatic valve (1-3), the flow pump (1-4) and the blower (2-7) to ensure the safety of the reaction.

[0055] Among them, P m It is the maximum internal pressure that the gas collecting tank can withstand;

[0056] σ is the allowable stress of the material, which can be determined based on the yield strength and safety factor of the material;

[0057] ν is the Poisson’s ratio of the material;

[0058] r is the inner radius of the gas collecting tank or reaction system.

[0059] After each anaerobic digestion, the intelligent control system records the fitting parameter A of methane production and days. X , B X , C X , and compared with the previous record, the initial dosage X0 of the next rhamnolipid is corrected. The specific process is as follows:

[0060] After the nth reaction, the intelligent control system obtains the methane production dynamic parameters of this reaction based on the fitting results. and And compared with the results of the previous n-1 times, we get:

[0061]

[0062] in,

[0063] The intelligent control system calculates the initial dosage of rhamnolipid for the n+1th time

[0064]

[0065] Beneficial effects: The present invention promotes the methanogenesis process of the excess sludge by adding rhamnolipids to the excess sludge. The research results provide a new way to optimize the use of rhamnolipids in anaerobic digestion of excess sludge composed of sewage plants, kitchen waste and livestock and poultry manure. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments of the present invention are briefly introduced below.

[0067] Figure 1 This is the system logic diagram.

[0068] Figure 2 Physical diagram of the system.

[0069] Figure 3 It is a cross-sectional view of the dosing system (1).

[0070] Figure 4 is a cross-sectional view of the reaction system (2).

[0071] Among them, dosing system-1, reaction system-2, monitoring system-3, intelligent control system-4;

[0072] Driving device A-1-1, sampling port A-1-2, valve-1-3, flow pump-1-4, motor A-1-5, connecting shaft A-1-6, rotating shaft A-1-7, stirring paddle-1-8, height indicator-1-9, dosage indicator-1-10;

[0073] Feeding port-2-1, feeding filter port-2-3, vent hole-2-4, sampling hole B-2-5, heating device-2-6, blower-2-7, motor B-2-8, connecting shaft B-2-9, rotating shaft B-2-10, fixing frame-2-11, lifting pipe-2-12, spiral stirring blade-2-13, feeding hole-2-14, slope-2-15;

[0074] Temperature sensor A-3-1, air pressure sensor A-3-2, temperature sensor B-3-3, liquid level sensor-3-4, air pressure sensor B-3-5;

[0075] Input module-4-1, output module-4-2, warning module-4-3;

[0076] Gas collecting barrel-5, check valve-5-1, sampling hole C-5-2;

[0077] RL-rhamnolipid, WAS-waste sludge. DETAILED DESCRIPTION

[0078] The technical solution of the present invention will be described in detail below in conjunction with specific embodiments:

[0079] Reference Figure 1 , 2 As shown, a low-carbon intelligent system for adding rhamnolipid to improve the resource utilization of solid waste includes a adding system 1, a reaction system 2, a monitoring system 3, and an intelligent control system 4; wherein the adding system 1 and the reaction system 2 are connected; the monitoring system 3 is installed on the adding system 1 and the reaction system 2, monitors the status of the adding system and the reaction system in real time, and transmits the status to the intelligent control system 4 through electrical signals; the intelligent control system 4 reacts to the adding system 1 and the reaction system 2 through analysis and fitting, inputs commands to remotely control the motor power, valve opening, heating device, or responds to emergencies through the early warning module 4-3 to achieve emergency shutdown of the system.

[0080] Reference Figure 2 As shown in FIG. 3 , the dosing system includes: a driving device A1-1, a sampling port A1-2, a valve 1-3, and a flow pump 1-4; the internal structure of the dosing system 1 includes: a motor A1-5, a connecting shaft A1-6, a rotating shaft A1-7, and a stirring paddle 1-8; wherein the motor A1-5 is used as a power source, and its power is controlled by an intelligent control system, and the power is transmitted to the rotating shaft A1-7 through the connecting shaft A1-6, thereby driving the stirring paddle 1-8 to stir, thereby increasing the fluidity of the raw material rhamnolipid, facilitating transmission and reaction, and the treated rhamnolipid is put into the reaction system 2.

[0081] Reference Figure 2 , 4 As shown, the reaction system 2 includes an anaerobic fermentation device and a gas collecting device. In particular, the top of the anaerobic fermentation device is provided with a driving device B2-2, a feeding port 2-1, and a feed filter 2-3. The upper part of the side wall is provided with a vent 2-4, the lower part of the side wall is provided with a sampling hole B2-5, and the bottom is provided with a heating device 2-6; the feed filter 2-3 is used to pass the pretreated activated sludge, and through the real-time response and control of the monitoring system 3 and the intelligent control system 4, the feeding port 2-1 is controlled to adjust the dosage of the agent, the heating device 2-6 and the driving device B2-2 to produce gas under the optimal conditions. The gas produced by the anaerobic fermentation device is connected to the lower side of the gas collecting device through a blower 2-7. The gas collecting device includes: a gas collecting barrel 5, a barrel body is provided with a sampling hole C5-2, and a check valve 5-1 is provided on the connecting pipe with the anaerobic fermentation device.

[0082] The internal structure of the anaerobic fermentation device includes: motor B2-8, connecting shaft B2-9, rotating shaft B2-10, fixing frame 2-11, lifting pipe 2-12, spiral stirring blade 2-13, feeding hole 2-14, and slope 2-15. Among them, motor B2-8 is used as a power source, and its power is controlled by an intelligent control system, and the power is transmitted to the rotating shaft B2-10 through the connecting shaft B2-9, thereby driving the spiral stirring blade 2-13 to stir; the mixed raw materials are stirred by the spiral stirring blade 2-13, and are lifted in the lifting pipe 2-12, and flow out from the top of the lifting pipe. Due to the stirring action of the blades and the transportation of the slope 2-15, the sludge outside the lifting pipe enters the lifting pipe 2-12 again at the feeding hole 2-14 for stirring and lifting, thereby repeatedly generating an oscillating effect. This device makes the mixing more complete and uniform, and the gas production effect is better.

[0083] The monitoring system includes: temperature sensor A3-1, air pressure sensor A3-2, temperature sensor B3-3, liquid level sensor 3-4, air pressure sensor B3-5, wherein temperature sensor A3-1 is arranged on dosing system 1, temperature sensor B3-3 and liquid level sensor 3-4 are arranged on reaction system 2, and air pressure sensor B3-5 is arranged on gas collecting barrel 5. The parameters detected by the temperature sensor, liquid level sensor and air pressure sensor of the monitoring system are transmitted to input module 4-1 of intelligent control system through electrical signals, and are output to output module 4-2 and early warning module 4-3 through fitting and analysis to remotely control valves and devices, and further guide the progress of dosing and reaction to ensure safe and efficient operation of the reaction.

[0084] A method for improving the resource utilization of solid waste by adding rhamnolipid in a low-carbon and intelligent manner comprises the following steps:

[0085] Step 1: solid waste is taken, and after pretreatment, it is mixed according to the best ratio to obtain anaerobic fermentation raw materials; rhamnolipid is taken and put into the dosing device 1; nitrogen is introduced into the vent 2-4 of the reaction system 2, and the sampling port C5-2 of the gas collection barrel is opened for 3-5 minutes to ensure the anaerobic environment of the reaction;

[0086] Step 2, reaction stage: the pretreated anaerobic fermentation raw materials are added into the reaction system 2 from the feed filter port 2-3, rhamnolipid is added from the feed port 2-1, and pH regulator is added from the feed port 2-1. Anaerobic reaction occurs in the reaction system to generate methane gas, which is transported to the gas collection barrel; the pH concentration of the reactor is maintained at 6.5-7.2, the reaction temperature is 32-36°C, and stirring is performed every 4-6 hours at a speed of 150-200 rpm, and each stirring lasts 60-90 minutes.

[0087] Step 3, control stage: The monitoring system inputs the information of the temperature sensor and the liquid level sensor to the input module 4-1, and then inputs the signal to the output module 4-2 to start the dosing device and the reaction device as required, and the raw materials are mixed and stirred while producing gas.

[0088] Step 4: After the anaerobic digestion is completed, correct the initial dosage X0 of the next rhamnolipid.

[0089] Example 1

[0090] The waste sludge (WAS) used in this example was taken from a sewage treatment plant in a city in Nanjing, China, the kitchen waste was taken from a restaurant in a city in Nanjing, China, and the livestock and poultry feces were taken from a livestock and poultry farm in Nanjing, China. Rhamnolipid was purchased from Daqing Professional Preparation Company in China. The rhamnolipid content was 90%.

[0091] Before using the residual sludge, filter the sludge with a 2.0mm stainless steel mesh to remove the large particles, then naturally settle at 4°C for 24 hours, remove the supernatant for concentration, and use a pH regulator to adjust the pH value. The total suspended solids (TSS) of the residual sludge after pretreatment is 20.61≤30.00g / L, and the volatile suspended solids (VSS) is 10.17≤15.00g / L; the pH is 6.8, within the range of 6.5-7.2;

[0092] The kitchen waste was crushed into slurry using a filter press, and the pH value was adjusted using a pH adjuster. After pretreatment, the total suspended solids (TSS) concentration was 18.61 g / L, meeting the 15.00-20.00 g / L range, and the volatile suspended solids (VSS) concentration was 18.91 g / L, meeting the 10.00-15.00 g / L range; the pH was 6.2, meeting the 6.0-6.5 range;

[0093] The livestock and poultry manure uses a stainless steel screen to filter the sludge to remove the large particles, and the pH value is adjusted using a pH regulator. The volatile suspended solids (VSS) concentration of the pretreated kitchen waste is 29g / L, meeting the 25-35g / L requirement, and the pH is 7.6, meeting the 7.0-8.0 requirement.

[0094] Before the formal operation, the optimal addition ratio of the three solid wastes is first determined through pre-operation. The specific steps are as follows:

[0095] The addition ratio of excess sludge is m1, the addition ratio of food waste is m2, and the addition ratio of livestock and poultry manure is m3. The three satisfy m1+m2+m3=1. The central composite design (CCD) is used to determine the optimal ratio of m1, m2 and m3. The five levels of m1, m2 and m3 addition are set to 0, 0.2, 0.4, 0.6 and 0.8 respectively. The addition ratio matrix used in the pre-run is shown in the following table:

[0096]

[0097] Among them, batches 1-3 are vertex experiments, batches 4-6 are edge midpoint experiments, batch 7 is center point experiments, and batches 8-12 are other experimental points.

[0098] Each batch of experiments was run for 10 days, and the monitoring system 3 recorded the cumulative methane production from the start of the reaction to the 10th day. The modified Gompertz equation was used to simulate the maximum methane production potential P of each batch of experiments. m The maximum methane production potential P of each batch of experiments m As the response value, the response surface model was established using R software to determine the optimal addition ratio of excess sludge, kitchen waste and livestock and poultry manure. and

[0099] In the reaction stage, the information from the temperature sensor and the liquid level sensor is input to the input module 4-1, and then the signal is input to the output module 4-2 to start the dosing device and the reaction device as required, and the raw materials are mixed and stirred while producing gas. The pH value of the reactor is kept in the range of 6.5-7.2, the temperature of the reactor is 32-36°C, and the speed is 150-200rpm and stirred every 4-6 hours, and each stirring time is 60-90 minutes.

[0100] During the control phase, based on the sensor information and sampling analysis information, the control system performs data analysis and inputs the electrical signal to the input module 4-1, and then inputs the signal to the output module 4-2 remote control device to re-optimize the dosage.

[0101] The monitoring system 3 monitors the gas production and methane concentration in the gas collection barrel 5 in real time every day. On the tth day, the hourly gas production is obtained by monitoring Among them, t is the number of days of reaction; at the same time, the concentration of methane in the gas is monitored every hour. Calculate the gas production G on day t t :

[0102]

[0103] The actual cumulative gas production on the tth day is obtained by statistics.

[0104]

[0105] At the same time, the cumulative gas production of system 3 from the start of the reaction to day t-1 is monitored The modified Gompertz equation was used to simulate the methane production.

[0106]

[0107] The maximum methanogenesis rate on day t-1 is obtained by fitting and maximum methane production potential And calculate the estimated cumulative gas production on day t based on the fitting results Calculate the ratio of actual cumulative gas production to expected cumulative gas production In addition, the cumulative gas production from the start of the reaction to the tth day The modified Gompertz equation was also used to simulate the maximum methanogenesis rate on day t. and maximum methane production potential

[0108] The dosing system corrects the dosage of rhamnolipid on day t-1 to obtain the dosage on day t:

[0109]

[0110] Since a<0.8 is satisfied, k1=0.8 is taken.

[0111] Rhamnolipid is added to the reaction system 2 from the feed port 2-1 according to the calculation results.

[0112] Example 2

[0113] This embodiment is different from Embodiment 1 in that:

[0114] Before the formal operation, the optimal addition ratio of the three solid wastes is first determined through pre-operation. The specific steps are as follows:

[0115] The addition ratio of excess sludge is m1, the addition ratio of food waste is m2, and the addition ratio of livestock and poultry manure is m3. The three satisfy m1+m2+m3=1. The central composite design (CCD) is used to determine the optimal ratio of m1, m2 and m3. The five levels of m1, m2 and m3 addition are set to 0, 0.2, 0.4, 0.6 and 0.8 respectively. The addition ratio matrix used in the pre-run is shown in the following table:

[0116]

[0117] Among them, batches 1-3 are vertex experiments, batches 4-6 are edge midpoint experiments, batch 7 is center point experiments, and batches 8-12 are other experimental points.

[0118] Each batch of experiments was run for 10 days, and the monitoring system 3 recorded the cumulative methane production from the start of the reaction to the 10th day. The modified Gompertz equation was used to simulate the maximum methane production potential P of each batch of experiments. m The maximum methane production potential P of each batch of experiments m As the response value, the response surface model was established using R software to determine the optimal addition ratio of excess sludge, kitchen waste and livestock and poultry manure. and

[0119] The monitoring system 3 monitors the gas production and methane concentration in the gas collection barrel 5 in real time every day. On the tth day, the hourly gas production is obtained by monitoring Among them, t is the number of days of reaction; at the same time, the concentration of methane in the gas is monitored every hour. Calculate the gas production G on day t t :

[0120]

[0121] The actual cumulative gas production on the tth day is obtained by statistics.

[0122]

[0123] At the same time, the cumulative gas production of system 3 from the start of the reaction to day t-1 is monitored The modified Gompertz equation was used to simulate the methane production.

[0124]

[0125] The maximum methanogenesis rate on day t-1 is obtained by fitting and maximum methane production potential And calculate the estimated cumulative gas production on day t based on the fitting results Calculate the ratio of actual cumulative gas production to expected cumulative gas production In addition, the cumulative gas production from the start of the reaction to the tth day The modified Gompertz equation was also used to simulate the maximum methanogenesis rate on day t. and maximum methane production potential

[0126] The dosing system corrects the rhamnolipid dosing amount on the (t - 1)-th day to obtain the dosing amount on the t-th day:

[0127]

[0128] Since 0.8 < a < 1.2, k1 = 1 is taken.

[0129] The reaction system 2 inputs rhamnolipid from the feeding port 2-1 according to the calculation result.

[0130] Example 3

[0131] In this example, the difference from Example 1 is:

[0132] Before the formal operation, the optimal dosing ratios of the three solid wastes are first determined through pre-operation. The specific steps are as follows:

[0133] Denote the dosing ratio of excess sludge as m1, the dosing ratio of food waste as m2, and the dosing ratio of livestock manure as m3, and m1 + m2 + m3 = 1. The central composite design (CCD) is used to determine the optimal ratios of m1, m2, and m3. Five levels of the dosing amounts of m1, m2, and m3 are set as 0, 0.2, 0.4, 0.6, and 0.8 respectively. The dosing ratio matrix used in the pre-operation is shown in the following table:

[0134]

[0135] Among them, batches 1 - 3 are vertex experiments, batches 4 - 6 are edge midpoint experiments, batch 7 is the central point experiment, and batches 8 - 12 are other experimental points.

[0136] Each batch of experiments runs for 10 days, and the monitoring system 3 records the cumulative methane production per day from the start of the reaction to the 10th day. The modified Gompertz equation is used for simulation to obtain the maximum methane production potential P of each batch of experiments. m . Taking the maximum methane production potential P of each batch of experiments m as the response value, the response surface model is established using R software to determine the optimal dosing ratios of excess sludge, food waste, and livestock manure as and

[0137] The monitoring system 3 monitors the gas production volume and methane concentration in the gas collection barrel 5 in real time every day. On the t-th day, the gas production volume per hour is monitored. where t is the number of days of the reaction; meanwhile, the methane concentration in the gas per hour is monitored. The gas production volume G on the t-th day is calculated.t :

[0138]

[0139] The actual cumulative gas production on the tth day is obtained by statistics.

[0140]

[0141] At the same time, the cumulative gas production of system 3 from the start of the reaction to day t-1 is monitored The modified Gompertz equation was used to simulate the methane production.

[0142]

[0143] The maximum methanogenesis rate on day t-1 is obtained by fitting and maximum methane production potential And calculate the estimated cumulative gas production on day t based on the fitting results Calculate the ratio of actual cumulative gas production to expected cumulative gas production In addition, the cumulative gas production from the start of the reaction to the tth day The modified Gompertz equation was also used to simulate the maximum methanogenesis rate on day t. and maximum methane production potential

[0144] The dosing system corrects the rhamnolipid dosage on day t-1 to obtain the dosage on day t

[0145]

[0146] Since a>1.2 is satisfied, k1=1.2.

[0147] Rhamnolipid is added to the reaction system 2 from the feed port 2-1 according to the calculation results.

[0148] 4) After the three anaerobic digestions, the intelligent control system records the fitting parameter A of methane production and days. X , B X , C X , and compared with the previous record, the initial dosage X0 of the next rhamnolipid is corrected. The specific process is as follows:

[0149] After the third reaction, the intelligent control system obtains the methanogenic dynamic parameters of this reaction based on the fitting results. and And compared with the previous 2 results, we get:

[0150]

[0151] Since max(a,b,c)<1.25 and min(a,b,c)>0.75, the initial dosage of rhamnolipid for the next time is

[0152] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A low-carbon intelligent system for adding rhamnolipid to improve the resource utilization of solid waste, characterized in that: The invention comprises a dosing system (1), a reaction system (2), a monitoring system (3), and an intelligent control system (4); wherein the intelligent control system (4) is connected to the dosing system (1), the reaction system (2), and the monitoring system (3) at the same time; the monitoring system (3) is connected to the dosing system (1) and the reaction system (2); the monitoring system (3) monitors the states of the dosing system and the reaction system in real time, and transmits the states to the intelligent control system (4) via electrical signals; the intelligent control system (4) reacts to the dosing system (1) and the reaction system (2) through analysis and fitting, and inputs commands to remotely control the motor power and valve opening thereof; The dosing system is provided with an external drive device A (1-1); a motor A (1-5), a connecting shaft A (1-6), a rotating shaft A (1-7), and a stirring paddle (1-8) are provided therein; the motor A (1-5) is connected to the drive device A (1-1); the motor A (1-5) serves as a power source, and its power is controlled by an intelligent controller of the drive device A (1-1); the motor A (1-5) transmits power to the rotating shaft A (1-7) through the connecting shaft A (1-6), thereby driving the stirring paddle (1-8) to perform stirring, and the dosing system is used for pretreatment of rhamnose; a sampling port A (1-2) and a discharge port connected to a reaction system (2) are provided on the side wall of the dosing system; a valve (1-3) and a flow pump (1-4) are provided on the connecting channel; an observation port (1-5) is provided on the side wall of the device; and a dosing height indicator (1-9) and a dosing amount indicator (1-10) are provided on the side; The reaction system (2) comprises an anaerobic fermentation device and a gas collecting device. The top of the anaerobic fermentation device is provided with a driving device B (2-2), a feeding port (2-1), and a feed filter port (2-3); the upper part of the side wall is provided with a vent hole (2-4), the lower part of the side wall is provided with a sampling hole B (2-5), and the bottom is provided with a heating device (2-6); the feed filter port (2-3) is used to pass pre-treated activated sludge, and the feeding port (2-1) is used to add a reagent; the gas produced by the anaerobic fermentation device is connected to the lower side of the gas collecting device through a blower (2-7); the gas collecting device comprises: a gas collecting barrel (5), the barrel body is provided with a sampling hole C (5-2), and a check valve (5-1) is provided on the connecting pipe with the anaerobic fermentation device; The internal structure of the anaerobic fermentation device includes: a motor B (2-8), a connecting shaft B (2-9), a rotating shaft B (2-10), a fixing frame (2-11), a lifting pipe (2-12), a spiral stirring blade (2-13), a feeding hole (2-14), and a slope (2-15); wherein the motor B (2-8) is used as a power source, and the power thereof is controlled by an intelligent controller connected to the driving device B (2-2); the motor B is connected to the rotating shaft B (2-10) via the connecting shaft B (2-9), A spiral stirring blade (2-13) is provided on the rotating shaft B; the spiral stirring blade is arranged in the lifting pipe (2-12); the mixed raw material is stirred by the spiral stirring blade (2-13), lifted in the lifting pipe (2-12), and flows out from the top of the lifting pipe; the sludge outside the lifting pipe enters the lifting pipe (2-12) again from the feeding hole (2-14) at the bottom of the lifting pipe due to the stirring action of the blade and the conveying of the bottom slope (2-15) to be stirred and lifted, thereby repeatedly generating an oscillating effect; The monitoring system comprises: a temperature sensor, an air pressure sensor, and a liquid level sensor; wherein a temperature sensor is arranged on the dosing system (1), a temperature sensor and a liquid level sensor are arranged on the reaction system (2), and an air pressure sensor is arranged on the gas collecting barrel (5); the parameters detected by the monitoring system are transmitted to the input module (4-1) of the intelligent control system via electrical signals, and after fitting and analysis, are output to the output module (4-2) and the early warning module (4-3), remotely controlling valves and devices, and further guiding the dosing and reaction progress, thereby ensuring the safe and efficient operation of the reaction.

2. A method for improving solid waste resource utilization by adding rhamnolipid based on the system for improving solid waste resource utilization by adding rhamnolipid based on low-carbon intelligently according to claim 1, characterized in that: Here are the steps: Step 1: solid waste is taken, pre-treated, and mixed according to an optimal ratio to obtain anaerobic fermentation raw materials; rhamnolipid is taken and added to a dosing device (1), a temperature sensor A (3-1) monitors that the temperature is lower than 25° C., and an intelligent control system (4) turns on a driving device A (1-1) on the dosing device (1) to stir, thereby increasing the fluidity of the rhamnolipid raw material for easy addition; nitrogen is introduced into the vent (2-4) of the reaction system (2), and a sampling port C (5-2) of the gas collection barrel is opened for 3-5 minutes to ensure an anaerobic environment of the reaction system (2); Step 2, reaction stage: the pretreated anaerobic fermentation raw materials are added into the reaction system (2) from the feed filter port (2-3), the pretreated rhamnolipid is added from the feed port (2-1), and the pH regulator is added from the feed port (2-1), an anaerobic reaction occurs in the reaction system, methane gas is generated, and the gas is transported to the gas collection tank; the pH range of the reaction system is maintained at 6.5-7.2, the reaction temperature is 32-36°C, and the reaction system is stirred at a speed of 150-200 rpm every 4-6 hours, and each stirring time is 60-90 minutes; Step 3, control stage: the monitoring system inputs the parameter information detected by the temperature sensor and the liquid level sensor into the input module (4-1), and then inputs the signal into the output module (4-2) to start the dosing device and the reaction device as required, and the raw materials are mixed and stirred while producing gas; Step 4: After the anaerobic digestion is completed, correct the initial dosage of rhamnolipid for the next time X0.

3. The method of low-carbon intelligent addition of rhamnolipid to improve solid waste resource utilization according to claim 2, characterized in that: The real-time height h of rhamnolipid is obtained by means of the height indicator (1-9) on the side wall of the dosing system. t The flow rate Q1 delivered by the flow pump is calculated by the following formula and displayed on the dosage indicator (1-10); Among them, Q1 is the flow rate delivered by the flow pump, the unit is m 3 / h; S1 is the bottom area of ​​the dosing system (1), in m 2 ; t1 is the opening time of the pneumatic valve (1-3), in seconds.

4. The method of claim 2 for improving solid waste resource utilization by adding rhamnolipid in a low-carbon and intelligent manner, characterized in that: The solid waste is a mixture of residual sludge from urban sewage treatment plants, kitchen waste and livestock and poultry manure from livestock and poultry farms. The pretreatment methods and requirements are as follows: Residual sludge: Before use, filter the sludge with a stainless steel mesh to remove large particles, then naturally settle at 4°C, remove the supernatant for concentration, and use a pH regulator to adjust the pH value; the residual sludge after pretreatment should meet the following requirements: total suspended solids (TSS) ≤ 30.00g / L, volatile suspended solids (VSS) ≤ 15.00g / L; pH value range 6.5-7.2; Food waste: crush it into slurry using a filter press, and adjust the pH value using a pH adjuster; the pretreated food waste should meet the following requirements: total suspended solids (TSS) concentration of 15.00-20.00 g / L, volatile suspended solids (VSS) concentration of 10.00-15.00 g / L; pH value range of 6.0-6.5; Livestock and poultry manure: Use a stainless steel sieve to filter the sludge to remove large particles, and use a pH adjuster to adjust the pH value; the pretreated livestock and poultry manure should meet the following requirements: the volatile suspended solids (VSS) concentration is 25-35g / L, and the pH value range is 7.0-8.

0.

5. The method of claim 2 for improving solid waste resource utilization by adding rhamnolipid in a low-carbon and intelligent manner, characterized in that: In step 1, the optimal ratio of the solid waste (the optimal percentage of residual sludge, kitchen waste and livestock and poultry manure for co-digestion) is determined by the following method, which specifically comprises the following steps: The addition ratio of excess sludge is m1, the addition ratio of food waste is m2, and the addition ratio of livestock and poultry manure is m3. The three satisfy m1+m2+m3=1. The central composite design (CCD) is used to determine the optimal ratio of m1, m2 and m3. The five levels of m1, m2 and m3 addition are set to 0, 0.2, 0.4, 0.6 and 0.8 respectively. The addition ratio matrix used in the pre-run is shown in the following table: Among them, batches 1-3 are vertex experiments, batches 4-6 are edge midpoint experiments, batch 7 is center point experiments, and batches 8-12 are other experimental points; Each batch of experiments was run for 10 days, and the monitoring system (3) recorded the cumulative methane production from the start of the reaction to the 10th day. The modified Gompertz equation was used to simulate and obtain the maximum methane production potential P of each batch of experiments. m ; The maximum methane production potential P of each batch of experiments m The response value was used to establish a response surface model using R software to determine the optimal addition ratio of excess sludge, kitchen waste and livestock and poultry manure, which was and 6. The method of claim 2 for improving solid waste resource utilization by adding rhamnolipid in a low-carbon and intelligent manner, characterized in that: In step 2, the dosage of rhamnolipid in the reaction stage is adjusted in real time according to the methane production, and the specific adjustment method is: 1) From the beginning of the reaction, the monitoring system (3) monitors the gas production and methane concentration in the gas collection barrel (5) in real time every day. On the tth day, the hourly gas production is obtained by monitoring Among them, t is the number of days of reaction; at the same time, the concentration of methane in the gas is monitored every hour. Calculate the gas production G on day t t : The actual cumulative gas production on the tth day is obtained by statistics. 2) Simultaneously monitor the system (3) for the cumulative gas production from the start of the reaction to day t-1 The modified Gompertz equation was used to simulate the methane production: The maximum methanogenesis rate on day t-1 is obtained by fitting and maximum methane production potential And calculate the estimated cumulative gas production on day t based on the fitting results Calculate the ratio of actual cumulative gas production to expected cumulative gas production In addition, the cumulative gas production from the start of the reaction to the tth day The modified Gompertz equation was also used to simulate the maximum methanogenesis rate on day t. and maximum methane production potential 3) The dosing system corrects the dosage of rhamnolipid on day t-1 to obtain the dosage on day t: Where, X t , X t-1 are the dosages of rhamnolipid on day t and day t-1, respectively; k1 is the gas production fitting correction coefficient, k2 is the methane rate correction coefficient, and k3 is the methane production potential correction coefficient; where the value of k1 satisfies: The reaction system (2) corrects the amount of rhamnolipid added from the feed port (2-1) according to the calculation results.

7. The method of claim 6 for improving solid waste resource utilization by adding rhamnolipid in a low-carbon and intelligent manner, characterized in that: In step 3, the intelligent control system simulates the methane production Y X Relationship between different rhamnolipid dosages and days: Y X =∫0 T A X T 2 +B X T+C X Wherein, X is the dosage of rhamnolipid; The fermentation days T should meet 32d≤T≤36d; The intelligent control system simulates the relationship between hydrogen production Y2 and rhamnolipid dosage X: Y2=∫0 T B2X+C2 The fermentation days T should satisfy 2d≤T≤14d; the coefficient 1.5≤B2≤2.0; The gas content is detected by using an Agilent 7820A gas chromatograph, and the intelligent control system selects the optimal yield and controls the optimal dosage of rhamnolipid through data simulation; To maintain system safety, the detection control procedures are as follows: When P ≥ 0.85P m When P≥0.95Pm, the intelligent control system early warning module (4-3) remotely closes the pneumatic valve (1-3), the flow pump (1-4) and the blower (2-7) to ensure the safety of the reaction; Among them, P m It is the maximum internal pressure that the gas collecting tank can withstand; σ is the allowable stress of the material, which can be determined based on the yield strength and safety factor of the material; ν is the Poisson’s ratio of the material; r is the inner radius of the gas collecting tank or reaction system.

8. The method of claim 2 for improving solid waste resource utilization by adding rhamnolipid in a low-carbon and intelligent manner, characterized in that: The modification of step 4 is: after each anaerobic digestion, the intelligent control system records the fitting parameter A of methane production and days. X , B X , C X , and compared with the previous record, the initial dosage X0 of the next rhamnolipid is corrected. The specific process is as follows: After the nth reaction, the intelligent control system obtains the methane production dynamic parameters of this reaction based on the fitting results. and And compared with the results of the previous n-1 times, we get: in, The intelligent control system calculates the initial dosage of rhamnolipid for the n+1th time according to the above formula. Complete the correction of the initial dosage of rhamnolipid.

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