A catalyst for treating benzene series and polycyclic aromatic hydrocarbons, a preparation method thereof, and a treatment method of acetylene wastewater

Abstract

The application discloses a catalyst for treating benzene series and polycyclic aromatic hydrocarbons, a preparation method of the catalyst and a treatment method of acetylene wastewater. The catalyst carrier is porous carbon prepared from biomass, is pretreated by using silanol, is crosslinked by reaction between silanols to form Si-O-Si structure, is crossed in the porous carbon to form a mechanical interlocking structure, and forms a high-performance porous carbon structure with carbon as a main body and siloxane as a supporting network in a calcination process. The high-performance porous carbon structure has high specific surface area, developed pore structure and excellent mechanical properties, and loads active metal components including iron, nickel, copper, titanium and vanadium in the form of oxides. When the catalyst is used for treating acetylene wastewater containing benzene series and polycyclic aromatic hydrocarbons, the concentration of characteristic pollutants and COD in the wastewater can be effectively reduced, the biodegradability of the wastewater is improved, and the difficulty in treating the wastewater is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, specifically to the treatment of recalcitrant acetylene wastewater, and more specifically to a catalyst for treating benzene compounds and polycyclic aromatic hydrocarbons, as well as a method for treating acetylene wastewater containing benzene compounds and polycyclic aromatic hydrocarbons. Background Technology

[0002] The partial oxidation process for producing acetylene from natural gas involves oxidation and cracking reactions of natural gas and oxygen in an acetylene furnace under high-temperature conditions. 70% of the natural gas is used for oxidation and combustion, providing heat. The significant heat generated by the oxidation reaction heats the remaining 30% of the natural gas, causing it to crack into acetylene at 1200℃–1600℃. The acetylene then reacts further, producing carbon black as a byproduct. Rapid cooling of the cracked gas with water significantly slows down the formation of this byproduct. The carbon black and organic matter in the cracked gas dissolve in the quenched water, resulting in organic wastewater containing a large amount of carbon black. Currently, the industry treats this wastewater by removing carbon black particles through coagulation and flocculation before sending it to a biological treatment system. Because the natural gas cracking reaction mechanism is relatively complex, the cracked gas contains many types of impurities with complex composition, resulting in complex organic components carried in the quench water, including a large amount of benzene series compounds and polycyclic aromatic hydrocarbons, which are toxic to biological bacteria. The wastewater has a high COD and poor biodegradability, posing a great challenge to the stable operation of the biological system. This is a technical problem that urgently needs to be solved in the industry.

[0003] In summary, to solve the problem of difficult wastewater treatment from acetylene plants, there is an urgent need to develop a highly efficient catalyst with high treatment efficiency, low operating costs, and mild reaction conditions. Summary of the Invention

[0004] One of the objectives of this invention is to prepare a highly efficient catalyst for the treatment of wastewater containing benzene compounds and polycyclic aromatic hydrocarbons. The catalyst support is bio-based porous carbon with a mechanically interlocked structure, which overcomes the shortcomings of existing porous carbon such as poor mechanical properties and pore collapse and clogging.

[0005] Another object of the present invention is to provide a method for preparing the catalyst and a method for treating acetylene wastewater containing benzene compounds and polycyclic aromatic hydrocarbons using the catalyst.

[0006] To achieve the above objectives, the technical solution provided by this patent is as follows:

[0007] A catalyst for treating benzene compounds and polycyclic aromatic hydrocarbons comprises a support and an active component, wherein the support is porous carbon prepared from biomass, and the active component comprises iron, nickel, copper, titanium, and vanadium in oxide form.

[0008] As a preferred embodiment, the catalyst contains the following active metals based on the weight of the support:

[0009] Iron 0.1-3 wt%, preferably 1-2 wt%;

[0010] Nickel 0.2–0.9 wt%, preferably 0.3–0.45 wt%;

[0011] Copper 0.05–0.35 wt%, preferably 0.1–0.2 wt%;

[0012] Titanium 0.4–4 wt%, preferably 0.5–1 wt%;

[0013] Vanadium 0.01–0.3 wt%, preferably 0.01–0.19 wt%.

[0014] The catalyst of the present invention is supported by porous carbon prepared from biomass. It is pretreated with silanol to form a mechanically interlocked structure, and a high-performance porous carbon structure with carbon as the main body and siloxane as the supporting network is formed during calcination.

[0015] As a preferred embodiment, the method for preparing the catalyst support includes the following steps:

[0016] S1: Biomass pretreatment: Dry the biomass raw material, control the moisture content to ≤3wt%, crush it to a particle size of 5-10mm, and then soak it in silanol solvent for 24-72h at a temperature of 20-80℃.

[0017] S2: Preparation of bio-based porous carbon: The product of S1 was calcined at 400-800℃ in a nitrogen atmosphere for 1-5 hours;

[0018] S3: Carrier ultrasound: The product of S2 is ultrasounded at an ultrasound frequency of 50-100Hz, a power of 50-200W, and an ultrasound time of 20-50min. Then it is dried at 100-150℃ for 1-5h and then extruded.

[0019] In S1, the biomass is at least one of distiller's grains, rice husks, bamboo shavings, bamboo, and wood chips.

[0020] In S1, the silanol is at least one of trimethylsilanol, dimethylsilanol, methylsilanol, dimethylvinylsilanol, and vinylsilanol.

[0021] The carrier described in this invention has a length of 1-3 cm, a diameter of 0.5-1 cm, a high specific surface area (2000-4000 m² / g), a well-developed pore structure (porosity 85-95%, through pores), and excellent mechanical properties (fracture strength 10-20 MPa).

[0022] The method for preparing the catalyst of the present invention includes the following steps:

[0023] The carrier is pretreated in a vacuum impregnator for 0.5–2 hours at a vacuum level of 5–100 kPa. After pretreatment, the carrier is impregnated in a solution containing iron salts, nickel salts, copper salts, titanium salts, and vanadium salts in equal volumes. The impregnation atmosphere is nitrogen, the impregnation pressure is controlled at gauge pressure of 0.1–1 MPa, and the impregnation time is 1–5 hours. The carrier is then dried and calcined.

[0024] In the catalyst preparation method of the present invention, when the support is treated and stored in an air atmosphere, air will enter the internal pores, occupy the active sites, and affect the adhesion of the active metal. Vacuum pretreatment is used to eliminate the influence of internal air and provide more active sites, and to further remove impurities in the pores.

[0025] In the catalyst preparation method of the present invention, the drying temperature is 105-135℃ and the drying time is 10-60 min.

[0026] In the catalyst preparation method of the present invention, the calcination temperature is 600-900℃ and the calcination time is 0.5-4h.

[0027] The catalyst prepared by this invention is used for the treatment of acetylene containing benzene series and polycyclic aromatic hydrocarbon wastewater. The treatment method includes a raw water tank, a pH adjustment tank, a catalytic reaction tower, and a tail gas adsorption device, and includes the following steps: pumping the oxidant and wastewater into the catalytic reaction tower filled with the catalyst of this invention, wherein the molar ratio of oxidant to COD is 1 to 3.

[0028] In the wastewater treatment method of the present invention, the pH of the wastewater is 6-12, optionally adjusted by acid or alkali; the acid is at least one of boric acid, carbonic acid, sulfuric acid, hydrochloric acid, and nitric acid, with a concentration of 1-98 wt%; the alkali is at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, and calcium hydroxide, with a concentration of 1-32 wt%.

[0029] In the wastewater treatment method of this invention, the temperature of the wastewater is 20–50°C. A water bath can be used to preheat the wastewater so that it can reach the reaction temperature as quickly as possible in the catalytic reaction tower.

[0030] In the wastewater treatment method of this invention, the oxidant is at least one of peracetic acid, sodium hypochlorite, sodium percarbonate, hydrogen peroxide, and potassium persulfate, with an oxidant concentration of 10–27.5 wt% and an oxidant / COD molar ratio controlled at 1–3. The reaction temperature is controlled at 65–95°C, and the HRT (residence time) is controlled at 0.5–5 h.

[0031] Under the action of the catalyst of this invention, the reactants are transformed into reactive structures, and the reaction can be completed under low activation energy conditions. Therefore, the reaction rate is extremely fast. The oxidant acts on the characteristic pollutants in the wastewater to oxidize and break the chain, thereby achieving the purpose of removing COD and improving the biodegradability of the wastewater.

[0032] This invention utilizes biomass to prepare porous carbon and pretreats it with silanols. The silanols react and crosslink to form a Si-O-Si structure, which is interwoven within the porous carbon. During calcination, a mechanically interlocked structure is formed with porous carbon as the main body and siloxanes as the supporting network. This produces a bio-based porous carbon carrier with high specific surface area (2000-4000 m² / g), well-developed pore structure (porosity 85-95%, through pores), and excellent mechanical properties (fracture strength 10-20 MPa). This overcomes the shortcomings of existing porous carbon materials, such as poor mechanical properties (fracture strength <1 MPa), pore collapse during calcination, and difficulty in practical application.

[0033] This invention can bring the following effects:

[0034] (1) A highly efficient catalyst for the treatment of wastewater containing benzene series compounds and polycyclic aromatic hydrocarbons was prepared. The catalyst support is bio-based porous carbon with mechanical interlocking structure, which has high specific surface area, high porosity (through pores) and good mechanical properties, overcoming the shortcomings of existing porous carbon such as poor mechanical properties and pore collapse and blockage.

[0035] (2) The reaction conditions are mild and the reaction efficiency is high. The effective removal of benzene compounds and polycyclic aromatic hydrocarbons can be completed quickly at a low temperature and normal pressure.

[0036] (3) It greatly improves the biochemical properties of the effluent, makes the operation of the biochemical system more stable, and ensures that the effluent meets the discharge standards, thus transforming the difficult-to-treat wastewater into easily treatable wastewater and solving the industry problem.

[0037] (4) It requires few control parameters, few limit conditions, and has low operating costs. Except for supplementation, no manual operation is required during operation, and it has good prospects for industrial application. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the process for treating acetylene wastewater according to the present invention. Detailed Implementation

[0039] The following detailed description of the invention is provided in conjunction with specific preferred embodiments. It should be understood that the preferred embodiments are intended to help those skilled in the art better understand the invention and to fully convey the technology. Any experimental form that can realize the invention is protected by the invention and should not be limited to the preferred embodiments.

[0040] COD was measured using the rapid digestion spectrophotometric method for COD in water (HJT 399-2007), and biochemical properties were measured using the dilution and inoculation method (HJ 505-2009). All experimental data met the requirements of industry standards.

[0041] Example 1 Preparation of Catalyst #1

[0042] S1: Biomass pretreatment: The biomass raw material is placed in an oven for drying until the moisture content is 3wt%. Then it is crushed by a crusher. The particle size after crushing is 5-6mm. The crushed biomass particles are soaked in trimethylsilyl alcohol solvent for 24 hours at a temperature of 80℃.

[0043] S2: Preparation of bio-based porous carbon: The pretreated biomass was placed in a muffle furnace and calcined at 600°C in a nitrogen atmosphere for 3 hours.

[0044] S3: After calcination, the prepared bio-based porous carbon with mechanical interlocking structure is taken out and subjected to ultrasonic treatment. The ultrasonic frequency is 100Hz, the power is 50w, and the ultrasonic time is 50min. The ultrasonically treated material is dried at 150℃ for 1h (nitrogen atmosphere), and then extruded into shape using an extruder. The carrier is 3cm long, 0.5cm in diameter, has a porosity of 85%, a specific surface area of ​​4000㎡ / g, and a tensile strength of 13MPa.

[0045] S4: The shaped bio-based porous carbon support was pretreated in a vacuum impregnator for 0.5 h at a vacuum degree of 100 kPa. After pretreatment, the support was impregnated in an equal volume solution containing 1.1 mol / L ferric nitrate, 0.21 mol / L nickel nitrate, 0.13 mol / L copper nitrate, 0.12 mol / L titanium tetrachloride, and 0.11 mol / L sodium vanadate. The impregnation atmosphere was nitrogen, the impregnation pressure was controlled at 0.6 MPa, and the impregnation time was 3 h. After impregnation, the catalyst was removed and placed in a vacuum oven for drying at 105 °C for 60 min. The dried catalyst was then placed in a muffle furnace for calcination at 600 °C for 4 h. After calcination, the final desired catalyst #1 was obtained, containing 2.68 wt% iron, 0.54 wt% nickel, 0.35 wt% copper, 0.25 wt% titanium, and 0.24 wt% vanadium.

[0046] Example 2 Preparation of Catalyst #2

[0047] S1: Biomass pretreatment: The biomass raw material is placed in an oven for drying. After drying, the moisture content is 2.5wt%. Then, it is crushed by a crusher. The particle size after crushing is 9-10mm. The crushed biomass particles are soaked in vinyl silanol solvent for 72 hours at a temperature of 20℃.

[0048] S2: Preparation of bio-based porous carbon: The pretreated biomass was placed in a muffle furnace and calcined at 400°C in a nitrogen atmosphere for 5 hours.

[0049] S3: After calcination, the prepared bio-based porous carbon with mechanical interlocking structure is taken out and subjected to ultrasonic treatment. The ultrasonic frequency is 80Hz, the power is 150w, and the ultrasonic time is 30min. The ultrasonically treated material is dried at 130℃ for 2h (nitrogen atmosphere), and then extruded into shape using an extruder. The carrier is 2cm long, 0.7cm in diameter, has a porosity of 85%, a specific surface area of ​​3500㎡ / g, and a tensile strength of 20MPa.

[0050] S4: The shaped bio-based porous carbon support was pretreated in a vacuum impregnator for 1 hour at a vacuum level of 50 kPa. After pretreatment, the support was impregnated in an equal volume solution containing appropriate amounts of 0.6 mol / L ferric nitrate, 0.3 mol / L nickel nitrate, 0.07 mol / L copper nitrate, 1.88 mol / L titanium tetrachloride, and 0.08 mol / L sodium vanadate. The impregnation atmosphere was nitrogen, the impregnation pressure was controlled at 1 MPa, and the impregnation time was 1 hour. After impregnation, the catalyst was removed and placed in a vacuum oven for drying at 135°C for 10 minutes. The dried catalyst was then placed in a muffle furnace for calcination at 900°C for 0.5 hours. After calcination, the final desired catalyst #2 was obtained, containing 1.46 wt% iron, 0.77 wt% nickel, 0.19 wt% copper, 3.9 wt% titanium, and 0.18 wt% vanadium.

[0051] Example 3 Preparation of Catalyst #3

[0052] S1: Biomass pretreatment: The biomass raw material is placed in an oven for drying. After drying, the moisture content is 1wt%. Then, it is crushed by a crusher. The particle size after crushing is 6-8mm. The crushed biomass particles are soaked in methylsilanol solvent for 46 hours at a temperature of 40℃.

[0053] S2: Preparation of bio-based porous carbon: The pretreated biomass was placed in a muffle furnace and calcined at 800°C in a nitrogen atmosphere for 1 hour;

[0054] S3: After calcination, the prepared bio-based porous carbon with mechanical interlocking structure is taken out and subjected to ultrasonic treatment. The ultrasonic frequency is 50Hz, the power is 200w, and the ultrasonic time is 20min. The ultrasonically treated material is dried at 100℃ for 5h (nitrogen atmosphere), and then extruded into shape using an extruder. The carrier is 1cm long, 1cm in diameter, has a porosity of 90%, a specific surface area of ​​2000㎡ / g, and a tensile strength of 10MPa.

[0055] S4: The shaped bio-based porous carbon support was pretreated in a vacuum impregnator for 2 hours at a vacuum degree of 5 kPa. After pretreatment, the support was impregnated in an equal volume solution containing appropriate amounts of 0.2 mol / L ferric nitrate, 0.1 mol / L nickel nitrate, 0.03 mol / L copper nitrate, 0.67 mol / L titanium tetrachloride, and 0.03 mol / L sodium vanadate. The impregnation atmosphere was nitrogen, the impregnation pressure was controlled at 0.1 MPa, and the impregnation time was 5 hours. After impregnation, the catalyst was removed and placed in a vacuum oven for drying at 120°C for 40 minutes. The dried catalyst was then placed in a muffle furnace for calcination at 700°C for 2 hours. After calcination, the final desired catalyst #3 was obtained, containing 0.49 wt% iron, 0.26 wt% nickel, 0.08 wt% copper, 1.4 wt% titanium, and 0.07 wt% vanadium.

[0056] Example 4: Application of catalyst #3 in acetylene wastewater treatment

[0057] S1: Inject wastewater into the raw water tank, use a peristaltic pump to lift the wastewater to the pH adjustment tank, heat it to 45℃ using a water bath, adjust the peristaltic pump speed to 500ml / min, slowly inject 32wt% sodium hydroxide into the pH adjustment tank using a peristaltic pump to control the pH of the wastewater to about 11, use a portable pH meter to test the pH of the wastewater in the pH adjustment tank, and after the test is qualified, inject the wastewater in the pH adjustment tank into the catalytic reaction tower through a peristaltic pump;

[0058] S2: The bottom of the catalytic reaction tower is filled with about 75ml of 6mm inert ceramic balls. The inert ceramic balls are used to support the catalyst. After the ceramic balls are filled, about 150ml of No. 3 catalyst is added. The external water bath circulation temperature is controlled at 90℃. The concentration of hydrogen peroxide as oxidant is 27.5wt%. It is injected into the catalytic reaction tower at a rate of 6.6ml / min through a peristaltic pump. The molar ratio of oxidant to COD is 2.

[0059] S3: After reacting in the catalytic reaction tower for 1 hour, the peristaltic pump pumps out the peristaltic water and injects it into the peristaltic water collection tank. The gas generated during the reaction is adsorbed by activated carbon. The activated carbon used is wood-based columnar activated carbon. Under the action of catalyst #3, the reactants are transformed into reactive structures, and the reaction can be completed under low activation energy conditions. Therefore, the reaction rate is extremely fast. It acts on the characteristic pollutants in the wastewater to oxidize and break the chain, thereby achieving the purpose of removing COD and improving the biodegradability of the wastewater.

[0060] The COD, benzene series compounds, polycyclic aromatic hydrocarbons and biochemical properties of the produced water obtained by the above method are shown in Table 1. It can be seen that the catalyst is extremely suitable for the treatment of wastewater containing benzene series compounds and polycyclic aromatic hydrocarbons.

[0061] Table 1 Water Quality Comparison

[0062]

[0063] Example 5: Application of Catalyst #2 in Acetylene Wastewater Treatment

[0064] S1: Inject wastewater into the raw water tank, use a peristaltic pump to lift the wastewater to the pH adjustment tank, heat it to 30℃ using a water bath, adjust the peristaltic pump speed to 250ml / min, slowly inject 98wt% sulfuric acid into the pH adjustment tank using a peristaltic pump to control the pH of the wastewater to about 6, use a portable pH meter to test the pH of the wastewater in the pH adjustment tank, and after the test is qualified, inject the wastewater in the pH adjustment tank into the catalytic reaction tower through a peristaltic pump;

[0065] S2: The bottom of the catalytic reaction tower is filled with about 75ml of 6mm inert ceramic balls. The inert ceramic balls are used to support the catalyst. After the ceramic balls are filled, about 150ml of No. 2 catalyst is added. The external water bath circulation temperature is controlled at 65℃. The concentration of sodium hypochlorite as oxidant is 10wt%. It is injected into the catalytic reaction tower at a rate of 26.8ml / min through a peristaltic pump. The molar ratio of oxidant to COD is 1.

[0066] S3: After reacting in the catalytic reaction tower for 5 hours, the peristaltic pump pumps out the peristaltic water and injects it into the peristaltic water collection tank. The gas generated during the reaction is adsorbed by activated carbon. The activated carbon used is wood-based columnar activated carbon. Under the action of catalyst #2, the reactants are transformed into reactive structures, and the reaction can be completed under low activation energy conditions. Therefore, the reaction rate is extremely fast. It acts on the characteristic pollutants in the wastewater to oxidize and break the chain, thereby achieving the purpose of removing COD and improving the biodegradability of the wastewater.

[0067] The COD, benzene series compounds, polycyclic aromatic hydrocarbons and biochemical properties of the produced water obtained by the above method are shown in Table 2. It can be seen that the catalyst is extremely suitable for the treatment of wastewater containing benzene series compounds and polycyclic aromatic hydrocarbons.

[0068] Table 2 Water Quality Comparison

[0069]

[0070] Example 6: Application of Catalyst #1 in Acetylene Wastewater Treatment

[0071] S1: Inject wastewater into the raw water tank, use a peristaltic pump to lift the wastewater to the pH adjustment tank, heat it to 25℃ using a water bath, adjust the peristaltic pump speed to 50ml / min, slowly inject 1wt% sodium hydroxide into the pH adjustment tank using a peristaltic pump to control the pH of the wastewater to about 9, use a portable pH meter to test the pH of the wastewater in the pH adjustment tank, and after the test is qualified, inject the wastewater in the pH adjustment tank into the catalytic reaction tower through a peristaltic pump;

[0072] S2: The bottom of the catalytic reaction tower is filled with about 75ml of 6mm inert ceramic balls. The inert ceramic balls are used to support the catalyst. After the ceramic balls are filled, about 150ml of No. 1 catalyst is added. The external water bath circulation temperature is controlled at 80℃. The concentration of hydrogen peroxide as oxidant is 27.5wt%. It is injected into the catalytic reaction tower at a rate of 1.5ml / min through a peristaltic pump. The molar ratio of oxidant to COD is 3.

[0073] S3: After reacting in the catalytic reaction tower for 3 hours, the peristaltic pump pumps out the peristaltic water and injects it into the peristaltic water collection tank. The gas generated during the reaction is adsorbed by activated carbon. The activated carbon used is wood-based columnar activated carbon. Under the action of catalyst #1, the reactants are transformed into reactive structures, and the reaction can be completed under low activation energy conditions. Therefore, the reaction rate is extremely fast. It acts on the characteristic pollutants in the wastewater to oxidize and break the chain, thereby achieving the purpose of removing COD and improving the biodegradability of the wastewater.

[0074] The COD, benzene series compounds, polycyclic aromatic hydrocarbons and biochemical properties of the produced water obtained by the above method are shown in Table 3. It can be seen that the catalyst is extremely suitable for the treatment of wastewater containing benzene series compounds and polycyclic aromatic hydrocarbons.

[0075] Table 3 Water Quality Comparison

[0076]

[0077]

[0078] Comparative Example 1

[0079] Catalyst preparation

[0080] S1: Biomass pretreatment: The biomass raw material is placed in an oven for drying. After drying, the moisture content is 1wt%. Then, it is crushed by a crusher. The particle size after crushing is 6-8mm. The crushed biomass particles are soaked in water for 46 hours at a temperature of 40℃.

[0081] S2: Preparation of bio-based porous carbon: The pretreated biomass was placed in a muffle furnace and calcined at 800°C in a nitrogen atmosphere for 1 hour;

[0082] S3: After calcination, the bio-based porous carbon is taken out and subjected to ultrasonic treatment. The ultrasonic frequency is 50Hz, the power is 200w, and the ultrasonic time is 20min. The ultrasonically treated material is dried at 100℃ for 5h (nitrogen atmosphere), and then extruded into shape using an extruder. The carrier is 1cm long, 1cm in diameter, has a porosity of 50%, a specific surface area of ​​400㎡ / g, and a tensile strength of 0.1MPa.

[0083] S4: The shaped bio-based porous carbon support was pretreated in a vacuum impregnator for 2 hours at a vacuum degree of 5 kPa. After pretreatment, the support was impregnated in an equal volume solution containing appropriate amounts of 0.2 mol / L ferric nitrate, 0.1 mol / L nickel nitrate, 0.03 mol / L copper nitrate, 0.67 mol / L titanium tetrachloride, and 0.03 mol / L sodium vanadate. The impregnation atmosphere was nitrogen, the impregnation pressure was controlled at 0.1 MPa gauge pressure, and the impregnation time was 5 hours. After impregnation, the catalyst was removed and placed in a vacuum oven for drying at 120℃ for 40 minutes. The dried catalyst was then placed in a muffle furnace for calcination at 700℃ for 2 hours. After calcination, the resulting catalyst contained 0.49 wt% iron, 0.26 wt% nickel, 0.08 wt% copper, 1.4 wt% titanium, and 0.07 wt% vanadium.

[0084] Wastewater treatment

[0085] S1: Inject wastewater into the raw water tank, use a peristaltic pump to lift the wastewater to the pH adjustment tank, heat it to 45℃ using a water bath, adjust the peristaltic pump speed to 500ml / min, slowly inject 32wt% sodium hydroxide into the pH adjustment tank using a peristaltic pump to control the pH of the wastewater to about 11, use a portable pH meter to test the pH of the wastewater in the pH adjustment tank, and after the test is qualified, inject the wastewater in the pH adjustment tank into the catalytic reaction tower through a peristaltic pump;

[0086] S2: The bottom of the catalytic reaction tower is filled with about 75ml of 6mm inert ceramic balls. The inert ceramic balls are used to support the catalyst. After the ceramic balls are filled, about 150ml of catalyst is added. The external water bath circulation temperature is controlled at 90℃. The concentration of the oxidant hydrogen peroxide is 27.5wt%. It is injected into the catalytic reaction tower at a rate of 6.6ml / min through a peristaltic pump. The oxidant / COD molar ratio is 2.

[0087] S3: After reacting in the catalytic reaction tower for 1 hour, the permeate is pumped out by a peristaltic pump and injected into the permeate collection tank. The gas generated during the reaction is adsorbed by activated carbon, specifically wood-based columnar activated carbon. The COD, benzene series compounds, polycyclic aromatic hydrocarbons, and biochemical properties of the permeate obtained by the above method are shown in Table 4. It can be seen that the effect of this catalyst is far inferior to that of catalyst #3.

[0088] Table 4 Water Quality Comparison

[0089] name <![CDATA[COD / mg.L -1 ]]> <![CDATA[Benzene series / mg.L -1 > <![CDATA[Polycyclic Aromatic Hydrocarbons / mg.L -1 > B / C raw water 1700 100 40 0.14 water production 1400 90 32 0.18

[0090] The specific implementation examples of the present invention have been described in detail above. It should be understood that the above examples are merely illustrative and not exhaustive. For those skilled in the art, any adjustments / modifications to the above implementation examples or equivalent substitutions without departing from the principles of the present invention are obvious. Any solution that falls within the spirit of this patent should be within the scope of this patent.

Claims

1. A catalyst for treating benzene compounds and polycyclic aromatic hydrocarbons, comprising a support and an active component, wherein the support is porous carbon prepared from biomass, and the active component comprises iron, nickel, copper, titanium, and vanadium in oxide form; the method for preparing the support comprises the following steps: S1: Biomass pretreatment: Dry the biomass raw material, control the moisture content to ≤3wt%, crush it to a particle size of 5~10mm, and then soak it in silanol solvent for 24~72h at a temperature of 20~80℃. S2: Preparation of bio-based porous carbon: The product of S1 was calcined at 400~800℃ in a nitrogen atmosphere for 1~5h; S3: Carrier ultrasound: The product of S2 is ultrasounded at an ultrasound frequency of 50~100Hz, a power of 50~200w, and an ultrasound time of 20~50min. Then it is dried at 100~150℃ for 1~5h and then extruded into shape.

2. The catalyst according to claim 1, characterized in that, In the catalyst, the content of active metals, based on the weight of the support, is as follows: Iron 0.1~3wt%; Nickel 0.2~0.9wt%; Copper 0.05~0.35wt%; Titanium 0.4~4wt%; Vanadium 0.01~0.3wt%.

3. The catalyst according to claim 1, characterized in that, In the catalyst, the content of active metals, based on the weight of the support, is as follows: Iron 1~2wt%; Nickel 0.3~0.45wt%; Copper 0.1~0.2wt%; Titanium 0.5~1wt%; Vanadium 0.01~0.19wt%.

4. The catalyst according to claim 1, characterized in that, The carrier has a length of 1-3 cm, a diameter of 0.5-1 cm, a specific surface area of ​​2000-4000 m² / g, a porosity of 85-95%, is through-pore, and has a tensile strength of 10-20 MPa.

5. The catalyst according to claim 1, characterized in that, The biomass is at least one of the following: distiller's grains, rice husks, bamboo shavings, bamboo, and wood chips.

6. The catalyst according to claim 1, characterized in that, The silanol is at least one of trimethylsilanol, dimethylsilanol, methylsilanol, dimethylvinylsilanol, and vinylsilanol.

7. A method for preparing the catalyst according to any one of claims 1-6, comprising the following steps: The carrier is pretreated in a vacuum impregnator for 0.5-2 hours at a vacuum level of 5-100 kPa. After pretreatment, the carrier is impregnated in a solution containing iron salt, nickel salt, copper salt, titanium salt, and vanadium salt in equal volume. The impregnation atmosphere is nitrogen, the impregnation pressure is controlled at 0.1-1 MPa, and the impregnation time is 1-5 hours. The carrier is then dried and calcined.

8. The method according to claim 7, characterized in that, The calcination temperature is 600~900℃, and the time is 0.5~4h.

9. A method for treating acetylene wastewater, comprising the following steps: The oxidant and wastewater are pumped into a catalytic reaction tower filled with the catalyst according to any one of claims 1-6, wherein the molar ratio of oxidant to COD is 1 to 3.

10. The method according to claim 9, characterized in that, The oxidant is at least one of peracetic acid, sodium hypochlorite, sodium percarbonate, hydrogen peroxide, and potassium persulfate.

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