CN102276081A - Process for treating industrial organic waste water by serial catalytic oxidization - Google Patents

Abstract

The invention relates to a process for treating industrial organic waste water by serial catalytic oxidization and belongs to the technical field of environment protection. The process for treating industrial organic waste water by serial catalytic oxidization realizes the quick treatment of complex organic pollutants in pretreated industrial waste water by coordination between oxidizers in a mode of serially connecting and coordinating catalytic oxidization by ozone and catalytic oxidization by hydrogen peroxide. In the first catalytic oxidization process, a large amount of free radicals are formed by catalytic oxidization by ozone, so that organic matters in waste water are oxidized and decomposed; and the rest ozone and organic pollutants enter the second hydrogen peroxide catalytic decomposition process, so that the organic matters are decomposed, the degradation action and coordinated reaction of the hydrogen peroxide and ozone are activated and the organic pollutants are degraded quickly. The process for treating industrial organic waste water by serial catalytic oxidization not only improves the processing capacity of nondegradable organic pollutants, but also improves the utilization rate of oxidizers and effectively reduces operation cost.

Description

A series catalytic oxidation process for industrial organic wastewater treatment

technical field

The invention relates to a series catalytic oxidation process for treating industrial organic wastewater, which belongs to the technical field of environmental protection.

Background technique

Wastewater from industrial parks is difficult to treat, with complex sources and components. The organic pollutants in it are often refractory to biodegradable organic matter, which is difficult to treat. The COD in this part is usually greater than 2000mg/L, with a benzene ring structure, and a large proportion of stable organic pollutants, which increases the difficulty of treatment. At present, industrial park wastewater adopts a single oxidant treatment method: H ₂ O ₂ catalytic oxidation method or O ₃ catalytic oxidation method, which oxidizes and decomposes organic matter in wastewater into small molecular organic matter or CO ₂ and H ₂ O, thereby removing Organic Pollutants. The traditional chemical oxidation method often cannot achieve the ideal oxidation effect only relying on the oxidation ability of the oxidant, so some auxiliary means are used to improve the oxidation efficiency. Catalytic oxidation methods such as UV/O ₃ , UV/H ₂ O ₂ , and Fenton have appeared, which have improved the treatment efficiency of chemical oxidation methods. At the same time, other treatment methods such as wet catalytic oxidation have also appeared. For example, the wet oxidation technology (WAO) proposed by FJZimmermann in 1958 uses air or pure oxygen as the oxidant. ) conditions, the refractory organic matter in the wastewater is oxidized and decomposed into small molecule organic matter or CO ₂ and H ₂ O. Due to the high temperature and pressure used in WAO technology, it brings considerable difficulties to the manufacture and operation of the equipment. The operating conditions of high temperature and high pressure have always been the main reason why this technology cannot be promoted. In 1894, Fenton discovered that the mixture of ferrous iron and hydrogen peroxide would produce hydroxyl radicals (-OH). Because of its extremely high oxidation potential (2.8V), -OH has a strong oxidation ability and can be compatible with most organic pollutants. Rapid chain reaction occurs, non-selective oxidation of harmful substances into CO ₂ , H ₂ O or mineral salts, without secondary pollution. Fenton's reagent solves the problem of using catalytic oxidation technology at normal temperature and pressure, and significantly improves the treatment efficiency. After the 1980s, the application of ozone and hydrogen peroxide catalytic water treatment technology in industrial wastewater has gradually become the main method for improving the biodegradability of industrial wastewater and effectively reducing the concentration of pollution. In the process of use, this method of simply using a single catalyst to catalyze and oxidize complex organic pollutants also has the phenomenon that the oxidant has different treatment activities for different organic pollutants, and the treatment types are limited. Industrial organic wastewater, In particular, the organic wastewater in industrial parks has complex sources and components, and the organic pollutants in it are often refractory organic matter, which is difficult to treat and is refractory organic wastewater. The COD in this part is usually greater than 2000mg/L, with a benzene ring structure, and a large proportion of stable organic pollutants, which increases the difficulty of treatment. Therefore, the method of combining multiple oxidation methods for treatment has gradually been applied in industrial practical applications, such as adding FeSO4 in the early stage, degrading the precipitate, and then performing oxidation of the oxidant, but for considering the synergistic effect between different oxidants, Improve the utilization rate of oxidant, improve the technology of treatment effect, also do not see report.

Contents of the invention

For above-mentioned existing problem, the object of the present invention is to provide a kind of tandem catalytic oxidation treatment industrial organic wastewater process. In order to realize above-mentioned object, the technical solution of the present invention is as follows:

A serial catalytic oxidation treatment process for industrial organic wastewater, the catalytic oxidation treatment method adopted for the pretreated organic wastewater is a first-stage catalytic oxidation and a second-stage synergistic catalytic oxidation. The first-level catalytic oxidation means that industrial organic wastewater enters the first-level catalytic oxidation pool body, and the catalyst is placed in the pool body according to the mass ratio of water: first-level catalyst = 1000: 1. After the water intake is completed, ozone is added, and the amount of ozone added is 100 ~ 800g/T·h, the reaction time is 30 minutes, the wastewater in the pool undergoes the internal circulation of the first-stage catalytic oxidation, and the circulation process lasts for 40 minutes, so that the wastewater and the first-stage catalyst fully contact and react, and the first-stage catalytic oxidation reaction ends.

The two-stage synergistic catalytic oxidation refers to that the industrial organic wastewater after the primary catalytic reaction is discharged from the first-stage reaction pool to the second-stage reaction pool, and the catalyst is placed in the pool body according to the mass ratio of water: secondary catalyst=1100:1 , and collect unreacted ozone in the first-stage catalytic oxidation process to the second-stage reaction tank, aerate into the second-stage catalytic oxidation tank body, pump in 20% hydrogen peroxide 100-700g/T h, and stay for 30 Minutes, during which the internal circulation is carried out, and the circulation process lasts for 30 minutes, and the second-stage catalytic oxidation reaction ends.

The first-stage catalyst uses activated carbon as a carrier, and the surface is compounded with manganese-containing metal ions, and the compounding amount is 3g/kg.

The secondary catalyst uses activated carbon as a carrier, and the surface is compounded with iron-containing metal ions, and the compounding amount is 5g/kg.

Due to the adoption of the above technical scheme, the serial catalytic oxidation treatment process of industrial organic wastewater of the present invention adopts the serial and synergistic mode of catalytic ozonation and catalytic hydrogen peroxide hydration, and connects various oxidant catalytic methods in series to realize the synergy between oxidants and the synergy between them. Rapid treatment of complex organic pollutants, the series catalytic oxidation process is to fix the first catalyst in the first catalytic oxidation process under normal temperature and normal pressure conditions, which is an ozone catalytic oxidation process: using an immobilized catalyst to catalyze the decomposition of ozone, Generate a large number of hydroxyl radicals (.OH), use the .OH redox potential and electrophilicity to break the chromophore in the molecular structure of organic pollutants, so that the organic pollutants in the water can be degraded rapidly, and the polymer oxides in the wastewater A position C-H bond, β-C bond, γ-C bond, C-C breaks into low molecular compounds, so as to oxidize and decompose the organic matter in the wastewater, and quickly degrade the organic matter COD; the remaining ozone and the remaining organic pollutants enter the second Catalytic decomposition process, in this process, the second catalyst is used to catalyze the decomposition of hydrogen peroxide to generate OH free radicals to degrade and oxidize the remaining organic pollutants, and the ozone entering the process undergoes a chain reaction with hydrogen peroxide to generate more free radicals, The degradation effect of hydrogen peroxide and ozone is activated, and the synergistic reaction is achieved to rapidly degrade organic pollutants.

The serial catalytic oxidation process of the present invention for treating industrial organic wastewater not only improves the treatment efficiency of refractory organic pollutants, but also improves the utilization efficiency of oxidants; it can effectively reduce operating costs and expand the application field of the process. It changes the problems of the existing industrial organic wastewater that only uses hydrogen peroxide or ozone catalytic oxidation treatment, which has limited types of wastewater, high operating costs, and complicated operation. Applied under the same operating conditions, the present invention can greatly improve the treatment efficiency of industrial organic wastewater, reduce equipment investment cost and operating cost, and make it applicable to a wider range of industrial organic wastewater, such as papermaking wastewater, textile printing and dyeing wastewater or pesticide wastewater, etc. Kind of processing.

Description of drawings

The accompanying drawing is a process flow diagram of a series catalytic oxidation treatment of industrial organic wastewater according to the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments, see the drawings.

A serial catalytic oxidation process for treating industrial organic wastewater, the process flow is: industrial organic wastewater → homogenization and aeration → neutralization coagulation sedimentation → intermediate pool → primary catalytic oxidation → secondary synergistic catalytic oxidation → effluent

The organic wastewater pretreatment includes a homogeneous aeration process and a neutralization coagulation sedimentation process for the wastewater. The homogeneous aeration process adopts a homogeneous aeration tank, and the homogeneous aeration tank controls the air aeration intensity to 1-7m ³ / m ² .h to make all kinds of industrial organic wastewater fully homogeneous; the neutralization coagulation sedimentation process uses a neutralization coagulation sedimentation tank, and a cut-off valve is used in the neutralization zone to add slaked lime or hydrochloric acid to adjust the pH value and control the pH value to 6 ~9, add 0.5% coagulant aid PAC in the end, and control the dosage of 1~10mg/L; remove most of the suspended solids and oil in the wastewater through the pretreatment process.

The catalytic oxidation treatment method adopted for the organic wastewater after the pretreatment process is primary catalytic oxidation and secondary synergistic catalytic oxidation. Put the primary catalyst in the body according to the mass ratio of water: primary catalyst = 1000: 1. The primary catalyst is based on activated carbon as a carrier, and the surface is compounded with manganese metal ions. The composite amount is 3g/kg, and ozone is added after the water intake is completed. , the amount of ozone added is 100-800g/T h, and the reaction time is 30 minutes. The wastewater in the pool is internally circulated in the first-stage catalytic oxidation pool. The circulation process lasts for 40 minutes, so that the wastewater and the catalyst are fully contacted. The catalytic oxidation reaction ends.

The two-stage synergistic catalytic oxidation means that the industrial organic wastewater after the primary catalytic reaction is discharged from the first-stage reaction pool to the second-stage catalytic oxidation pool, and the pool body is placed according to the mass ratio of water: secondary catalyst = 1100:1 A secondary catalyst, the secondary catalyst is based on activated carbon as a carrier, and the surface is compounded with iron-containing metal ions, the composite amount is 5g/kg, and the unreacted ozone in the primary catalytic oxidation process is collected into the secondary reaction tank, exposed to Gas enters the second-stage catalytic oxidation tank body, pumps 20% hydrogen peroxide at a concentration of 100-700g/T·h, and stays for 30 minutes for treatment, during which internal circulation is carried out. The circulation process lasts for 30 minutes, and the second-stage catalytic oxidation reaction ends.

The series catalytic oxidation process is under the condition of normal temperature and normal pressure, the fixed catalyst is in the first catalytic oxidation process, which is the ozone catalytic oxidation process: the fixed catalyst is used to catalyze the decomposition of ozone to generate a large number of hydroxyl radicals (.OH), Use .OH oxidation-reduction potential and electrophilicity to break the chromogenic group in the molecular structure of organic pollutants, so that the organic pollutants in the water can be degraded rapidly, and the a-position C-H bond, β-C bond, The γ-C bond and C-C are broken to form low molecular compounds, so as to oxidize and decompose the organic matter in the wastewater, and quickly degrade the organic matter COD; the remaining ozone and the remaining organic pollutants enter the second catalytic decomposition process. In this process, adopt Another catalyst catalyzes the decomposition of hydrogen peroxide to generate OH free radicals to degrade and oxidize the remaining organic pollutants, and the ozone entering the process undergoes a chain reaction with hydrogen peroxide, generating more free radicals and activating the degradation of hydrogen peroxide and ozone , synergistic reaction, to achieve the purpose of rapid degradation of organic pollutants.

The series catalytic oxidation process adopts a two-stage treatment process, which is composed of water intake-reaction, circulation-drainage process, and runs continuously; industrial organic wastewater enters the first-stage catalytic oxidation tank body, and ozone is added after the water intake is completed. COD concentration, add 100-800g/T h, air intake for 30 minutes, the first-stage catalytic oxidation of wastewater in the pool is internally circulated, and the circulation process lasts for 40 minutes, so that the wastewater and the filler are fully contacted and reacted, and the first-stage catalytic oxidation reaction is completed; Wastewater is discharged from the first-stage reaction pool to the second-stage circulation pool, and the unreacted ozone is collected, aerated into the second-stage catalytic oxidation pool body, and the concentration of 20% hydrogen peroxide is pumped in 100-700g/T·h, and it stays After 30 minutes of treatment, the wastewater in the pool starts the second-stage catalytic oxidation internal circulation, and the circulation process lasts for 20 minutes. After the second-stage catalytic oxidation reaction ends, the power supply is cut off; The process for treating industrial organic wastewater by serial catalytic oxidation is characterized in that the homogenization and aeration tank preferably controls the aeration intensity to 1-7m ³ /m ² .H.

Specific examples:

Embodiment one: by above-mentioned technological process:

The organic wastewater is pharmaceutical wastewater, the index is: the treatment capacity is 1T, and the concentration is COD: 2000mg/L; the pretreatment of the organic wastewater includes the homogenization and aeration process of the wastewater and the neutralization coagulation sedimentation process, and the homogenization and aeration process The homogenization and aeration tank is used, and the air aeration intensity of the homogenization aeration tank is 7m ³ /m ² .h, which is fully homogenized; the neutralization coagulation sedimentation process adopts a neutralization coagulation sedimentation tank, and a shut-off valve is used in the neutralization area Add slaked lime or hydrochloric acid or hydrochloric acid to adjust the pH value, control the pH value from 6 to 9, then add 0.5% coagulant aid PAC, and control the dosage of 8mg/L; remove most of the suspended solids and oil in the wastewater through the pretreatment process .

The organic wastewater after the pretreatment process enters the first-stage catalytic oxidation tank body through the intermediate pool, and 1000g of activated carbon catalyst with a loading capacity of 3g/kg composite manganese metal ions is placed in the pool body. After the water inflow is completed, ozone is added. The amount of ozone added is 700g/T h, and the reaction time is 30 minutes. The first-stage catalytic oxidation of the wastewater in the pool is internally circulated. The circulation process lasts for 40 minutes, so that the wastewater and the catalyst can fully contact and react. The stage catalytic oxidation reaction ends.

The industrial organic wastewater after the first-stage catalytic reaction is discharged from the first-stage reaction pool to the second-stage reaction pool, and 910 g of activated carbon catalysts with a loading capacity of 5 g/kg of composite iron-containing metal ions are placed in the pool body. The unreacted ozone is collected, aerated into the second-stage catalytic oxidation tank body, and 800g/T h of hydrogen peroxide with a concentration of 20% is pumped in, and the treatment is stopped for 30 minutes, during which internal circulation is carried out, and the circulation process lasts for 30 minutes. The secondary catalytic oxidation reaction ends. The water treatment process is over; the effluent index is: the treatment capacity is 1T, and the concentration is COD: 800mg/L.

Embodiment two: by above-mentioned technological process:

The organic wastewater is pharmaceutical wastewater, the index is: the treatment capacity is 1T, and the concentration is COD: 2000mg/L. The pretreatment of the organic wastewater includes the homogenization and aeration process of the wastewater and the neutralization coagulation sedimentation process, and the homogenization and aeration process The uniform aeration tank is adopted, and the air aeration intensity of the uniform aeration tank is 6m ³ /m ² .h, which is fully uniform; the neutralization coagulation sedimentation process adopts a neutralization coagulation sedimentation tank, and a shut-off valve is used in the neutralization area Add slaked lime or hydrochloric acid to adjust the pH value, control the pH value to 6-9, then add 0.5% coagulant PAC, and control the dosage to 5mg/L; remove most of the suspended solids and oil in the wastewater through the pretreatment process.

The organic wastewater after the pretreatment process enters the first-stage catalytic oxidation tank body through the intermediate pool, and 1000g of activated carbon catalyst with a loading capacity of 3g/kg composite manganese metal ions is placed in the pool body. After the water inflow is completed, ozone is added. The amount of ozone added is 400g/T h, and the reaction time is 30 minutes. The first-stage catalytic oxidation of the wastewater in the pool is internally circulated. The circulation process lasts for 40 minutes, so that the wastewater and the catalyst can fully contact and react. The stage catalytic oxidation reaction ends;

The industrial organic wastewater after the first-stage catalytic reaction is discharged from the first-stage reaction pool to the second-stage reaction pool, and 910 g of activated carbon catalysts with a loading capacity of 5 g/kg of composite iron-containing metal ions are placed in the pool body. And unreacted ozone is collected, aerated into the second-stage catalytic oxidation tank body, pumped into the concentration of 20% hydrogen peroxide 500g/T h, stay for 30 minutes, during which internal circulation is carried out, and the circulation process lasts for 30 minutes. The secondary catalytic oxidation reaction ends. The water treatment process is over; the effluent index is: the treatment capacity is 1T, and the concentration is COD: 1000mg/L

Embodiment three: by above-mentioned technological process:

The organic wastewater is pharmaceutical wastewater, the index is: the treatment capacity is 1T, and the concentration is COD: 2000mg/L. The pretreatment of the organic wastewater includes the homogenization and aeration process of the wastewater and the neutralization coagulation sedimentation process, and the homogenization and aeration process The uniform aeration tank is adopted, and the air aeration intensity of the uniform aeration tank is controlled to 1m ³ /m ² .h, which is fully uniform; the neutralization coagulation sedimentation process adopts a neutralization coagulation sedimentation tank, and a shut-off valve is used in the neutralization area Add slaked lime or hydrochloric acid to adjust the pH value, control the pH value to 6-9, then add 0.5% coagulant aid PAC, control the dosage of 1mg/L; remove most of the suspended solids and oil in the wastewater through the pretreatment process.

The organic wastewater after the pretreatment process enters the first-stage catalytic oxidation tank body through the intermediate pool, and 1000g of activated carbon catalyst with a loading capacity of 3g/kg composite manganese metal ions is placed in the pool body. After the water inflow is completed, add ozone, the amount of ozone added is 100g/T h, and the reaction time is 30 minutes. The first-stage catalytic oxidation of wastewater in the pool is internally circulated. The cycle lasts for 40 minutes, so that the wastewater and the catalyst can fully contact and react. The stage catalytic oxidation reaction ends;

The industrial organic wastewater after the first-stage catalytic reaction is discharged from the first-stage reaction pool to the second-stage reaction pool, and 910 g of activated carbon catalysts with a loading capacity of 5 g/kg of composite iron-containing metal ions are placed in the pool body. And the unreacted ozone is collected, aerated into the second-stage catalytic oxidation tank body, pumped with a concentration of 20% hydrogen peroxide 100g/T h, and stayed for 30 minutes, during which internal circulation was carried out, and the circulation process lasted for 30 minutes. The secondary catalytic oxidation reaction ends. The water treatment process is over; the effluent index is: the treatment capacity is 1T, and the concentration is COD: 1800mg/L

Embodiment four: by above-mentioned technological process:

The organic wastewater is printing and dyeing wastewater, the index is: the treatment capacity is 1T, and the concentration is COD: 2000mg/L. The homogenizing aeration tank is adopted, and the air aeration intensity of the homogenizing aeration tank is 4m ³ /m ² .h, which is fully homogenized; the neutralization coagulation sedimentation process adopts a neutralization coagulation sedimentation tank, and a shut-off valve is used in the neutralization area Add slaked lime or hydrochloric acid to adjust the pH value, control the pH value to 6-9, then add 0.5% coagulant aid PAC, and control the dosage to 8mg/L; remove most of the suspended solids and oil in the wastewater through the pretreatment process.

The organic wastewater after the pretreatment process enters the first-stage catalytic oxidation tank body through the intermediate pool, and 1000g of activated carbon catalyst with a loading capacity of 3g/kg composite manganese metal ions is placed in the pool body. After the water inflow is completed, ozone is added. The amount of ozone added is 800g/T h, and the reaction time is 30 minutes. The first-stage catalytic oxidation of wastewater in the pool is internally circulated. The circulation process lasts for 40 minutes, so that the wastewater and the catalyst can fully contact and react. The stage catalytic oxidation reaction ends;

The industrial organic wastewater after the first-stage catalytic reaction is discharged from the first-stage reaction pool to the second-stage reaction pool, and 910 g of activated carbon catalysts with a loading capacity of 5 g/kg of composite iron-containing metal ions are placed in the pool body. The unreacted ozone is collected, aerated into the second-stage catalytic oxidation tank body, and 800g/T h of hydrogen peroxide with a concentration of 20% is pumped in for 30 minutes, during which internal circulation is carried out, and the circulation process lasts for 30 minutes. The secondary catalytic oxidation reaction ends. The water treatment process is over; the effluent index is: the treatment capacity is 1T, and the concentration is COD: 800mg/L

Embodiment five: by above-mentioned technological process:

The organic wastewater is papermaking wastewater, the index is: the treatment capacity is 1T, the concentration is COD: 2000mg/L, and the pretreatment of the organic wastewater includes the homogenization and aeration process of the wastewater and the neutralization coagulation sedimentation process, and the homogenization and aeration process The homogenization and aeration tank is used, and the air aeration intensity of the homogenization aeration tank is 7m ³ /m ² .h, which is fully homogenized; the neutralization coagulation sedimentation process adopts a neutralization coagulation sedimentation tank, and a shut-off valve is used in the neutralization area Add slaked lime or hydrochloric acid to adjust the pH value, control the pH value to 6-9, then add 0.5% coagulant PAC, and control the dosage to 2mg/L; remove most of the suspended solids and oil in the wastewater through the pretreatment process.

The organic wastewater after the pretreatment process enters the first-stage catalytic oxidation tank body through the intermediate pool, and 1000g of activated carbon catalyst with a loading capacity of 3g/kg composite manganese metal ions is placed in the pool body. After the water inflow is completed, ozone is added. The amount of ozone added is 800g/T h, and the reaction time is 30 minutes. The first-stage catalytic oxidation of wastewater in the pool is internally circulated. The circulation process lasts for 40 minutes, so that the wastewater and the catalyst can fully contact and react. The stage catalytic oxidation reaction ends;

The industrial organic wastewater after the first-stage catalytic reaction is discharged from the first-stage reaction pool to the second-stage reaction pool, and 910 g of activated carbon catalysts with a loading capacity of 5 g/kg of composite iron-containing metal ions are placed in the pool body. And the unreacted ozone is collected, aerated into the second-stage catalytic oxidation tank body, pumped into the concentration of 20% hydrogen peroxide 600g/T h, stay for 30 minutes, during which the internal circulation is carried out, and the circulation process lasts for 30 minutes. The secondary catalytic oxidation reaction ends. The water treatment process is over; the effluent index is: the treatment capacity is 1T, and the concentration is COD: 800mg/L

Claims (3)

1. A tandem catalytic oxidation treatment of industrial organic wastewater process, which includes carrying out pretreatment and catalytic oxidation treatment of industrial organic wastewater, characterized in that: the catalytic oxidation treatment method adopted for the organic wastewater after the pretreatment process is one-level Catalytic oxidation and secondary synergistic catalytic oxidation, the first-level catalytic oxidation refers to industrial organic wastewater entering the first-level catalytic oxidation pool body, and the catalyst is placed in the pool body according to the mass ratio of water: first-level catalyst = 1000: 1, after the water intake is completed Add ozone, the amount of ozone added is 100-800g/T h, and the reaction time is 30 minutes. The wastewater in the pool undergoes the first-stage catalytic oxidation internal circulation. The first-level catalytic oxidation reaction ends, and the second-level synergistic catalytic oxidation refers to that the industrial organic wastewater after the first-level catalytic reaction is discharged from the first-level reaction pool to the second-level reaction pool, and in the pool body, water: secondary catalyst =1100:1 place the secondary catalyst, collect the unreacted ozone in the primary catalytic oxidation process from the secondary reaction tank, aerate it into the secondary catalytic oxidation tank body, pump in 20% hydrogen peroxide at a concentration of 100-700g/ T h, stay for 30 minutes, during which internal circulation is carried out, the circulation process lasts for 30 minutes, and the second-stage catalytic oxidation reaction ends. 2. The tandem catalytic oxidation process for treating industrial organic wastewater according to claim 1, characterized in that: the first-stage catalyst uses activated carbon as a carrier, and the surface is compounded with manganese-containing metal ions, and the compounding amount is 3g/kg. 3. The tandem catalytic oxidation process for industrial organic wastewater treatment according to claim 1, characterized in that: the secondary catalyst is activated carbon as a carrier, and the surface is compounded with iron-containing metal ions, and the compounding amount is 5g/kg.

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