CN107417018B - A method of removing oil from wastewater - Google Patents

Abstract

The invention discloses a method for removing oil from wastewater. The wastewater passes through a buffer pool, a coarse grid, a microbubble air floating oil adsorption device, an oil catalytic rechemical desorption reactor, a pH value adjustment tank, a primary sedimentation tank, and an organic rhodium catalytic reaction in sequence. tank, biological denitrification tank, secondary sedimentation tank, water purification tank. The method creatively utilizes the catalytic effect of π-allyl nickel compound on oil molecules. When the oil in the wastewater is adsorbed by modified diatomite and is at a temperature of 200-250 °C, the π-allyl nickel compound Under the catalysis, the C-H bond in the oil molecule will be broken for a short time, and quickly recombine into a C-C bond or a C-H bond, and the C-H bond will be broken again, and the C-C bond will be broken due to π ‑Allyl nickel compounds have a limited catalytic effect and will not break again, so oil molecules with shorter carbon chains can be gradually synthesized into heavy oil molecules with longer carbon chains.

Description

A method of removing oil from wastewater

technical field

The invention relates to a method for degreasing treatment of catering wastewater, belonging to the field of wastewater treatment in environmental protection.

Background technique

Among domestic sewage, oily sewage from catering is one of the main water bodies. Many restaurants, canteens, food processing enterprises and residents will discharge a large amount of sewage in their daily life, which contains a large amount of animal and vegetable oils and fats. source.

At present, the existing catering wastewater degreasing methods include the following four.

(1) The physical method mainly includes filtration separation method and air flotation separation method, but they are only suitable for separating oil products with larger particles in wastewater, the treatment efficiency is 60-80%, and the oil content in the effluent is about 100-200 mg/ Lift. Small oil droplets and emulsified oils in wastewater are difficult to remove.

(2) The advantages of chemical treatment are that the equipment cost is low, the treatment effect is good, and the operation is simple;

(3) Physical and chemical methods mainly include air flotation method, adsorption method, electrochemical method, ultrasonic separation method, etc. These methods generally have the advantages of strong adaptability and wide selectivity.

(4) Biochemical (biochemical) treatment method uses the biochemical action of microorganisms to decompose complex organic matter into simple substances, thereby converting toxic substances into non-toxic substances, and purifying oily sewage. Microorganisms can use organic matter as nutrients, so that part of them can be absorbed and transformed into organic components in the microorganisms or proliferated into new microorganisms, and the rest can be oxidized and decomposed into simple organic or inorganic substances by microorganisms.

Since the above traditional treatment methods all have certain shortcomings, it is necessary to get rid of the existing treatment technology route, open up a new way to treat domestic sewage and remove oil, and then develop a new form of domestic sewage degreasing treatment technology.

SUMMARY OF THE INVENTION

In order to solve the deficiencies in the prior art, the present invention provides a method for degreasing catering wastewater. The catering wastewater enters a buffer pool through a waste water pipeline, where centralized collection and stabilization are performed, and the outlet of the buffer pool is connected to the coarse grid through a waste water pipeline. The grid is used to remove large-diameter solid substances in the catering wastewater. The outlet of the coarse grid is connected to the micro-bubble oil adsorption device through the wastewater pipeline. The bottom of the micro-bubble oil adsorption device is equipped with 9 ultra-fine bubble generators. It can accommodate a horizontally placed π-allyl nickel compound modified diatomite adsorption membrane. The upper left side is equipped with a water inlet valve, and the right bottom is equipped with a water outlet valve. After the coarse grid, the large particle size is initially removed. The oil-containing food waste water enters the device through the inlet valve on the upper left side of the micro-bubble oil adsorption device, and 9 ultra-fine bubble generators start to work to generate ultra-fine bubbles with a diameter of less than 50 μm. The ultra-fine bubbles will be entrained in the wastewater. The oil molecules floated up together, and were adsorbed by the modified diatomite adsorption film containing π-allyl nickel compound above the liquid surface. Therefore, an aerogel felt insulation layer is attached, and the top of the aerogel felt insulation layer is equipped with a stainless steel mechanical arm and a ball bearing; the oil catalytic desorption reactor is made of high-strength stainless steel, and its bottom is equipped with 5 electric heaters Blower, a set of stainless steel membrane frame is installed inside the device. On the membrane frame, 5 sheets of π-allyl nickel compound modified diatomite adsorption membrane to be treated at high temperature can be placed vertically. There is a heavy oil discharge port on the right side of the bottom. ; The π-allyl nickel compound-modified diatomite adsorption membrane that completely adsorbs oil is grabbed by a stainless steel manipulator and placed vertically on the stainless steel membrane frame in the oil catalytic desorption reactor. The bottom of the reactor is The 5 electric heating blowers of the machine start to work, generating high temperature air at 200~250℃. Under the catalysis of π-allyl nickel compound, the C-H bond in the oil molecule will be broken and quickly combined into a C-C bond, and the C-C bond will be It will not break again, so the oil molecules with shorter carbon chains can be gradually synthesized into heavy oil molecules with longer carbon chains, and at the same time, the heavy oil molecules will be adsorbed from the modified diatomite containing π-allyl nickel compounds at high temperature It is desorbed in the membrane, collected and discharged from the heavy oil outlet on the right side of the bottom of the reactor, which can be collected and reused centrally; the outlet of the microbubble air floating oil adsorption device is connected to the pH value adjustment tank through the waste water pipeline, where the pH value of the waste water is adjusted. The pH value is adjusted to near neutrality, the outlet of the pH adjustment tank is connected to the primary sedimentation tank 6 through the waste water pipeline, and the wastewater is subjected to precipitation and clarification treatment. The outer layer of the tank is wrapped with an insulating protective layer of the tank body, the upper right part of the reaction tank is provided with a water inlet valve, the lower left part is provided with a water outlet valve, and the central part of the tank body is installed with dichlorotetracarbonyl dirhodium porous filler, which is used as a polymerization catalyst. A particle discharge port is connected to the lower part of the packing layer, a high-voltage discharge electrode is installed in the middle of the left and right side wall plates, and a stirring blade is installed on the left and right sides of the bottom of the reaction tank. The wastewater passes through the organic rhodium catalyzed polymerization reaction tank The water inlet valve enters the inside of the reaction tank, The high-voltage discharge electrode conducts a high-voltage discharge every 0.2s to generate a high-voltage arc. The high energy generated by the high-voltage arc is absorbed by the oil remaining in the wastewater, and the C-H bond in the oil molecule is excited by the energy. Under the catalysis of dirhodium tetracarbonyl, the C-H bond is broken and recombined, and finally macromolecular polymer particles are formed, which are dispersed in water in the form of suspension, and discharged from the reaction tank through the water outlet valve on the right side of the reaction tank, and enter the secondary sedimentation tank. Here, all the remaining insoluble substances in the wastewater are removed, the outlet of the secondary sedimentation tank is connected to the purification tank through the waste water pipeline, and the outlet of the purification tank discharges the treated purified effluent through the waste water pipeline.

The effective volume of the microbubble air flotation oil adsorption device is 155m ³ , the ultra-fine bubble generator can generate ultra-fine bubbles with a diameter of less than 50 μm, the normal working voltage is 20V, and the working life is generally 5000h.

Its oil catalytic desorption reactor has a volume of 330m ³ , its electric heating blower can generate hot air at 200~250℃, and its normal working voltage is 380V.

The area of the π-allyl nickel compound modified diatomite adsorption membrane was 10.2 m ² , the content of the π-allyl nickel compound was 16.6 g/m ² , and the purity of the π-allyl nickel compound was 95.2%.

The advantages of the present invention are:

(1) The present invention gets rid of the existing catering wastewater oil purification treatment mode, creatively adopts a technical route combining physical means and chemical methods, and makes full use of the adsorption effect of modified diatomite and π-allyl nickel compounds. The catalytic synthesis effect of the catalyst makes the oil in the catering wastewater be adsorbed and enriched, and a synthesis reaction occurs to generate a usable heavy oil, and the oil removal efficiency reaches 99.8%.

(2) The present invention uses hot air as a heating source, and adopts the method of dispersing the π-allyl nickel compound in the modified diatomite, so that the synthesis reaction is more complete, the reaction efficiency is improved, and the whole process is improved. The processing power of the system.

(3) The modified diatomite adsorption membrane used in the present invention is regenerated after the thermal desorption process, and can be reused to absorb oil in wastewater, realizing the reuse of materials and greatly reducing the operating cost.

(4) The principle of the present invention is simple and easy to implement, the design and construction cost is low, the treatment effect is good, and the operation and maintenance cost is low, which is conducive to wide-scale popularization and application.

Description of drawings

FIG. 1 is a schematic diagram of the apparatus of the present invention.

In the picture: 1-buffer pool, 2-coarse grid, 3-microbubble air-floating oil adsorption device, 4-oil catalytic heavy chemical desorption reactor, 5-pH value adjustment tank, 6-primary sedimentation tank, 7-organic Rhodium catalytic reaction tank, 8-secondary sedimentation tank, 9-purification tank;

Figure 2 is a schematic diagram of a microbubble air-floating oil adsorption device and an oil catalytic recombination desorption reactor.

32-Ultra-fine bubble generator, 33-Ultra-fine bubbles, 34-Stainless steel robotic arm, 35-Rotary ball bearing, 36-Water inlet valve, 37-Water outlet valve; 41-Aerogel felt insulation layer, 42-π -Allyl nickel compound modified diatomite adsorption membrane, 43-stainless steel membrane frame, 44-electric heating blower, 45-heavy oil discharge port.

Figure 3 is a schematic diagram of a high voltage discharge organorhodium catalyzed polymerization reaction tank.

71- High voltage discharge electrode, 72- Dichlorotetracarbonyl dirhodium porous filler, 73- Tank insulation protection layer, 74- Water inlet valve, 75- Water outlet valve, 76- Stirring blade, 77- Particle discharge port.

Detailed ways

As shown in Fig. 1, the oil-containing catering wastewater enters the buffer pool 1 through the waste water pipeline, where centralized collection and preliminary stable adjustment are carried out. The outlet of the buffer pool 1 is connected to the coarse grid 2 through the waste water pipeline. This removes the large-diameter solid matter in the catering wastewater, the outlet of the coarse grid 2 is connected to the microbubble air floating oil adsorption device 3 through the waste water pipeline, and the π-allyl nickel compound in the microbubble air floating oil adsorption device 3 is modified The diatomite adsorption film 42 will be grabbed by the stainless steel mechanical arm 34 after completely adsorbing the oil, and sent to the oil catalytic recombination and desorption reactor 4, and the heavy oil generated in the oil catalytic recombination and desorption reactor 4 is discharged from the heavy oil outlet 45. It is discharged and recycled and reused. At the same time, the outlet of the microbubble air floating oil adsorption device 3 is connected to the pH value adjustment tank 5 through the waste water pipeline, and the pH value of the wastewater is adjusted to near neutrality. The outlet of the pH value adjustment tank 6 passes through the wastewater The pipeline is connected to the primary sedimentation tank 6, where the wastewater is subjected to precipitation and clarification, and the outlet of the primary sedimentation tank 6 is connected to the organic rhodium catalytic reaction tank 7 through the wastewater pipeline, and the remaining grease in the wastewater is polymerized by high-pressure discharge catalysis into insoluble. The particulate matter of the water is connected to the secondary sedimentation tank 8 through the waste water pipeline, where all the remaining insoluble substances in the waste water are removed, the outlet of the secondary sedimentation tank 8 is connected to the clean water tank 9 through the waste water pipeline, and the outlet of the clean water tank 9 is connected to the waste water pipeline. The treated purified effluent is discharged; wherein, the micro-bubble air-floating oil adsorption device 3 is made of high-strength glass fiber reinforced plastic, with an effective volume of 155m ³ , and 9 ultra-fine bubble generators 32 are installed at the bottom thereof, which can generate particles with a diameter less than 50 μm. The ultra-fine bubbles 33 can accommodate a laterally placed π-allyl nickel compound modified diatomite adsorption film 42 above the liquid surface of the device, the adsorption film area is 10.2m ² , π-allyl nickel compound The content of π-allyl nickel compound is 16.6g/m ² , the purity of π-allyl nickel compound is 95.2%, the water inlet valve 36 is installed on the upper left side, and the water outlet valve 37 is installed on the bottom right side. The oil catalytic heavy chemical desorption reactor 4 is connected to each other, so it is covered with aerogel felt insulation layer 41, and the top of the aerogel felt insulation layer 41 is equipped with a stainless steel mechanical arm 34 and a ball bearing 35; The desorption reactor 4 is made of high-strength stainless steel and has a volume of 330m ³ . There are 5 electric heating blowers 44 at the bottom, which can generate hot air at 200-250°C. A set of stainless steel membrane frame 43 is installed inside the device. 5 sheets of π-allyl nickel compound modified diatomite adsorption films 42 to be treated at high temperature can be placed vertically, and a heavy oil discharge port 45 is provided on the right side of the bottom; The catering wastewater containing oil enters the device through the inlet valve 36 on the upper left side of the microbubble air-floating oil adsorption device 3, and 9 ultra-fine bubble generators 32 start to work to generate ultra-fine bubbles 33 with a diameter of less than 50 μm. 33 will entrain the oil molecules in the wastewater to float together, and make it adsorbed by the modified diatomite adsorption film 42 containing π-allyl nickel compound above the liquid surface, completely adsorbing the oil. The adsorption membrane 42 of diatomite modified with π-allyl nickel compound is grabbed by the stainless steel manipulator 34 and placed vertically on the stainless steel membrane frame 43 in the oil catalytic desorption reactor 4. The 5 electric heating blowers 44 start to work to generate high temperature air at 200~250°C. Under the catalysis of π-allyl nickel compound, the CH bond in the oil molecule will be broken for a short time, and quickly recombine into CC bond Or CH bond, and CH bond will break again, CC bond will not break again due to the limited catalytic effect of π-allyl nickel compound, so oil molecules with shorter carbon chains can be gradually synthesized into shorter carbon chains. Long heavy oil molecules. At the same time, the heavy oil molecules will be desorbed from the π-allyl nickel compound-modified diatomite adsorption membrane 42 at high temperature, and will be discharged from the heavy oil discharge port 45 on the right side of the bottom of the reactor after convergence, which can be collected and reused. . The outer layer of the high-voltage discharge organic rhodium catalyzed polymerization reaction tank ⁷ is wrapped with a tank insulation protection layer 73, and the interior is a silicon carbide ceramic structure. There is a water outlet valve 75 in the middle part of the tank, and a dichlorotetracarbonyl dirhodium porous filler 72 is installed in the central part of the tank body. As a polymerization catalyst, the pore diameter of the filler is 5.2mm, the specific surface area is 6.5cm ² /g, and the lower part of the filler layer is connected with particulate matter Discharge port 77, a high-voltage discharge electrode 71 is installed in the middle of the left and right side wall plates, a stirring blade 76 is installed on the left and right sides of the bottom of the reaction tank, and the sewage passes through the high-voltage discharge organic rhodium catalyzed polymerization reaction tank 7 The water inlet valve 74 enters the reaction tank, and the high-voltage discharge electrode 71 performs a high-voltage discharge every 0.1s. The discharge voltage range is 8500~15000V. A high-voltage arc across the tank body will be generated in the reaction tank. The high energy of the oil is absorbed by the oil in the wastewater, the CH bond in the oil molecule is in an unstable state by the energy excitation, and the CH bond is broken and recombined under the surface catalysis of dichlorotetracarbonyl dirhodium, and finally a macromolecular polymer is formed. The particulate matter is dispersed in the water in the form of suspended matter, and is discharged from the reaction tank through the water outlet valve on the right side of the reaction tank, and enters the tertiary sedimentation tank 8 .

The microbubble air flotation oil adsorption device 3 has an effective volume of 275m ³ , the ultra-fine bubble generator 32 can generate ultra-fine bubbles 33 with a diameter of less than 50 μm, the normal working voltage is 20V, and the working life is generally 5000h. The volume of the oil catalytic recombination and desorption reactor 4 is 330 m ³ , which can accommodate 5 vertically placed π-allyl nickel compound modified diatomite adsorption films 42 to be treated at high temperature, and the electric heating blower 44 can It produces hot air at 200~250℃, and the working voltage is 380V. The area of the diatomite adsorption membrane 42 modified by the π-allyl nickel compound is 10.2 m ² , the content of the π-allyl nickel compound is 16.6 g/m ² , and the purity of the π-allyl nickel compound is 95.2% .

The oil removal efficiency of the catering wastewater treated by this system can reach 99.8%.

Claims (1)

1. a waste water degreasing method, it is characterized in that, catering waste water enters buffer pool by waste water pipeline, carries out centralized collection and stabilization here, and the outlet of buffer pool connects coarse grille by waste water pipeline, and removes the large diameter in waste water here. For solid substances, the outlet of the coarse grid is connected to the microbubble air-floating oil adsorption device through the waste water pipeline. The bottom of the microbubble air-floating oil adsorption device is equipped with 9 ultra-fine bubble generators. The π-allyl nickel compound modified diatomite adsorption membrane is equipped with a water inlet valve on the upper left side and a water outlet valve on the bottom right side. The water inlet valve on the upper left side of the microbubble air-floating oil adsorption device enters the inside of the device, and 9 ultra-fine bubble generators start to work to generate ultra-fine bubbles with a diameter of less than 50 μm. The ultra-fine bubbles will carry the oil molecules in the wastewater to float together. And make it adsorbed by the modified diatomite adsorption film containing π-allyl nickel compound above the liquid level. Because the right side wall of the device is connected with the high-temperature oil catalytic desorption reactor, it is covered with gas condensate. Rubber felt insulation layer, the top of aerogel felt insulation layer is equipped with stainless steel manipulator arm and ball bearing; A set of stainless steel membrane frame is installed, and five π-allyl nickel compound modified diatomite adsorption membranes to be treated at high temperature are placed vertically on the membrane frame, and there is a heavy oil discharge port on the right side of the bottom; -The allyl nickel compound modified diatomite adsorption membrane is grabbed by the stainless steel manipulator and placed vertically on the stainless steel membrane frame in the oil catalytic desorption reactor. There are 5 electric heating blowers at the bottom of the reactor It starts to work and generates high temperature air at 200~250℃. Under the catalysis of π-allyl nickel compound, the CH bond in the oil molecule will be broken and quickly combined into a CC bond, and the CC bond will not be broken again, so The oil molecules with shorter carbon chains are gradually synthesized into heavy oil molecules with longer carbon chains. At the same time, the heavy oil molecules will be desorbed from the adsorption film of modified diatomite containing π-allyl nickel compound at high temperature, and after aggregation, they will be removed from the reaction The heavy oil discharge port on the right side of the bottom of the device is discharged, and is collected and reused in a centralized manner; the outlet of the microbubble air floating oil adsorption device is connected to the pH value adjustment tank through the waste water pipeline, where the pH value of the waste water is adjusted to near neutral, and the pH value is adjusted. The outlet of the tank is connected to the primary sedimentation tank through the waste water pipeline, where the wastewater is subjected to precipitation and clarification. The outlet of the primary sedimentation tank is connected to the organic rhodium catalyzed polymerization reaction tank through the wastewater pipeline, and the outer layer of the organic rhodium catalyzed polymerization reaction tank is wrapped with tank insulation. In the protective layer, the upper right part of the reaction tank is provided with a water inlet valve, and the lower left part is provided with a water outlet valve. The central part of the tank body is equipped with a porous packing of dichlorotetracarbonyl dirhodium, which is used as a polymerization catalyst. The lower part of the packing layer is connected with a particle discharge port. A high-voltage discharge electrode is installed in the middle of the left and right side wall plates, and a stirring blade is installed on the left and right sides of the bottom of the reaction tank. The waste water enters the reaction tank through the water inlet valve of the organic rhodium catalyzed polymerization reaction tank. The high-voltage discharge electrode conducts a high-voltage discharge every 0.2s, A high-voltage arc is generated. The high energy generated by the high-voltage arc is absorbed by the oil remaining in the wastewater. The CH bond in the oil molecule is excited by the energy and is in an unstable state, and the CH bond is broken under the catalysis of dichlorotetracarbonyl dirhodium. And recombination, and finally generate macromolecular polymer particles, which are dispersed in water in the form of suspended matter, and discharged from the reaction tank through the water outlet valve at the lower left of the reaction tank into the secondary sedimentation tank, where all the remaining insoluble substances in the wastewater are removed. The outlet of the secondary sedimentation tank is connected to the purification tank through the waste water pipeline, and the outlet of the purification tank discharges the treated purified effluent through the waste water pipeline; wherein, the area of the π-allyl nickel compound modified diatomite adsorption membrane is 10.2 m ² , the content of π-allyl nickel compound is 16.6g/m ² , the purity of π-allyl nickel compound is 95.2%; the microbubble air floating oil adsorption device has an effective volume of 155m ³ , and the ultra-fine bubbles The generator can generate ultra-fine bubbles with a diameter of less than 50μm, and the working voltage is 20V.

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