CN108545837B - Airlift reactor for treating and refining soybean oil wastewater by using mucoid hyphomycete - Google Patents

Abstract

An airlift reactor for treating and refining soybean oil wastewater by using mucor-dermatomyces neomyces belongs to the technical field of wastewater treatment. The invention aims to design an air-lift reactor for treating and refining soybean oil wastewater by using mucoid hyphomycete, which can realize the treatment and resource utilization of the wastewater from refining soybean oil and can also obviously improve the wastewater treatment efficiency aiming at the characteristics of the soybean oil wastewater. The reaction tank is externally coated with a water bath jacket, and the water bath jacket is provided with a heat preservation water inlet and a heat preservation water outlet; the communicating barrel of upper and lower and retort body is installed through the bracer in retort internal portion, and the first half of barrel is low PH district, and the lower half is high PH district, and the gas outlet that the trachea passed retort body and barrel is arranged in between low PH district and the high PH district to the gas outlet is upwards, installs gas distributor in tracheal gas outlet department, installs the whirl board on the barrel. The invention uses air as driving force to realize the circulation flow of water, and has no need of mechanical stirring and pump lifting, and the invention has the characteristics of simple structure, low energy consumption and the like, and can be widely applied to the fields of bioengineering, energy chemical industry, environmental protection and the like.

Description

Airlift Reactor for Treatment of Refined Soybean Oil Wastewater by N.

technical field

The invention belongs to the technical field of wastewater treatment.

Background technique

Refined soybean oil wastewater contains high concentrations of oil and organic matter. If it is directly discharged without treatment, it will cause water pollution. Domestic refined soybean oil wastewater treatment methods generally adopt oil separation - coagulation flotation - aerobic biological treatment. However, the above-mentioned process has high investment cost, large floor space and complicated process, and only aims to remove the oil in the wastewater and reduce the COD of the wastewater. Some microorganisms such as yeasts, bacteria and molds use carbohydrates and oils as carbon and nitrogen sources to produce microbial oils in microbial cells. Microbial oil can not only prepare functional oil, relieve the tension of vegetable oil to a certain extent, but also alleviate the global energy crisis by using biodiesel prepared from it.

At present, the bioreactors used for yeast to treat wastewater and produce microbial oil all use fixed pH conditions, while the pH conditions required for the growth and reproduction stage of yeast cells and the stage of accumulating oil are different, and the pH required for the growth and reproduction stage of yeast cells is lower ( 5 to 6), the pH required for the oil accumulation stage is high (6 to 7). These bioreactors generally use a unified intermediate value, which reduces the yeast growth and oil production capacity, and cannot meet the requirements of efficient wastewater treatment.

SUMMARY OF THE INVENTION

The purpose of the present invention is to design a kind of gas for treating refined soybean oil wastewater by N. corticosteroids, which can not only realize the treatment and resource utilization of refining soybean oil wastewater, but also can significantly improve the wastewater treatment efficiency according to the characteristics of soybean oil wastewater. lift reactor.

In the present invention, the reaction tank is covered with a water bath jacket, and the water bath jacket is provided with a thermal insulation water inlet and an thermal insulation water outlet; inside the reaction tank body is installed a cylinder body that communicates with the reaction tank body from top to bottom through a support block. The upper half is the low pH area, the lower half is the high pH area, the gas pipe is placed between the low pH area and the high pH area through the gas outlet of the reaction tank and the cylinder body, and the gas outlet is upward, and one end of the gas pipe is connected to the air pump. A gas flow meter is installed on the gas pipe, and a gas distributor is installed at the gas outlet of the gas pipe. The top of the gas distributor is a semicircle, and an air outlet is opened on the semicircle; a swirl flow is installed on the upper end of the cylinder. Plate, swirl plate structure: the support ring is fixedly connected to the cylinder, the support ring and the blind plate are installed with beveled blades, and the beveled blades are provided with sieve holes; there is an exhaust port at the upper end of the reaction tank, and an outlet at the bottom end. Water inlet; an upper sampling port is opened at the reaction tank corresponding to the low pH area, and a lower sampling port is opened at the reaction tank corresponding to the high pH area; a water inlet is opened on the tank body; The side wall communicates with the low pH area; a pH meter, a dissolved oxygen meter, and a temperature meter are installed on the tank body.

In the present invention, an annular support plate is fixedly installed on the inner wall of the tank, and the outer edge of the bottom end of the cylinder is lapped on the annular support plate.

The diameter of the air outlet hole of the present invention is 2-4 mm, the radial angle of the air outlet hole is 30°-60°, and the aperture ratio of the gas distributor is in the range of 15%-30%.

The pitch angle of the oblique blade in the present invention is 45°-60°, and the radial angle is 18°-25°; the opening rate of the swirl plate is in the range of 40%-70%; the sieve hole is a polygonal hole Or circular holes or special-shaped holes; the aperture of the sieve hole is between 2 and 4 mm.

The present invention is to the treatment method of refining soybean oil wastewater:

The operating temperature of the air-lift reactor is 25-30 °C, and the refining soybean oil wastewater adjusted to pH 7 is added to 5/6 of the reaction tank from the water inlet of the reaction tank, and then the yeast suspension is removed from the reaction tank. The feed port is added, and the air pump transports the gas for the reactor. The air enters from the convex gas distributor. The gas is dispersed through the gas distributor and then bubbles into the liquid phase. The gas flow meter controls the intake flow rate to be 0.25-0.45m ³ /h; in the low pH area, the pH value is in the range of 5.2 to 5.8, the yeast consumes oxygen, and uses the organic matter in the wastewater for bacterial growth and reproduction, during which the bacterial metabolism produces small molecular organic acids, keeping the area low pH; the wastewater rises together with the bubbles to the swirl plate, and a part of the gas-liquid-solid three-phase flow moves along the slanted blades, creating a turbulent space where the gas-liquid swirling and churning, the gas-liquid-solid three-phase fully contacts, and the radial and axial mixing The strength is greatly enhanced, the oxygen mass transfer coefficient is improved, and another part of the large bubbles in the gas-liquid-solid three-phase flow is cut and broken into small bubbles by the sieve holes; after the mixture reaches the top of the reaction tank, a part of the bubbles burst at the gas-liquid interface, The gas is discharged from the exhaust port, and the other part of the gas enters the downflow area with the wastewater in the form of small bubbles, and enters the upflow area through the bottom baffle to provide oxygen for the yeast to accumulate grease; in the high pH area, the pH value range is 6.5 ~7. Yeasts use the oil in wastewater to accumulate microbial oil in the bacteria. As the content of fatty acids and other acidic substances in the wastewater decreases, the pH value of this area maintains a high level. When a certain amount of oil is accumulated in the yeast. , the net weight of the bacterial cells increases, sinking to the bottom of the reaction tank; pH measuring meter, dissolved oxygen measuring device and thermometer monitor the situation in the reaction tank in real time, every 12h from the upper sampling port and the lower sampling port to measure Oil content and COD removal rate in refined soybean oil wastewater; after the reactor runs for 100 hours, the treated wastewater is discharged from the water outlet.

The air-lift reactor of the invention is a multi-phase flow reactor that realizes the circulating flow of water with air as the driving force and does not need mechanical stirring and pump lifting, because of its simple structure, low energy consumption, regular internal flow field, interphase mass transfer and The characteristics of high heat transfer efficiency, good sealing, easy cleaning and maintenance have been widely used in many fields such as bioengineering, energy chemical industry and environmental protection. The main principle of the airlift reactor is to introduce air into the upflow area through an air pipe, so that the density of the gas-liquid mixture in the upflow area is reduced. Due to the difference in the density difference between the upflow area and the downflow area, the Realize the circulating flow of gas, liquid or gas, liquid and solid mixture. The airlift reactor was first proposed in the 1950s, and was widely studied after the 1980s. There are some domestic literature reports in this regard, the theory of airlift reactor tends to be perfect, the design tends to be multifunctional, and its application is more and more extensive. In the airlift reactor in practical industrial application, the bubbles tend to coalesce during the rising process, and the adjustment range of operating parameters is relatively narrow, so the versatility and flexibility of the equipment are limited to a certain extent. Increasing the reaction rate becomes a very real and urgent problem. ① The present invention builds an air-lift reactor suitable for the treatment of refined soybean oil wastewater by N. The high pH area of oil accumulation improves the yeast growth and oil production capacity, and realizes the efficient treatment and resource utilization of refined soybean oil wastewater. ②The present invention adopts the convex gas distributor made of rubber material for the first time. The convex distributor can not only shear the gas from the air pump into fine bubbles, but also the spray direction of the bubbles is different from the flow direction of the liquid phase, and the bubbles react in the reaction The distribution in the reactor is more uniform, the turbulence of the liquid phase is more intense, the mass transfer efficiency is significantly improved, and the wastewater treatment time is reduced. ③The airlift reactor built by the present invention is equipped with a swirl plate in the guide tube, and a number of sieve holes are opened on the blades of the swirl plate. A part of the gas-liquid two-phase flow moves upward along the swirl plate, and the other part The large bubbles in the gas-liquid two-phase flow are cut and broken into small bubbles by the sieve holes, which strengthens the micro-mixing in the radial and axial directions, helps to prevent the bubbles from coalescing, and reduces the size of the bubbles.

Description of drawings

Figure 1 is a schematic structural diagram of the present invention; in the figure: 1 reaction tank, 2 cylinder, 3 swirl plate, 4 gas distributor, 5 upflow area, 6 downflow area, 7 low pH area, 8 high pH area, 9 Air pump, 10 Gas flow meter, 11 Air pipe, 12 Water inlet, 13 Material inlet, 14 Water outlet, 15 Water bath jacket, 16 Inlet of insulated water, 17 Outlet of insulated water, 18 Upper sampling port, 19 Lower sampling port, 20 Exhaust port, 21 pH meter, 22 dissolved oxygen meter, 23 temperature meter, 24 support block, 25 support plate, 26 blind plate, 27 bevel vane, 28 support ring, 29 mesh hole, 30 air outlet;

Fig. 2 is the top view of the swirl plate of the present invention;

3 is a schematic diagram of the structure of the oblique blade of the present invention;

Fig. 4 is the structural representation of gas distributor of the present invention;

Fig. 5 is the top view of Fig. 4 of the present invention;

Fig. 6 is the oil content and CODcr removal rate curve diagram of the refining soybean oil wastewater of example 1 of the present invention;

Fig. 7 is the oil content and CODcr removal rate curve figure of the present invention's example 2 refining soybean oil wastewater;

FIG. 8 is a graph showing the oil content and CODcr removal rate of the refining soybean oil wastewater in Example 3 of the present invention.

Detailed ways

In the present invention, a water bath jacket 15 is covered outside the reaction tank 1, and a thermal insulation water inlet 16 and an thermal insulation water outlet 17 are installed on the water bath jacket 15; 1. The connected cylinder 2, the upper half of the cylinder 2 is the low PH area 7, the lower half is the high PH area 8, and the gas pipe 11 passes through the gas outlet of the reaction tank 1 and the cylinder 2 and is placed in the low PH area 7 and 2. Between the high PH area 8, and the gas outlet is upward, one end of the gas pipe 11 is connected to the gas pump 9, a gas flow meter 10 is installed on the gas pipe 11, a gas distributor 4 is installed at the gas outlet of the gas pipe 11, and the gas distributor 4 The top is a semicircle, and there is an air outlet 30 on the semicircle; a swirl plate 3 is installed on the upper end of the cylinder body 2, and the structure of the swirl plate 3: the support ring 28 is fixedly connected with the cylinder body 2, and the support ring 28 is connected to the blind The plate 26 is provided with an oblique angle blade 27, and a sieve hole 29 is opened on the oblique angle blade 27; there is an exhaust port 20 at the upper end of the reaction tank body 1, and a water outlet 14 at the bottom end; in the reaction tank body corresponding to the low pH area 7 An upper sampling port 18 is opened at 1 place, and a lower sampling port 19 is opened at the reaction tank 1 corresponding to the high pH area 8; a water inlet 12 is opened on the tank body 1; the feed port 13 passes through the side wall of the tank body 1 It communicates with the low pH zone 7 ; a pH meter 21 , a dissolved oxygen meter 22 , and a temperature meter 23 are installed on the tank body 1 .

In the present invention, an annular support plate 25 is fixedly installed on the inner wall of the tank body 1 , and the outer edge of the bottom end of the cylinder body 2 is placed on the annular support plate 25 .

The diameter of the air outlet hole 30 in the present invention is 2-4 mm, the radial angle of the air outlet hole is 30°-60°, and the opening ratio of the gas distributor 4 is in the range of 15%-30%.

The oblique angle blade 27 of the present invention has an elevation angle of 45° to 60° and a radial angle of 18° to 25°; the opening ratio of the swirl plate 3 is in the range of 40% to 70%; the sieve holes 29 It is a polygonal hole or a circular hole or a special-shaped hole; the diameter of the sieve hole is between 2 and 4 mm.

The present invention is to the treatment method of refining soybean oil wastewater:

The operating temperature of the air-lift reactor is 25-30 °C, and the refining soybean oil wastewater adjusted to pH 7 is added to 5/6 of the reaction tank from the water inlet 12 of the reaction tank 1, and then the yeast is suspended. The liquid is added from the feed port 13, while the air pump 9 transports gas for the reactor, the air enters from the convex gas distributor 4, and the gas bubbles into the liquid phase after being dispersed by the gas distributor 4, and the gas flow meter 10 controls the inlet. The air flow is 0.25-0.45m ³ /h; in the low pH zone 7, the pH value is in the range of 5.2-5.8, the yeast consumes oxygen, and uses the organic matter in the wastewater for bacterial growth and reproduction, during which the bacterial metabolism produces small molecular organic acid to maintain a low pH in this area; the waste water rises together with the air bubbles to the swirl plate 3, and a part of the gas-liquid-solid three-phase flow moves along the angled blades 27, creating a turbulent space where the gas-liquid rotates and turns, and the gas-liquid-solid three-phase flow moves. Fully contacted, the mixing strength in the radial and axial directions is greatly enhanced, and the oxygen mass transfer coefficient is improved. Another part of the large bubbles in the gas-liquid-solid three-phase flow is cut and broken into small bubbles by the sieve hole 29; the mixture reaches the reaction tank. After the top, a part of the bubbles burst at the gas-liquid interface, the gas is discharged from the exhaust port 20, and the other part of the gas enters the downflow area 6 with the wastewater in the form of small bubbles, and enters the upflow area 5 through the bottom baffle, which is the accumulation of yeast. The oil provides oxygen; in the high pH zone 8, the pH value ranges from 6.5 to 7, and the yeast use the oil in the wastewater to accumulate microbial oil in the bacteria. Maintain a relatively high level, when a certain amount of grease is accumulated in the yeast, the net weight of the bacteria increases and sinks to the bottom of the reaction tank; the pH meter 21, the dissolved oxygen meter 22 and the temperature meter 23 monitor the reaction in real time In the case of the tank, samples were taken from the upper sampling port 18 and the lower sampling port 19 every 12 hours to measure the oil content and COD removal rate in the refining soybean oil wastewater; after the reactor was running for 100 hours, the treated wastewater was discharged from the water outlet 14.

The present invention is described in further detail below: The construction of the airlift reactor is as shown in Figure 1:

The invention includes: a reaction tank body, a cylinder body, a swirl plate and a convex gas distributor; an air inlet is arranged in the middle of the reaction tank body, and a feed inlet is arranged above the air inlet, and the reaction The lower side of the tank body is provided with a water inlet, and the bottom is provided with a water outlet; the cylinder body and the reaction tank body are coaxially arranged and located inside the reaction tank body, and are used to divide the reaction tank body into The upflow area in the middle and the downflow area around, the upflow area is divided into an upper low pH area and a lower high pH area; the swirl plate is coaxially arranged with the reaction tank and is located at 4 of the cylinder. /5 is used to guide part of the three-phase flow in the up-flow area, and the blades of the swirl plate are provided with a number of sieve holes to guide the remaining three-phase flows in the up-flow area. flow and break bubbles; the convex gas distributor is arranged at 1/2 to 3/5 of the cylinder, separates the low pH area and the high pH area, and is connected to the air inlet , which is used to shear the gas from the gas pump into fine bubbles.

The reaction tank body, the cylinder body and the swirl plate are all made of plexiglass, and the convex gas distributor is made of rubber.

The diameter of the reaction tank is 200 mm, the height-diameter ratio is 7, and the cross-sectional area ratio of the upflow region to the downflow region is 0.8.

An air pump is arranged on one side of the tower body and is connected to the air inlet for outputting gas into the reaction tank, and a gas flow meter is arranged between the air pump and the air inlet.

An exhaust port is provided on the top of the reaction tank for removing part of the air when the pressure in the reaction tank is too large.

A water bath jacket is arranged on the outer periphery of the reaction tank to keep the materials in the reaction tank at a constant temperature; wherein, a thermal insulation water inlet is arranged at the lower part of the water bath jacket, and an upper part of the water bath jacket is arranged There is a thermal water outlet.

The upper part of the reaction tank is provided with an upper sampling port for collecting samples from the upper part of the reaction tank.

The lower part of the reaction tank is provided with a lower sampling port for collecting samples from the lower part of the reaction tank.

A pH meter is arranged on the upper part of the reaction tank for detecting the pH of the low pH region and the high pH region.

A dissolved oxygen measuring device is arranged on the upper part of the reaction tank, which is located on one side of the pH meter, and is used to detect the dissolved oxygen amount in the reaction tank.

A thermometer is arranged on the upper part of the reaction tank, located on one side of the dissolved oxygen measuring device, for detecting the temperature in the reaction tank.

The swirl plate includes: a blind plate, a blade and a support body; the diameter of the support ring is the same as the inner diameter of the cylinder; the ratio of the diameter of the blind plate to the inner diameter of the cylinder is 1:4; the swirl plate The number of blades is 12 to 16; the thickness of the swirl plate blade is 2 mm; the elevation angle of the swirl plate blade is 45° to 60°; the radial angle of the swirl plate blade is 18° to 25°; The opening ratio of the swirl plate is in the range of 40% to 70%; the sieve holes are polygonal holes, circular holes or special-shaped holes; and the pore diameter of the sieve holes is between 2 and 4 mm.

The shape of the convex gas distributor is like a hemisphere; the wall thickness of the convex gas distributor is 3-6 mm; The diameter of the air outlet is 2˜4 mm, the radial angle of the air outlet is 30°˜60°, and the aperture ratio of the convex gas distributor is in the range of 15%˜30%.

Convex gas distributor and swirl plate. There are several air outlets evenly distributed on the surface of the convex gas distributor. The diameter of the air outlet is 2-4mm, and the angle between the opening angle of the air outlet and the horizontal plane is 30°～ 60°, the convex distributor can not only shear the gas from the air pump into fine bubbles, but also the spray direction of the bubbles is different from the flow direction of the liquid phase, the bubbles are more uniformly distributed in the reactor, and the turbulent liquid phase It is more intense and the mass transfer performance is improved; the swirl plate is placed in the upflow area, and when the gas drives the liquid to rise, a part of the gas-liquid-solid three-phase flow moves along the swirl plate, creating a turbulent space where the gas and liquid rotate and roll, and the gas The liquid-solid three phases are fully contacted, the mixing strength in the radial and axial directions is greatly enhanced, and the oxygen mass transfer coefficient is improved. Another part of the large bubbles in the gas-liquid-solid three-phase flow is cut and broken into small bubbles by the sieve holes, which are entrained into the liquid. The air bubbles in the downflow area are increased, and the air bubbles enter the high pH area from the bottom deflecting area, and are used for the yeast to accumulate grease, thereby enhancing the wastewater treatment effect.

The reaction system in the reaction tank is air-water two-phase, when the gas flow meter range is 0.08-0.15m ³ /h, the gas content is 0.68%-2.32%, and the volumetric oxygen mass transfer coefficient is 0.00034s ^{- 1} to 0.00078s ^-1 .

Preliminary preparation:

Preparation of N. marctoformis suspension: a single colony of N. marctoformis Cutaneotrichosporon mucoides with the strain number CGMCC NO: 2.571 stored on the slant was inserted into 2-3L of In the seed medium of the bacteria, culture at 180 rpm on a shaking table at 30°C for 1 day to obtain a cultured suspension of N. mucortiformis, and store the obtained bacterial suspension in a 4°C refrigerator for future use; wherein The dosage of each component in the seed medium of N. marctoformis is: glucose 70g/L; yeast extract powder 2g/L; MgSO ₄ ·7H ₂ O 1.2g/L; KH ₂ PO ₄ 0.8g/L ; (NH ₄ ) ₂ SO ₄ 2.5 g/L; pH=6.0.

Operation of Airlift Reactor and Treatment of Refined Soybean Oil Wastewater:

The operating temperature of the present invention is 25-30°C, and the refining soybean oil wastewater adjusted to pH 7 is added to 5/6 of the reaction tank from the water inlet 12 of the reaction tank 1, and then the above-mentioned preparatory work is obtained. The yeast suspension is added from the feeding port 13, and the air pump 9 is the reactor transporting gas simultaneously, and the air enters from the convex gas distributor 4, and the gas is bubbled into the liquid phase after being dispersed through the gas distributor 4, and the gas flow rate Meter 10 controls the intake air flow to be 0.25~0.45m ³ /h; in low pH zone 7 (pH value range is about 5.2~5.8), yeast consumes oxygen, and uses organic matter in wastewater for bacterial growth and reproduction. Body metabolism produces small molecular organic acids to maintain a low pH in this area; the wastewater rises together with the air bubbles to the swirl plate 3, and a part of the gas-liquid-solid three-phase flow moves along the swirl plate blades 25, resulting in a turbulent flow of gas-liquid swirling and tossing In the space, the gas-liquid-solid three phases are fully contacted, the mixing strength in the radial and axial directions is greatly enhanced, and the oxygen mass transfer coefficient is improved, and the large bubbles in the other part of the gas-liquid-solid three-phase flow are cut and broken into small bubbles by the sieve hole 27; After the mixture reaches the top of the reaction tank, a part of the bubbles burst at the gas-liquid interface, the gas is discharged from the exhaust port 20, and the other part of the gas enters the downflow zone 6 with the waste water in the form of small bubbles, and enters the upflow through the bottom deflection. Zone 5 provides oxygen for yeast to accumulate grease; in high pH zone 8 (pH value range is around 6.5 to 7), yeast uses grease in wastewater to accumulate microbial grease in bacteria, and with the acidity of fatty acids in wastewater When the substance content decreases, the pH value of this area maintains a relatively high level. When a certain amount of grease is accumulated in the yeast, the net weight of the bacteria increases and sinks to the bottom of the reaction tank; the pH measuring meter 21, the dissolved oxygen measuring device 22 and the The thermometer 23 monitors the situation in the reaction tank in real time, and samples from the upper sampling port 18 and the lower sampling port 19 every 12h to measure the oil content and the removal rate of COD in the refining soybean oil wastewater; The waste water is discharged from the water outlet 14. The oil content and COD removal rate after 100h of wastewater treatment were measured, and the removal rates were 78.8%-82.2% and 85.9%-89.4%, respectively; the oil content of yeast cells was measured, and the removal rates were 37%-40%.

Example 1: Operation of Airlift Reactor and Treatment of Refined Soybean Oil Wastewater

Construction of airlift reactor: As shown in Figure 1, it includes a reaction tank body, a cylinder body, a swirl plate, and a convex gas distributor; an air inlet is provided in the middle of the reaction tank, and an air inlet is provided above the air inlet. There is a feeding port, the lower side of the reaction tank is provided with a water inlet, and the bottom is provided with a water outlet; the cylinder and the reaction tank are coaxially arranged and located inside the reaction tank, which is used to divide the reaction tank into the middle part. The up-flow area and the surrounding down-flow area, the up-flow area is divided into an upper low pH area and a lower high pH area; the swirl plate is arranged coaxially with the reaction tank and is located at 4/5 of the cylinder, used to convert the up-flow area. Part of the three-phase flow in the flow zone is guided, and the blades of the swirl plate are provided with a number of sieve holes to guide the remaining three-phase flow in the up-flow zone and break bubbles; the convex gas distributor is arranged in the At 1/2 of the cylinder, the low pH area and the high pH area are separated and connected to the air inlet for shearing the gas from the air pump into fine air bubbles.

The reaction tank body, the cylinder body and the swirl plate are made of plexiglass, and the convex gas distributor is made of rubber;

The diameter of the reaction tank is 200mm, the height-diameter ratio is 7, and the cross-sectional area ratio of the up-flow area and the down-flow area is 0.8;

An air pump is arranged on one side of the tower body and is connected with the air inlet for outputting gas into the reaction tank, and a gas flow meter is arranged between the air pump and the air inlet;

An exhaust port is provided on the top of the reaction tank for removing part of the air when the pressure in the reaction tank is too large;

A water bath jacket is arranged on the outer periphery of the reaction tank to keep the material in the reaction tank at a constant temperature; wherein, a thermal insulation water inlet is arranged at the lower part of the water bath jacket, and a thermal insulation water outlet is arranged at the upper part of the water bath jacket;

The upper part of the reaction tank is provided with an upper sampling port for collecting samples from the upper part of the reaction tank;

The lower part of the reaction tank is provided with a lower sampling port for collecting samples from the lower part of the reaction tank;

A pH meter is arranged on the upper part of the reaction tank for detecting the pH of the low pH zone and the high pH zone;

A dissolved oxygen measuring device is arranged on the upper part of the reaction tank, located on one side of the pH measuring meter, for detecting the amount of dissolved oxygen in the reaction tank;

A thermometer is provided on the upper part of the reaction tank, located on one side of the dissolved oxygen measuring device, for detecting the temperature in the reaction tank;

The swirl plate includes: a blind plate, a blade and a support body; the diameter of the support ring is the same as the inner diameter of the cylinder; the ratio of the diameter of the blind plate to the inner diameter of the cylinder is 1:4; the number of swirl plate blades is 12; the thickness of the swirl plate blades is 2mm; the elevation angle of the swirl plate blade is 45°; the radial angle of the swirl plate blade is 18°; the opening rate of the swirl plate is 40%; the sieve hole is a circular hole; the aperture of the sieve hole is 2mm.

The convex gas distributor is made of rubber, and its shape is like a hemisphere; the wall thickness of the convex gas distributor is 3mm; the convex gas distributor is provided with several air outlets evenly distributed on its surface along the circumferential direction, and the diameter of the air outlet is 2mm, the radial angle of the air outlet is 30°, and the opening rate of the convex gas distributor is 15%.

The reaction system in the reaction tank is air-water two-phase, when the gas flow meter is 0.08 m ³ /h, the gas content is 0.68%, and the volumetric oxygen mass transfer coefficient is 0.00034 s ^-1 .

Treatment of refined soybean oil wastewater: build an air-lift reactor as described above. Refined soybean oil wastewater is added from the water inlet of the reaction tank, the yeast suspension is added from the feed inlet, the air enters from the convex gas distributor, and the gas is dispersed through the gas distributor and then bubbles into the liquid phase to control the air intake. The flow rate is 0.08m ³ /h; in the low pH area, when the pH is about 5.2, the yeast consumes oxygen and uses the organic matter in the wastewater to grow and reproduce the bacteria. Low pH; the wastewater rises together with the air bubbles to the swirl plate, and a part of the gas-liquid-solid three-phase flow moves along the swirl plate, creating a turbulent space where the gas-liquid swirling and tumbling, and the gas-liquid-solid three phases are fully contacted, radially and axially. The mixing strength in the direction is greatly enhanced, and the oxygen mass transfer coefficient is improved. Another part of the large bubbles in the gas-liquid-solid three-phase flow is cut and broken into small bubbles by the sieve holes; after the mixture reaches the top of the reaction tank, a part of the bubbles in the gas-liquid The interface ruptures, the gas is discharged from the exhaust port, and the other part of the gas enters the downflow area with the wastewater in the form of small bubbles, and enters the upflow area through the bottom baffle to provide oxygen for the yeast to accumulate grease; in the high pH area, at this time When the pH is about 6.5, the yeast uses the oil in the wastewater to accumulate microbial oil in the bacteria. As the content of fatty acids and other acidic substances in the wastewater decreases, the pH value in this area maintains a high level. When the yeast accumulates a certain amount of oil After the grease, the net weight of the bacteria increases and sinks to the bottom of the reaction tank; the pH meter, the dissolved oxygen meter and the temperature meter monitor the situation in the reaction tank in real time, and measure the samples from the upper sampling port and the lower sampling port every 12h. Oil content and COD removal rate in the wastewater from refining soybean oil; after the reactor runs for 100 hours, the treated wastewater is discharged from the water outlet.

The oil content and COD removal rate after 100h of wastewater treatment were determined, and the removal rates were 78.8% and 85.9%, respectively; the oil content of yeast cells was determined to reach 37.5%.

Example 2: Operation of Airlift Reactor and Treatment of Refined Soybean Oil Wastewater

Construction of the airlift reactor: The construction of the airlift reactor is basically the same as that of Example 1, the difference is that the convex gas distributor is arranged at 3/5 of the cylinder, and the wall thickness of the convex gas distributor is 5mm ; The diameter of the air outlet is 3mm, the radial angle of the air outlet is 45°, and the opening rate of the convex gas distributor is 20%.

The reaction system in the reaction tank is air-water two-phase, when the gas flow meter is 0.12 m ³ /h, the gas content is 1.74%, and the volumetric oxygen mass transfer coefficient is 0.00062 s ^-1 .

Treatment of refined soybean oil wastewater: the operating temperature of the airlift reactor is 27 °C, the refined soybean oil wastewater adjusted to pH 7 is added from the water inlet of the reaction tank, the yeast suspension is added from the feed inlet, and the air Entering from the convex gas distributor, the gas bubbles into the liquid phase after being dispersed by the gas distributor, and the air flow rate is controlled to be 0.11m ³ /h; in the low pH area, the pH is about 5.5 at this time, and the yeast consumes oxygen, And the organic matter in the wastewater is used for bacterial growth and reproduction, during which the bacterial metabolism produces small molecular organic acids to maintain a low pH in the area; the wastewater rises together with the bubbles to the swirl plate, and part of the gas-liquid-solid three-phase flow follows the vortex. The movement of the flow plate produces a turbulent space in which the gas-liquid swirling and tumbling, the gas-liquid-solid three-phase flow is fully contacted, the mixing strength in the radial and axial directions is greatly enhanced, and the oxygen mass transfer coefficient is improved. The air bubbles are cut and broken into small air bubbles by the sieve holes; after the mixture reaches the top of the reaction tank, a part of the air bubbles are broken at the gas-liquid interface, the gas is discharged from the exhaust port, and the other part of the gas enters the downflow area with the wastewater in the form of small air bubbles. It enters the upflow area through the bottom baffle to provide oxygen for the yeast to accumulate oil; in the high pH area, when the pH is about 6.8, the yeast uses the oil in the wastewater to accumulate microbial oil in the bacteria. The content of acidic substances such as fatty acids is reduced, and the pH value of this area is maintained at a high level. When a certain amount of oil accumulates in the yeast, the net weight of the bacteria increases and sinks to the bottom of the reaction tank; pH meter, dissolved oxygen meter and temperature The measuring meter monitors the situation in the reaction tank in real time, and takes samples from the upper sampling port and the lower sampling port every 12h to determine the oil content and COD removal rate in the refining soybean oil wastewater; after the reactor runs for 100h, the treated wastewater is removed from the The water outlet is discharged.

The oil content and COD removal rate after 100h of wastewater treatment were determined, and the removal rates were 79.6% and 87.3%, respectively; the oil content of yeast cells was determined to reach 38.7%.

Example 3: Operation of Airlift Reactor and Treatment of Refined Soybean Oil Wastewater

The construction of the airlift reactor is basically the same as that of Example 1, except that the convex gas distributor is arranged at 3/5 of the cylinder, the number of swirl plate blades is 16, and the elevation angle of the swirl plate blades is 60 °; the radial angle of the swirl plate blade is 25°; the opening rate of the swirl plate is 70%; the sieve holes are special-shaped holes; the aperture of the sieve holes is 4 mm.

The wall thickness of the convex gas distributor is 6 mm; the diameter of the air outlet is 4 mm, the radial angle of the air outlet is 60°, and the opening rate of the convex gas distributor is 30%.

The reaction system in the reaction tank is air-water two-phase, when the gas flow meter is 0.15 m ³ /h, the gas content is 2.32%, and the volumetric oxygen mass transfer coefficient is 0.00078 s ^-1 .

Treatment of refined soybean oil wastewater: the operating temperature of the airlift reactor is 30°C, the refined soybean oil wastewater adjusted to pH 7 is added from the water inlet of the reaction tank, and the obtained yeast suspension is added from the feed inlet , the air enters from the convex gas distributor, and the gas bubbles into the liquid phase after being dispersed by the gas distributor, and the intake air flow is controlled to be 0.15m ³ /h; in the low pH area, the pH is about 5.7 at this time, and the yeast consumes Oxygen, and use the organic matter in the wastewater for bacterial growth and reproduction, during which the bacterial metabolism produces small molecular organic acids to maintain a low pH in the area; the wastewater rises together with the air bubbles to the swirl plate, and part of the gas-liquid-solid three-phase flows along the With the movement of the swirl plate, a turbulent space in which the gas and liquid rotate and toss is generated, the gas-liquid-solid three-phase flow is fully contacted, the mixing strength in the radial and axial directions is greatly enhanced, and the oxygen mass transfer coefficient is improved. The other part of the gas-liquid-solid three-phase flow The large bubbles are cut and broken into small bubbles by the sieve holes; after the mixture reaches the top of the reaction tank, some of the bubbles are broken at the gas-liquid interface, the gas is discharged from the exhaust port, and the other part of the gas enters the downflow with the wastewater in the form of small bubbles In the high pH area, when the pH is about 7, the yeast uses the oil in the wastewater to accumulate microbial oil in the bacteria body. The content of fatty acids and other acidic substances in the wastewater is reduced, and the pH value of this area is maintained at a high level. When a certain amount of oil is accumulated in the yeast, the net weight of the bacteria increases and sinks to the bottom of the reaction tank; pH measuring meter, dissolved oxygen measuring device Monitor the situation in the reaction tank in real time with a thermometer, and take samples from the upper sampling port and the lower sampling port every 12h to measure the oil content and the removal rate of COD in the refining soybean oil wastewater; after the reactor runs for 100h, the treated wastewater discharged from the water outlet.

The oil content and COD removal rate after 100h of wastewater treatment were determined, and the removal rates were 82.2% and 89.4%, respectively; the oil content of yeast cells was determined to reach 40%.

Claims (5)

1. An airlift reactor for the treatment of refined soybean oil wastewater by N. corticosteroids, characterized in that: the reaction tank body (1) is covered with a water bath jacket (15), and the water bath jacket is covered with a water bath jacket (15). (15) is installed with an insulating water inlet (16) and an insulating water outlet (17); a cylinder (2) that communicates with the reaction tank (1) up and down is installed inside the reaction tank (1) through a support block (24). ), the upper part of the cylinder (2) is the low pH zone (7), the lower half is the high pH zone (8), and the gas pipe (11) passes through the reaction tank (1) and the air outlet of the cylinder (2) It is placed between the low pH zone (7) and the high pH zone (8), and the gas outlet is upward, one end of the gas pipe (11) is connected to the gas pump (9), and a gas flow meter (10) is installed on the gas pipe (11). , a gas distributor (4) is installed at the air outlet of the gas pipe (11), the top of the gas distributor (4) is a semicircle, and an air outlet (30) is opened on the semicircle; A swirl plate (3) is installed on the upper end, and the structure of the swirl plate (3) includes a blind plate (26), an oblique blade (27) and a support ring (28), and the support ring (28) is fixedly connected to the cylinder (2). , the support ring (28) and the blind plate (26) are provided with beveled blades (27), the beveled blades (27) are provided with sieve holes (29); the upper end of the reaction tank (1) is provided with an exhaust port ( 20), there is a water outlet (14) at the bottom; an upper sampling port (18) is opened at the reaction tank (1) corresponding to the low pH area (7), and the reaction tank (1) corresponding to the high pH area (8) is opened. ) is provided with a lower sampling port (19); a water inlet (12) is provided on the reaction tank (1); the feed port (13) passes through the side wall of the reaction tank (1) and the low pH zone (7). ) are connected; a pH meter (21), a dissolved oxygen meter (22), and a temperature meter (23) are installed on the reaction tank (1), wherein the low pH zone (7) and the high pH zone (8) The pH ranges were 5.2-5.8 and 6.5-7, respectively. 2. The airlift reactor for the treatment of refined soybean oil wastewater by N. corticosteroids according to claim 1, characterized in that: an annular support plate (25) is fixedly installed on the inner wall of the reaction tank (1). ), and the outer edge of the bottom end of the cylinder (2) rests on the annular support plate (25). 3 . The airlift reactor for treating refined soybean oil wastewater according to claim 1 , wherein the diameter of the air outlet ( 30 ) is 2-4 mm, and the outlet The radial angle of the air holes is 30°˜60°, and the opening ratio of the gas distributor (4) is in the range of 15%˜30%. 4. The airlift reactor for the treatment of refined soybean oil wastewater by N. cortex according to claim 1, wherein the angle of elevation of the oblique blade (27) is 45° to 60°, and the diameter is 45° to 60°. The direction angle is 18° to 25°; the opening rate of the swirl plate (3) is in the range of 40% to 70%; the sieve holes (29) are circular holes or special-shaped holes; The aperture is between 2 and 4mm. 5. the airlift reactor of the treatment of Refined soybean oil waste water by N. corticosteroids according to claim 1, it is characterized in that: the treatment method to Refined soybean oil waste water is: The operating temperature of the airlift reactor is 25-30°C, and the refining soybean oil wastewater adjusted to pH 7 is added to 5/6 of the reaction tank from the water inlet (12) of the reaction tank (1), and then The yeast suspension is added from the feeding port (13), while the air pump (9) transports gas for the reactor, the air enters from the gas distributor (4), and the gas is dispersed and bubbled into the gas distributor (4). In the liquid phase, the gas flow meter (10) controls the intake air flow to be 0.25-0.45m ³ /h; in the low pH zone (7), the pH value is in the range of 5.2-5.8, the yeast consumes oxygen and utilizes the organic matter in the wastewater During the growth and reproduction of the bacteria, the bacteria metabolize to produce small molecular organic acids to maintain a low pH in the area; the wastewater rises together with the air bubbles to the swirl plate (3), and a part of the gas-liquid-solid three-phase flow runs along the angled blades ( 27) Movement, resulting in a turbulent space where the gas-liquid swirling and tumbling, the gas-liquid-solid three-phase flow is fully contacted, the mixing strength in the radial and axial directions is greatly enhanced, and the oxygen mass transfer coefficient is improved. The air bubbles are cut and broken into small air bubbles by the sieve hole (29); after the mixture reaches the top of the reaction tank, a part of the air bubbles are broken at the gas-liquid interface, the gas is discharged from the exhaust port (20), and the other part of the gas is in the form of small air bubbles. The wastewater enters the downflow area (6), and enters the upflow area (5) through the bottom baffle to provide oxygen for the yeast to accumulate grease; in the high pH area (8), the pH value ranges from 6.5 to 7, and the yeast utilizes the wastewater The oil in the yeast accumulates microbial oil in the bacteria. With the reduction of fatty acid acid content in the wastewater, the pH value of this area maintains a high level. When a certain amount of oil is accumulated in the yeast, the net weight of the bacteria increases and sinks to The bottom of the reaction tank; the pH meter (21), the dissolved oxygen meter (22) and the temperature meter (23) monitor the conditions in the reaction tank in real time, and take samples from the upper sampling port (18) and the lower sampling port (18) every 12 hours. The sampling port (19) takes samples to measure the oil content and COD removal rate in the refining soybean oil wastewater; after the reactor runs for 100 hours, the treated wastewater is discharged from the water outlet (14).

Images