Method for preparing adsorption catalytic composite material by synergistically utilizing waste incineration fly ash and printing and dyeing sludge as well as product and application of adsorption catalytic composite material

Abstract

The invention discloses a method for preparing an adsorption catalytic composite material by synergistically utilizing waste incineration fly ash and printing and dyeing sludge as well as a product and application thereof. The preparation process is simple, the required main raw materials are the waste incineration fly ash and the printing and dyeing sludge, and full resource utilization of the waste incineration fly ash and the printing and dyeing sludge can be achieved. The adsorption and catalysis composite material prepared through secondary pyrolysis has catalysis and adsorption performance, the maximum adsorption capacity of COD (Chemical Oxygen Demand), heavy metal, ammonia nitrogen and total phosphorus is 1563 mg / g, 102 mg / g, 257 mg / g and 186 mg / g, and the converted maximum adsorption capacity of COD, heavy metal, ammonia nitrogen and total phosphorus is 2985 mg / g, 287 mg / g, 443 mg / g and 324 mg / g respectively after the catalytic function is superimposed.

Description

Technical Field

[0001] The present invention belongs to the field of resource utilization of hazardous waste, and particularly relates to a method for co-utilizing incineration fly ash and printing and dyeing sludge to prepare an adsorption and catalytic composite material, as well as products and applications thereof. Background Art

[0002] Incineration fly ash is fine particulate matter generated during the incineration of municipal solid waste, containing a large amount of heavy metals (such as lead, cadmium, mercury, chromium, etc.), dioxins, and other toxic and harmful substances. If these fly ashes are directly landfilled or stacked without effective treatment, heavy metals and organic pollutants will gradually migrate into the soil and water under natural conditions, causing long-term and irreversible environmental pollution. Currently, common methods for treating incineration fly ash include cement solidification, chemical agent stabilization, melting treatment, etc. However, these methods often have problems such as high treatment costs, resource waste, and the risk of secondary pollution. For example, the cement solidification process requires a large amount of cement and other solidifying agents, increasing the treatment cost and volume, and there are still potential risks in the long-term stability of the solidified body; the melting treatment has extremely high equipment requirements, high energy consumption, and the generated glass body is difficult to further utilize.

[0003] Printing and dyeing sludge is waste generated during the textile printing and dyeing process in the printing and dyeing industry, mainly containing a large amount of organic matter, heavy metal ions, and pathogens. Currently, the main treatment methods for printing and dyeing sludge include landfill, incineration, and composting. However, landfill will occupy a large amount of land resources and there is a risk of leachate pollution; incineration treatment requires a large amount of energy consumption and may produce harmful gas emissions; composting is difficult to achieve effective fertilizer utilization due to the complex organic matter and high heavy metal content in printing and dyeing sludge.

[0004] In the context of resource recycling and sustainable development, the co - resource utilization of municipal solid waste incineration fly ash and printing and dyeing sludge to prepare an adsorption - catalytic composite material with high added value can not only effectively solve the disposal problems of these two hazardous wastes, but also develop new environmental treatment materials to turn waste into treasure. Traditional adsorption materials or catalytic materials often have problems such as high costs, scarce raw materials, or complex preparation processes, which limit their application in large - scale environmental remediation projects. However, the various components rich in municipal solid waste incineration fly ash and printing and dyeing sludge, such as minerals like silicon, aluminum, and calcium in fly ash, as well as organic matter and some metal ions in printing and dyeing sludge, provide a rich raw material basis for preparing an adsorption - catalytic composite material with excellent performance. Through scientific and reasonable process design, the effective components in these two wastes can play a synergistic role in the composite material. On the one hand, the minerals in fly ash are used to construct an adsorption matrix with a high specific surface area and a specific pore structure. On the other hand, the organic matter and metal ions in printing and dyeing sludge are used to modify or load on the matrix, thereby endowing the composite material with efficient adsorption performance and catalytic activity to achieve the simultaneous removal and degradation of various pollutants such as dyes and heavy metal ions in wastewater. This not only helps to reduce the cost of environmental treatment, but also promotes the development of the solid waste treatment industry towards the direction of resource - based, harmless, and efficient, with significant social, environmental, and economic benefits. Therefore, it is imperative to research and develop this method. Summary of the Invention

[0005] Object of the Invention: The technical problem to be solved by the present invention is to provide a method for co - utilizing municipal solid waste incineration fly ash and printing and dyeing sludge to prepare an adsorption - catalytic composite material.

[0006] Another technical problem to be solved by the present invention is to provide the adsorption - catalytic composite material prepared by the above - mentioned method.

[0007] The last technical problem to be solved by the present invention is to provide the application of the above - mentioned adsorption - catalytic composite material in the treatment of landfill leachate.

[0008] Technical Solution: To solve the above - mentioned technical problems, the present invention provides a method for co - utilizing municipal solid waste incineration fly ash and printing and dyeing sludge to prepare an adsorption - catalytic composite material, which includes the following steps: (1) Mix printing and dyeing sludge and municipal solid waste incineration fly ash, and stir evenly to obtain fly ash - printing and dyeing sludge. (2) Pyrolyze the fly ash - printing and dyeing sludge, recover the flue gas generated by pyrolysis, and obtain carbonized slag and flue gas dust. (3) Grind the carbonized slag into powder to obtain carbonized powder. (4) Mix water and carbonized powder and stir, and perform solid - liquid separation to obtain the solid as desalted carbonized sludge. (5) Mix flue gas dust, alkali salt, and desalted carbonized sludge, and stir evenly to obtain metal - loaded carbonized mixed sludge. (6) Mix water and the metal-loaded carbonized mixed sludge, stir for 2 to 6 hours, perform solid-liquid separation to obtain a solid, and dry the separated solid to obtain a secondary pre-dried material; (7) Pyrolyze the secondary pre-dried material to obtain an adsorption catalytic composite material.

[0009] Among them, in step (1), the mass ratio of the mixed printing and dyeing sludge to the waste incineration fly ash is 40 to 80:100.

[0010] Among them, in step (2), the pyrolysis temperature is 550 to 850 °C, and the pyrolysis time is 0.5 to 3.5 hours.

[0011] Among them, in step (3), the grinding time is 5 to 25 minutes.

[0012] Among them, in step (4), the liquid-solid ratio of water to carbonized powder is 2.5 to 12.5:1 mL / g, and the stirring time is 0.5 to 2.5 hours.

[0013] Among them, in step (5), the alkali salt is any one of sodium hydroxide, sodium carbonate, calcium oxide, and calcium hydroxide, and the mass ratio of the flue gas dust, alkali salt, and desalted carbonized sludge is (0.5 to 2.5):(4 to 12):100.

[0014] Among them, in step (6), the liquid-solid ratio of water to the metal-loaded carbonized mixed sludge is 1 to 3:1 mL / g.

[0015] Among them, in step (7), the pyrolysis temperature is 550 to 750 °C, and the pyrolysis time is 0.5 to 2.5 hours.

[0016] The present invention also includes the adsorption catalytic composite material prepared by the above method.

[0017] The present invention also includes the application of the adsorption catalytic composite material in the treatment of landfill leachate.

[0018] The reaction mechanism of the present invention is as follows: fly ash printing and dyeing mud is pyrolyzed, and organic pollutants in the printing and dyeing mud are pyrolyzed to form a carbon-based surface. The heat released by the pyrolysis of organic pollutants and the generated gases have a thermal excitation effect on the mineral components in the fly ash printing and dyeing mud, promote the fusion of minerals in the fly ash printing and dyeing mud, and intermix with the formed carbon. At the same time, the inorganic chloride salts in the printing and dyeing mud and the fly ash of garbage incineration are promoted to continuously undergo chlorination reactions with heavy metal pollutants through carbon thermal chlorination and volatilize into the flue gas. Water and carbonized powder are mixed, and the soluble inorganic salts in the carbonized powder are dissolved in water and removed by solid-liquid separation. Water and metal-loaded carbonized mixed mud are mixed, and the alkali salt releases hydroxide during the stirring process, which reacts with heavy metal chloride to form a heavy metal hydroxide coprecipitate. The formed heavy metal hydroxide coprecipitate is attached to the surface of the carbon material or filled in the pores of the carbon material. The secondary pre-baked material is pyrolyzed, and the heavy metal hydroxide coprecipitate is decomposed to form heavy metal oxides. Some heavy metal oxides are combined with carbon to be further reduced, thereby obtaining an adsorption catalytic composite material mixed with heavy metal oxides, heavy metal elements, carbon materials, and inorganic minerals.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following advantages: the preparation process of the present invention is simple, the main raw materials required are waste incineration fly ash and printing and dyeing sludge, and the full resource utilization of waste incineration fly ash and printing and dyeing sludge can be achieved. The adsorption catalytic composite material prepared by secondary pyrolysis of the present invention has both catalytic and adsorption properties, and the maximum adsorption capacity of COD, heavy metals, ammonia nitrogen and total phosphorus is 1563mg / g, 102mg / g, 257mg / g, and 186mg / g. After superimposing the catalytic function, the converted maximum COD, heavy metals, ammonia nitrogen and total phosphorus adsorption capacity are 2985mg / g, 287mg / g, 443mg / g, and 324mg / g, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a flow chart of the processing method of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] Preparation of landfill leachate and mercury-containing landfill leachate: The landfill leachate used in the experiment was taken from Zhuji Sanfeng Environmental Protection Energy Co., Ltd. The COD mass concentration of this batch of landfill leachate was 4152 mg / L, the total phosphorus concentration was 305 mg / L, and the ammonia nitrogen concentration was 1075 mg / L. 500 mg of mercury was added to 1 L of landfill leachate and stirred evenly to prepare mercury-containing landfill leachate.

[0023] Waste incineration fly ash: The waste incineration fly ash was provided by the Second Domestic Waste Incineration Power Plant in Changshu, Jiangsu, and mainly included 38.14% CaO, 24.05% Cl, 10.21% SO3, 12.15% Na2O, 6.21% K2O, 3.17% SiO2, 1.41% Fe2O3, 1.19% Al2O3 and other components (loss on ignition and other inevitable impurities).

[0024] Printing and dyeing sludge: The printing and dyeing sludge was provided by Shaoxing Keqiao Tianyu Printing and Dyeing Co., Ltd., and its chemical components mainly included 43.86% SO3, 36.34% Fe2O3, 7.01% SiO2, 5.82% Al2O3, 2.93% CaO and other components (loss on ignition and other inevitable impurities).

[0025] Example 1 Influence of the mass ratio of printing and dyeing sludge to waste incineration fly ash on the performance of the prepared adsorption and catalytic composite material The printing and dyeing sludge and waste incineration fly ash were mixed at mass ratios of 25:100, 30:100, 35:100, 40:100, 60:100, 80:100, 90:100, 100:100, and 110:100 respectively, stirred evenly to obtain 9 portions of fly ash printing and dyeing sludge. The 9 portions of fly ash printing and dyeing sludge were pyrolyzed respectively, and the flue gas generated by pyrolysis was recovered to obtain 9 portions of carbonized slag and 9 portions of flue gas dust. The pyrolysis temperature was 550 °C and the pyrolysis time was 0.5 hour. The 9 portions of carbonized slag were ground into powder to obtain 9 portions of carbonized powder, and the grinding time was 5 minutes. Water and the 9 portions of carbonized powder were mixed at a liquid-solid ratio of 2.5:1 mL / g, stirred for 0.5 hour, and then solid-liquid separation was carried out. The separated solid was desalted carbonized sludge. The flue gas dust, alkali salt and desalted carbonized sludge were mixed at a mass ratio of 0.5:4:100, stirred evenly to obtain 9 portions of metal-loaded carbonized mixed sludge, and the alkali salt was sodium hydroxide. Water and the 9 portions of metal-loaded carbonized mixed sludge were mixed at a liquid-solid ratio of 1:1 mL / g, stirred for 2 hours, and then solid-liquid separation was carried out. The separated solid was dried to obtain 9 portions of secondary pre-dried materials. The 9 portions of secondary pre-dried materials were pyrolyzed to obtain 9 portions of adsorption and catalytic composite materials, and the pyrolysis temperature was 550 °C and the pyrolysis time was 0.5 hour.

[0026] Adsorption test: The 9 portions of 1 g adsorption and catalytic composite materials were respectively put into 1 L of mercury-containing landfill leachate, stirred at a speed of 120 rmp for 120 min, and then centrifuged at a speed of 5000 rpm for solid-liquid separation. The concentrations of different pollutants in the separated liquid were detected and the adsorption capacity was calculated. The specific detection and calculation are as follows: Detection of COD concentration and calculation of COD adsorption capacity: The chemical oxygen demand (COD) concentration of the leachate was determined according to the national standard "Water Quality - Determination of Chemical Oxygen Demand - Dichromate Method" (GB 11914-1989). The COD removal capacity was calculated according to formula (1), where is the COD adsorption capacity (mg / g), and are the COD concentrations (mg / L) of the mercury-containing landfill leachate before and after treatment, respectively. m is the mass of the adsorption catalytic composite material (1 g), and V is the volume of the mercury-containing landfill leachate (1 L).

[0027]

[0028] Total phosphorus concentration detection and total phosphorus adsorption capacity calculation: The total phosphorus concentration of the leachate is determined according to the standard "Water Quality - Determination of Phosphate and Total Phosphorus - Continuous Flow - Ammonium Molybdate Spectrophotometry" (HJ 670-2013). The total phosphorus adsorption capacity is calculated according to formula (2), where is the total phosphorus adsorption capacity (mg / g), and are the total phosphorus concentrations (mg / L) of the domestic waste landfill leachate before and after treatment, respectively. m is the mass of the adsorption catalytic composite material (1 g), and V is the volume of the mercury-containing landfill leachate (1 L).

[0029]

[0030] Ammonia nitrogen concentration detection and ammonia nitrogen adsorption capacity calculation: The concentration of ammonia nitrogen in the leachate is determined according to "Water Quality - Determination of Ammonia Nitrogen - Salicylic Acid Spectrophotometry" (HJ536-2009). The ammonia nitrogen adsorption capacity is calculated according to formula (3), where is the ammonia nitrogen adsorption capacity (mg / g), is the initial concentration of ammonia nitrogen in the leachate before treatment (mg / L), is the remaining concentration of ammonia nitrogen in the treated leachate (mg / L). m is the mass of the adsorption catalytic composite material (1 g), and V is the volume of the mercury-containing landfill leachate (1 L).

[0031]

[0032] Mercury ion concentration detection and adsorption capacity calculation: The mercury ion concentration in the leachate is determined according to "Water Quality - Determination of Mercury, Arsenic, Selenium, Bismuth and Antimony - Atomic Fluorescence Spectrometry" (HJ 694-2014). The mercury ion adsorption capacity is calculated according to formula (4), where is the mercury ion adsorption capacity (mg / g), is the initial concentration of mercury ions in the leachate before treatment, (mg / L), is the mercury ion concentration in the treated leachate (mg / L). m is the mass of the adsorption catalytic composite material (1 g), and V is the volume of the mercury-containing landfill leachate (1 L).

[0033]

[0034] The test results of this example are shown in Table 1.

[0035] Table 1 Influence of the mass ratio of printing and dyeing sludge to fly ash from waste incineration on the performance of the prepared adsorption and catalytic composite material

[0036] As can be seen from Table 1, when the mass ratio of printing and dyeing sludge to fly ash from waste incineration is less than 40:100 (as in Table 1, when the mass ratio of printing and dyeing sludge to fly ash from waste incineration = 35:100, 30:100, 25:100 and lower ratios not listed in Table 1), the addition of printing and dyeing sludge is less, and the reaction between printing and dyeing sludge and fly ash from waste incineration is insufficient during the subsequent pyrolysis process, resulting in a significant decrease in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacities of the prepared adsorption and catalytic composite material with the decrease in the mass ratio of printing and dyeing sludge to fly ash from waste incineration. When the mass ratio of printing and dyeing sludge to fly ash from waste incineration is equal to 40 - 80:100 (as in Table 1, when the mass ratio of printing and dyeing sludge to fly ash from waste incineration = 40:100, 60:100, 80:100), the fly ash and printing and dyeing sludge are pyrolyzed, and the organic pollutants in the printing and dyeing sludge undergo pyrolysis to form a carbon-based surface. The heat released and the gases generated during the pyrolysis of organic pollutants have a thermal excitation effect on the mineral components in the fly ash and printing and dyeing sludge, promoting the fusion of the minerals in the fly ash and printing and dyeing sludge and intermixing with the formed carbon. At the same time, through carbothermal chlorination, the inorganic chlorides and heavy metal pollutants in the printing and dyeing sludge and fly ash from waste incineration continue to undergo chlorination reactions and volatilize into the flue gas. Finally, the COD removal capacity of the prepared adsorption and catalytic composite material is higher than 1123 mg / g, the total phosphorus removal capacity is higher than 76 mg / g, the ammonia nitrogen removal capacity is higher than 189 mg / g, and the mercury removal capacity is higher than 145 mg / g. When the mass ratio of printing and dyeing sludge to fly ash from waste incineration is greater than 80:100 (as in Table 1, when the mass ratio of printing and dyeing sludge to fly ash from waste incineration = 90:100, 100:100, 110:100 and higher ratios not listed in Table 1), the addition of printing and dyeing sludge is excessive, and the reaction between printing and dyeing sludge and fly ash from waste incineration is unbalanced during the pyrolysis process, resulting in a significant decrease in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacities of the prepared adsorption and catalytic composite material with the further increase in the mass ratio of printing and dyeing sludge to fly ash from waste incineration. Generally speaking, considering the benefits and costs, when the mass ratio of printing and dyeing sludge to fly ash from waste incineration is equal to 40 - 80:100, it is most beneficial to improve the performance of the prepared adsorption and catalytic composite material.

[0037] Example 2 Influence of the mass ratio of flue gas dust, alkali salts, and desalted carbonized sludge on the performance of the prepared adsorption and catalytic composite material Mix printing and dyeing sludge and municipal solid waste incineration fly ash in a mass ratio of 80:100, stir evenly to obtain fly ash printing and dyeing mud. Pyrolyze the fly ash printing and dyeing mud, recover the flue gas generated by pyrolysis, and obtain carbonized slag and flue gas dust, where the pyrolysis temperature is 700 °C and the pyrolysis time is 2 hours. Grind the carbonized slag into powder to obtain carbonized powder, where the grinding time is 15 minutes. Mix water and carbonized powder in a liquid-solid ratio of 7.5:1 mL / g, stir for 1.5 hours, and perform solid-liquid separation. The separated solid is desalted carbonized mud. Mix flue gas dust, alkali salt, and desalted carbonized mud in mass ratios of 0.25:4:100, 0.3:4:100, 0.4:4:100, 0.5:2.5:100, 0.5:3:100, 0.5:3.5:100, 0.5:4:100, 1.5:4:100, 2.5:4:100, 0.5:8:100, 1.5:8:100, 2.5:8:100, 0.5:12:100, 1.5:12:100, 2.5:12:100, 2.5:14:100, 2.5:16:100, 2.5:18:100, 3:12:100, 3.5:12:100, 4:12:100 respectively, stir evenly to obtain 21 portions of metal-loaded carbonized mixed mud, where the alkali salt is sodium carbonate. Mix water and 21 portions of metal-loaded carbonized mixed mud in a liquid-solid ratio of 2:1 mL / g, stir for 4 hours, perform solid-liquid separation, and dry the separated solid to obtain 21 portions of secondary pre-dried materials. Pyrolyze the 21 portions of secondary pre-dried materials to obtain 21 portions of adsorption and catalytic composite materials, where the pyrolysis temperature is 650 °C and the pyrolysis time is 1.5 hours.

[0038] Perform adsorption tests, COD concentration detection and COD adsorption capacity calculation, total phosphorus concentration detection and total phosphorus adsorption capacity calculation, ammonia nitrogen concentration detection and ammonia nitrogen adsorption capacity calculation, and mercury ion concentration detection and adsorption capacity calculation on 21 portions of adsorption and catalytic composite materials. The calculation methods are the same as those in Example 1. The test results of this example are shown in Table 2.

[0039] Table 2 Influence of mass ratio of flue gas dust, alkali salt and desalted carbonized mud on the performance of the prepared adsorption and catalytic composite material

[0040] It can be seen from Table 2 that when the mass ratio of flue gas dust, alkali salt and desalted carbonized mud is less than 0.5:4:100 (such as in Table 2, the mass ratio of flue gas dust, alkali salt and desalted carbonized mud = 0.5:3.5:100, 0.5:3:100, 0.5:2.5:100, 0.4:4:100, 0.3:4:100, 0.25:4:100 and lower ratios not listed in Table 2), the addition of flue gas dust and alkali salt is small, and the flue gas dust, alkali salt and desalted carbonized mud do not react fully during the pyrolysis of the secondary pre-baked material, resulting in the COD, total phosphorus, ammonia nitrogen and mercury removal capacity of the prepared adsorption catalyst being significantly reduced with the decrease of the mass ratio of flue gas dust, alkali salt and desalted carbonized mud. When the mass ratio of flue gas dust, alkali salt and desalination carbonization mud is equal to 0.5~2.5:4~12:100 (as in Table 2, the mass ratio of flue gas dust, alkali salt and desalination carbonization mud = 0.5:4:100, 1.5:4:100, 2.5:4:100, 0.5:8:100, 1.5:8:100, 2.5:8:100, 0.5:12:100, 1.5:12:100, 2.5:12:100), water and carbonization powder are mixed, and the soluble inorganic salts in the carbonization powder are dissolved in water and removed by solid-liquid separation. When mixing water and metal-loaded carbonization mixed mud, the alkali salt releases hydroxide during the stirring process, which reacts with heavy metal chloride to form heavy metal hydroxide co-precipitation. The formed heavy metal hydroxide co-precipitation is attached to the surface of the carbon material or filled in the pores of the carbon material. The secondary pre-baked material is pyrolyzed, and the heavy metal hydroxide coprecipitation is decomposed to form heavy metal oxides. Some heavy metal oxides are further reduced by combining with carbon, thereby obtaining an adsorption catalytic composite material mixed with heavy metal oxides, heavy metal elements, carbon materials, and inorganic minerals. Finally, the prepared adsorption catalytic composite material has a COD removal capacity higher than 1208 mg / g, a total phosphorus removal capacity higher than 86 mg / g, an ammonia nitrogen removal capacity higher than 205 mg / g, and a mercury removal capacity higher than 157 mg / g. When the mass ratio of flue gas dust, alkali salt and desalination carbonized mud is greater than 2.5:12:100 (as in Table 2, the mass ratio of flue gas dust, alkali salt and desalination carbonized mud = 2.5:14:100, 2.5:16:100, 2.5:18:100, 3:12:100, 3.5:12:100, 4:12:100 and higher ratios not listed in Table 2), the flue gas dust and alkali salt are added excessively, and the reaction of flue gas dust, alkali salt and desalination carbonized mud is unbalanced during the secondary pyrolysis process, resulting in the COD, total phosphorus, ammonia nitrogen and mercury removal capacity of the prepared adsorption catalytic composite material significantly decreasing with the further increase of the mass ratio of flue gas dust, alkali salt and desalination carbonized mud. In summary, considering the benefits and costs, when the mass ratio of flue gas dust, alkali salt and desalted carbonized mud is equal to 0.5~2.5:4~12:100, it is most conducive to improving the performance of the prepared adsorption catalytic composite material.

[0041] Example 3: Influence of Secondary Pyrolysis Temperature on the Performance of the Prepared Adsorption Catalytic Composite Material Mix 9 parts of printing and dyeing sludge and 9 parts of MSWI fly ash respectively according to a mass ratio of 80:100, stir evenly to obtain 9 parts of fly ash printing and dyeing mud. Pyrolyze the 9 parts of fly ash printing and dyeing mud, recover the flue gas generated by pyrolysis, and obtain 9 parts of carbonized slag and 9 parts of flue gas dust, where the pyrolysis temperature is 850 °C and the pyrolysis time is 3.5 hours. Grind the 9 parts of carbonized slag into powder to obtain 9 parts of carbonized powder, where the grinding time is 25 minutes. Mix water and 9 parts of carbonized powder respectively according to a liquid-solid ratio of 12.5:1 mL / g, stir for 2.5 hours, and perform solid-liquid separation. The separated solid is desalted carbonized mud. Mix flue gas dust, alkali salt and desalted carbonized mud respectively according to a mass ratio of 2.5:12:100, stir evenly to obtain 9 parts of metal-loaded carbonized mixed mud, where the alkali salt is calcium oxide. Mix water and metal-loaded carbonized mixed mud according to a liquid-solid ratio of 3:1 mL / g, stir for 6 hours, perform solid-liquid separation, and dry the separated solid to obtain 9 parts of secondary pre-dried material. Pyrolyze the 9 parts of secondary pre-dried material respectively to obtain an adsorption catalytic composite material, where the pyrolysis temperatures are 475 °C, 500 °C, 525 °C, 550 °C, 650 °C, 750 °C, 775 °C, 800 °C, 825 °C respectively, and the pyrolysis time is 2.5 hours.

[0042] Perform adsorption tests, COD concentration detection and COD adsorption capacity calculation, total phosphorus concentration detection and total phosphorus adsorption capacity calculation, ammonia nitrogen concentration detection and ammonia nitrogen adsorption capacity calculation, mercury ion concentration detection and adsorption capacity calculation on the 9 parts of adsorption catalytic composite materials respectively. The experimental methods are the same as those in Example 1. The test results of this example are shown in Table 3.

[0043] Table 3 Influence of Secondary Pyrolysis Temperature on the Performance of the Prepared Adsorption Catalytic Composite Material

[0044] It can be seen from Table 3 that when the secondary pyrolysis temperature is less than 550°C (such as in Table 3, the secondary pyrolysis temperature = 0.5:3.5:100, 0.5:3:100, 0.5:2.5:100, 0.4:4:100, 0.3:4:100, 0.25:4:100 and lower ratios not listed in Table 3), the pyrolysis temperature is low, and the material reaction is insufficient during the pyrolysis of the secondary pre-baked material, resulting in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacity of the prepared adsorption catalytic composite material being significantly reduced as the secondary pyrolysis temperature decreases. When the secondary pyrolysis temperature is equal to 550~750°C (such as in Table 3, the secondary pyrolysis temperature = 550°C, 650°C, 750°C), the secondary pre-baked material is pyrolyzed, and the heavy metal hydroxide co-precipitation is decomposed to form heavy metal oxides. Some heavy metal oxides are further reduced by combining with carbon, thereby obtaining an adsorption catalytic composite material mixed with heavy metal oxides, heavy metal elements, carbon materials, and inorganic minerals. Finally, the COD removal capacity prepared was higher than 1412 mg / g, the total phosphorus removal capacity was higher than 96 mg / g, the ammonia nitrogen removal capacity was higher than 223 mg / g, and the mercury removal capacity was higher than 168 mg / g. When the secondary pyrolysis temperature was greater than 750 °C (as shown in Table 3, the secondary pyrolysis temperature = 775 °C, 800 °C, 825 °C, and higher ratios not listed in Table 3), the secondary pyrolysis temperature was too high, and the material reaction was unbalanced during the secondary pyrolysis process, resulting in the COD, total phosphorus, ammonia nitrogen, and mercury removal capacity of the prepared adsorption catalytic composite material being significantly reduced as the secondary pyrolysis temperature further increased. In summary, combining benefits and costs, when the secondary pyrolysis temperature is equal to 550~750 °C, it is most conducive to improving the performance of the prepared adsorption catalytic composite material.

[0045] Comparative example: Effects of different comparative processes on the performance of prepared adsorption catalytic composite materials The process of the present invention is as follows: the printing and dyeing sludge and the waste incineration fly ash are mixed in a mass ratio of 80:100, stirred evenly, and fly ash printing and dyeing mud is obtained. The fly ash printing and dyeing mud is pyrolyzed, and the flue gas generated by the pyrolysis is recovered to obtain carbonized slag and flue gas dust, wherein the pyrolysis temperature is 850°C and the pyrolysis time is 3.5 hours. The carbonized slag is ground into powder to obtain carbonized powder, wherein the grinding time is 25 minutes. Water and carbonized powder are mixed in a liquid-solid ratio of 12.5:1mL / g, stirred for 2.5 hours, and the solid-liquid separation is performed, and the separated solid is desalted carbonized mud. Flue gas dust, alkali salt and desalted carbonized mud are mixed in a mass ratio of 2.5:12:100, stirred evenly, and metal-loaded carbonized mixed mud is obtained, wherein the alkali salt is calcium hydroxide. Water and metal-loaded carbonized mixed mud are mixed in a liquid-solid ratio of 3:1mL / g, stirred for 4 hours, and the solid-liquid separation is performed, and the separated solid is dried to obtain a secondary pre-baked material. The secondary pre-baked material is pyrolyzed to obtain an adsorption catalytic composite material, wherein the pyrolysis temperature is 650° C. and the pyrolysis time is 2.5 hours.

[0046] Comparative Process 1: Mix printing and dyeing sludge and municipal solid waste incineration fly ash in a mass ratio of 80:100, stir evenly to obtain fly ash printing and dyeing mud. Pyrolyze the fly ash printing and dyeing mud, recover the flue gas generated by pyrolysis, and obtain carbonized slag and flue gas dust. The pyrolysis temperature is 850 °C and the pyrolysis time is 3.5 hours. Grind the carbonized slag into powder to obtain carbonized powder, with a grinding time of 25 minutes. Mix water and carbonized powder in a liquid-solid ratio of 12.5:1 mL / g, stir for 2.5 hours, and perform solid-liquid separation. The separated solid is desalted carbonized mud. Mix flue gas dust and desalted carbonized mud in a mass ratio of 2.5:100, stir evenly to obtain mixed dust and mud. Mix water and mixed dust and mud in a liquid-solid ratio of 3:1 mL / g, stir for 4 hours, perform solid-liquid separation, and dry the separated solid to obtain secondary pre-dried material. Pyrolyze the secondary pre-dried material to obtain an adsorption and catalytic composite material, where the pyrolysis temperature is 650 °C and the pyrolysis time is 2.5 hours.

[0047] Comparative Process 2: Mix printing and dyeing sludge and municipal solid waste incineration fly ash in a mass ratio of 80:100, stir evenly to obtain fly ash printing and dyeing mud. Pyrolyze the fly ash printing and dyeing mud, recover the flue gas generated by pyrolysis, and obtain carbonized slag and flue gas dust. The pyrolysis temperature is 850 °C and the pyrolysis time is 3.5 hours. Grind the carbonized slag into powder to obtain carbonized powder, with a grinding time of 25 minutes. Mix water and carbonized powder in a liquid-solid ratio of 12.5:1 mL / g, stir for 2.5 hours, and perform solid-liquid separation. The separated solid is desalted carbonized mud. Mix flue gas dust, alkali salt, and desalted carbonized mud in a mass ratio of 2.5:12:100, stir evenly to obtain a metal-loaded carbonized mixed mud, where the alkali salt is calcium hydroxide. Mix water and metal-loaded carbonized mixed mud in a liquid-solid ratio of 3:1 mL / g, stir for 4 hours, perform solid-liquid separation, and dry the separated solid to obtain an adsorption and catalytic composite material.

[0048] Photocatalytic removal test: Respectively put 1 g of the catalytic composite material prepared by the process of the present invention, the adsorption and catalytic composite materials prepared by Comparative Process 1 and Comparative Process 2 into 1 L of mercury-containing landfill leachate, stir at a speed of 120 rpm while irradiating with an ultraviolet lamp for 120 min or without ultraviolet lamp irradiation, and then centrifuge at a speed of 5000 rpm for solid-liquid separation. Detect the concentrations of different pollutants in the separated liquid and calculate the removal rate. The specific detection and calculation are the same as in Example 1.

[0049] The adsorption test, COD concentration detection and COD adsorption capacity calculation, total phosphorus concentration detection and total phosphorus adsorption capacity calculation, ammonia nitrogen concentration detection and ammonia nitrogen adsorption capacity calculation, mercury ion concentration detection and adsorption capacity calculation are all the same as in Example 1. The test results of this example are shown in 4.

[0050] Table 4 Influence of different comparative processes on the performance of the prepared adsorption and catalytic composite material

[0051] As can be seen from Table 4, the adsorption composite catalytic material prepared by the process of the present invention has remarkable adsorption and photocatalytic properties. The COD, total phosphorus, ammonia nitrogen, and mercury removal capacities achieved by the composite catalytic material prepared by the process of the present invention are significantly higher than those of Comparative Process 1 and Comparative Process 2 under the corresponding conditions with or without light.

Claims

1. A method for co - utilizing waste incineration fly ash and printing and dyeing sludge to prepare an adsorption - catalytic composite material, characterized in that, It includes the following steps: (1) Mix printing and dyeing sludge and fly ash from waste incineration, and stir evenly to obtain fly ash printing and dyeing mud; (2) Pyrolyze the fly ash printing and dyeing mud, recover the flue gas generated by pyrolysis, and obtain carbonized slag and flue gas dust; (3) Grind the carbonized slag into powder to obtain carbonized powder; (4) Mix water and carbonized powder and stir, and perform solid-liquid separation to obtain the solid as desalted carbonized mud; (5) Mix flue gas dust, alkali salt and desalted carbonized mud, and stir evenly to obtain metal-loaded carbonized mixed mud; (6) Mix water and metal-loaded carbonized mixed mud, stir for 2 to 6 hours, perform solid-liquid separation to obtain the solid, and dry the separated solid to obtain a secondary pre-dried material; (7) Pyrolyze the secondary pre-dried material to obtain an adsorption and catalytic composite material.

2. The method for co-using incineration fly ash and printing and dyeing sludge to prepare an adsorption and catalytic composite material according to claim 1, characterized in that, In step (1), the mass ratio of the mixed printing and dyeing sludge to the fly ash from waste incineration is 40 to 80:

100.

3. The method for co-utilizing waste incineration fly ash and printing and dyeing sludge to prepare an adsorption and catalytic composite material according to claim 1, characterized in that, In step (2), the pyrolysis temperature is 550 to 850 °C, and the pyrolysis time is 0.5 to 3.5 hours.

4. The method for co-utilizing waste incineration fly ash and printing and dyeing sludge to prepare an adsorption and catalytic composite material according to claim 1, wherein, The grinding time in step (3) is 5 to 25 minutes.

5. The method for co-using waste incineration fly ash and printing and dyeing sludge to prepare an adsorption and catalytic composite material according to claim 1, wherein In step (4), the liquid-solid ratio of water to carbonized powder is 2.5 to 12.5:1 mL / g, and the stirring time is 0.5 to 2.5 hours.

6. The method for co-utilizing waste incineration fly ash and printing and dyeing sludge to prepare an adsorption and catalytic composite material according to claim 1, characterized in that, In step (5), the alkali salt is any one of sodium hydroxide, sodium carbonate, calcium oxide, and calcium hydroxide, and the mass ratio of the flue gas dust, alkali salt and desalted carbonized mud is (0.5 to 2.5):(4 to 12):

100.

7. The method for co-utilizing waste incineration fly ash and printing and dyeing sludge to prepare an adsorption and catalytic composite material according to claim 1, characterized in that, In step (6), the liquid-solid ratio of water to metal-loaded carbonized mixed mud is 1 to 3:1 mL / g.

8. The method for co-utilizing waste incineration fly ash and printing and dyeing sludge to prepare an adsorption and catalytic composite material according to claim 1, characterized in that, In step (7), the pyrolysis temperature is 550 to 750 °C, and the pyrolysis time is 0.5 to 2.5 hours.

9. An adsorption and catalytic composite material prepared by the method according to any one of claims 1 to 8.

10. Application of the adsorption and catalytic composite material according to claim 9 in the treatment of landfill leachate.

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