Method for processing anesthetic residual liquid in whole process based on adsorption-high temperature incineration

Abstract

This invention discloses a comprehensive treatment method for residual anesthetic drugs based on adsorption-high-temperature incineration, belonging to the technical field of harmless treatment of residual anesthetic drugs. The method includes: passing the residual anesthetic drug into an adsorption unit filled with porous silica adsorbent material modified with a silane coupling agent, so that the active ingredients of fentanyl and propofol are adsorbed and solidified; after adsorption saturation, nitrogen gas is introduced for purging treatment, and the exhaust gas is introduced into an exhaust gas purification system; the adsorbent material loaded with anesthetic drug is transferred to a high-temperature incineration unit, first heated to a first temperature range at a first heating rate for pre-carbonization treatment, and then heated to a second temperature range at a second heating rate for incineration treatment; the exhaust gas generated by incineration is introduced into an exhaust gas purification system including a cyclone separator, an acid gas absorption tower, and an activated carbon adsorption bed for multi-stage purification. This method achieves safe disposal of residual anesthetic drugs throughout the entire process through the synergy of adsorption solidification and staged incineration.

Description

Technical Field

[0001] This invention relates to the field of harmless treatment technology for residual anesthetic drugs, specifically a whole-process treatment method for residual anesthetic drugs based on adsorption-high temperature incineration. Background Technology

[0002] Residual anesthetic solutions are liquid waste generated during clinical surgery and anesthesia. Common fentanyl and propofol drugs have regulated status and biotoxicity; direct discharge will cause water pollution and public safety risks. Current practice typically involves collecting these residual liquid solutions as medical waste and entrusting them to specialized agencies for incineration. However, liquid anesthetic solutions have a high water content, and directly injecting them into the incinerator will cause drastic temperature fluctuations in the combustion zone, incomplete combustion of organic matter, and the generation of secondary pollutants such as polycyclic aromatic hydrocarbons and dioxins. Furthermore, a large amount of auxiliary fuel is required to maintain combustion, resulting in high operating costs.

[0003] Another technical approach involves using porous adsorbent materials for pretreatment of liquid drugs, transferring the drug components from the liquid phase to the solid phase before incineration. Commonly used adsorbent materials, such as activated carbon and zeolite, primarily rely on physical adsorption for fentanyl and propofol drugs. This results in low adsorption capacity and poor selectivity. Furthermore, the coexisting water and solvent molecules in the drug solution compete for adsorption sites, leading to weak immobilization of the active ingredient and easy desorption and escape during subsequent transport and storage. The limited contact between the adsorbent material and the drug solution often results in channeling and short-circuiting, leading to low adsorption utilization and premature breakthrough, thus affecting the overall processing efficiency of the adsorption unit.

[0004] Directly feeding adsorbent materials loaded with organic drugs into a high-temperature incinerator can introduce new problems. During rapid heating, drug molecules on the surface and within the pores of the adsorbent material undergo violent pyrolysis, releasing large amounts of volatile organic compounds and tar-like substances in a short period. These intermediate products not only easily condense and accumulate in the flue, clogging the equipment, but also increase the load on the end-of-pipe exhaust gas purification system. The instantaneous peak concentrations of acidic gases and fine particulate matter often exceed the design operating conditions of the purification equipment, leading to the risk of exceeding emission standards. How to efficiently and firmly adsorb and solidify the target drugs in residual anesthetic solutions, and decompose them in an orderly and controlled manner during the incineration stage, avoiding secondary diffusion and exhaust gas impact in the intermediate stages, remains a key challenge that current technologies have not yet solved. Summary of the Invention

[0005] This invention provides a complete process treatment method for residual anesthetic drugs based on adsorption-high temperature incineration. The method utilizes porous silica adsorbent material modified with silane coupling agent to achieve efficient adsorption and solidification of fentanyl and propofol active ingredients. Combined with staged temperature-controlled incineration under nitrogen protection and multi-stage exhaust gas purification, the residual anesthetic drugs are completely destroyed in a closed process, avoiding drug desorption and leakage and secondary pollution generated during the incineration process.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a whole-process treatment method for residual anesthetic liquid based on adsorption-high-temperature incineration, comprising: passing residual anesthetic liquid into an adsorption unit, the adsorption unit being filled with porous silica adsorption material modified with a silane coupling agent; the residual anesthetic liquid flowing along the axial direction of the adsorption unit through the porous silica adsorption material at a preset flow rate, so that the fentanyl and propofol active ingredients in the residual anesthetic liquid are adsorbed and solidified; when the adsorption saturation of the porous silica adsorption material in the adsorption unit reaches a preset threshold, the passage of residual anesthetic liquid is stopped, and the remaining liquid is then transferred to… Nitrogen gas is purged through the adsorption unit, and the purged exhaust gas is then introduced into the exhaust gas purification system. Porous silica adsorbent material loaded with anesthetic liquid is transferred to a high-temperature incineration unit. In the high-temperature incineration unit, it is first heated to a first temperature range at a first heating rate for pre-carbonization, and then heated to a second temperature range at a second heating rate for incineration. The second temperature range is higher than the first temperature range. The incineration exhaust gas generated by the high-temperature incineration unit is then introduced into the exhaust gas purification system for multi-stage purification. The exhaust gas purification system includes a cyclone separator, an acid gas absorption tower, and an activated carbon adsorption bed connected in sequence. This method, by combining adsorption solidification with staged incineration, achieves safe, efficient, and harmless treatment of residual anesthetic liquid, avoiding the potential risks to the environment and human health from direct emissions. Furthermore, the entire process is closed and controllable, and the exhaust gas is deeply purified.

[0007] As a preferred embodiment of the present invention, when the residual anesthetic solution is introduced into the adsorption unit, the initial concentration and initial volume data of the residual anesthetic solution are first collected. Based on the initial concentration data and the adsorption capacity per unit mass of the porous silica adsorbent material, the minimum filling amount required for the adsorption unit is determined. The minimum filling amount is then added to the redundant filling amount corresponding to a redundancy coefficient determined based on the content of unknown impurities in the residual anesthetic solution to obtain the actual filling amount of the adsorption unit. The porous silica adsorbent material of the actual filling amount is then filled into the adsorption unit in a layered stacking manner, with a metal mesh partition between adjacent layers. In this way, the amount of adsorbent material can be precisely configured according to the actual characteristics of the solution, ensuring that the effective components are fully adsorbed while avoiding material waste. The metal mesh partition helps to evenly distribute the liquid flow and prevent local blockage of the adsorbent material.

[0008] Preferably, the process of the residual anesthetic solution flowing along the axial direction of the adsorption unit through the porous silica adsorbent material at a preset flow rate is as follows: Based on the viscosity data of the residual anesthetic solution and the average pore size data of the porous silica adsorbent material, the theoretical residence time of the residual anesthetic solution in the adsorption unit is determined. This theoretical residence time is positively correlated with the viscosity data and negatively correlated with the average pore size data. Based on the theoretical residence time and the effective length of the adsorption unit, a preset flow rate is determined. The inlet pump is controlled to pump the residual anesthetic solution from the bottom inlet of the adsorption unit at the preset flow rate, so that the residual anesthetic solution flows from bottom to top through the layered and stacked porous silica adsorbent material. Through bottom inlet and precise control of the flow rate, it is possible to ensure sufficient contact between the solution and the adsorbent material, improve the adsorption efficiency, and prevent short-circuiting or flow deviation.

[0009] To determine adsorption saturation, this invention installs an online concentration detector at the outlet of the adsorption unit to monitor the breakthrough concentration of the active ingredient in the outflowing liquid phase in real time. The breakthrough concentration is compared with the allowable breakthrough concentration corresponding to a preset threshold, which is the product of the preset threshold and the initial concentration of residual anesthetic solution. When the breakthrough concentration is greater than or equal to the allowable breakthrough concentration, the adsorption saturation of the porous silica adsorbent material in the adsorption unit is determined to have reached the preset threshold. This method achieves accurate online determination of the adsorption endpoint, avoiding premature or late switching and ensuring processing continuity and safety.

[0010] When transferring porous silica adsorbent material loaded with anesthetic liquid, the preferred method is as follows: Activate the vibration unloading device at the bottom of the adsorption unit, causing the porous silica adsorbent material to fall into the collection container along the discharge pipe under vibration. The vibration frequency and amplitude of the vibration unloading device are adjusted according to the particle size distribution data of the porous silica adsorbent material. The porous silica adsorbent material in the collection container is then transported to the inlet of the high-temperature incineration unit via a closed conveying device, which includes a combination of a screw conveyor and a pneumatic conveying pipe. A rotary feed valve is installed at the inlet, and the feeding rate of the porous silica adsorbent material is adjusted by controlling the rotation speed of the rotary feed valve. This unloading and conveying system operates in a closed environment, effectively preventing the leakage of anesthetic drug volatiles, and can adjust the unloading and feeding parameters according to particle characteristics, achieving stable and controllable material transfer.

[0011] For the pre-carbonization treatment, this invention obtains the initial combustion temperature of the porous silica adsorbent material and the carbonization decomposition temperature range of carbon-containing substances in the anesthetic solution, and uses the lower limit of the carbonization decomposition temperature range as the target temperature of the first temperature range; the heating element in the high-temperature combustion unit is controlled to heat from room temperature to the target temperature at a first heating rate of a specified temperature per minute (degrees Celsius), and the pre-carbonization time is maintained at the target temperature for a duration determined according to the content of carbon-containing substances; during the pre-carbonization treatment, oxygen-deficient air with an oxygen volume fraction of 5% is introduced into the high-temperature combustion unit, and the flow rate of the oxygen-deficient air is adjusted according to the escape rate of volatile gases generated during the pre-carbonization treatment. The pre-carbonization stage, through slow heating and an oxygen-deficient atmosphere, allows the organic matter to gradually carbonize without violent combustion, effectively preventing local overheating and fly ash generation, and reducing the instantaneous release of harmful gases.

[0012] After pre-carbonization, the concentration of carbon monoxide gas in the high-temperature incineration unit is monitored. When the carbon monoxide concentration is lower than a preset safe concentration, incineration is initiated. The second heating rate is set to be greater than the first heating rate, and heating is performed at the second heating rate to a second temperature range. The lower limit of the second temperature range is higher than the target temperature of the pre-carbonization treatment. During incineration, the combustion-supporting gas introduced into the high-temperature incineration unit is switched to pure oxygen, and the flow rate of pure oxygen is proportionally adjusted according to the real-time measurement of the oxygen concentration in the high-temperature incineration unit. This segmented heating and atmosphere control strategy ensures the complete incineration of carbonized residues, improves incineration efficiency, and, combined with pure oxygen combustion support, significantly reduces flue gas volume and lowers the exhaust gas treatment load.

[0013] In the multi-stage purification treatment of exhaust gas, the incineration exhaust gas is first passed into a cyclone separator. The cyclone separator uses centrifugal force to separate particulate matter in the incineration exhaust gas with a particle size greater than or equal to a preset particle size threshold. The preset particle size threshold is determined based on the allowable feed particle concentration of the subsequent acid gas absorption tower. The exhaust gas treated by the cyclone separator is then passed into the acid gas absorption tower, which is filled with a sodium hydroxide solution as an alkaline absorbent. The incineration exhaust gas enters from the bottom of the acid gas absorption tower and passes upward through the alkaline absorbent in the form of bubbles. This combination can efficiently remove particulate matter and acid gases, protect the subsequent activated carbon adsorption bed, and extend its service life.

[0014] Preferably, during the operation of the acidic gas absorption tower, the pH value of the alkaline absorbent is monitored, and the pH value is obtained in real time using an online pH meter. When the pH value falls below a preset lower pH limit, a replenishment pump is activated to add fresh sodium hydroxide solution to the acidic gas absorption tower. The flow rate of the replenishment pump is proportionally adjusted according to the rate of pH decrease. Simultaneously, the drain valve at the bottom of the acidic gas absorption tower is opened to discharge some of the waste liquid that has absorbed the acidic gas, maintaining a constant liquid level within the absorption tower. This achieves automatic replenishment and level balance of the absorbent, ensuring a stable and reliable removal effect for the acidic gas.

[0015] As another preferred technical solution, the rotational speed of the rotary feeder valve is controlled by feedforward based on the temperature change rate within the high-temperature combustion unit to maintain temperature fluctuations in the second temperature range within ±10 degrees Celsius. By adjusting the feedforward rate, furnace temperature changes caused by fluctuations in the material's calorific value can be effectively buffered, improving the stability and safety of the combustion process.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: A porous silica adsorbent modified with a silane coupling agent is used as the adsorption medium. Utilizing the condensation of one end of the silane coupling agent molecule with the active hydroxyl groups on the silica surface, and the specific interactions such as hydrophobic interactions, hydrogen bonds, or π-π stacking between the introduced organic functional groups at the other end and fentanyl and propofol molecules, the adsorption selectivity for target drug molecules is significantly improved while maintaining a high specific surface area. This modified adsorbent material contacts residual anesthetic liquid along the axial direction at a preset flow rate, flowing upwards through a layered stacked adsorption bed. The metal mesh partitions between adjacent layers redistribute the liquid flow, eliminating the channeling effect and ensuring that the active ingredient is fully retained and solidified throughout the entire adsorbent bed. The modified layer on the surface of the adsorbent material anchors drug molecules within the pores, significantly reducing the probability of desorption and escape during nitrogen purging and closed-loop transfer, achieving a safe phase transition of the drug liquid from liquid to solid, and providing a uniform and stable solid feed for controlled incineration.

[0017] The combination of staged temperature-controlled incineration and a closed-loop logistics system prevents concentrated pyrolysis shocks from occurring in the high-temperature treatment of the adsorbent material loaded with anesthetic solutions. The pre-carbonization stage heats the material to the carbonization decomposition temperature range at a low rate while operating in an oxygen-deficient atmosphere. This allows the organic drug molecules on the adsorbent material to undergo an orderly carbonization and condensation process, gradually transforming the hydrocarbon structure into fixed carbon and a small amount of low-molecular-weight gases, thus inhibiting tar formation. After pre-carbonization, the temperature is switched to a higher incineration range, and pure oxygen is introduced to thoroughly mineralize residual carbon and difficult-to-decompose components, ensuring a high incineration removal rate. Nitrogen purging and a closed-loop conveying system connect the adsorption unit, unloading unit, and incineration unit into a gas-isolated transfer channel, preventing the material from being exposed to ambient air between equipment and blocking the external diffusion pathways of volatile drugs. The incineration exhaust gas undergoes multi-stage purification through a cyclone separator, an acid gas absorption tower, and an activated carbon adsorption bed. The treatment load is evenly distributed at each stage, and even during the phased temperature increase and conversion, there will be no situation where the pollutant concentration peaks exceed the removal capacity of the device, thus effectively curbing secondary pollution throughout the entire process. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a flowchart of a complete treatment method for residual anesthetic liquid based on adsorption-high temperature incineration; Figure 2 This is a flowchart of the adsorption and treatment process for residual anesthetic drugs; Figure 3 This is a flowchart of the control process for the pre-carbonization and incineration of residual anesthetic solutions; Figure 4 This is the outlet concentration breakthrough curve of the residual anesthetic drug adsorption unit; Figure 5 These are thermogravimetric and carbonization decomposition temperature range analysis curves of anesthetic solutions loaded on porous silica adsorbent materials. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] See Figure 1This invention provides a comprehensive treatment method for residual anesthetic drugs based on adsorption-high-temperature incineration. The method involves introducing the residual anesthetic drug into an adsorption unit, allowing it to flow along the axial direction of the unit at a preset flow rate through a porous silica adsorbent material modified with a silane coupling agent. The fentanyl and propofol active ingredients in the residual anesthetic drug are adsorbed and solidified onto the porous silica adsorbent material. During adsorption, the adsorption saturation of the porous silica adsorbent material is monitored in real-time or intermittently. When the adsorption saturation reaches a preset threshold, the introduction of residual anesthetic drug into the adsorption unit is stopped, and nitrogen gas is introduced to purge the unit. The nitrogen gas carries away residual volatile components and free liquids from the adsorption unit, and the exhaust gas generated during purging is introduced into an exhaust gas purification system. Subsequently, the porous silica adsorbent material loaded with the anesthetic drug is transferred from the adsorption unit to a high-temperature incineration unit. Within the high-temperature incineration unit, the material is first heated to a first temperature range at a first heating rate for pre-carbonization. After pre-carbonization, it is then heated to a second temperature range at a second heating rate for incineration, where the second temperature range is higher than the first temperature range. The high-temperature incineration exhaust gas generated during the incineration process is introduced into an exhaust gas purification system, which includes a cyclone separator, an acid gas absorption tower, and an activated carbon adsorption bed connected in sequence. The incineration exhaust gas flows through these devices sequentially for multi-stage purification before being discharged.

[0022] Example 1: In specific implementation, please refer to Figure 2 Initial concentration and volume data of residual anesthetic solution were collected. The initial concentration data of the residual anesthetic solution was measured using a UV-Vis spectrophotometer. The measurement wavelengths were selected from the characteristic absorption wavelengths of fentanyl-type active ingredients and propofol-type active ingredients. The concentrations of fentanyl-type and propofol-type active ingredients were calculated separately using a dual-wavelength method, and the sum of these two concentrations was used as the initial concentration data of the residual anesthetic solution. The initial volume data of the residual anesthetic solution was obtained through a weighing module installed in the residual anesthetic solution storage tank. The mass read by the weighing module was converted into volume using the density of the residual anesthetic solution to obtain the initial volume data.

[0023] The adsorption capacity per unit mass of porous silica adsorbent material is obtained by the following method: a standard of porous silica adsorbent material modified with silane coupling agent is taken, a mixed solution of fentanyl and propofol of known concentration is prepared, a static adsorption experiment is carried out at a constant temperature, and after adsorption equilibrium is reached, the concentration of the remaining effective components in the solution is measured, and the total mass of effective components adsorbed per unit mass of adsorbent material is calculated as the adsorption capacity per unit mass of porous silica adsorbent material.

[0024] Based on the initial concentration data of the residual anesthetic solution and the adsorption capacity per unit mass of the porous silica adsorbent material, the minimum packing quantity required for the adsorption unit is calculated. The calculation method is as follows: multiply the initial concentration data of the residual anesthetic solution by the initial volume data to obtain the total mass of the effective component to be treated, and then divide the total mass of the effective component to be treated by the adsorption capacity per unit mass of the porous silica adsorbent material. The quotient obtained is the minimum packing quantity.

[0025] The redundancy coefficient is determined as follows: A full-scan analysis of the residual anesthetic solution is performed using gas chromatography-mass spectrometry (GC-MS) to identify and quantify the total concentration of unknown impurities. A mapping table between the total concentration of unknown impurities and the redundancy coefficient is pre-stored in the control system database. This mapping table is derived from historical batch adsorption experimental data. When the total concentration of unknown impurities is 0 to 100 mg / L, the redundancy coefficient is 0.15; when the total concentration is 100 to 500 mg / L, the redundancy coefficient is 0.25; and when the total concentration exceeds 500 mg / L, the redundancy coefficient is 0.40. Based on the measured total concentration of unknown impurities in the current residual anesthetic solution to be processed, the specific value of the corresponding redundancy coefficient is obtained by querying the mapping table.

[0026] The actual fill weight of the adsorption unit is obtained by adding the calculated minimum fill weight to the redundant fill weight corresponding to the redundancy factor. The redundant fill weight is the product of the minimum fill weight and the redundancy factor. The actual fill weight is equal to the sum of the minimum fill weight and the redundant fill weight.

[0027] The porous silica adsorbent material, in its actual quantity, is filled into the adsorption unit using a layered stacking method. The adsorption unit is a vertical cylindrical container with an outlet distribution plate and a support grid at the bottom. During filling, a layer of 316L stainless steel wire mesh is first placed on the support grid, with the mesh size smaller than the smallest 10% volume fraction of particles in the porous silica adsorbent material's particle size distribution. A layer of porous silica adsorbent material is then evenly spread on top of the wire mesh layer, with a thickness 0.5 times the inner diameter of the adsorption unit. Another layer of wire mesh is then placed on top of this layer, and so on. This layering and stacking process is repeated until the total mass of the filled porous silica adsorbent material reaches the actual filling quantity. A layer of metal wire mesh is placed on top of the porous silica adsorbent material, and then a clamping device is installed to prevent the porous silica adsorbent material from fluidizing or shifting under fluid impact.

[0028] During the adsorption phase, viscosity data of the residual anesthetic solution and average pore size data of the porous silica adsorbent were obtained. The viscosity of the residual anesthetic solution was measured using a rotational viscometer under isothermal conditions, with the measurement temperature consistent with the adsorption operation temperature. The measurement rotation speed was selected to ensure the torque reading was between 30% and 70% of full scale. The average pore size data of the porous silica adsorbent was determined using mercury intrusion porosimetry. Before measurement, the porous silica adsorbent was vacuum-dried to constant weight at 150°C. The mercury intrusion porosimetry pressure ranged from 0.5 psi to 60,000 psi, and the average pore size data was calculated based on the relationship between mercury ingress volume and pressure.

[0029] The formula used to calculate the theoretical residence time of residual anesthetic solution within the adsorption unit is as follows: in, The theoretical dwell time is in minutes. Viscosity data for residual anesthetic solution, in millipascal-seconds; The data represents the average pore size of the porous silica adsorbent material, in nanometers. This is a composite constant. It is the viscosity index factor. This is the aperture index factor.

[0030] , and The value of was obtained through nonlinear regression fitting of dynamic penetration test data from a previous laboratory-scale experiment. During fitting, the operating temperature was fixed at 25℃. Multiple sets of residual anesthetic solutions with different viscosities and multiple sets of porous silica adsorbent material samples with different average pore sizes were selected. The actual residence time was measured on a small-scale adsorption unit experimental device. Using the actual residence time as the target value, least-squares fitting was performed using the above formula to obtain . , , The viscosity of the residual anesthetic solution was measured once for each batch, and the average pore size of the porous silica adsorbent material was measured once for each batch of adsorbent material upon arrival at the factory. The measured viscosity and average pore size data were substituted into the formula to calculate the theoretical residence time under the current operating conditions.

[0031] The preset flow rate is determined based on the theoretical residence time and the effective length of the adsorption unit. The effective length of the adsorption unit is the vertical distance between the bottom and top metal wire mesh partitions, i.e., the total height of the porous silica adsorption material packing layer. The preset flow rate is the ratio of the effective length to the theoretical residence time, expressed in meters per minute.

[0032] The inlet pump is controlled to pump residual anesthetic solution into the adsorption unit from the bottom inlet at a preset flow rate. The inlet pump is a pulseless metering pump with a pump head made of polytetrafluoroethylene (PTFE) and ultra-high molecular weight polyethylene (UHMWPE), and the flow rate adjustment accuracy is ±1% of the set flow rate. The programmable logic controller (PLC) receives the preset flow rate value and calculates the volumetric flow rate based on the cross-sectional area of ​​the adsorption unit cylinder. The cross-sectional area is the circular area calculated from the inner diameter of the adsorption unit. The volumetric flow rate is equal to the product of the preset flow rate and the cross-sectional area. The PLC outputs a 4-20mA analog signal to the frequency converter driver of the pulseless metering pump to adjust the pump speed, stabilizing the pumped flow rate at the calculated volumetric flow rate value. After entering from the bottom inlet of the adsorption unit, the residual anesthetic solution sequentially passes through the bottom support grid, each layer of metal wire mesh partitions, and the porous silica adsorption material layer, flowing from bottom to top and finally exiting from the top outlet of the adsorption unit. During this flow process, fentanyl-like and propofol-like active ingredients are adsorbed and solidified by the porous silica adsorption material.

[0033] Example 2: In practice, an online concentration detector is installed on the outlet pipe of the adsorption unit. The online concentration detector employs an ultraviolet-visible fiber optic spectroscopy system, consisting of a light source module, a flow cell probe, a spectrometer module, and a signal processing unit. The flow cell probe is directly mounted via a flange on the bypass of the liquid outlet pipe at the top of the adsorption unit. Both ends of the bypass pipe are connected to the main liquid outlet pipe via three-way valves, which are configured to allow a portion of the effluent to continuously flow through the flow cell probe before returning to the main outlet pipe. The light source module uses a pulsed xenon lamp with a wavelength range of 200 nm to 800 nm and a pulse frequency set to 10 Hz. The spectrometer module is equipped with a 2048-pixel charge-coupled device (CCD) array detector with a wavelength resolution set to 0.5 nm.

[0034] An online concentration detector monitors the real-time breakthrough concentrations of fentanyl-related and propofol-related active ingredients in the outflowing liquid phase. The signal processing unit performs real-time analysis of the absorbance spectra acquired by the spectrometer module. The analysis process involves selecting the absorbance value at the characteristic absorption wavelength of 240 nm for fentanyl-related active ingredients and the absorbance value at the characteristic absorption wavelength of 270 nm for propofol-related active ingredients. The concentration calculation model built into the processing unit is established based on the Lambert-Beer law. The coefficient matrix of the concentration calculation model is obtained through standard solution calibration experiments. The calibration experiments use a series of mixed standard solutions prepared with known concentrations of fentanyl and propofol standard solutions. The absorbance matrix is ​​measured at both wavelengths of 240 nm and 270 nm, and the extinction coefficient matrix is ​​obtained through multiple linear regression. The signal processing unit outputs the breakthrough concentration values ​​of fentanyl-related and propofol-related active ingredients in the liquid phase at each scan cycle, and the sum of these two values ​​is taken as the breakthrough concentration of the active ingredients in the liquid phase. The scan cycle is consistent with the pulse frequency of the pulsed xenon lamp, which is 0.1 seconds.

[0035] The programmable logic controller (PLC) stores a preset threshold value in its memory. The preset threshold value is set to 0.05. The basis for setting it to 0.05 is as follows: According to the definition of the penetration point of the adsorption treatment unit in the environmental emission risk assessment of narcotic drugs, when the outlet concentration reaches 5% of the inlet concentration, the adsorbent layer enters the penetration state. Continued operation will cause the outlet concentration to rise rapidly and exceed the emission limit. Therefore, the preset threshold value is set to 0.05 to reserve an adsorption margin from the penetration point to complete failure.

[0036] The programmable logic controller (PLC) retrieves the initial concentration data of the residual anesthetic solution from its memory. This initial concentration data is input by the operator via a human-machine interface and stored in the PLC's memory before batch processing begins, or it is obtained and stored from the upstream process control system via a data communication interface. The PLC multiplies a preset threshold by the initial concentration data of the residual anesthetic solution to obtain the allowable penetration concentration. The expression for calculating the allowable penetration concentration is: in, Permissible penetration concentration, in milligrams per liter; The preset threshold is dimensionless and has a value of 0.05. The initial concentration data for residual anesthetic solution is given in milligrams per liter.

[0037] In each scan cycle, the programmable logic controller (PLC) compares the measured breakthrough concentration of the active ingredient in the liquid phase, transmitted from the online concentration detector, with the calculated allowable breakthrough concentration. When the measured breakthrough concentration is less than the allowable breakthrough concentration, the PLC maintains its current operating state. When the measured breakthrough concentration is greater than or equal to the allowable breakthrough concentration, the PLC determines that the adsorption saturation of the porous silica adsorbent material in the adsorption unit has reached a preset threshold. Within the same scan cycle where the adsorption saturation is determined to have reached the preset threshold, the PLC outputs a shut-off signal to the frequency converter driver of the inlet pump to stop the pump's operation, and simultaneously outputs an open signal to the electromagnetic shut-off valve on the nitrogen supply line to begin purging the adsorption unit with nitrogen.

[0038] See Figure 4 In the graph, the horizontal axis represents time in minutes, and the vertical axis represents the breakthrough concentration in milligrams per liter. The curves show the trends of breakthrough concentration of fentanyl-related active ingredients (red dashed line), breakthrough concentration of propofol-related active ingredients (purple dashed line), total breakthrough concentration of active ingredients in the liquid phase (blue solid line), and allowable breakthrough concentration (gray dotted line) over time.

[0039] In the initial stage of the adsorption unit operation (from 0 to about 15 minutes), the breakthrough concentrations of fentanyl and propofol active ingredients were close to zero, and the total breakthrough concentration of active ingredients in the liquid phase remained at a low level, indicating that the porous silica adsorbent material has a high adsorption capacity for the active ingredients in the residual anesthetic solution and no breakthrough phenomenon occurred.

[0040] As time continued (approximately 15 to 30 minutes), the three breakthrough concentration curves gradually increased, indicating a rapid increase in the total breakthrough concentration of the active ingredient in the liquid phase. This suggests that the adsorbent material gradually became saturated, its adsorption performance weakened, and consequently, the concentration of the active ingredient in the effluent increased. The breakthrough concentration of fentanyl-related active ingredients was higher than that of propofol-related active ingredients. The trend of the total breakthrough concentration curve of the active ingredients was consistent with the trend of the breakthrough concentration of each type of component individually, exhibiting typical adsorption breakthrough curve characteristics.

[0041] The breakthrough concentration curve reached a plateau at approximately 30 minutes. The breakthrough concentration of fentanyl-related active ingredients stabilized at approximately 60 mg / L, and the breakthrough concentration of propofol-related active ingredients stabilized at approximately 40 mg / L. The total breakthrough concentration of active ingredients in the liquid phase remained at approximately 100 mg / L, all of which were significantly higher than the allowable breakthrough concentration shown in the figure (approximately 4.5 mg / L). This indicates that the adsorption saturation of the porous silica adsorbent material in the adsorption unit has reached the preset threshold.

[0042] According to the monitoring data from the online concentration detector in Example 2, when the penetration concentration reaches or exceeds the allowable penetration concentration, the system determines that the adsorption saturation has reached a preset threshold, triggering the cessation of residual anesthetic solution injection and initiating a nitrogen purging process. The time point in the figure where the penetration concentration exceeds the allowable penetration concentration is approximately 20 minutes. This specific value corresponds to the allowable penetration concentration calculated in real-time by the programmable logic controller in the example, verifying the effectiveness and responsiveness of the online detection system.

[0043] Example 3: In practice, after the nitrogen purging process is completed, the electromagnetic shut-off valve on the nitrogen supply pipeline is closed, and the vibration unloading device at the bottom of the adsorption unit is activated. The vibration unloading device consists of a vibration motor, an elastic support assembly, and a hopper vibration cone. The vibration motor is fixed to the outer wall of the hopper vibration cone, and the elastic support assembly includes four sets of rubber spring dampers evenly distributed along the circumference of the hopper vibration cone. The rubber spring dampers elastically connect the hopper vibration cone to the fixed frame of the adsorption unit.

[0044] The programmable logic controller (PLC) pre-stores the correspondence between vibration frequency and amplitude and particle size distribution data of the porous silica adsorbent material. The particle size distribution data of the porous silica adsorbent material is measured using a laser particle size analyzer when each batch of porous silica adsorbent material arrives at the factory. The measurement results are expressed as a volume distribution curve. The particle size values ​​D10 (corresponding to a cumulative volume percentage of 10%), D50 (corresponding to a cumulative volume percentage of 50%), and D90 (corresponding to a cumulative volume percentage of 90%) are extracted from the volume distribution curve. These three particle size values ​​(D10, D50, and D90) are used as characterization parameters for the particle size distribution data.

[0045] The vibration frequency is adjusted as follows: when the D50 particle size of the porous silica adsorbent material is greater than or equal to 500 micrometers, the programmable logic controller (PLC) sets the operating frequency of the vibration motor to 25 Hz; when the D50 particle size is between 200 and 500 micrometers, the PLC sets the operating frequency to 35 Hz; and when the D50 particle size is less than 200 micrometers, the PLC sets the operating frequency to 45 Hz. The vibration frequency setting is based on the following: larger particles have lower inter-particle friction and better flowability, so a lower vibration frequency is sufficient for stable unloading, avoiding excessive collision and breakage of particles due to excessively high frequencies; smaller particles have stronger inter-particle adhesion and are prone to forming material arches, requiring a higher vibration frequency to overcome the inter-particle forces.

[0046] The amplitude is adjusted as follows: the programmable logic controller (PLC) calculates the amplitude adjustment coefficient based on the ratio of the difference between D10 and D90 of the porous silica adsorbent material to D50. The expression for calculating the amplitude adjustment coefficient is: in, This is the amplitude adjustment coefficient, which is dimensionless. The particle size value, in micrometers, corresponds to a cumulative volume percentage of 10% in the particle size distribution data of porous silica adsorbent materials. The particle size value, in micrometers, corresponds to a cumulative volume percentage of 50% in the particle size distribution data of porous silica adsorbent materials. The particle size value, in micrometers, corresponds to the cumulative volume percentage of 90% in the particle size distribution data of porous silica adsorbent materials.

[0047] When the amplitude adjustment coefficient is less than or equal to 1.5, the programmable logic controller (PLC) sets the vibration motor amplitude to 0.5 mm; when the amplitude adjustment coefficient is greater than 1.5 and less than or equal to 3.0, the PLC sets the vibration motor amplitude to 1.0 mm; and when the amplitude adjustment coefficient is greater than 3.0, the PLC sets the vibration motor amplitude to 1.5 mm. The amplitude adjustment coefficient reflects the width of the particle size distribution. A larger amplitude adjustment coefficient indicates a wider particle size distribution and a more pronounced filling effect between particles of different sizes, requiring a larger amplitude to loosen the material layer. The vibration motor is a double-eccentric block type. The amplitude is set by adjusting the relative angle of the two eccentric blocks. The PLC adjusts the eccentric block angle position through a stepper motor driver.

[0048] Under vibration, the porous silica adsorbent material falls along the discharge pipe. The discharge pipe is welded to the discharge port flange at the bottom of the adsorption unit. The inner diameter of the discharge pipe is one-third of the inner diameter of the adsorption unit cylinder, and the angle between the discharge pipe and the horizontal plane is 60 degrees. The outlet of the discharge pipe is located above the collection container. The collection container is a sealed stainless steel container with a volume 1.2 times the volume of the porous silica adsorbent material packed in the adsorption unit. The top of the collection container is equipped with an inlet and an outlet. The inlet is connected to the outlet of the discharge pipe through a flexible sealing sleeve, and the outlet is equipped with a membrane filter bag to discharge replacement air.

[0049] After all the porous silica adsorbent material has fallen into the collection container, the vibrating unloading device stops operating. A closed conveying device transports the porous silica adsorbent material from the collection container to the inlet of the high-temperature incineration unit. The closed conveying device consists of a combination of a screw conveyor and a pneumatic conveying pipeline. The horizontal section of the screw conveyor's inlet is connected to the bottom discharge valve of the collection container via a flange, and the screw conveyor's outlet is connected to the Venturi injector inlet hopper of the pneumatic conveying pipeline. The screw conveyor adopts a shaftless screw structure, with 304 stainless steel screw blades and a pitch 0.8 times the diameter of the screw blades. The screw conveyor speed is adjusted by a variable frequency motor, with a speed range set from 20 rpm to 60 rpm.

[0050] The conveying medium in the pneumatic conveying pipeline is nitrogen, sourced from the plant's main nitrogen pipeline. The nitrogen pressure is adjusted to 0.3 MPa via a pressure reducing valve. A Venturi ejector accelerates and entrains the porous silica adsorbent material fed in by the screw conveyor into the pneumatic conveying pipeline, a 50 mm inner diameter stainless steel pipe. The pipeline outlet connects to a gas-solid separator above the inlet of the high-temperature incineration unit. The gas-solid separator is a cyclone separator that separates the porous silica adsorbent material from the conveyed nitrogen. The porous silica adsorbent material settles to the inlet of the high-temperature incineration unit under gravity, while the separated nitrogen is discharged after dust removal.

[0051] A rotary feed valve is installed at the feed inlet of the high-temperature incineration unit. The valve body is made of heat-resistant cast steel, and the rotor inside the valve body has eight evenly distributed grooved chambers. The rotor is driven to rotate by a servo motor through a reducer. The programmable logic controller outputs pulse signals to the servo driver to control the speed of the servo motor, thereby adjusting the speed of the rotary feed valve and realizing the regulation of the feeding rate of the porous silica adsorbent material.

[0052] The rotational speed of the rotary feeder valve is further controlled by a programmable logic controller (PLC) based on the temperature change rate within the high-temperature incineration unit. The temperature change rate within the high-temperature incineration unit is obtained by real-time temperature measurement using thermocouples installed in the middle section of the furnace, calculating the temperature change per unit time. The temperature sampling period is 1 second, and the temperature change rate calculation period is 30 seconds. The calculation method is the difference between the current sampling temperature and the temperature value sampled 30 seconds ago, divided by 30 seconds. When the temperature change rate is positive and its absolute value is greater than 2 degrees Celsius per minute, the PLC reduces the rotational speed of the rotary feeder valve by 10% of the current speed. When the temperature change rate is negative and its absolute value is greater than 2 degrees Celsius per minute, the PLC increases the rotational speed of the rotary feeder valve by 10% of the current speed. When the absolute value of the temperature change rate is less than or equal to 2 degrees Celsius per minute, the rotary feeder valve maintains its current rotational speed. Through this feedforward control, the temperature fluctuation in the second temperature range is maintained within ±10 degrees Celsius.

[0053] Example 4: In specific implementation, please refer to Figure 3 The initial incineration temperature of the porous silica adsorbent material was obtained as follows: Thermogravimetric analysis (TGA) was performed on the porous silica adsorbent material sample loaded with anesthetic solution. The TGA was set to a heating rate of 10 degrees Celsius per minute, with an air atmosphere, from room temperature to 1000 degrees Celsius. The thermogravimetric curve of sample mass change with temperature was recorded. The temperature point at which mass loss first occurred on the thermogravimetric curve was defined as the initial incineration temperature of the porous silica adsorbent material. The initial incineration temperature of the porous silica adsorbent material was measured once for each batch of porous silica adsorbent material upon arrival at the factory and stored in the memory of the programmable logic controller (PLC).

[0054] The method for obtaining the carbonization decomposition temperature range of carbonaceous substances in anesthetic solutions is as follows: The residual anesthetic solution is subjected to vacuum distillation to separate the liquid carbonaceous components. These components are then injected into a thermogravimetric analyzer for analysis under a nitrogen atmosphere. The heating rate is set to 10 degrees Celsius per minute. The starting and ending temperatures of the obvious weight loss peaks on the weight loss curve are recorded. The starting temperature is taken as the lower limit of the carbonization decomposition temperature range, and the ending temperature is taken as the upper limit. The lower and upper limits together constitute the carbonization decomposition temperature range. Carbonaceous substances in anesthetic solutions include fentanyl-like active ingredients, propofol-like active ingredients, and organic excipients.

[0055] The programmable logic controller (PLC) reads the lower limit of the carbonization decomposition temperature range from the memory and sets it as the target temperature of the first temperature range. When the lower limit of the carbonization decomposition temperature range is lower than the initial combustion temperature of the porous silica adsorbent, the PLC uses the lower limit as the target temperature of the first temperature range. When the lower limit of the carbonization decomposition temperature range is higher than or equal to the initial combustion temperature of the porous silica adsorbent, the PLC uses the initial combustion temperature of the porous silica adsorbent minus 20 degrees Celsius as the target temperature of the first temperature range to avoid thermal decomposition of the porous silica adsorbent during the pre-carbonization process.

[0056] A programmable logic controller (PLC) controls the heating elements within the high-temperature incineration unit to heat from room temperature to a target temperature within a first temperature range at a first heating rate. The heating elements are silicon carbide electric heating elements, evenly arranged around the perimeter of the furnace chamber of the high-temperature incineration unit. The first heating rate is set via a human-machine interface, and is set to one degree Celsius per minute. The rationale for setting the first heating rate to one degree Celsius per minute is that the pre-carbonization stage requires slow heating to ensure sufficient carbonization of the carbonaceous material without violent pyrolysis that would produce large amounts of tar and volatile gases, thus reducing the impact of instantaneous volatile gas escape on the furnace pressure.

[0057] The programmable logic controller (PLC) determines the pre-carbonization time based on the carbon content in the anesthetic solution. The carbon content in the anesthetic solution is determined using a total organic carbon (TOC) analyzer. Before measurement, a sample of residual anesthetic solution is taken, and the TOC value is measured. The TOC value is multiplied by the total volume of the residual anesthetic solution to obtain the total mass of carbon-containing substances. The formula for calculating the pre-carbonization time is: in, Pre-carbonization time, in minutes; The total mass of carbonaceous substances in the anesthetic solution, expressed in grams; This is the pre-carbonization time coefficient, expressed in minutes per gram.

[0058] Pre-carbonization time coefficient The value is set at 0.15 minutes per gram. This value is based on the results obtained through laboratory tube furnace simulation pre-carbonization experiments. Under the conditions of a heating rate of one degree Celsius per minute and a target temperature, the average time required for complete carbonization of one gram of carbon-containing material is 0.15 minutes. This value was obtained through linear regression of carbonization experimental data from multiple batches of residual anesthetic solutions. After reaching the target temperature in the first temperature range, the programmable logic controller starts the pre-carbonization timer and maintains the target temperature unchanged until the actual timing reaches the pre-carbonization duration.

[0059] During the pre-carbonization process, the programmable logic controller (PLC) controls the gas supply system to introduce oxygen-deficient air (5% oxygen by volume) into the high-temperature combustion unit. This oxygen-deficient air is produced by mixing compressed air and nitrogen in a specific ratio using a gas mixer. An oxygen concentration sensor installed on the gas mixer continuously monitors the oxygen volume fraction of the mixture. The sensor outputs a signal to the PLC, which then adjusts the opening of the compressed air and nitrogen pipelines via proportional control valves to stabilize the oxygen volume fraction of the mixture at the target value of 5%.

[0060] The flow rate of the oxygen-deficient air is adjusted based on the escape rate of volatile gases generated during the pre-carbonization process. The escape rate of volatile gases is measured in real-time by an online total hydrocarbon analyzer installed at the flue outlet of the high-temperature combustion unit. This online total hydrocarbon analyzer uses the flame ionization detection principle, and the measured value is expressed as the increase in hydrocarbon concentration per minute. The programmable logic controller (PLC) has a built-in mapping table between the volatile gas escape rate and the oxygen-deficient air flow rate. This mapping table was established based on data from previous pilot-scale pre-carbonization experiments. The experiments recorded the volatile gas escape rate at different anesthetic feed rates, and the carbon monoxide concentration in the furnace was maintained within a safe range by adjusting the oxygen-deficient air flow rate, thus obtaining the corresponding relationship between the volatile gas escape rate and the oxygen-deficient air flow rate. During real-time operation, the PLC reads the volatile gas escape rate value from the online total hydrocarbon analyzer every five seconds, obtains the corresponding oxygen-deficient air flow rate setpoint by looking up the table, and sends it to the mass flow controller on the oxygen-deficient air pipeline to adjust the flow rate of the oxygen-deficient air.

[0061] After the pre-carbonization period reaches the specified threshold, the pre-carbonization process is completed. The concentration of carbon monoxide in the high-temperature combustion unit at the end of the pre-carbonization process is monitored using an online carbon monoxide analyzer installed at the flue outlet of the high-temperature combustion unit. This analyzer employs the non-dispersive infrared absorption method to collect real-time carbon monoxide concentration values ​​in the flue gas and transmit them to the programmable logic controller (PLC). A preset safe concentration is stored in the PLC's memory, set at 50 parts per million (ppm). The rationale for setting the preset safe concentration to 50 ppm is that when the carbon monoxide concentration is below 50 ppm, it indicates that the volatile combustible gases from the pre-carbonization stage have been largely released, there is no risk of combustible gas accumulation in the furnace, and the conditions for safely switching to high-temperature combustion are met.

[0062] When the carbon monoxide concentration measured by the online carbon monoxide analyzer is below the preset safe concentration of 50 parts per million, the programmable logic controller (PLC) determines that incineration can be performed. The second heating rate is set to be greater than the first heating rate, with a preset value of 5 degrees Celsius per minute, input via the human-machine interface. The PLC controls the power output of the silicon carbide heating element to heat from the target temperature of the first temperature range to the second temperature range at a heating rate of 5 degrees Celsius per minute. The lower limit of the second temperature range is higher than the target temperature of the pre-carbonization treatment; the lower limit of the second temperature range is set to 800 degrees Celsius, and the upper limit is set to 1000 degrees Celsius. The reason for setting the lower limit of the second temperature range to 800 degrees Celsius is that the complete decomposition temperature of fentanyl and propofol compounds is above 750 degrees Celsius, and setting it to 800 degrees Celsius provides sufficient temperature drive to ensure complete incineration.

[0063] When the furnace temperature reaches the lower limit of 800 degrees Celsius in the second temperature range, the programmable logic controller (PLC) switches the gas supply system to supply pure oxygen as the combustion-supporting gas to the high-temperature combustion unit. The pure oxygen is supplied via a pressure-reducing valve after vaporization from a liquid oxygen storage tank, and its purity is greater than or equal to 99.5%. The flow rate of the pure oxygen is proportionally adjusted based on the real-time measurement of the oxygen concentration within the high-temperature combustion unit. A zirconia oxygen analyzer is installed inside the furnace of the high-temperature combustion unit. The probe of the zirconia oxygen analyzer is inserted into the furnace outlet area to measure the oxygen concentration in real time and output it as a volume percentage. The PLC compares the real-time oxygen concentration measurement obtained by the zirconia oxygen analyzer with the set target oxygen concentration value, which is set to 6%. A proportional control algorithm is used to calculate the adjustment amount of the pure oxygen flow rate, with a proportional gain coefficient set to 2.5 and a control cycle of three seconds. The programmable logic controller sends the calculated pure oxygen flow rate setpoint to the mass flow controller on the pure oxygen pipeline to adjust the pure oxygen flow rate, so that the oxygen concentration in the furnace is maintained near the target value, ensuring that the incineration process is carried out under oxygen-enriched conditions.

[0064] See Figure 5 In the figure, the left side of the vertical axis represents the percentage of residual thermogravimetric mass, the right side represents the rate of change of the derivative thermogravimetric curve, and the horizontal axis represents temperature. The blue solid line in the figure is the thermogravimetric curve, the red dashed line is the derivative thermogravimetric curve, the gray dashed line is the initial combustion temperature of the porous silica adsorbent material, and the purple dotted lines distinguish the lower and upper limits of the carbonization decomposition temperature range.

[0065] The thermogravimetric curves (TGA) show that the sample maintains nearly 100% mass as the temperature rises from room temperature to approximately 200°C, indicating that the sample mass is essentially stable within this temperature range. At approximately 200°C, a significant peak appears in the TGA, but the overall mass change is minimal, suggesting that this temperature corresponds to a stage of slight mass loss, possibly due to the slow release of some volatile components from the adsorbent material. The initial combustion temperature, marked by the gray dashed line, is located near this slight mass loss peak, indicating the temperature at which the porous silica adsorbent material begins to undergo thermal decomposition.

[0066] Starting from approximately 300℃, the thermogravimetric curve shows a significant decrease, with the mass rapidly decreasing until it stabilizes around 600℃, indicating that this temperature range represents the carbonization and decomposition stage of carbonaceous substances in the anesthetic solution. The corresponding derivative thermogravimetric curve exhibits a large negative peak within this range, reflecting a drastic mass loss process. The lower and upper limits of the carbonization and decomposition temperature range, marked by purple dashed lines, are approximately 300℃ and 600℃, respectively, which highly coincide with the variation ranges of the thermogravimetric curve and the derivative thermogravimetric curve.

[0067] Above 600℃, the thermogravimetric curve tends to flatten out, the residual mass stabilizes at about 20%, and the micro-thermogravimetric curve is close to zero, indicating that the material has basically completed carbonization and decomposition and entered the stable residue stage.

[0068] Example 5: In practice, the combustion exhaust gas generated by the high-temperature incineration unit is discharged from the furnace outlet pipe of the incineration unit. The furnace outlet pipe is lined with refractory castable and led to the inlet of the cyclone separator through a high-temperature flue gas duct. The cyclone separator is a tangential reverse-flow structure, consisting of a cylindrical body, a conical body, and an exhaust pipe. The inner diameter of the cylindrical body is determined according to the designed gas volume to be processed by the combustion exhaust gas, which is 1.2 times the amount of exhaust gas generated when the incineration unit is running at full load. The combustion exhaust gas enters the cyclone separator tangentially, forming a high-speed rotating airflow within the cylindrical and conical bodies. Solid particles in the combustion exhaust gas are thrown against the inner wall of the cyclone separator under centrifugal force, slide down the wall of the conical body, and are collected in the ash hopper at the bottom. The purified exhaust gas is discharged upwards from the center of the exhaust pipe into subsequent equipment.

[0069] The preset particle size threshold is determined based on the allowable feed particle concentration of the subsequent acid gas absorption tower. The allowable feed particle concentration of the acid gas absorption tower is determined by the tolerance limit of the packing material within the tower to particulate matter blockage. The acid gas absorption tower uses structured perforated corrugated packing with a pore size of 12 mm, and the allowable feed particle concentration is set at 5 mg / m³. A cyclone separator classification efficiency curve is established in the control system. This curve is obtained by measuring the classification efficiency of the cyclone separator at different particle sizes using simulated dust with the same physicochemical properties as the incineration exhaust gas on a cold-state test bench. The correlation function between classification efficiency and particle size is fitted, and the classification efficiency curve is stored in the programmable logic controller's memory. Based on the allowable feed particle concentration of 5 mg / m³ and the particulate matter concentration of the incineration exhaust gas at the cyclone separator inlet, the required total separation efficiency of the cyclone separator is calculated. Then, the corresponding particulate matter particle size value is calculated from the classification efficiency curve, and this particle size value is used as the preset particle size threshold. When the particulate matter concentration at the inlet of the incineration exhaust gas fluctuates within a certain range, the programmable logic controller updates the preset particle size threshold in real time according to the method described above. Once the structural parameters of the cyclone separator are determined, its separation performance ensures that particles with a diameter greater than or equal to the preset particle size threshold can be effectively separated.

[0070] The exhaust gas, after being processed by the cyclone separator, is discharged from the exhaust pipe and then fed into the acid gas absorption tower through a corrosion-resistant pipe. The acid gas absorption tower is a vertical cylindrical packed tower made of polypropylene. A gas distribution device is located at the bottom of the tower, above which are packing support plates and a packing layer. The packing layer is filled with an alkaline absorbent solution, which is a sodium hydroxide solution. The sodium hydroxide solution has a mass concentration of 10%. It is prepared by dissolving deionized water and industrial-grade caustic soda flakes in a mixing tank and then pumped into the liquid distributor of the acid gas absorption tower by an alkali-resistant pump. The liquid distributor evenly sprays the sodium hydroxide solution onto the top of the packing layer, and the solution flows down the packing to wet the packing surface. The combustion exhaust gas enters the gas distribution device through the side inlet at the bottom of the acid gas absorption tower, passing upwards through the packing layer in the form of bubbles. It comes into countercurrent contact with the downward-flowing sodium hydroxide solution on the packing surface. The acidic gas components in the combustion exhaust gas, such as hydrogen chloride and sulfur oxides, react with the sodium hydroxide and are absorbed. The exhaust gas after absorption treatment is discharged from the top outlet pipe of the acid gas absorption tower into the inlet pipe of the activated carbon adsorption bed.

[0071] During the operation of the acidic gas absorption tower, the pH value of the alkaline absorption liquid is monitored online. An online pH meter is installed on the liquid phase outlet pipe at the bottom of the acidic gas absorption tower. The outlet pipe leads out from the side of the liquid pool at the bottom of the absorption tower and returns to the liquid pool via a circulation loop. An online pH meter probe is connected in series in the circulation loop. A circulation pump continuously flows the alkaline absorption liquid from the pool through the online pH meter probe. The circulation pump flow rate is set to 10 liters per minute to ensure the real-time representativeness of the online pH meter reading. The online pH meter measurement signal is transmitted as a 4-20mA analog signal to the analog input module of the programmable logic controller (PLC). The PLC reads the measured pH value of the alkaline absorption liquid in each scan cycle.

[0072] The preset lower pH limit is set to 10. This setting is based on the fact that when the pH of the alkaline absorbent is below 10, the absorption efficiency of the sodium hydroxide solution for acidic gases decreases significantly, and the concentration of acidic gases at the absorber outlet may exceed the emission limit. The programmable logic controller (PLC) compares the measured pH value of the alkaline absorbent with the lower pH limit. When the measured pH value is greater than or equal to 10, the PLC keeps the replenishment pump and drain valve in a stopped or closed state. When the measured pH value is below 10, the PLC starts the replenishment pump to add fresh sodium hydroxide solution to the acidic gas absorber and simultaneously opens the drain valve at the bottom of the absorber.

[0073] The flow rate of the replenishment pump is proportionally adjusted based on the rate of pH decrease of the alkaline absorbent solution. The rate of pH decrease is calculated by the programmable logic controller (PLC) as follows: at the trigger moment when the measured pH value first falls below 10, the PLC records the current pH value and the corresponding timestamp. Subsequently, it records the pH value every 30 seconds. The difference between the current pH value and the pH value from 30 seconds ago is calculated, and this difference is divided by 30 seconds to obtain the rate of pH decrease, expressed in units of pH per minute. The expression for adjusting the replenishment pump flow rate is: in, The flow rate of the replenishing pump is expressed in liters per minute. This is a proportionality coefficient, with units of liters per minute and per unit pH per minute; This is the change in pH value of the alkaline absorption solution within a preset time interval, i.e., the difference between the current pH value and the pH value before the preset time interval. The preset time interval is 0.5 minutes.

[0074] proportionality coefficient The value is taken as 15 liters per unit pH per minute. Proportionality coefficient. The value of 15 liters per unit pH per minute is based on the following: Through cold-model absorption experiments in an acidic gas absorption tower, the amount of fresh alkali solution required to maintain pH stability was determined under different pH decrease rates. A linear regression was used to obtain the relationship curve between the replenishment flow rate and the pH decrease rate, and the slope of the regression line was determined to be 15. After the programmable logic controller (PLC) calculates the setpoint for the replenishment pump flow rate, it outputs a 4-20mA analog signal to the frequency converter driver of the replenishment pump. The replenishment pump is a diaphragm metering pump, and the frequency converter driver adjusts the reciprocating frequency of the diaphragm metering pump according to the received current signal to achieve flow rate regulation.

[0075] Simultaneously, the programmable logic controller (PLC) opens the drain valve at the bottom of the acid gas absorption tower. This drain valve is a pneumatic diaphragm valve installed on the drain pipe at the bottom of the acid gas absorption tower. The liquid level in the acid gas absorption tower is monitored in real time by a pressure-type level transmitter installed in the bottom liquid pool. The level transmitter measures the static pressure in the pool and converts it into a liquid level, transmitting this signal as a 4-20mA analog signal to the PLC. The PLC stores a set liquid level value, which is 50% of the height of the liquid pool at the bottom of the acid gas absorption tower. During the operation of the drain valve, the programmable logic controller (PLC) uses the liquid level height measured by the level transmitter as feedback to perform closed-loop control of the drain valve opening: when the liquid level height is higher than the set liquid level value plus 10 mm, the PLC increases the drain valve opening by 5% in each step; when the liquid level height is lower than the set liquid level value minus 10 mm, the PLC decreases the drain valve opening by 5% in each step; when the liquid level height is within ±10 mm of the set liquid level value, the current drain valve opening is maintained. Through this closed-loop liquid level control, the liquid level in the acid gas absorption tower is kept constant.

[0076] With the combined action of the replenishment pump adding fresh sodium hydroxide solution and the drain valve discharging waste liquid, the pH value of the alkaline absorption liquid in the acidic gas absorption tower gradually rises to above 10. When the measured pH value detected by the online pH meter is greater than or equal to 11, the programmable logic controller stops the replenishment pump and closes the drain valve after a 10-second delay, and the acidic gas absorption tower returns to normal operation.

[0077] The exhaust gas discharged from the top outlet of the acid gas absorption tower enters the activated carbon adsorption bed. The activated carbon adsorption bed is a horizontal fixed bed structure, internally filled with cylindrical coal-based activated carbon particles in layers. The iodine adsorption value of the activated carbon particles is not less than 950 mg / g, the specific surface area is not less than 1,000 m² / g, the filling thickness is 0.6 m, and the bulk density is 450 kg / m³. The exhaust gas enters the activated carbon adsorption bed from the front distribution chamber, uniformly passing through the activated carbon filling layer. Residual trace organic matter and possible gaseous pollutants are adsorbed and removed by the activated carbon. The purified gas is collected in the rear collection chamber and discharged through the exhaust pipe in compliance with standards.

[0078] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for the whole-process treatment of residual anesthetic liquid based on adsorption-high temperature incineration, characterized in that, The method includes: The residual anesthetic solution is passed into the adsorption unit, which is filled with a porous silica adsorption material modified with a silane coupling agent. The residual anesthetic solution flows through the porous silica adsorption material along the axial direction of the adsorption unit at a preset flow rate, so that the fentanyl and propofol active ingredients in the residual anesthetic solution are adsorbed and solidified. When the adsorption saturation of the porous silica adsorbent material in the adsorption unit reaches a preset threshold, the flow of the residual anesthetic liquid is stopped, and nitrogen gas is introduced into the adsorption unit for purging. The exhaust gas after purging is introduced into the exhaust gas purification system. The porous silica adsorbent material loaded with anesthetic liquid is transferred to a high-temperature incineration unit. In the high-temperature incineration unit, it is first heated to a first temperature range at a first heating rate for pre-carbonization treatment, and then heated to a second temperature range at a second heating rate for incineration treatment. The second temperature range is higher than the first temperature range. The combustion exhaust gas generated by the high-temperature incineration unit is introduced into the exhaust gas purification system for multi-stage purification treatment. The exhaust gas purification system includes a cyclone separator, an acid gas absorption tower, and an activated carbon adsorption bed connected in sequence.

2. The method for treating residual anesthetic liquid based on adsorption-high temperature incineration according to claim 1, characterized in that, The step of passing residual anesthetic solution into the adsorption unit includes: The initial concentration and initial volume data of the residual anesthetic solution are collected, and the minimum filling amount required for the adsorption unit is calculated based on the ratio of the initial concentration data to the adsorption capacity per unit mass of the porous silica adsorption material. The actual filling amount of the adsorption unit is obtained by adding the minimum filling amount to the redundant filling amount corresponding to the redundancy coefficient. The redundancy coefficient is determined based on the content of unknown impurity components in the residual anesthetic solution. The porous silica adsorbent material of the actual filling amount is filled into the adsorption unit in a layered stacking manner, with a metal wire mesh partition between adjacent layers.

3. The method for treating residual anesthetic liquid based on adsorption-high temperature incineration according to claim 2, characterized in that, The residual anesthetic solution flows along the axial direction of the adsorption unit through the porous silica adsorption material at a preset flow rate, including: Based on the viscosity data of the residual anesthetic solution and the average pore size data of the porous silica adsorption material, the theoretical residence time of the residual anesthetic solution in the adsorption unit is calculated. The theoretical residence time is positively correlated with the viscosity data and negatively correlated with the average pore size data. Based on the theoretical residence time and the effective length of the adsorption unit, the preset flow rate is determined, whereby the preset flow rate is the ratio of the effective length to the theoretical residence time. The inlet pump is controlled to pump the residual anesthetic solution into the bottom inlet of the adsorption unit at the preset flow rate, so that the residual anesthetic solution flows from bottom to top through the layered and stacked porous silica adsorption material.

4. The method for the whole-process treatment of residual anesthetic liquid based on adsorption-high temperature incineration according to claim 1, characterized in that, When the adsorption saturation of the porous silica adsorbent material in the adsorption unit reaches a preset threshold, the following steps are included: An online concentration detector is installed at the outlet of the adsorption unit to monitor the breakthrough concentration of the active ingredient in the outflowing liquid phase in real time. The penetration concentration is compared with the allowable penetration concentration corresponding to the preset threshold, wherein the allowable penetration concentration is the product of the preset threshold and the initial concentration data of the residual anesthetic solution; When the penetration concentration is greater than or equal to the allowable penetration concentration, it is determined that the adsorption saturation of the porous silica adsorption material in the adsorption unit has reached the preset threshold.

5. The method for the whole-process treatment of residual anesthetic liquid based on adsorption-high temperature incineration according to claim 1, characterized in that, The process of transferring the porous silica adsorbent material loaded with anesthetic solution to the high-temperature incineration unit includes: The vibration unloading device at the bottom of the adsorption unit is activated, so that the porous silica adsorbent material falls into the collection container along the discharge pipe under vibration. The vibration frequency and amplitude of the vibration unloading device are adjusted according to the particle size distribution data of the porous silica adsorbent material. The porous silica adsorbent material in the collection container is transported to the feed inlet of the high-temperature incineration unit through a closed conveying device, which includes a combination of a screw conveyor and a pneumatic conveying pipeline. A rotary feed valve is installed at the feed inlet, and the feed rate of the porous silica adsorbent material is adjusted by controlling the rotation speed of the rotary feed valve.

6. The method for treating residual anesthetic liquid based on adsorption-high temperature incineration according to claim 1, characterized in that, The pre-carbonization treatment, which involves heating to a first temperature range at a first heating rate, includes: The initial combustion temperature of the porous silica adsorbent material and the carbonization decomposition temperature range of the carbon-containing substances in the anesthetic solution are obtained, and the lower limit of the carbonization decomposition temperature range is taken as the target temperature of the first temperature range. The heating element in the high-temperature incineration unit is controlled to heat from room temperature to the target temperature at a first heating rate of degrees Celsius per minute, and the pre-carbonization time is maintained at the target temperature for a duration determined according to the content of the carbon-containing material. During the pre-carbonization process, oxygen-deficient air with an oxygen volume fraction of 5% is introduced into the high-temperature combustion unit, and the flow rate of the oxygen-deficient air is adjusted according to the escape rate of the volatile gases generated by the pre-carbonization process.

7. The method for the whole-process treatment of residual anesthetic liquid based on adsorption-high temperature incineration according to claim 6, characterized in that, The incineration process, which involves heating the material to a second temperature range at a second heating rate, includes: The concentration of carbon monoxide gas in the high-temperature incineration unit is detected at the end of the pre-carbonization treatment. When the concentration of carbon monoxide gas is lower than the preset safe concentration, the incineration treatment is performed. The second heating rate is set to be greater than the first heating rate, and the temperature is heated to the second temperature range at the second heating rate, wherein the lower limit of the second temperature range is higher than the target temperature of the pre-carbonization treatment; During the incineration process, the combustion-supporting gas introduced into the high-temperature incineration unit is switched to pure oxygen, and the flow rate of the pure oxygen is proportionally adjusted according to the real-time measurement value of the oxygen concentration in the high-temperature incineration unit.

8. The method for the whole-process treatment of residual anesthetic liquid based on adsorption-high temperature incineration according to claim 1, characterized in that, The step of introducing the combustion exhaust gas generated by the high-temperature incineration unit into the exhaust gas purification system for multi-stage purification treatment includes: The incineration exhaust gas is first passed into the cyclone separator, which separates particulate matter in the incineration exhaust gas with a particle size greater than or equal to a preset particle size threshold based on centrifugal force. The preset particle size threshold is determined according to the allowable feed particle concentration of the subsequent acid gas absorption tower. The exhaust gas treated by the cyclone separator is fed into the acid gas absorption tower, which is filled with an alkaline absorbent liquid, namely a sodium hydroxide solution. The combustion exhaust gas enters from the bottom of the acid gas absorption tower and passes upward through the alkaline absorbent liquid in the form of bubbles.

9. The method for the whole-process treatment of residual anesthetic liquid based on adsorption-high temperature incineration according to claim 8, characterized in that, The step of passing the exhaust gas treated by the cyclone separator into the acid gas absorption tower includes: The pH value of the alkaline absorption solution is monitored, and the pH value is obtained in real time by an online pH meter; When the pH value is lower than the preset lower pH limit, the replenishment pump is started to replenish fresh sodium hydroxide solution into the acidic gas absorption tower. The flow rate of the replenishment pump is adjusted proportionally according to the rate of decrease of the pH value. At the same time, the drain valve at the bottom of the acid gas absorption tower is opened to discharge part of the waste liquid that has absorbed the acid gas, thereby maintaining a constant liquid level inside the acid gas absorption tower.

10. The method for treating residual anesthetic liquid based on adsorption-high temperature incineration according to claim 5, characterized in that, The rotational speed of the rotary feeder valve is fed forward based on the temperature change rate within the high-temperature incineration unit to maintain the temperature fluctuation in the second temperature range within ±10 degrees Celsius.

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