A comprehensive resource treatment method for waste adsorption materials

Abstract

The present invention discloses a comprehensive resource treatment method for waste adsorption materials, which relates to the technical field of wastewater adsorption material regeneration. The comprehensive resource treatment method for waste adsorption materials of the present invention significantly improves the regeneration efficiency and resource utilization rate of waste adsorption materials. Among them, microwave-assisted crushing and screening technology can quickly and evenly crush the waste adsorption materials to a target particle size, and low-temperature plasma surface modification technology can destroy the chemical bonds of surface pollutants, improve the repairability of the pore structure, and lay the foundation for subsequent pyrolysis regeneration. The oxygen-controlled gradient pyrolysis regeneration technology achieves directional cracking of organic matter and regeneration of the adsorbent microporous structure by precisely controlling the oxygen concentration and heating rate. At the same time, the addition of Fe / Ce bimetallic catalyst promotes the degradation and activation efficiency of pollutants, and significantly improves the performance of the regenerated adsorption material.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater adsorption material regeneration, in particular to a comprehensive resource treatment method for waste adsorption materials. Background Art

[0002] Adsorption materials are widely used in various production and environmental protection fields. In chemical production, adsorption materials are used to separate and purify products, improving their quality. In wastewater treatment plants, adsorption removes heavy metal ions, organic pollutants, and other substances from water to ensure water quality. In waste gas purification, adsorption materials can effectively capture harmful gases and reduce atmospheric pollutant emissions. However, as the adsorption process continues, the adsorption material gradually loses its activity and becomes waste. If these waste adsorption materials are not properly handled, they will place tremendous pressure on the environment and resources.

[0003] At present, the existing waste adsorption material treatment technologies mainly include physical, chemical and biological methods, but they generally have many shortcomings. The physical method mainly relies on mechanical crushing and screening, which is difficult to effectively remove harmful components in the adsorption material and has high energy consumption; although the chemical method can achieve a certain degree of desorption and regeneration, the chemical reagents used are corrosive and toxic, which easily leads to secondary pollution problems; in addition, traditional pyrolysis regeneration technology usually uses a single temperature zone for treatment, which cannot achieve directional cracking of different pollutants and effective repair of the microporous structure of the adsorbent. For the selective leaching of heavy metals, the existing methods mostly rely on a single acid solution, which has poor selectivity and low efficiency, and cannot achieve efficient recycling of heavy metals, resulting in waste of resources.

[0004] To sum up, the existing waste adsorbent material treatment technology has defects and cannot achieve the comprehensive resource treatment of waste adsorbent materials in an efficient, environmentally friendly and economical manner. Developing a new treatment method to overcome the shortcomings of existing technology and achieve full process optimization from pretreatment to final product utilization is of great significance for solving the environmental and resource problems brought about by waste adsorbent materials. Summary of the Invention

[0005] The purpose of the present invention is to make up for the shortcomings of the existing technology and provide a comprehensive resource treatment method for waste adsorption materials, which can improve the regeneration efficiency and resource utilization rate of waste adsorption materials through microwave-assisted crushing and screening, low-temperature plasma surface modification and oxygen-controlled gradient pyrolysis regeneration. Among them, microwave-assisted crushing and screening technology can quickly and evenly crush the waste adsorption materials to the target particle size; low-temperature plasma surface modification technology can destroy the chemical bonds of surface pollutants, improve the repairability of the pore structure, and lay the foundation for subsequent pyrolysis regeneration; oxygen-controlled gradient pyrolysis regeneration technology realizes the directional cracking of organic matter and the regeneration of the adsorbent microporous structure by precisely controlling the oxygen concentration and heating rate. At the same time, the addition of Fe / Ce bimetallic catalyst promotes the degradation and activation efficiency of pollutants, significantly improving the performance of the regenerated adsorption material.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a comprehensive treatment method for waste adsorption materials, the specific steps of the method are:

[0007] S100, the waste adsorption material is crushed and screened by microwave-assisted crushing, and subjected to low-temperature plasma surface modification treatment under an inert atmosphere to destroy the chemical bonds of the surface pollutants;

[0008] S200: The pretreated adsorption material is fed into a multi-temperature zone oxygen-controlled pyrolysis furnace for pyrolysis. Under gradient temperature conditions, the oxygen concentration is controlled in stages to achieve directional cracking of organic matter and regeneration of the adsorbent microporous structure. An Fe / Ce bimetallic catalyst is simultaneously added to promote pollutant degradation and activation efficiency.

[0009] S300, regulating the pH of the pyrolyzed adsorption material, extracting the heavy metals remaining in the adsorption material using a citric acid-sodium thiosulfate composite leaching agent combined with ultrasonic enhanced treatment, and recovering the metal elements from the leachate by electrochemical deposition;

[0010] S400, after desulfurization and dust removal, the combustible gas generated during the pyrolysis process is returned to the combustion chamber of the pyrolysis furnace as auxiliary fuel for self-supplied heat energy;

[0011] S500: Mix the adsorption material residue after leaching with the pyrolysis ash, add a silicate binder and press into shape to prepare a soil conditioner, thereby completing comprehensive resource processing.

[0012] Furthermore, during the microwave-assisted fragmentation in S100, the microwave power is 300W-800W, and the fragmentation time is 5min-15min.

[0013] Furthermore, during the low temperature plasma surface modification treatment in S100, the treatment voltage is 8kV-15kV, the treatment temperature is 50 -200 The treatment time is 10 min-25 min, and the inert atmosphere is one of nitrogen and argon.

[0014] Furthermore, the Fe / Ce bimetallic catalyst in S200 is a composite solution of ferric nitrate and cerium nitrate, the amount of the Fe / Ce bimetallic catalyst added is 0.5%-3% of the total mass of the catalyst (including the carrier) to the mass of the adsorption material, and the molar ratio of Fe to Ce is 2:1-4:1;

[0015] The multi-temperature zone oxygen-controlled pyrolysis furnace is divided into three temperature zones:

[0016] Low temperature zone: 200-400 , oxygen concentration ≤ 5%, residence time 0.5-1.5h;

[0017] Medium temperature zone: 500-700 , oxygen concentration 8-12%, catalyst loading 2-5%, the catalyst loading refers to the mass ratio of active components Fe and Ce on the carrier;

[0018] High temperature area: 800-900 , oxygen-free environment, calcination time 1-3h.

[0019] Furthermore, the ratio of the citric acid-sodium thiosulfate composite leaching agent in S300 is 1.5:1-3:1, and the pH value is controlled at 2.5-4.0;

[0020] The ultrasonic treatment frequency is 28-40kHz, the power density is 0.5-1.2W / cm², and the leaching time is 30-60min;

[0021] The current density of the electrochemical deposition is 50-200A / m², and the electrolyte temperature is 25-60 .

[0022] Furthermore, the pyrolysis gas in S400 is mixed with natural gas at a volume ratio of 1:3 after dust removal and activated carbon adsorption desulfurization, and is burned to provide 40-60% of the heat energy input to the pyrolysis furnace;

[0023] The hydrogen sulfide content in the pyrolysis gas after dust removal and activated carbon adsorption desulfurization is ≤10 mg / m³, and the particulate matter concentration is ≤20 mg / m³.

[0024] Furthermore, the mixing mass ratio of the adsorption material residue after leaching in S500 to the pyrolysis ash is 2:1-5:1, and the added amount of the silicate binder accounts for 8%-15% of the total mass.

[0025] Furthermore, the waste adsorption material includes at least one of activated carbon, zeolite molecular sieve, and ion exchange resin, and the adsorbed pollutants include at least one of organic compounds and heavy metals.

[0026] Compared with the existing technology, this comprehensive treatment method for waste adsorption materials has the following beneficial effects:

[0027] 1. The comprehensive resource treatment method for waste adsorption materials of the present invention significantly improves the regeneration efficiency and resource utilization rate of waste adsorption materials. Among them, microwave-assisted crushing and screening technology can quickly and evenly crush waste adsorption materials to the target particle size, and low-temperature plasma surface modification technology can destroy the chemical bonds of surface pollutants, improve the repairability of the pore structure, and lay the foundation for subsequent pyrolysis regeneration. The oxygen-controlled gradient pyrolysis regeneration technology achieves directional cracking of organic matter and regeneration of the adsorbent microporous structure by precisely controlling the oxygen concentration and heating rate. At the same time, the addition of Fe / Ce bimetallic catalyst promotes the degradation and activation efficiency of pollutants, significantly improving the performance of the regenerated adsorption material.

[0028] 2. The comprehensive resource treatment method for waste adsorption materials of the present invention also focuses on environmental pollution control and energy consumption reduction. In the selective leaching and recovery of heavy metals, a citric acid-sodium thiosulfate composite leaching agent is used in combination with ultrasonic enhanced treatment to achieve efficient and selective extraction of heavy metals, and the metal elements are recovered from the leachate through electrochemical deposition technology, thereby realizing the recycling of heavy metal resources. It not only reduces the pollution risk of heavy metals to the environment, but also improves the recycling rate of resources. At the same time, in the internal circulation of pyrolysis gas energy, the combustible gas generated in the pyrolysis process is desulfurized, dust-removed and purified, and then returned to the pyrolysis furnace combustion chamber as auxiliary fuel, thereby achieving self-sufficiency in internal thermal energy of the system and reducing energy consumption during the treatment process.

[0029] Other advantages, objects and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be learned from the practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0031] Figure 1 The present invention is a flow chart of a comprehensive resource treatment method for waste adsorption materials. DETAILED DESCRIPTION

[0032] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0033] like Figure 1 As shown, the present invention proposes a specific process of a comprehensive treatment method for waste adsorption materials, and the specific steps of the method are:

[0034] S100, the waste adsorption material is subjected to microwave-assisted crushing and screening, the microwave power is set to 300W-800W, the crushing time is 5min-15min, and after the crushing and screening is completed, the waste adsorption material is subjected to low-temperature plasma surface modification treatment in an inert atmosphere, the treatment voltage is 8kV-15kV, the treatment temperature is 50 -200 The treatment time is 10 min to 25 min, wherein the inert atmosphere is one of nitrogen and argon to destroy the chemical bonds of surface pollutants, the waste adsorption material includes at least one of activated carbon, zeolite molecular sieve, and ion exchange resin, and the adsorbed pollutants include at least one of organic compounds and heavy metals;

[0035] S200, the pretreated adsorption material is sent to a multi-temperature zone oxygen-controlled pyrolysis furnace for pyrolysis. The multi-temperature zone oxygen-controlled pyrolysis furnace is divided into three temperature zones and pyrolysis is carried out under gradient temperature rising conditions: the temperature of the low temperature zone is controlled at 200-400 , oxygen concentration ≤ 5%, the residence time of adsorption material in this temperature zone is 0.5-1.5h; the temperature in the medium temperature zone is 500-700 , the oxygen concentration is controlled at 8-12%. At this stage, Fe / Ce bimetallic catalyst is added to the furnace. The catalyst is a composite solution of ferric nitrate and cerium nitrate. The addition amount is 0.5%-3% of the mass of the adsorption material. The molar ratio of Fe to Ce is 2:1-4:1, and the catalyst loading is 2-5%. The temperature in the high temperature zone is 800-900 , maintain an oxygen-free environment, the calcination time is 1-3h, and the directional cracking of organic matter and regeneration of the adsorbent microporous structure are achieved by segmented regulation of oxygen concentration. At the same time, Fe / Ce bimetallic catalyst is used to promote pollutant degradation and activation efficiency; S300, the pH of the adsorbent material after pyrolysis is regulated, and the pH value is controlled at 2.5-4.0. A citric acid-sodium thiosulfate composite leaching agent is used with a ratio of 1.5:1-3:1, and combined with ultrasonic enhanced treatment, the ultrasonic treatment frequency is 28-40kHz, the power density is 0.5-1.2W / cm², and the leaching time is 30-60min to extract the heavy metals remaining in the adsorbent material. Afterwards, the metal element is recovered from the leachate by electrochemical deposition. The current density of the electrochemical deposition is 50-200A / m², and the electrolyte temperature is 25-60 ;

[0036] S400: The combustible gas generated during the pyrolysis process is first subjected to dust removal and activated carbon adsorption desulfurization treatment. After desulfurization, the hydrogen sulfide content in the gas is ≤10mg / m³ and the particulate matter concentration is ≤20mg / m³. The purified combustible gas is mixed with natural gas in a volume ratio of 1:3 and burned. The gas is then fed back into the pyrolysis furnace combustion chamber as auxiliary fuel, providing 40-60% of the heat energy input to the pyrolysis furnace, achieving self-sufficiency in heat energy.

[0037] S500, the adsorption material residue after leaching is mixed with the pyrolysis ash at a mixing mass ratio of 2:1-5:1, 8%-15% of the total mass of a silicate binder is added, and the soil conditioner is prepared by pressing and molding to complete the comprehensive resource processing.

[0038] Example 1

[0039] The specific steps for comprehensive resource recovery treatment of 100 kg of waste activated carbon that has adsorbed heavy metals (mainly copper ions and lead ions) and organic pollutants (mainly phenolic compounds) are as follows:

[0040] Pretreatment of waste adsorption materials: Place the waste activated carbon in a microwave-assisted crusher, set the microwave power to 300W, and after turning on the equipment, microwaves act evenly on the activated carbon, causing rapid heat generation inside it. Under the action of thermal stress, the activated carbon gradually breaks down, and the crushing stops after 5 minutes. Then, the broken activated carbon is transferred to a low-temperature plasma treatment device, and nitrogen is introduced to create an inert atmosphere. The treatment voltage is set to 8kV and the temperature is 50 , the treatment time is 10 min. During this process, the high-energy particles in the low-temperature plasma interact with the pollutants on the surface of the activated carbon, destroying their chemical bonds;

[0041] Oxygen controlled gradient pyrolysis regeneration: The pre-treated activated carbon is fed into a multi-temperature zone oxygen controlled pyrolysis furnace, which is first heated to a low temperature zone (200 ), and the oxygen concentration is controlled at 3%. The activated carbon stays in this area for 0.5h, during which some organic matter begins to decompose and then enters the medium temperature zone (500 ), at this time the oxygen concentration is increased to 8%, and the Fe / Ce bimetallic catalyst composed of ferric nitrate and cerium nitrate is added according to 0.5% of the mass of the adsorption material, wherein the molar ratio of Fe to Ce is 2:1 and the catalyst loading is 2%. In the medium temperature zone, the catalyst promotes the cracking of organic matter and the degradation of pollutants. Finally, the activated carbon enters the high temperature zone (800 ), maintain an oxygen-free environment and calcine for 1 hour to regenerate the microporous structure of the adsorbent;

[0042] Selective leaching and recovery: Place the activated carbon after pyrolysis into a reaction vessel, adjust the pH of the system to 2.5 by adding dilute sulfuric acid, then add citric acid-sodium thiosulfate composite leaching agent at a ratio of 1.5:1, place the reaction vessel in an ultrasonic device, set the ultrasonic frequency to 28kHz, the power density to 0.5W / cm², and continue leaching for 30 minutes. After the leaching is completed, transfer the leachate for electrochemical deposition, set the current density to 50A / m², the electrolyte temperature to 25 , so that heavy metal ions are reduced to metal elements on the electrode for recovery;

[0043] Internal circulation of pyrolysis gas energy: The pyrolysis gas generated during the pyrolysis process first passes through a bag filter to remove solid particles, and then passes through a desulfurization tower equipped with activated carbon for adsorption desulfurization. The desulfurized and dust-removed pyrolysis gas is mixed with natural gas in a volume ratio of 1:3 and sent to the combustion chamber of the pyrolysis furnace for combustion, providing part of the heat energy for the subsequent operation of the pyrolysis furnace.

[0044] Harmless waste residue resource utilization: Mix the activated carbon residue after leaching and the ash produced by pyrolysis in a mass ratio of 2:1, then add 8% of the total mass of silicate binder, stir thoroughly, pour into a mold, and press into shape under a certain pressure to make a soil conditioner.

[0045] Treatment effect: After the treatment method of this embodiment, the regenerated adsorbent was tested, and it was found that its adsorption performance was significantly restored, and the adsorbent regeneration rate reached 70%. By analyzing the leachate and recovered metals, the heavy metal recovery rate was 75%. The energy consumption reduction rate of this embodiment reached 35%. The energy consumption reduction rate was calculated by comparing the total energy consumption of traditional treatment methods (such as single pyrolysis + chemical leaching), including electrical energy (microwave, plasma, ultrasound, electrochemical deposition), natural gas consumption (pyrolysis furnace auxiliary fuel) and heat energy recycling. In this embodiment, the pyrolysis gas recirculation provides 40%-60% of self-supplied heat energy, greatly reducing the external natural gas consumption, and the comprehensive energy consumption reduction rate reached 35%. The waste gas and wastewater generated during the treatment process were tested, and the pollutant emission compliance rate was 100%, and all the leaching residues and pyrolysis ash were fully utilized, and the waste residue utilization rate reached 95%.

[0046] Example 2

[0047] The specific steps for comprehensive resource treatment of 150 kg of waste zeolite molecular sieve adsorbed with heavy metals (mainly cadmium ions and mercury ions) are as follows:

[0048] Pretreatment of waste adsorption materials: put the waste zeolite molecular sieve into the microwave-assisted crusher, set the microwave power to 500W, and the crushing time to 10min. The heat generated by the microwave changes the internal structure of the molecular sieve, thereby achieving crushing. After crushing, put it into the low-temperature plasma treatment equipment, introduce argon as an inert atmosphere, set the processing voltage to 12kV and the temperature to 120 , the treatment time is 15min to destroy the chemical bonds of surface pollutants;

[0049] Oxygen controlled gradient pyrolysis regeneration: the pre-treated zeolite molecular sieve is sent to a multi-temperature zone oxygen controlled pyrolysis furnace, and the low temperature zone of the pyrolysis furnace is heated to 300 The oxygen concentration is controlled at 4%. The molecular sieve stays in this area for 1 hour to initially decompose some organic matter. Then it enters the medium temperature zone and the temperature rises to 600 , the oxygen concentration was 10%, and Fe / Ce bimetallic catalyst (Fe to Ce molar ratio 3:1, catalyst loading 3%) was added according to 1.5% of the adsorption material mass to further promote the degradation and activation of pollutants. Finally, in the high temperature zone (850 ), maintain calcination in an oxygen-free environment for 2 hours to complete the regeneration of the microporous structure;

[0050] Selective leaching and recovery: Place the zeolite molecular sieve after pyrolysis in a reaction vessel, adjust the pH to 3.0 with dilute hydrochloric acid, add a citric acid-sodium thiosulfate composite leaching agent with a ratio of 2:1, place it in an ultrasonic device, set the frequency to 35kHz, the power density to 0.8W / cm², and leach for 45 minutes. Then transfer the leachate to an electrochemical deposition device, set the current density to 120A / m², the electrolyte temperature to 40 , recycling heavy metals;

[0051] Internal circulation of pyrolysis gas energy: The pyrolysis gas is first dedusted by a cyclone dust collector and then desulfurized by activated carbon adsorption. The purified pyrolysis gas is mixed with natural gas at a ratio of 1:3 and transported to the combustion chamber of the pyrolysis furnace to provide part of the heat for the pyrolysis furnace.

[0052] Harmless waste residue resource utilization: Mix the leaching residue and pyrolysis ash in a mass ratio of 3:1, add 12% of the total mass of silicate binder, stir evenly and press into shape to prepare a soil conditioner.

[0053] Treatment Results: The regenerated zeolite molecular sieve exhibited excellent adsorption performance, with an adsorbent regeneration rate of 75%. A quantitative analysis of the recovered heavy metals revealed a recovery rate of 80%. Energy consumption monitoring equipment compared the process to traditional treatment methods revealed a 40% reduction in energy consumption. Pollutant emissions generated during the treatment process met 100% of standards, and the waste residue utilization rate reached 96%.

[0054] Example 3

[0055] There are 200kg of waste ion exchange resin that adsorbs organic pollutants (mainly benzene series). The specific steps for comprehensive resource treatment are as follows:

[0056] Pretreatment of waste adsorption materials: The waste ion exchange resin was placed in a microwave-assisted crusher, the microwave power was set to 800W, and the crushing was carried out for 15 minutes. The crushed resin was transferred to a low-temperature plasma treatment equipment under a nitrogen inert atmosphere, and the treatment voltage was set to 15kV and the temperature was set to 200. , treated for 25 min for surface modification;

[0057] Oxygen controlled gradient pyrolysis regeneration: The pretreated ion exchange resin is sent to a multi-temperature zone oxygen controlled pyrolysis furnace. The low temperature zone of the pyrolysis furnace is heated to 400 , the oxygen concentration is controlled at 5%, the resin stays for 1.5 hours, and the temperature in the medium temperature zone is raised to 700 , the oxygen concentration was 12%, Fe / Ce bimetallic catalyst (Fe to Ce molar ratio 4:1, catalyst loading 5%) was added at 3% of the mass of the adsorption material, and the temperature in the high temperature zone reached 900 , keep calcining in an oxygen-free environment for 3h;

[0058] Selective leaching and recovery: put the pyrolyzed ion exchange resin into the reaction vessel, adjust the pH to 4.0 with dilute nitric acid, add citric acid-sodium thiosulfate composite leaching agent with a ratio of 3:1, set the frequency to 40kHz and power density to 1.2W / cm² in the ultrasonic equipment, leach for 60min, transfer the leachate to the electrochemical deposition device, set the current density to 200A / m² and the electrolyte temperature to 60 , recovering the heavy metals present;

[0059] Internal circulation of pyrolysis gas energy: The pyrolysis gas is dedusted by an electrostatic precipitator and then desulfurized by activated carbon adsorption. The purified pyrolysis gas is mixed with natural gas at a ratio of 1:3 and fed back to the combustion chamber of the pyrolysis furnace as auxiliary fuel.

[0060] Harmless waste residue resource utilization: Mix the leaching residue and pyrolysis ash in a mass ratio of 5:1, add 15% of the total mass of silicate binder, stir evenly and press into shape to prepare a soil conditioner.

[0061] Treatment effect: The adsorption performance of the regenerated ion exchange resin recovered well, and the adsorbent regeneration rate reached 80%. Since the adsorption was mainly organic pollutants and the heavy metal content was very small, the heavy metal recovery rate was still detected to be 85%. Energy consumption monitoring showed that compared with traditional treatment methods, the energy consumption reduction rate was 45%, the pollutant emission compliance rate generated during the treatment process was 100%, and the waste residue utilization rate reached 98%.

[0062] Example 4

[0063] The specific steps for comprehensive resource recovery treatment using 120 kg of a mixture of waste activated carbon and zeolite molecular sieve (mass ratio 1:1) that simultaneously adsorbs heavy metals (mainly zinc ions and nickel ions) and organic pollutants (mainly aldehyde compounds) are as follows:

[0064] Pretreatment of waste adsorption materials: put the mixed materials into a microwave-assisted crusher, set the microwave power to 400W, crush for 8 minutes, and then put the mixed materials into a low-temperature plasma treatment equipment under an argon inert atmosphere, set the treatment voltage to 10kV and the temperature to 100 , treated for 12 min for surface modification;

[0065] Oxygen controlled gradient pyrolysis regeneration: the pre-treated mixed material is sent to a multi-temperature zone oxygen controlled pyrolysis furnace, and the low temperature zone of the pyrolysis furnace is heated to 250 , the oxygen concentration is controlled at 3.5%, and the mixed material stays for 0.8h. The temperature in the medium temperature zone rises to 550 , the oxygen concentration was 9%, and Fe / Ce bimetallic catalyst (Fe to Ce molar ratio 2.5:1, catalyst loading 2.5%) was added at 1% of the mass of the adsorption material. The temperature in the high temperature zone reached 820 , maintain calcination in an oxygen-free environment for 1.5h;

[0066] Selective leaching and recovery: put the pyrolyzed mixed material into the reaction vessel, adjust the pH to 2.8 with dilute phosphoric acid, add citric acid-sodium thiosulfate composite leaching agent with a ratio of 1.8:1, set the frequency to 30kHz and the power density to 0.6W / cm² in the ultrasonic equipment, and leach for 35min. Transfer the leachate to the electrochemical deposition device, set the current density to 80A / m² and the electrolyte temperature to 30 , recycling heavy metals;

[0067] Internal circulation of pyrolysis gas energy: The pyrolysis gas is dusted by a bag filter and then desulfurized by activated carbon adsorption. The purified pyrolysis gas is mixed with natural gas at a ratio of 1:3 and fed back to the combustion chamber of the pyrolysis furnace to provide heat energy.

[0068] Harmless waste residue resource utilization: Mix the leaching residue and pyrolysis ash in a mass ratio of 2.5:1, add 10% of the total mass of silicate binder, stir evenly and press into shape to prepare a soil conditioner.

[0069] Treatment effect: The adsorption performance of the adsorbent was effectively restored after regeneration, and the adsorbent regeneration rate reached 72%. Analysis of the recovered heavy metals showed a heavy metal recovery rate of 78%. Through energy consumption comparison, the energy consumption reduction rate was 38%. During the treatment process, the pollutant emission compliance rate was 100%, and the waste residue utilization rate reached 95%.

[0070] Example 5

[0071] The specific steps for comprehensive resource recovery treatment of 180 kg of waste ion exchange resin and activated carbon mixed material (mass ratio 2:1) that adsorbs organic pollutants (mainly ketone compounds) are as follows:

[0072] Pretreatment of waste adsorption materials: put the mixed materials into a microwave-assisted crusher, set the microwave power to 600W, crush for 12 minutes, put the mixed materials into a low-temperature plasma treatment equipment under a nitrogen inert atmosphere, set the treatment voltage to 13kV and the temperature to 150 , treated for 20 min for surface modification;

[0073] Oxygen controlled gradient pyrolysis regeneration: the pre-treated mixed material is sent to a multi-temperature zone oxygen controlled pyrolysis furnace, and the low temperature zone of the pyrolysis furnace is heated to 350 The oxygen concentration is controlled at 4.5%, the mixed material stays for 1.2 hours, and the temperature in the medium temperature zone rises to 650 , the oxygen concentration was 11%, and Fe / Ce bimetallic catalyst (Fe to Ce molar ratio 3.5:1, catalyst loading 4%) was added at 2% of the mass of the adsorption material. The temperature in the high temperature zone reached 880 , maintain calcination in an oxygen-free environment for 2.5h;

[0074] Selective leaching and recovery: put the pyrolyzed mixed material into the reaction vessel, adjust the pH to 3.5 with dilute sulfuric acid, add citric acid-sodium thiosulfate composite leaching agent with a ratio of 2.5:1, set the frequency to 38kHz and the power density to 1.0W / cm² in the ultrasonic equipment, leach for 50min, transfer the leachate to the electrochemical deposition device, set the current density to 150A / m² and the electrolyte temperature to 50 , recovering the heavy metals present;

[0075] Internal circulation of pyrolysis gas energy: The pyrolysis gas is dusted by a cyclone dust collector and then desulfurized by activated carbon adsorption. The purified pyrolysis gas is mixed with natural gas at a ratio of 1:3 and fed back to the combustion chamber of the pyrolysis furnace as auxiliary fuel.

[0076] Harmless waste residue resource utilization: Mix the leaching residue and pyrolysis ash in a mass ratio of 4:1, add 13% of the total mass of silicate binder, stir evenly and press into shape to prepare a soil conditioner.

[0077] Treatment effect: The adsorption performance of the regenerated adsorbent is significantly improved, and the adsorbent regeneration rate reaches 78%. Although the adsorbed pollutants are mainly organic pollutants, the heavy metal recovery rate still reaches 83%. Compared with traditional treatment methods, the energy consumption is reduced by 42%. The pollutant emission compliance rate during the treatment process is 100%, and the waste residue utilization rate reaches 97%.

[0078] Comparative Example 1

[0079] 100 kg of the same waste activated carbon as in Example 1 was taken and crushed only by an ordinary mechanical crusher. The crusher parameters were adjusted to crush the activated carbon. Then, simple screening was performed to remove larger particles and fine powder. No other treatment steps such as pyrolysis and chemical leaching were performed.

[0080] Treatment effect: The activated carbon after treatment was tested and found that its internal structure was not effectively repaired, the adsorption performance was limited, and the adsorbent regeneration rate was only 20%. Since no targeted heavy metal recovery method was adopted, heavy metals could not be recovered, and the heavy metal recovery rate was only 10%. The mechanical crushing process consumed a lot of electricity. Compared with the treatment method of the present invention, it not only did not reduce energy consumption, but increased energy consumption due to mechanical treatment, and the energy consumption reduction rate was 0. During the treatment process, due to simple crushing and screening, a large amount of heavy metals and organic pollutants still remained in the activated carbon. Improper subsequent treatment can easily cause pollution, and the pollutant emission compliance rate is only 30%. The treated waste residue is not effectively utilized, and the waste residue utilization rate is only 20%.

[0081] Comparative Example 2

[0082] 100 kg of the same waste activated carbon as in Example 1 was selected and placed in a reactor containing a single acid solution (hydrochloric acid) with a concentration of 5 mol / L at 80 The activated carbon was immersed in the acid solution for 2 hours for desorption and regeneration. After the immersion, the activated carbon was separated from the acid solution by filtration without performing other steps such as pyrolysis and microwave treatment.

[0083] Treatment effect: After testing, the adsorption performance of the activated carbon after treatment has been restored, but the effect is not good. The adsorbent regeneration rate is 40%. Due to the poor selectivity of hydrochloric acid for heavy metals, although some heavy metals can be leached, there are more impurities in the leachate, and subsequent separation is difficult, resulting in a heavy metal recovery rate of only 45%. Hydrochloric acid is corrosive and will produce acidic waste gas and wastewater during use. Improper treatment can easily cause secondary pollution. After testing, the pollutant emission compliance rate is 70%. The pyrolysis gas is not utilized during the treatment process, and the waste residue is not properly treated. Compared with the treatment method of the present invention, the energy consumption reduction rate is only 10%, and the waste residue utilization rate is only 50%.

[0084] In summary, according to the treatment effect indicators of the comprehensive treatment method for recycling waste adsorption materials provided in Examples 1 to 5 and Comparative Examples 1 and 2, the specific data are shown in the following table:

[0085]

[0086] As shown in the table above, the comprehensive treatment method for treating waste adsorption materials proposed by the present invention is significantly different from the traditional single treatment method. By comparing the treatment effects of the embodiments and the comparative examples, from the perspective of adsorbent regeneration rate, the adsorbent regeneration rates of Examples 1 to 5 are between 70% and 80%. For example, in Example 1, the waste activated carbon is subjected to microwave-assisted crushing and screening, low-temperature plasma surface modification, and oxygen-controlled gradient pyrolysis regeneration, and the regeneration rate reaches 70%, while Comparative Example 1 adopts a single physical method, only mechanical crushing and screening, and the regeneration rate is only 20%; the traditional chemical method of Comparative Example 2, using a single acid solution soaking, although the steps are simple, requires long-term high temperature (80°C, 2h) and subsequent wastewater treatment, high energy consumption, and the regeneration rate is only 40%. The present invention uses microwave-assisted crushing (5min), low-temperature plasma (50°C, 10min) High-efficiency pretreatment technologies such as the above shorten the processing time, and the heat self-circulation system significantly reduces the external energy demand, resulting in lower comprehensive energy consumption. In addition, the multi-step coordinated treatment of the present invention can effectively repair the adsorbent structure and restore its adsorption performance, far exceeding the traditional single method. In terms of heavy metal recovery rate, the heavy metal recovery rate in the embodiments is between 75% and 85%. For example, in Example 2, the recovery rate of the waste zeolite molecular sieve that adsorbs multiple heavy metals is 80%. In comparison, the recovery rate of Comparative Example 1 is only 10% due to the lack of targeted recovery. Comparative Example 2 uses a single acid solution with poor selectivity and a recovery rate of only 45%. The citric acid-sodium thiosulfate composite leaching agent used in the present invention is combined with ultrasonic enhanced treatment to greatly improve the heavy metal recovery efficiency; the energy consumption reduction rate is an important indicator for measuring the quality of the treatment method. The energy consumption reduction rate of Examples 1 to 5 is 35%-45%. In Example 3, the pyrolysis gas is purified and then fed back to the pyrolysis furnace as an auxiliary fuel to achieve self-supply of heat energy, thereby reducing energy consumption. The mechanical crushing energy consumption of Comparative Example 1 is high and there is no effect of reducing energy consumption. Although Comparative Example 2 has a certain energy consumption reduction, it is only 10%, which is much lower than the method of the present invention; the pollutant emission compliance rate is higher than that of the present invention. , the examples are all 100%, and the treatment process effectively controls the emission of waste gas and wastewater. Due to simple treatment, the pollutant residues in comparative example 1 are high, and the compliance rate is only 30%; comparative example 2 uses corrosive acid liquid, which produces secondary pollution, and the compliance rate is 70%; the waste residue utilization rate also reflects the environmental protection and resource utilization advantages of the present invention. The waste residue utilization rate of the examples is 95%-98%. For example, in example 5, the leaching residue and pyrolysis ash are made into soil conditioner. The waste residue in comparative example 1 is simply piled up, and the utilization rate is only 20%; the waste residue in comparative example 2 is simply landfilled, and the utilization rate is 50%.

[0087] In summary, the comprehensive resource treatment method for waste adsorption materials of the present invention is superior to traditional single treatment methods in terms of adsorbent regeneration, heavy metal recovery, energy consumption reduction, pollutant control and waste residue utilization. This method realizes efficient resource treatment of waste adsorption materials and reduces environmental pollution.

[0088] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A comprehensive resource treatment method for waste adsorption materials, characterized in that: The specific steps of this method are: S100, the waste adsorption material is crushed and screened by microwave-assisted crushing, and subjected to low-temperature plasma surface modification treatment under an inert atmosphere to destroy the chemical bonds of the surface pollutants; S200, the pretreated adsorption material is fed into a multi-temperature zone oxygen-controlled pyrolysis furnace for pyrolysis. Under gradient temperature conditions, the oxygen concentration is controlled in stages to achieve directional cracking of organic matter and regeneration of the adsorbent microporous structure. An Fe / Ce bimetallic catalyst is simultaneously added to promote pollutant degradation and activation efficiency. The Fe / Ce bimetallic catalyst is a composite solution of ferric nitrate and cerium nitrate, and the addition amount is 0.5%-3% of the mass of the adsorption material, and the molar ratio of Fe to Ce is 2:1-4:1; The multi-temperature zone oxygen-controlled pyrolysis furnace is divided into three temperature zones: Low temperature zone: 200-400℃, oxygen concentration ≤5%, residence time 0.5-1.5h; Medium temperature zone: 500-700℃, oxygen concentration 8-12%, catalyst loading 2-5%; High temperature zone: 800-900℃, oxygen-free environment, calcination time 1-3h; S300, controlling the pH of the pyrolyzed adsorption material, extracting the heavy metals remaining in the adsorption material using a citric acid-sodium thiosulfate composite leaching agent combined with ultrasonic enhanced treatment, and recovering the metal elements from the leachate by electrochemical deposition, wherein the ratio of the citric acid-sodium thiosulfate composite leaching agent is 1.5:1-3:1, and the pH value is controlled at 2.5-4.0; The ultrasonic treatment frequency is 28-40kHz and the power density is 0.5-1.2W / cm 2 , leaching time is 30-60min; The current density of the electrochemical deposition is 50-200A / m 2 , the electrolyte temperature is 25-60℃; S400, after desulfurization and dust removal, the combustible gas generated during the pyrolysis process is returned to the combustion chamber of the pyrolysis furnace as auxiliary fuel for self-supplied heat energy; S500: Mix the adsorption material residue after leaching with the pyrolysis ash, add a silicate binder and press into shape to prepare a soil conditioner, thereby completing comprehensive resource processing.

2. A comprehensive treatment method for waste adsorption materials according to claim 1, characterized in that: During the microwave-assisted fragmentation in S100, the microwave power is 300W-800W, and the fragmentation time is 5min-15min.

3. The method for comprehensive resource treatment of waste adsorption materials according to claim 1, characterized in that: During the low-temperature plasma surface modification treatment in S100, the treatment voltage is 8 kV-15 kV, the treatment temperature is 50° C.-200° C., the treatment time is 10 min-25 min, and the inert atmosphere is one of nitrogen and argon.

4. The method for comprehensive resource treatment of waste adsorption materials according to claim 1, characterized in that: The pyrolysis gas in S400 is mixed with natural gas at a volume ratio of 1:3 after dust removal and activated carbon adsorption desulfurization, and is burned to provide 40-60% of the heat energy input to the pyrolysis furnace; The hydrogen sulfide content in the pyrolysis gas after dust removal and activated carbon adsorption desulfurization is ≤10mg / m 3 , particle concentration ≤ 20mg / m 3 .

5. The method for comprehensive resource recovery of waste adsorption materials according to claim 1, characterized in that: The mixing mass ratio of the adsorption material residue after leaching and the pyrolysis ash in S500 is 2:1-5:1, and the added amount of the silicate binder accounts for 8%-15% of the total mass.

6. The method for comprehensive resource treatment of waste adsorption materials according to claim 1, characterized in that: The waste adsorption material includes at least one of activated carbon, zeolite molecular sieve, and ion exchange resin, and the adsorbed pollutants include at least one of organic compounds and heavy metals.

Images