CN104909427A - Construction and application method of photoassisted porous copper bismuthate activated persulfate water treatment high-grade oxidation technology - Google Patents

Abstract

The invention provides a construction and application method of light-assisted porous copper bismuth acid activated persulfate salt water treatment advanced oxidation technology, which belongs to the field of water treatment technology and environmental functional materials. Porous copper bismuthate can be in the shape of powder or granules, and bismuth nitrate, copper nitrate and polyvinylpyrrolidone are used as the main materials to prepare porous copper bismuthate materials with high specific surface area, which can improve the freedom of activated persulfate under light-assisted conditions. The ability to degrade coumarin. The present invention aims at the poor removal effect of coumarin in existing conventional sewage treatment, proposes a novel porous copper bismuthate as a catalyst, and realizes its successful application in the persulfate system, which is a coumarin compound The removal technology provides a theoretical reference, and provides a scientific basis and technical support for ensuring water quality safety and improving the water quality environment.

Description

Construction and application method of light-assisted porous copper bismuth acid activated persulfate brine treatment advanced oxidation technology

technical field

The invention relates to water pollution control technology and an environmental functional material.

Background technique

Coumarin compounds are a class of aromatic compounds that widely exist in nature. They are distributed in many plants and spices, and also exist in metabolites of animals and microorganisms. Their core is a benzo-a-pyrone structure. According to the different substituents of the benzene ring and their positions, coumarins can be divided into simple coumarins, furanocoumarins, pyranocoumarins and other coumarins, etc., which are an important flavor enhancer and are widely used Used in light industries such as perfumes, cosmetics, and detergents. Coumarin compounds not only have antihypertensive and anticoagulant pharmacological effects on the human body, but also have harmful effects on the physiological toxicity of organisms. For example, some coumarin compounds can cause liver damage. With the increasing production, usage and discharge of coumarin compounds, the content of coumarin compounds in the water environment has increased significantly, which poses new challenges to domestic sewage treatment and reuse technologies in my country. Therefore, it is of great theoretical and practical significance to carry out basic theoretical and applied research on the removal technology of coumarin compounds to ensure water quality safety.

Advanced oxidation technology mainly relies on highly active oxygen-containing free radicals to oxidize and decompose refractory pollutants in water. Among them, the activated persulfate advanced oxidation technology is a new advanced oxidation technology developed in recent years that uses sulfate radicals as the main active substance to degrade pollutants. Sulfate free radicals have strong oxidation ability and non-selective oxidation, and the oxidation product sulfate has little impact on microorganisms and aquatic organisms in the water environment. The ability of persulfate itself to oxidize pollutants is limited and the reaction is slow. Under the conditions of light, heat, sound, transition metal ions and catalysts, persulfate can be strengthened and decomposed into sulfate radicals to achieve efficient degradation of pollutants and Detox.

Copper bismuthate with spinel structure, as a typical p-type semiconductor material, has attracted attention due to its wide band gap and good photocatalytic performance. Studies have found that copper bismuthate is an excellent visible light photocatalytic material with a band gap of 1.5eV; its magnetic, dielectric, optical and photoelectric properties have been widely studied. Copper bismuthate has super strong visible light response performance in a wide wavelength range, good thermal stability and a certain degree of luminescence performance, so it can be used as a promising photocatalyst. By introducing the surfactant polyvinylpyrrolidone into the copper bismuthate preparation process, the porous copper bismuthate with high surface area and developed pores can be prepared, which can further enhance the catalytic performance of copper bismuthate under light-assisted conditions. Therefore, in the advanced oxidation system, porous copper bismuthate is used as a catalyst to activate persulfate under light-assisted conditions, and in situ coupling of hydroxyl radicals generated by photocatalysis and sulfate radicals generated by activated persulfate to achieve refractory organic degradation. Enhanced removal of pollutants, and provide a theoretical reference for the application of photoactivated persulfate.

Contents of the invention

The present invention aims at the polluted water body containing coumarin, and in order to solve the problem of poor treatment effect of the existing conventional sewage, it innovatively proposes a light-assisted porous bismuth acid copper activated persulfate salt water treatment advanced oxidation technology, and the porous bismuth acid The preparation and application conditions of the copper catalyst are described. The catalyst porous copper bismuthate prepared by the present invention utilizes its characteristic crystal structure, dual-element characteristics, higher specific surface area and multiple characteristics of well-developed channels to activate persulfate to generate sulfate radicals under light-assisted conditions, so as to realize the treatment of difficult Enhanced removal of degraded pollutants.

The invention provides a construction and application method of light-assisted porous copper bismuthate activated persulfate salt water treatment advanced oxidation technology, which is characterized in that (1) using the characteristic crystal structure and dual element characteristics of copper bismuthate to generate hydroxyl radicals by photocatalysis In situ coupling with activated persulfate to generate sulfate radicals to achieve enhanced removal of refractory organic pollutants; by introducing surfactants into the copper bismuthate preparation process to increase its specific surface area and expand pores, further strengthen copper bismuthate The ability to activate persulfate under light-assisted conditions realizes the efficient mineralization and detoxification of refractory organic pollutants; it is characterized in that (2) the preparation can be completed through the following process: (1) Precursor solution preparation, the mass is The bismuth nitrate of 0.01mol is dissolved in the nitric acid solution that 20mL concentration is 0.5mol/L, and continuous stirring makes bismuth nitrate dissolve completely; Adding the copper nitrate that quality is 0.005mol to above-mentioned solution, continuous stirring makes bismuth nitrate dissolve completely; Add 0.167g of polyvinylpyrrolidone into the solution, and keep stirring to completely dissolve the bismuth nitrate; (2) preparation of precipitating agent, adding 40.0g of sodium hydroxide to 40mL of water to form a sodium hydroxide solution with a concentration of 25.0mol/L; ( 3) Precipitation, adding the precipitant in (2) dropwise to the precursor solution prepared in (1) to form a mixed precipitate until the pH of the solution reaches 13.45; (4) aging, the prepared in (3) The precipitate was placed at room temperature for 12 hours; (5) washing, the precipitate obtained in (4) was washed with deionized water and ethanol, and excess sodium hydroxide and inorganic salts were removed. This process is repeated several times until the conductivity of the precipitation supernatant remains unchanged; (6) drying, drying the precipitate obtained in (5) at 70 ° C for 24 hours to obtain a dry powder; (7) calcining, the (6 ) The obtained powder is calcined in a high-temperature muffle furnace, and the furnace temperature is raised to 550° C. at a rate of 1° C./min, and the calcination is continued for 6 hours; (8) cooling, and the temperature is naturally lowered to room temperature.

The present invention provides a kind of application condition in the activated persulfate system of light-assisted porous copper bismuthate, it is characterized in that (3) this process realizes through following several steps: (1) the required ultraviolet light 360nm of process; (2) process The required concentration of persulfate is 0-10mmol/L; (3) the dosage of porous copper bismuthate required by the process is 1.0g/L; (4) the concentration of pollutants in the water body to be treated is 0.08-0.12mmol/L; ( 5) The contact time is 160-200 min; (6) The pH range of the reaction system is 2.63-11.00.

Attached content

Accompanying drawing is the removal efficiency diagram of p-coumarin in the light-assisted porous copper bismuth acid activated persulfate system obtained in the specific embodiment 1, wherein × represents the removal efficiency diagram of 360nm photodegradation coumarin, and ◆ represents 360nm ultraviolet light activation The removal efficiency diagram of persulfate, ■ indicates the removal efficiency diagram of persulfate activated by light-assisted copper bismuthate, and ▲ indicates the removal efficiency diagram of persulfate activated by light-assisted porous copper bismuthate. It can be seen from the figure that the efficiency of light-assisted porous copper bismuthate activated persulfate oxidation to remove coumarin is higher than that of simple UV degradation, UV-activated persulfate, and light-assisted copper bismuthate activated persulfate to remove coumarin Significantly improved, and realized the enhanced removal of coumarin in water.

Detailed ways

The construction and application method of this light-assisted porous copper bismuth acid activated persulfate salt water treatment advanced oxidation technology will be described. The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of various specific embodiments. .

Specific embodiment one: the preparation method of the porous copper bismuth acid of this embodiment is: (1) preparation of precursor solution, the bismuth nitrate that quality is 0.01mol is dissolved in the nitric acid solution that 20mL concentration is 0.5mol/L, and continuous stirring makes Bismuth nitrate dissolves completely; In the above-mentioned solution, add the copper nitrate that quality is 0.005mol, keep stirring and make bismuth nitrate dissolve completely; Add polyvinylpyrrolidone 0.167g in the above-mentioned solution, keep stirring and make bismuth nitrate dissolve completely; (2) precipitation agent Preparation, adding 40.0 g of sodium hydroxide into 40 mL of water to form a sodium hydroxide solution with a concentration of 25.0 mol/L; (3) Precipitation, adding the precipitant in (2) dropwise to the precursor prepared in (1) In the body solution, a mixed precipitate is formed until the pH of the solution reaches 13.45; (4) Aging, the precipitate prepared in (3) is placed at room temperature for 12 hours; (5) Washing, washing with deionized water and ethanol (4) Gained precipitation, remove excess sodium hydroxide and inorganic salt wherein. This process is repeated several times until the conductivity of the precipitation supernatant remains unchanged; (6) drying, drying the precipitate obtained in (5) at 70 ° C for 24 hours to obtain a dry powder; (7) calcining, the (6 ) The obtained powder is calcined in a high-temperature muffle furnace, and the furnace temperature is raised to 550° C. at a rate of 1° C./min, and the calcination is continued for 6 hours; (8) cooling, and the temperature is naturally lowered to room temperature.

The application method of the porous copper bismuthate prepared in this embodiment in the technology of activating persulfate advanced oxidation under light-assisted conditions is as follows: under the condition of 360nm ultraviolet light, add porous copper bismuthate catalyst to activate persulfate for oxidation treatment. The decontamination technology in the light-assisted porous copper bismuthate activated persulfate system is realized according to the following steps: (1) the ultraviolet light 360nm required for the process; (2) the persulfate concentration required for the process is 0-10mmol/L; (3) The dosage of porous copper bismuthate required by the process is 1.0g/L; (4) The concentration of pollutants in the water to be treated is 0.08-0.12mmol/L; (5) The contact time is 160-200min; (6) The pH range of the reaction system It is 2.63~11.00.

The water treatment method used in this embodiment to remove organic matter in water by catalyzing ozone oxidation of heat-treated red mud is exactly the same as the existing ozone oxidation system of the water plant, and the pretreatment and subsequent treatment processes of polluted water completely adopt the existing process, without the need for water treatment equipment. The catalytic ozonation reactor in this embodiment can be a batch reactor, or a continuous reactor or a multi-cascade reaction system.

Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that the application method of light-assisted porous copper bismuth acid activated persulfate decontamination technology in water treatment is as follows: urban domestic sewage passes through the grid-grit chamber-primary After the sedimentation tank-biochemical tank-secondary sedimentation tank is treated, the light-assisted porous copper bismuthate activates persulfate treatment, and then the water is discharged.

Specific embodiment three: the difference between this embodiment and specific embodiment one is that the application method of light-assisted porous copper bismuthate activated persulfate decontamination technology in water treatment is: industrial wastewater passes through the grid-grit chamber-primary sedimentation After the pool-biochemical pool-secondary sedimentation tank is treated, the light-assisted porous copper bismuthate activates persulfate treatment, and then the water is discharged.

The porous copper bismuthate catalyst prepared in this embodiment can remove more than 60% of coumarin by activating persulfate under light-assisted conditions, which is higher than that of simple ultraviolet light degradation, ultraviolet light activation of persulfate, light Copper bismuth acid activated persulfate can significantly improve the removal efficiency of coumarin, realizing the enhanced removal of coumarin in water.

Claims (3)

1. The present invention relates to a construction and application method of light-assisted porous copper bismuthate activated persulfate salt water treatment advanced oxidation technology, which is characterized in that: using the characteristic crystal structure and dual element characteristics of copper bismuthate, the photocatalytic generation of hydroxyl radicals In situ coupling with activated persulfate to generate sulfate radicals to achieve enhanced removal of refractory organic pollutants; by introducing surfactants into the copper bismuthate preparation process to increase its specific surface area and expand pores, further strengthen copper bismuthate The ability to activate persulfate under light-assisted conditions enables efficient mineralization and detoxification of refractory organic pollutants. 2. Porous copper bismuthate according to claim 1 is characterized in that the preparation is completed through the following process: (1) Precursor solution preparation, dissolving bismuth nitrate with a mass of 0.01mol in 20mL of nitric acid solution with a concentration of 0.5mol/L, stirring continuously to completely dissolve bismuth nitrate; adding copper nitrate with a mass of 0.005mol to the above solution , continue stirring to completely dissolve the bismuth nitrate; add 0.167 g of polyvinylpyrrolidone to the above solution, and continue stirring to completely dissolve the bismuth nitrate. (2) Precipitating agent preparation, adding 40.0 g of sodium hydroxide into 40 mL of water to form a sodium hydroxide solution with a concentration of 25.0 mol/L. (3) Precipitation, adding the precipitant in (2) dropwise to the precursor solution prepared in (1) to form a mixed precipitate until the pH of the solution reaches 13.45. (4) Aging, place the precipitate prepared in (3) at room temperature for 12 hours. (5) Washing, using deionized water and ethanol to wash the precipitate obtained in (4), to remove excess sodium hydroxide and inorganic salts; this process is repeated several times until the conductivity of the precipitate supernatant remains unchanged. (6) drying, drying the precipitate obtained in (5) at 70° C. for 24 hours to obtain dry powder. (7) Calcination. The powder obtained in (6) was calcined in a high-temperature muffle furnace, and the furnace temperature was raised to 550° C. at a rate of 1° C./min, and the calcination was continued for 6 hours. (8) cooling, naturally cooling to room temperature. 3. A kind of light-assisted porous copper bismuth acid activated persulfate salt water treatment advanced oxidation technology according to claim 1, realizes by following several steps: (1) Ultraviolet light 360nm; (2) The persulfate concentration required by the process is 0-10mmol/L; (3) The dosage of porous copper bismuthate required by the process is 1.0g/L; (4) The concentration of pollutants in the water body to be treated is 0.08-0.12mmol/L; (5) The contact time is 160-200 minutes; (6) The pH range of the reaction system is 2.63-11.00.