CN116813101A - A method for preparing fiber composite magnetic particles and its application as a biological carrier - Google Patents

Abstract

The invention discloses a method for preparing fiber composite magnetic particles and its application as a biological carrier. It relates to the technical field of biological fillers. The key points of its technical solution include the following steps: (1) Add ferroferric oxide magnetic particles into pure water. In the reactor, ultrasonic treatment, using mechanical stirring and homogenization under nitrogen protection; (2) Add modifiers and surfactants to the system at 35-55°C, and age; (3) Add dropwise to the system Mixed monomer solution of styrene, cross-linking agent and epoxy monomer; (4) After the dropwise addition, add fiber and stir evenly; (5) After stirring evenly, add initiator to the system and raise the temperature to 65- 85°C, and keep warm under stirring; (6) Filter to obtain fiber composite magnetic particles, wash with pure water and ethanol, and vacuum dry to constant weight; hydrolyze the above fiber composite magnetic particles or chelate metal particles after hydrolysis, as Biological carriers are used in aerobic or anaerobic biological water treatment.

Description

A method for preparing fiber composite magnetic particles and its application as a biological carrier

Technical field

The present invention relates to the technical field of biological fillers, and more specifically, to a preparation method of fiber composite magnetic particles and their application as biological carriers.

Background technique

Biological treatment is the mainstream technology for sewage treatment. Among them, the biofilm method based on biological fillers is widely used in urban sewage, aquaculture wastewater, chemical wastewater and other fields. It is characterized by the growth and reproduction of microorganisms attached to filter materials or certain carriers. It also forms film-like biological sludge. The biofilm intercepts microorganisms that have the function of removing pollutants, reduces the loss of functional microorganisms, and provides them with certain protection. Magnetic fillers have received widespread attention due to their high surface area and recyclability. The surface properties of fillers, such as hydrophilicity, roughness, porosity, specific surface area, surface charge, etc., are important factors affecting the adsorption and immobilization of microorganisms.

The existing patent application document with application publication number CN 113104959 A discloses a magnetic silica particle. The magnetic particles in the core have a shell structure. The silica in the shell can protect the magnetic particles and avoid oxidation and dissolution. ,Extended service life. When used in sewage treatment, it can significantly improve the removal of ammonia nitrogen and chemical oxygen demand (COD), but this study did not characterize the bioaffinity.

Please refer to the existing patent application document with application publication number CN 104609567 A, which discloses a hydrophilic magnetic suspension biological filler and its preparation method. By adding composite magnetic powder, rubber powder, zeolite powder, slag powder, polyethylene, etc., After extrusion molding, mechanical opening, short-wave UV irradiation and crushing, a hydrophilic suspended biological carrier is prepared, but the processing technology is complex and the cost is high.

None of the above-mentioned prior art solves the problem of bioaffinity as a carrier.

Contents of the invention

In view of the shortcomings of the existing technology, the first purpose of the present invention is to provide a preparation method of fiber composite magnetic particles, and the second purpose is to provide the application of the above fiber composite magnetic particles. The processed fiber composite magnetic particles, The problem of its bioaffinity as a carrier is solved.

In order to achieve the above first purpose, the present invention provides the following technical solution: a preparation method of fiber composite magnetic particles, including the following steps:

(1) Add ferroferric oxide magnetic particles into a reactor filled with pure water, conduct ultrasonic treatment for 15-30 minutes, and use mechanical stirring to homogenize under nitrogen protection;

(2) Add modifiers and surfactants to the system at 35-55°C and age for 2 hours;

(3) Then drop the mixed monomer solution of styrene, cross-linking agent and epoxy monomer into the system;

(4) After the dripping of the above mixed monomer solution is completed, add the fiber and stir evenly;

(5) After stirring evenly, add the initiator to the system, raise the temperature to 65-85°C, and keep it warm for 3-6 hours while stirring;

(6) Filter for solid-liquid separation to obtain fiber composite magnetic particles, wash with pure water and ethanol, and vacuum dry to constant weight.

Further, the mass ratio of the addition amount of the modifier to the ferroferroferrite magnetic particles is 1:1-1.5:1.

Further, based on the total mass of the mixed monomer solution of styrene, cross-linking agent and epoxy monomer, the styrene dosage is 60-80%, the cross-linking agent dosage is 10-20%, the The amount of epoxy monomer is 10-20%.

Further, the fiber diameter is 1-10 μm, and the fiber length is 300-1000 μm.

Further, the mass ratio of the fiber to the mixed monomer solution is 1:200-1:5.

Further, the fiber composite magnetic particles prepared above are hydrolytically modified, including the following steps:

Add the dried fiber composite magnetic particles into the reactor, add a hydrolyzing agent to the system, use mechanical stirring, hydrolyze at 70-90°C, the hydrolysis time is 0.5-6h; filter to obtain the hydrolyzed modified fiber composite magnetic particles. The particles were washed with pure water and ethanol, and vacuum dried to constant weight.

Further, the mass concentration of the hydrolyzing agent is 1-20%.

Further, the hydrolysis agent includes one or more of sodium hydroxide, potassium hydroxide, water glass, sodium phosphate, potassium phosphate, and sodium sulfide.

Further, the above-mentioned fiber composite magnetic particles are modified by chelating metal ions, including the following steps:

Add the above-mentioned dried and hydrolyzed fiber composite magnetic particles into the reactor, add a metal salt solution to the system, and stir at room temperature for 2-5 hours; filter to obtain the fiber composite magnetic particles that have been hydrolytically modified and chelated with metal ions. , washed with pure water and ethanol, and vacuum dried to constant weight.

Further, the metal salt solution includes one of ferric chloride, ferric sulfate, ferrous chloride, ferrous sulfate, copper chloride, copper sulfate, nickel chloride, nickel sulfate, manganese chloride, manganese sulfate or Various.

Further, the mass concentration of the metal salt solution is 1-20%, and the mass ratio of the amount of the metal salt solution to the fiber composite magnetic particles is (200-5):1.

In order to achieve the above second purpose, the present invention provides the following technical solutions:

The application of fiber composite magnetic particles or modified particles as a carrier in the treatment of sewage in an aerobic activated sludge reactor includes the following steps:

1) In the activated sludge reactor, add 1-20g/L aerobic activated sludge and fiber composite magnetic particles or modified particles with a concentration of 1-20g/L, and control the air flow through a gas rotor flowmeter to 200mL/ min;

2) Operate in sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes of drainage and water inlet operations; 500 mL of supernatant is discharged each time, and 490 mL of tap water and 10 mL of simulated sewage concentrate are added; among which , the simulated sewage concentrated liquid is prepared from ammonium chloride and sodium acetate, the ammonia nitrogen concentration of the simulated sewage concentrated liquid is 5g/L, and the COD concentration is 50g/L;

3) Run continuously for 10 days. Take samples before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, take 50mL of sludge to measure the oxygen consumption rate. After 10 days, observe the aerobic activity on the surface of fiber composite magnetic particles or modified particles. sludge.

The application of fiber composite magnetic particles or modified particles as a carrier in the treatment of sewage in an anaerobic activated sludge reactor includes the following steps:

1) In the sequencing batch reactor, add anaerobic activated sludge with a concentration of 5-40g/L and fiber composite magnetic particles or modified particles with a concentration of 1-15g/L, and use an intermittent stirring device to stir. The stirring frequency Stir for 5 minutes for 30 seconds, and control the temperature at 35±1°C;

2) Operate in sequential batch mode, with 12 hours as one cycle; 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes of drainage and water inlet operations; 100 mL of supernatant water is discharged each time, and 97.5 mL of tap water and 2.5 mL of simulated sewage concentrate are added. mL; wherein, the simulated sewage concentrated liquid is prepared from potassium nitrate and sodium acetate, the nitrate nitrogen concentration of the simulated sewage concentrated liquid is 5g/L, and the COD concentration is 50g/L;

3) Run continuously for 30 days. Take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles or modified particles.

To sum up, the present invention has the following beneficial effects: the fiber length of the fiber composite magnetic particles of the present invention is longer than that of the magnetic particles, and can protrude velvet-like protrusions on the surface of the carrier to increase the specific surface area of the magnetic particles; The fiber is hydrolyzed to form hydrophilic groups such as carboxyl groups, exposing the hydrophilic groups of the fiber, thereby achieving hydrophilic modification of the magnetic particles and improving the bioaffinity of the magnetic particles; through hydrolysis of the surface of the fiber composite magnetic particles The fibers chelate metal ions to further improve the bioaffinity of the magnetic particles and promote the electron transfer efficiency between microorganisms in activated sludge; applying the above fiber composite magnetic particles or modified particles to sewage treatment can improve the biofilm The film hanging speed promotes the degradation of COD and ammonia nitrogen in the aerobic system, and promotes the removal rate of COD and nitrate in the anaerobic system.

Description of the drawings

Figure 1 is a schematic structural diagram of the fiber composite magnetic particles of the present invention, where A: fiber composite magnetic particles, B: hydrolytically modified fiber composite magnetic particles, C: fiber composite magnetic particles that hydrolyze and chelate metal particles;

Figure 2 is a microscope image of the fiber composite magnetic particles prepared in Example 1;

Figure 3 is a scanning electron microscope image of the magnetic particles prepared in Comparative Example 1;

Figure 4 is a fluorescence microscope picture of the magnetic particles after 3 days of coating, in which (a): fiber composite magnetic particles prepared in Example 1, (b): hydrolysis-modified fiber composite magnetic particles prepared in Example 3, ( c): Magnetic particles prepared in Comparative Example 1.

Detailed ways

In some specific embodiments, the modifier is selected from the group consisting of oleic acid, tartaric acid, γ-aminotriethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltriethoxysilane, One or more of chlorosilane and γ-aminotrimethoxysilane.

In some specific embodiments, the surfactant is selected from one or more of sodium lauryl sulfate, sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium laurate, and sodium oleate. . More preferably, it is one or more of sodium dodecyl sulfate, sodium dodecyl sulfonate, and sodium dodecyl benzene sulfonate.

In some specific embodiments, the cross-linking agent is selected from one of divinylbenzene, N,N-methylene bisacrylamide, pentaerythritol triacrylate, ethylene glycol dimethacrylate, and pentaerythritol tetraacrylate. Or several.

In some specific embodiments, the epoxy monomer is selected from one or more of allyl glycidyl ether, glycidyl methacrylate, and glycidyl acrylate.

In some specific embodiments, the material of the fiber is one or more of polyester fiber, polyvinyl alcohol fiber, polyamide fiber, polyacrylonitrile fiber, polypropylene fiber and polyvinyl chloride fiber.

In some specific embodiments, the initiator is selected from one of azobisisobutyronitrile, dibenzoyl peroxide, dodecanoyl peroxide, azobisisoheptanitrile, potassium persulfate, ammonium persulfate, or Various.

The present invention will be further described in detail below with reference to examples.

Example 1

(1) Preparation of fiber composite magnetic particles

Take 35g of ferroferric oxide magnetic particles and add it to a 250mL four-neck bottle filled with 100g of pure water. Ultrasonicate for 30 minutes. Under nitrogen protection, use mechanical stirring at 55°C for 30 minutes. Add 35g of oleic acid and 10% oleic acid to the system. 0.1g of sodium dialkyl sulfate, heated to 65°C, aged for 2 hours, and then a mixed solution of 75g styrene, 15g divinylbenzene and 15g glycidyl methacrylate was added dropwise to the system. After the dropwise addition of the mixed solution was completed, Add 0.7g of polyester fiber with a length of 350μm and a diameter of 2μm, stir evenly, add 6g of initiator azobisisobutyronitrile, incubate for 3h, filter to obtain fiber composite magnetic particles, wash with pure water and ethanol, and vacuum dry to constant weight. .

(2) Experiments on film formation and pollutant removal in aerobic sewage treatment system

In a 1000mL activated sludge reactor, add 800mL of aerobic activated sludge with a suspended solid content of 5000mg/L, add 3.6g of fiber composite magnetic particles obtained in the above step (1), and control the gas flow to 200mL/min through a gas rotor flowmeter. . It operates in sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes for drainage, water inlet and other operations. Each time, 500 mL of water is drained and 490 mL of water is fed. 10 mL of simulated sewage concentrate is added at the beginning of each cycle. The ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L and the COD concentration is 50g/L. Run continuously for 10 days. Samples were taken before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, 50 mL of sludge was taken to measure the oxygen consumption rate. After 10 days, the aerobic activated sludge on the surface of fiber composite magnetic particles was observed.

(3) Experiments on film formation and pollutant removal in anaerobic sewage treatment systems

In a 250 mL sequencing batch reactor, add inoculated anaerobic activated sludge and fiber composite magnetic particles, stir using an intermittent stirring device, the stirring frequency is 5 min for 30 s, and the temperature is controlled at 35±1°C. It operates in sequential batch mode, with a cycle of 12 hours. Each cycle has 11 hours of aeration, 30 minutes of settling, and 30 minutes for drainage, water inflow and other operations. Each time, 100 mL of water is drained and 97.5 mL of water is fed. 2.5 mL of simulated sewage concentrate is added at the beginning of each cycle. The nitrate nitrogen concentration of the simulated sewage concentrate is 5 g/L and the COD concentration is 50 g/L. Run continuously for 30 days, and take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles.

Example 2

(1) Preparation of fiber composite magnetic particles

Take 35g of ferroferric oxide magnetic particles and add it to a 250mL four-neck bottle filled with 100g of pure water. Ultrasonicate for 30 minutes. Under nitrogen protection, use mechanical stirring at 55°C for 30 minutes. Add 35g of oleic acid and 10% oleic acid to the system. 0.1g of sodium dialkyl sulfate was heated to 65°C and aged for 2 hours. Then a mixed solution of 75g of styrene, 15g of divinylbenzene and 15g of glycidyl methacrylate was added dropwise to the system. After the addition of the mixed solution was completed, Add 0.7g of polyvinyl alcohol fiber with a length of 400 μm and a diameter of 2 μm, stir evenly, add 6g of initiator dibenzoyl peroxide, incubate for 3 hours, filter to obtain fiber composite magnetic particles, wash with pure water and ethanol, and vacuum dry to constant temperature. Heavy.

(2) Experiments on film formation and pollutant removal in aerobic sewage treatment system

In a 1000mL activated sludge reactor, add 800mL of aerobic activated sludge with a suspended solid content of 5000mg/L, add 3.6g of fiber composite magnetic particles obtained in the above step (1), and control the gas flow to 200mL/min through a gas rotor flowmeter. . It operates in sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes for drainage, water inlet and other operations. Each time, 500 mL of water is drained and 490 mL of water is fed. 10 mL of simulated sewage concentrate is added at the beginning of each cycle. The ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L and the COD concentration is 50g/L. Run continuously for 10 days. Samples were taken before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, 50 mL of sludge was taken to measure the oxygen consumption rate. After 10 days, the aerobic activated sludge on the surface of fiber composite magnetic particles was observed.

(3) Experiments on film formation and pollutant removal in anaerobic sewage treatment systems

In a 250 mL sequencing batch reactor, add inoculated anaerobic activated sludge and fiber composite magnetic particles, stir using an intermittent stirring device, the stirring frequency is 5 min for 30 s, and the temperature is controlled at 35±1°C. It operates in sequential batch mode, with a cycle of 12 hours. Each cycle has 11 hours of aeration, 30 minutes of settling, and 30 minutes for drainage, water inflow and other operations. Each time, 100 mL of water is drained and 97.5 mL of water is fed. 2.5 mL of simulated sewage concentrate is added at the beginning of each cycle. The nitrate nitrogen concentration of the simulated sewage concentrate is 5 g/L and the COD concentration is 50 g/L. Run continuously for 30 days, and take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles.

Example 3

(1) Preparation of fiber composite magnetic particles

Take 35g of ferroferric oxide magnetic particles and add it to a 250mL four-neck bottle filled with 100g of pure water. Ultrasonicate for 30 minutes. Under nitrogen protection, use mechanical stirring at 55°C for 30 minutes. Add 40g of tartaric acid and dodecyl to the system. 0.1g of sodium alkyl sulfate, raise the temperature to 65°C, age for 2 hours, and then add dropwise a mixed solution of 75g styrene, 15g divinylbenzene and 15g glycidyl methacrylate to the system. After the dropwise addition of the mixed solution is completed, add Stir 0.7g of polyvinyl alcohol fiber with a length of 350 μm and a diameter of 2 μm, add 6 g of initiator dodecanoyl peroxide, incubate for 3 hours, filter to obtain fiber composite magnetic particles, wash with pure water and ethanol, and vacuum dry to constant weight.

(2) Hydrolysis modification of fiber composite magnetic particles

Add 100g of the fiber composite magnetic particles obtained in the above step (1) into the reactor, add 100g of sodium hydroxide solution with a mass concentration of 15%, use mechanical stirring, and hydrolyze at a high temperature of 80°C for 3 hours; filter to obtain the hydrolyzed fiber The composite magnetic particles were washed with pure water and ethanol, and vacuum dried to constant weight.

(3) Experiments on film formation and pollutant removal in aerobic sewage treatment system

In a 1000mL activated sludge reactor, add 800mL of aerobic activated sludge with a suspended solid content of 5000mg/L, add 3.6g of the hydrolyzed modified fiber composite magnetic particles obtained in step (2), and control the gas through a gas rotor flowmeter Flow rate 200mL/min. It operates in sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes for drainage, water inlet and other operations. Each time, 500 mL of water is drained and 490 mL of water is fed. 10 mL of simulated sewage concentrate is added at the beginning of each cycle. The ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L and the COD concentration is 50g/L. Run continuously for 10 days. Samples were taken before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, 50 mL of sludge was taken to measure the oxygen consumption rate. After 10 days, the aerobic activated sludge on the surface of fiber composite magnetic particles was observed.

(4) Experiments on film formation and pollutant removal in anaerobic sewage treatment systems

In a 250 mL sequential batch reactor, add the inoculated anaerobic activated sludge and the hydrolyzed modified fiber composite magnetic particles obtained in step (2), stir using an intermittent stirring device, the stirring frequency is 5 min and stir for 30 s, and the temperature is controlled at 35 ±1℃. It operates in sequential batch mode, with a cycle of 12 hours. Each cycle has 11 hours of aeration, 30 minutes of settling, and 30 minutes for drainage, water inflow and other operations. Each time, 100 mL of water is drained and 97.5 mL of water is fed. 2.5 mL of simulated sewage concentrate is added at the beginning of each cycle. The nitrate nitrogen concentration of the simulated sewage concentrate is 5 g/L and the COD concentration is 50 g/L. Run continuously for 30 days, and take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles.

Example 4

(1) Preparation of fiber composite magnetic particles

Take 35g of ferroferric oxide magnetic particles and add it to a 250mL four-neck bottle filled with 100g of pure water. Ultrasonicate for 30 minutes. Under nitrogen protection, use mechanical stirring at 55°C for 30 minutes. Add 35g of oleic acid and 10% oleic acid to the system. 0.1g of sodium dialkyl sulfate was heated to 65°C and aged for 2 hours. Then a mixed solution of 75g of styrene, 15g of pentaerythritol triacrylate and 15g of allyl glycidyl ether was added dropwise to the system. After the dropwise addition of the mixed solution was completed, Add 0.7g of polyamide fiber with a length of 450μm and a diameter of 3μm, stir evenly, add 6g of initiator azobisisoheptanitrile, incubate for 3h, filter to obtain fiber composite magnetic particles, wash with pure water and ethanol, and vacuum dry to constant weight. .

(2) Hydrolysis modification of fiber composite magnetic particles

Add 100g of the fiber composite magnetic particles obtained in step (1) into the reactor, add 150g of potassium hydroxide solution with a mass concentration of 5%, use mechanical stirring, and hydrolyze at a high temperature of 80°C for 2 hours; filter to obtain the hydrolyzed fiber composite The magnetic particles were washed with pure water and ethanol, and dried under vacuum to constant weight.

(3) Experiments on film formation and pollutant removal in aerobic sewage treatment system

In a 1000mL activated sludge reactor, add 800mL of aerobic activated sludge with a suspended solid content of 5000mg/L, add 3.6g of the hydrolyzed modified fiber composite magnetic particles obtained in step (2), and control the gas through a gas rotor flowmeter Flow rate 200mL/min. It operates in sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes for drainage, water inlet and other operations. Each time, 500 mL of water is drained and 490 mL of water is fed. 10 mL of simulated sewage concentrate is added at the beginning of each cycle. The ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L and the COD concentration is 50g/L. Run continuously for 10 days. Samples were taken before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, 50 mL of sludge was taken to measure the oxygen consumption rate. After 10 days, the aerobic activated sludge on the surface of fiber composite magnetic particles was observed.

(4) Experiments on film formation and pollutant removal in anaerobic sewage treatment systems

In a 250 mL sequential batch reactor, add the inoculated anaerobic activated sludge and the hydrolyzed modified fiber composite magnetic particles obtained in step (2), stir using an intermittent stirring device, the stirring frequency is 5 min and stir for 30 s, and the temperature is controlled at 35 ±1℃. It operates in sequential batch mode, with a cycle of 12 hours. Each cycle has 11 hours of aeration, 30 minutes of settling, and 30 minutes for drainage, water inflow and other operations. Each time, 100 mL of water is drained and 97.5 mL of water is fed. 2.5 mL of simulated sewage concentrate is added at the beginning of each cycle. The nitrate nitrogen concentration of the simulated sewage concentrate is 5 g/L and the COD concentration is 50 g/L. Run continuously for 30 days, and take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles.

Example 5

(1) Preparation of fiber composite magnetic particles

Take 35g of ferroferric oxide magnetic particles and add it to a 250mL four-neck bottle containing 100g of pure water. Ultrasonicate for 30 minutes. Under nitrogen protection, use mechanical stirring at 55°C for 30 minutes. Add vinyl triethoxy to the system. 35g of silane and 0.1g of sodium dodecyl sulfate, raise the temperature to 65°C, age for 2 hours, and then drop into the system a mixed solution of 75g of styrene, 15g of pentaerythritol triacrylate and 15g of glycidyl methacrylate. After the dropwise addition, add 0.7g of polyacrylonitrile fiber with a length of 500 μm and a diameter of 4 μm, stir evenly, add 6g of initiator potassium persulfate, incubate for 3 hours, filter, obtain fiber composite magnetic particles, wash with pure water and ethanol, and dry in a vacuum To constant weight.

(2) Hydrolysis modification of fiber composite magnetic particles

Add 100g of fiber composite magnetic particles obtained in step (1) into the reactor, add 200g of sodium hydroxide solution with a mass concentration of 10%, use mechanical stirring, and hydrolyze at a high temperature of 80°C for 6 hours; filter to obtain the hydrolyzed fiber composite The magnetic particles were washed with pure water and ethanol, and dried under vacuum to constant weight.

(3) Bioaffinity modification of fiber composite magnetic particles to chelate metal ions

Add 20g of the hydrolytically modified fiber composite magnetic particles obtained in the above step (2) into the reactor, add 500g of 15% copper chloride solution to the system, and stir for 2-5 hours at room temperature; filter to obtain the hydrolytically modified and chelated The fiber composite magnetic particles after combining metal ions are washed with pure water and ethanol, and vacuum dried to constant weight.

(4) Experiments on film formation and pollutant removal in aerobic sewage treatment system

In a 1000mL activated sludge reactor, add 800mL of aerobic activated sludge with a suspended solid content of 5000mg/L, add 3.6g of the hydrolytically modified and chelated metal ion fiber composite magnetic particles obtained in step (3), and pass through the gas The rotameter controls the gas flow to 200mL/min. It operates in a sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes for drainage, water inlet and other operations. Each time, 500 mL of water is drained and 490 mL of water is fed. 10 mL of simulated sewage concentrate is added at the beginning of each cycle. The ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L and the COD concentration is 50g/L. Run continuously for 10 days. Samples were taken before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, 50 mL of sludge was taken to measure the oxygen consumption rate. After 10 days, the aerobic activated sludge on the surface of fiber composite magnetic particles was observed.

(5) Experiments on film formation and pollutant removal in anaerobic sewage treatment systems

In a 250mL sequential batch reactor, add the inoculated anaerobic activated sludge and the fiber composite magnetic particles obtained in step (3) after hydrolysis modification and chelating metal ions, stir using an intermittent stirring device, and the stirring frequency is 5 minutes and 30 seconds. , the temperature is controlled at 35±1℃. It operates in sequential batch mode, with a cycle of 12 hours. Each cycle has 11 hours of aeration, 30 minutes of settling, and 30 minutes for drainage, water inflow and other operations. Each time, 100 mL of water is drained and 97.5 mL of water is fed. 2.5 mL of simulated sewage concentrate is added at the beginning of each cycle. The nitrate nitrogen concentration of the simulated sewage concentrate is 5 g/L and the COD concentration is 50 g/L. Run continuously for 30 days, and take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles.

Example 6

(1) Preparation of fiber composite magnetic particles

Take 35g of ferroferric oxide magnetic particles and add it to a 250mL four-neck bottle filled with 100g of pure water. Ultrasonicate for 30 minutes. Under nitrogen protection, use mechanical stirring at 55°C for 30 minutes. Add 35g of oleic acid and 10% oleic acid to the system. 0.1g sodium dialkyl sulfate, raise the temperature to 65°C, age for 2 hours, and then add a mixed solution of 75g styrene, 15g ethylene glycol dimethacrylate and 15g glycidyl acrylate dropwise to the system. The dropwise addition of the mixed solution is completed. Then, add 0.7g of polyvinyl chloride fiber with a length of 200 μm and a diameter of 5 μm, stir evenly, add 6g of initiator ammonium persulfate, incubate for 3 hours, filter to obtain fiber composite magnetic particles, wash with pure water and ethanol, and vacuum dry to constant weight. .

(2) Hydrolysis modification of fiber composite magnetic particles

Add 100g of dried fiber composite magnetic particles into the reactor, add 250g of potassium hydroxide solution with a mass concentration of 8%, use mechanical stirring, and hydrolyze at a high temperature of 80°C for 4 hours; filter to obtain the hydrolyzed fiber composite magnetic particles. , washed with pure water and ethanol, and vacuum dried to constant weight.

(3) Bioaffinity modification of fiber composite magnetic particles to chelate metal ions

Add 20g of the hydrolytically modified fiber composite magnetic particles obtained in step (2) into the reactor, add 400g of 10% ferrous sulfate solution to the system, and stir for 2-5 hours at room temperature; filter to obtain hydrolytically modified and chelated metals The ionized fiber composite magnetic particles were washed with pure water and ethanol, and vacuum dried to constant weight.

(4) Experiments on film formation and pollutant removal in aerobic sewage treatment system

In a 1000mL activated sludge reactor, add 800mL of aerobic activated sludge with a suspended solid content of 5000mg/L, add 3.6g of the hydrolytically modified and chelated metal ion fiber composite magnetic particles obtained in step (3), and pass through the gas The rotameter controls the gas flow to 200mL/min. It operates in a sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes for drainage, water inlet and other operations. Each time, 500 mL of water is drained and 490 mL of water is fed. 10 mL of simulated sewage concentrate is added at the beginning of each cycle. The ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L and the COD concentration is 50g/L. Run continuously for 10 days. Samples were taken before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, 50 mL of sludge was taken to measure the oxygen consumption rate. After 15 days, the aerobic activated sludge on the surface of fiber composite magnetic particles was observed.

(5) Experiments on film formation and pollutant removal in anaerobic sewage treatment systems

In a 250mL sequential batch reactor, add the inoculated anaerobic activated sludge and the fiber composite magnetic particles obtained in step (3) after hydrolysis modification and chelating metal ions, stir using an intermittent stirring device, and the stirring frequency is 5 minutes and 30 seconds. , the temperature is controlled at 35±1℃. It operates in sequential batch mode, with a cycle of 12 hours. Each cycle has 11 hours of aeration, 30 minutes of settling, and 30 minutes for drainage, water inflow and other operations. Each time, 100 mL of water is drained and 97.5 mL of water is fed. 2.5 mL of simulated sewage concentrate is added at the beginning of each cycle. The nitrate nitrogen concentration of the simulated sewage concentrate is 5 g/L and the COD concentration is 50 g/L. Run continuously for 30 days, and take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles.

Example 7

(1) Preparation of fiber composite magnetic particles

Take 35g of ferroferric oxide magnetic particles and add it to a 250mL four-neck bottle filled with 100g of pure water. Ultrasonicate for 30 minutes. Under nitrogen protection, use mechanical stirring at 55°C for 30 minutes. Add γ-glycidyl ether to the system. 35g of oxypropyltrimethoxysilane and 0.1g of sodium lauryl sulfate were heated to 65°C and aged for 2 hours. Then, 75g of styrene, 15g of divinylbenzene and 15g of allyl glycidyl ether were added dropwise to the system. Mix the solution. After the dripping of the mixed solution is completed, add 0.7g of polyamide fiber with a length of 400 μm and a diameter of 6 μm, stir evenly, add 6g of the initiator azobisisobutyronitrile, incubate for 3 hours, filter, and obtain composite fiber magnetic particles. Use pure Wash with water and ethanol, and dry under vacuum to constant weight.

(2) Hydrolysis modification of fiber composite magnetic particles

Add 100g of dried fiber composite magnetic particles into the reactor, add 300g of sodium phosphate solution with a mass concentration of 12%, use mechanical stirring, and hydrolyze at a high temperature of 90°C for 6 hours; filter to obtain the hydrolyzed fiber composite magnetic particles. Wash with pure water and ethanol, and dry under vacuum to constant weight.

(3) Experiments on film formation and pollutant removal in aerobic sewage treatment system

In a 1000mL activated sludge reactor, add 800mL of aerobic activated sludge with a suspended solid content of 5000mg/L, add 3.6g of the hydrolyzed modified fiber composite magnetic particles obtained in step (2), and control the gas through a gas rotor flowmeter Flow rate 200mL/min. It operates in sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes for drainage, water inlet and other operations. Each time, 500 mL of water is drained and 490 mL of water is fed. 10 mL of simulated sewage concentrate is added at the beginning of each cycle. The ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L and the COD concentration is 50g/L. Run continuously for 10 days. Samples were taken before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, 50 mL of sludge was taken to measure the oxygen consumption rate. After 10 days, the aerobic activated sludge on the surface of fiber composite magnetic particles was observed.

(4) Experiments on film formation and pollutant removal in anaerobic sewage treatment systems

In a 250 mL sequential batch reactor, add the inoculated anaerobic activated sludge and the hydrolyzed modified fiber composite magnetic particles obtained in step (2), stir using an intermittent stirring device, the stirring frequency is 5 min and stir for 30 s, and the temperature is controlled at 35 ±1℃. It operates in sequential batch mode, with a cycle of 12 hours. Each cycle has 11 hours of aeration, 30 minutes of settling, and 30 minutes for drainage, water inflow and other operations. Each time, 100 mL of water is drained and 97.5 mL of water is fed. 2.5 mL of simulated sewage concentrate is added at the beginning of each cycle. The nitrate nitrogen concentration of the simulated sewage concentrate is 5 g/L and the COD concentration is 50 g/L. Run continuously for 30 days, and take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles.

Example 8

(1) Preparation of fiber composite magnetic particles

Take 35g of ferroferric oxide magnetic particles and add it to a 250mL four-neck bottle filled with 100g of pure water. Ultrasonicate for 30 minutes. Under nitrogen protection, use mechanical stirring at 55°C for 30 minutes. Add vinyltrichlorosilane to the system. 35g and 0.1g of sodium dodecyl sulfate, raise the temperature to 65°C, age for 2 hours, and then add a mixed solution of 75g styrene, 15g pentaerythritol triacrylate and 15g glycidyl methacrylate dropwise to the system, and add the mixed solution dropwise After completion, add 0.7g of polypropylene fiber with a length of 350μm and a diameter of 7μm, stir evenly, add 6g of initiator potassium persulfate, incubate for 3h, filter to obtain fiber composite magnetic particles, wash with pure water and ethanol, and vacuum dry to constant weight. .

(2) Hydrolysis modification of fiber composite magnetic particles

Add 100g of dried fiber composite magnetic particles into the reactor, add 350g of sodium sulfide solution with a mass concentration of 5%, use mechanical stirring, and hydrolyze at a high temperature of 80°C for 0.5h; filter to obtain the hydrolyzed fiber composite magnetic particles. , washed with pure water and ethanol, and vacuum dried to constant weight.

(3) Experiments on film formation and pollutant removal in aerobic sewage treatment system

In a 1000mL activated sludge reactor, add 800mL of aerobic activated sludge with a suspended solid content of 5000mg/L, add 3.6g of the hydrolyzed modified fiber composite magnetic particles obtained in step (2), and control the gas through a gas rotor flowmeter Flow rate 200mL/min. It operates in a sequential batch mode, with 12 hours as one cycle, 11 hours of aeration per cycle, 30 minutes of settling, and 30 minutes for drainage, water inlet and other operations. Each time, 500 mL of water is drained and 490 mL of water is fed. 10 mL of simulated sewage concentrate is added at the beginning of each cycle. The ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L and the COD concentration is 50g/L. Run continuously for 10 days. Samples were taken before each cycle of drainage to measure the COD and ammonia nitrogen concentrations in the supernatant. After 10 days, 50 mL of sludge was taken to measure the oxygen consumption rate. After 10 days, the aerobic activated sludge on the surface of fiber composite magnetic particles was observed.

(4) Experiments on film formation and pollutant removal in anaerobic sewage treatment systems

In a 250 mL sequencing batch reactor, add the inoculated anaerobic activated sludge and the hydrolyzed modified fiber composite magnetic particles obtained in step (2), stir using an intermittent stirring device, the stirring frequency is 5 min and stir for 30 s, and the temperature is controlled at 35 ±1℃. It operates in sequential batch mode, with a cycle of 12 hours. Each cycle has 11 hours of aeration, 30 minutes of settling, and 30 minutes for drainage, water inflow and other operations. Each time, 100 mL of water is drained and 97.5 mL of water is fed. 2.5 mL of simulated sewage concentrate is added at the beginning of each cycle. The nitrate nitrogen concentration of the simulated sewage concentrate is 5 g/L and the COD concentration is 50 g/L. Run continuously for 30 days, and take samples before daily drainage to test the settling performance and COD removal effect of anaerobic activated sludge. After 30 days, observe the anaerobic activated sludge on the surface of fiber composite magnetic particles.

Comparative example 1

(1) Preparation of magnetic particles

Except for not including the step of "adding 0.7g of polyester fiber with a length of 350 μm and a diameter of 2 μm", ferroferric oxide polymer particles were prepared in the same manner as step (1) of Example 1.

(2) The film formation and pollutant removal in the aerobic sewage treatment system are the same as in Example 1.

(3) The film formation and pollutant removal in the anaerobic sewage treatment system are the same as in Example 1.

Test methods and results:

Microscopic observation: After drying, the prepared fiber composite magnetic particles and the hydrolytically modified, hydrolytically modified and chelated metal ion magnetic particles were observed under a microscope, and the fluorescence microscope pictures of the material samples were taken as shown in Figures 2 and 3. As shown, it can be found that the magnetic microspheres prepared in Example 1 have an obvious fibrous structure, while no fibrous structure is observed in the magnetic microspheres prepared in Comparative Example 1, that is, the method of Example 1 can successfully composite fibers into magnetic microspheres. inside the sphere, and the surface of the microsphere takes on a fibrous shape.

Adsorption activated sludge test: Take 1g of sterilized biological filler sample and add it to a 250mL Erlenmeyer flask containing 100mL of activated sludge suspension. Set up three parallel samples for each group. Place the above test sample bottle in a shaker oscillator at 37°C and 200 rpm. After shaking for 3 days, take out the magnetic particles for fluorescent staining. Under the same test conditions, take a fluorescence microscope picture of the material sample as follows: As shown in Figure 4, it can be found that Example 1 adsorbs significantly more activated sludge than Comparative Example 1, and the rich fibrous protrusions on the particles of Example 1 obviously have stronger fluorescence intensity, that is, the composite of fibers is conducive to adsorbing more sludge. Multiple activated sludge.

Aerobic water treatment application test: Put the fiber composite magnetic particles of the examples and the magnetic particles of the comparative example into a bioreactor to conduct the film-hanging and pollutant removal experiments of the aerobic sewage treatment system. The experimental plan is the same as the steps of Example 1. (2) Consistent. The COD concentration and ammonia nitrogen concentration used the corresponding kits from Lianhua Technology Co., Ltd. The test results are shown in Table 1, only taking the data on the 10th day as an example.

Anaerobic water treatment application test: Put the fiber composite magnetic particles of the example and the magnetic particles of the comparative example into a bioreactor to conduct the film-laying and pollutant removal test of the anaerobic sewage treatment system. The test plan is the same as the steps of Example 1. (3) Consistent, the COD concentration was tested using the corresponding kit from Lianhua Technology Co., Ltd., and the nitrate nitrogen concentration was tested using UV spectrophotometry. The test results are shown in Table 1, only taking the data on the 30th day as an example.

Table 1 Water treatment test results of each embodiment and comparative example

It can be seen from Table 1 that the COD and ammonia nitrogen degradation rates of fiber composite magnetic particles in aerobic water treatment are better than those of ordinary magnetic particles. After the fiber composite magnetic particles are hydrolytically modified and chelated with metal particles, their bioaffinity The properties are improved, so that the degradation rate of COD and ammonia nitrogen is higher than that of unmodified fiber composite magnetic particles; similarly, in anaerobic water treatment, the COD and nitrate removal rates of fiber composite magnetic particles are higher than that of ordinary magnetic particles, while After hydrolyzing the modified and chelated metal particles, their bioaffinity is further improved, so that the degradation rate of COD and ammonia nitrogen is higher than that of unmodified fiber composite magnetic particles.

This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to this embodiment without creative contribution as needed after reading this specification. However, as long as the rights of the present invention are All requirements are protected by patent law.

Claims (10)

1. The preparation method of the fiber composite magnetic particles is characterized by comprising the following steps:

(1) Adding ferroferric oxide magnetic particles into a reactor filled with pure water, carrying out ultrasonic treatment for 15-30min, and homogenizing under the protection of nitrogen by using mechanical stirring;

(2) Adding a modifier and a surfactant into the system at 35-55 ℃ and aging for 2 hours;

(3) Then adding a mixed monomer solution of styrene, a cross-linking agent and an epoxy monomer into the system in a dropwise manner;

(4) After the dripping of the mixed monomer solution is finished, adding fibers, and uniformly stirring;

(5) After stirring uniformly, adding an initiator into the system, heating to 65-85 ℃, and preserving heat for 3-6h under stirring;

(6) Filtering to obtain fiber composite magnetic particles, washing with pure water and ethanol, and vacuum drying to constant weight.

2. The method for preparing fiber composite magnetic particles according to claim 1, wherein the mass ratio of the modifier to the ferroferric oxide magnetic particles is 1:1-1.5:1..

3. The method for preparing fiber composite magnetic particles according to claim 1, wherein the amount of styrene is 60 to 80%, the amount of the crosslinking agent is 10 to 20%, and the amount of the epoxy-based monomer is 10 to 20% based on the total mass of the mixed monomer solution of styrene, the crosslinking agent and the epoxy-based monomer.

4. The method for producing a fiber composite magnetic particle according to claim 1, wherein the fiber diameter is 1 to 10 μm and the fiber length is 300 to 1000 μm.

5. A method of modifying a fibrous composite magnetic particle comprising the steps of:

adding the dried fiber composite magnetic particles into a reactor, adding a hydrolysis agent into the system, and hydrolyzing at 70-90 ℃ for 0.5-6h by using mechanical stirring; filtering to obtain hydrolyzed and modified fiber composite magnetic particles, washing with pure water and ethanol, and vacuum drying to constant weight.

6. A method of modifying a fibrous composite magnetic particle comprising the steps of:

adding the dried fiber composite magnetic particles subjected to hydrolysis modification according to claim 5 into a reactor, adding a metal salt solution into the system, and stirring for 2-5h at normal temperature; filtering to obtain fiber composite magnetic particles after hydrolysis modification and metal ion chelation, washing with pure water and ethanol, and vacuum drying to constant weight.

7. The method according to claim 5, wherein the hydrolytic agent comprises one or more of sodium hydroxide, potassium hydroxide, water glass, sodium phosphate, potassium phosphate and sodium sulfide, and the mass concentration of the hydrolytic agent is 1-20%.

8. The method according to claim 6, wherein the metal salt solution comprises one or more of ferric chloride, ferric sulfate, ferrous chloride, ferrous sulfate, cupric chloride, cupric sulfate, nickel chloride, nickel sulfate, manganese chloride and manganese sulfate, the mass concentration of the metal salt solution is 1-20%, and the mass ratio of the metal salt solution to the fiber composite magnetic particles is (200-5): 1.

9. use of the fiber composite magnetic particles or modified particles thereof according to any one of claims 1-8 as a carrier in the treatment of sewage in an aerobic activated sludge reactor, comprising the steps of:

1) Adding 1-20g/L of aerobic activated sludge and 1-20g/L of fiber composite magnetic particles or modified particles thereof into an activated sludge reactor, and controlling the air flow rate to be 200mL/min through a gas rotameter;

2) The method is operated in a sequencing batch mode, 12 hours is a period, each period of aeration is 11 hours, sedimentation is carried out for 30 minutes, and water draining and water inflow operations are carried out for 30 minutes; 500mL of supernatant liquid is discharged each time, 490mL of tap water and 10mL of simulated sewage concentrated solution are added; wherein the simulated sewage concentrate is prepared from ammonium chloride and sodium acetate, the ammonia nitrogen concentration of the simulated sewage concentrate is 5g/L, and the COD concentration is 50g/L;

3) And continuously running for 10 days, sampling and measuring COD and ammonia nitrogen concentration in supernatant before each period of drainage, taking 50mL of sludge after 10 days to measure oxygen consumption rate, and observing the surface aerobic activated sludge of the fiber composite magnetic particles or the modified particles after 10 days.

10. Use of the fiber composite magnetic particles or modified particles thereof according to any one of claims 1-8 as a carrier in anaerobic activated sludge reactor for treating sewage, comprising the steps of:

1) Adding anaerobic activated sludge with the concentration of 5-40g/L and fiber composite magnetic particles or modified particles with the concentration of 1-15g/L into a sequencing batch reactor, stirring by adopting an intermittent stirring device, wherein the stirring frequency is 5min, stirring is 30s, and the temperature is controlled at 35+/-1 ℃;

2) Operating in a sequencing batch mode, wherein 12h is a period; aeration is carried out for 11 hours each cycle, sedimentation is carried out for 30 minutes, and water draining and water inflow operations are carried out for 30 minutes; 100mL of supernatant water is discharged each time, 97.5mL of tap water and 2.5mL of simulated sewage concentrate are added; wherein the simulated sewage concentrate is prepared from potassium nitrate and sodium acetate, the nitrate nitrogen concentration of the simulated sewage concentrate is 5g/L, and the COD concentration is 50g/L;

3) The anaerobic activated sludge is continuously operated for 30 days, sampling is carried out before daily drainage, the sedimentation performance and COD removal effect of the anaerobic activated sludge are tested, and the anaerobic activated sludge on the surface of the fiber composite magnetic particles or modified particles thereof is observed after 30 days.