Oil-water separation device and method for separating oil phase

Abstract

The invention provides an oil-water separation device which comprises a sewage pool containing an oil-water mixture and a separation mechanism connected with the sewage pool through a liquid inlet pipe, and the separation mechanism comprises at least one upper floating column and an injection pipe arranged on the upper floating column and used for feeding solid particles. The oil discharging pipe is arranged above the injection pipe, and the solid particles and an oil phase in the oil-water mixture can form a light flocculus adhering body floating on the surface of a liquid phase.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of environmental protection, in particular to an oil-water separation device and a method for separating oil phase. BACKGROUND

[0002] Oil-water mixture is a common mixture in production and life, which widely exists in petroleum industry and daily life, such as produced oil, sewage system of refining enterprises, kitchen sewage system, etc. According to the dispersion of oil droplets in water, it is divided into dispersed oil and emulsified oil. In order to avoid environmental pollution and ecological damage, the oil-water separation operation is required before it is discharged.

[0003] At present, the separation of oil and water usually adopts methods such as air flotation. CN103979637B discloses a purification device and separation method for oil-containing sewage, which comprises: a water inlet distribution device, a column separator, a floating oil collection device, an aerated cyclone separator, at least one self-suction microbubble generator, at least one dissolved air microbubble generator, the column separator is at the upper part of the column, and the aerated cyclone separator is at the lower part of the column; the aerated point of the dissolved air microbubble generator is at the upper part of the column, and the aerated point of the self-suction microbubble generator is at the lower part of the column. CN105884087B discloses a method for treating sewage by using a coagulation air flotation machine, which comprises the following treatment steps: introducing the sewage treated by filtration, flocculation and sedimentation into the coagulation air flotation machine and adding a coagulant; the motor of the coagulation air flotation machine drives the blades to work and rotate through the shaft, so as to promote the mixing reaction of the coagulant and impurities in the sewage to form flocs; the ultrasonic transmitter air cavitation in the coagulation air flotation machine through the air inlet pipe to generate fine bubbles; the fine bubbles float up and adhere to and carry away the flocs in the process of floating up; the flocs form scum after floating up to the water surface, which is removed, and the water treated by the fine bubbles is discharged from the water outlet at the bottom of the coagulation air flotation machine.

[0004] It can be seen that in the prior art, air flotation is still the most common method for oil-water separation, but the separation of emulsified oil droplets by air flotation is not ideal, especially for oil droplets with a diameter of less than 20 μm, and the gas used in the air flotation oil-water separation process is a consumable and cannot be recycled.

[0005] Therefore, it is desirable in the art to provide an oil-water separation device to solve the above technical problems. SUMMARY

[0006] The present application aims to provide an oil-water separation device, which solves the problem of non-recyclable separation medium in the conventional air flotation method by dispersing oil droplets in water.

[0007] According to a first aspect of the present application, an oil-water separation device is provided, comprising a sewage tank containing an oil-water mixture, and

[0008] The separation mechanism is connected with the sewage pool through an inlet pipe, and comprises at least one floating column, an injection pipe arranged on the floating column and used for injecting solid particles, and a drain pipe arranged above the injection pipe,

[0009] The solid particles can form light-floc adhesion bodies floating on the surface of the liquid phase with the oil in the oil-water mixture.

[0010] In one embodiment, the oil-water separation device further comprises a hydrocyclone connected with the drain pipe and used for receiving the light-floc adhesion bodies, the hydrocyclone is connected with the inlet pipe through an overflow port, and a liquid outlet is arranged at the bottom end of the hydrocyclone,

[0011] The light-floc adhesion bodies can be separated in the hydrocyclone, the separated solid particles re-enter the floating column through the overflow port and the inlet pipe, and the separated oil phase is discharged through the liquid outlet.

[0012] In one embodiment, the fixed solid particles are at least one of hollow glass beads, silica particles and solid resin particles, the fixed solid particles have a non-smooth surface, and a plurality of spurs are arranged on the surface of the fixed solid particles.

[0013] In one embodiment, the density of the fixed solid particles is smaller than that of the water phase and the oil phase, and a cationic coating for generating electrostatic adsorption with the oil phase is arranged on the surface of the fixed solid particles.

[0014] In one embodiment, an inlet distributor for evenly distributing the inlet liquid is arranged in the floating column, the inlet distributor comprises a plurality of inlet discs arranged in an axial direction and in a sealed connection with the floating column,

[0015] A plurality of through holes allowing the solid particles to pass through are arranged on the inlet disc, and the through holes are arranged in a regular triangle on the inlet disc.

[0016] In one embodiment, the separation mechanism further comprises a drain pipe arranged on the floating column and below the drain pipe.

[0017] In one embodiment, the inlet pipe is arranged at the lower end surface of the floating column, and a pump body is arranged on the inlet pipe, the drain pipe and the drain pipe.

[0018] In one embodiment, the separation mechanism further comprises a partition arranged in the floating column and used for guiding the solid particles, the partition is arranged outside the drain pipe and comprises a first partition plate fixed to the inner wall of the floating column and a second partition plate arranged above the first partition plate.

[0019] In one embodiment, the first isolation plate is arranged obliquely, and the extension direction of the first isolation plate forms an angle of 10-80° with the horizontal direction.

[0020] In one embodiment, the total height of the isolation member is 2-8 times the pipe diameter of the drain pipe, and the upper edge of the second isolation plate is located at 0.5-6 times the pipe diameter above the upper edge of the drain pipe.

[0021] In one embodiment, the cross-sectional area of the floating column is any one of a circle and a square.

[0022] According to a second aspect of the present application, a method for separating an oil phase using the oil-water separation device as described above is provided, comprising the following steps:

[0023] S1, pumping an oil-water mixture into the floating column through the pump body;

[0024] S2, injecting the solid particles through the injection pipe, the solid particles being capable of forming light-floc adhesion bodies floating on the surface of the liquid phase with the oil phase in the oil-water mixture, and being transported into the hydrocyclone through the oil discharge pipe;

[0025] S3, separating the light-floc adhesion bodies through the hydrocyclone, the separated solid particles re-entering the floating column through the overflow port and the liquid inlet pipe, and the separated oil phase being discharged through the liquid outlet.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] Firstly, the present application is suitable for separation and collection of hazardous chemicals, especially in the field of oil-water separation, and solves the problem of non-recyclable separation medium in the traditional flotation method by dispersing oil droplets in water. In other words, the present application replaces the gas bubbles in the traditional flotation process with solid particles (low density), thereby not only improving the effect and quality of oil-water separation, but also enabling the solid particles used for separation to be reused, thus effectively avoiding resource waste and having good application prospects.

[0028] Specifically, the light-floc adhesion bodies entering the hydrocyclone are separated due to the centrifugal force, and since the density of the solid particles is still less than that of the oil phase, the oil phase acts as a heavy phase and is thrown to the wall of the conical section of the hydrocyclone, thereby being discharged to an external collector through the liquid outlet; and the solid particles act as a light phase and flow out of the overflow port and re-enter the liquid inlet pipe to enter the floating column again and participate in the next oil-water separation work, thereby enabling the solid particles to be recycled.

[0029] Secondly, the solid particles in the application can form light flocculation adherent bodies floating on the surface of the liquid phase with the oil droplets in the oil-water mixture, so as to further reduce the density difference between the oil droplets and the water, thereby helping the subsequent oil-water separation work.

[0030] Specifically, on the one hand, in the process of collision with the oil droplets, the solid particles can effectively promote the rupture of the water film outside the solid particles and the oil droplets by the sharp burrs arranged on the surface of the solid particles, thereby increasing the adhesion probability between the solid particles and the oil droplets, so as to further improve the effect and quality of oil-water separation; on the other hand, in the process of adhesion of the oil droplets, the solid particles can promote the solid particles to have positive charges by the cation coating coated on the surface, so as to more easily produce electrostatic adsorption effect with the oil droplets, thereby enhancing the adhesion between the solid particles and the oil droplets, so as to further improve the effect and quality of oil-water separation. BRIEF DESCRIPTION OF DRAWINGS

[0031] The application will be described in detail below with reference to the accompanying drawings, in which:

[0032] Figure 1 schematically shows the structure of the oil-water separation device according to the application;

[0033] Figure 2 is a preferred embodiment of the oil-water separation device according to the application;

[0034] Figure 3 is a structural schematic diagram of the particle adsorbent provided by the application or the particle adsorbent prepared by the method provided by the application, which shows the sharp burr-like rough structure on the surface of the particle adsorbent and the positive charges carried on the surface;

[0035] Figure 4 is a scanning electron microscope image of the particle adsorbent prepared in Example 1 of the application.

[0036] In the drawings, the same components are denoted by the same reference numerals. The drawings are not drawn according to the actual scale. DETAILED DESCRIPTION

[0037] In order to make the technical solutions and advantages of the application clearer, the exemplary embodiments of the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the application, not an exhaustive enumeration of all embodiments. And in the case of no conflict, the embodiments in the application and the features in the embodiments can be combined with each other.

[0038] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0039] In this invention, unless otherwise explicitly specified and limited, the terms "installation", "connection", "linking", "fixing", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components.

[0040] Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] The invention will now be further described with reference to the accompanying drawings.

[0042] Figure 1 The schematic diagram shows the structure of the oil-water separation device 100 according to the present invention.

[0043] The following is in conjunction with the appendix Figure 1 The first arrangement structure of the present invention is described below:

[0044] like Figure 1 As shown, according to a first aspect of the present invention, an oil-water separation device 100 is provided, which includes a wastewater tank 110 containing an oil-water mixture and a separation mechanism. In the present invention, the separation mechanism is connected to the wastewater tank 110 via an inlet pipe 121.

[0045] In one embodiment, such as Figure 1 As shown, the separation mechanism includes an upper float 120, an injection pipe 122 disposed on the upper float 120, and an oil discharge pipe 123 disposed on the upper float 120 and above the injection pipe 122. Preferably, both the injection pipe 122 and the oil discharge pipe 123 are radially mounted on the outer wall of the upper float 120.

[0046] In this invention, solid particles are introduced into the floating column 120 via the injection pipe 122. Preferably, because the solid particles have a low density, they rise after being introduced into the floating column 120. During their ascent, the solid particles adhere to the oil phase (oil droplets) in the oil-water mixture (i.e., the water film between them breaks down through collision to achieve adhesion), thereby forming a light flocculent adherent that floats on the surface of the liquid phase to form an adherent layer. Preferably, the adherent layer can be discharged through the oil drain pipe 123 to facilitate subsequent oil separation and recovery.

[0047] In one specific embodiment of the present invention, the solid particles are low-density solid particles. It is readily understood that the density of the solid particles in this invention should be much lower than the density of water and oil. Therefore, if a single solid particle is considered as a whole, its density value should not exceed 500 kg / m³. 3 In this invention, the density of the solid particles can be adjusted by changing the volume ratio of the airbag (not shown in the accompanying drawings).

[0048] Preferably, the solid particles in this invention can be selected from a variety of types, such as at least one of hollow glass microspheres, silica particles, and solid resin particles, and the particle size of the solid particles is preferably 10–50 μm. Optionally, the solid resin particles are made of any one of ABS plastic, polyamide resin, and polyvinyl chloride resin.

[0049] Preferably, since the oil droplets in the oil-water mixture carry a negative charge, the present invention performs cationic surface coating on the surface of the solid particles, thereby causing the solid particles to carry a positive charge. Therefore, the adhesion between the solid particles and the oil droplets can be enhanced through electrostatic adsorption, thereby further improving the effect and quality of oil-water separation.

[0050] In this invention, the solid particles have a non-smooth surface and sharp burrs on their surface, which makes it easier for the solid particles to collide and adhere with the oil droplets, thereby further promoting the rupture of the water film outside the two (solid particles and oil droplets), thereby increasing the adhesion probability between the solid particles and oil droplets, and further improving the effect and quality of oil-water separation.

[0051] In one embodiment of the present invention, the upper float 120 is constructed as a hollow vertical structure, and the cross-sectional area of ​​the upper float 120 is either circular or square. This design provides sufficient upward space for solid particles, effectively increasing the adhesion probability between solid particles and oil droplets, thereby improving the effect and quality of oil-water separation.

[0052] According to the present invention, such as Figure 1 As shown, the oil-water separation device 100 also includes a hydrocyclone 130. Preferably, the hydrocyclone 130 is connected to the oil drain pipe 123, thereby making it easier to receive the adhering layer from the upper float 120.

[0053] In this invention, the top of the hydrocyclone 130 is connected to the inlet pipe 121 via an overflow port 131, and a drain port 132 is provided at the bottom of the hydrocyclone 130. Preferably, the light flocs can be separated from the oil phase by the hydrocyclone 130, and the separated solid particles will re-enter the upper float 120 through the overflow port 131 and the inlet pipe 121 for reuse, while the separated oil phase will be discharged through the drain port 132 for recovery and collection.

[0054] In this field, the smaller the diameter of a hydrocyclone, the finer its separation. Therefore, the hydrocyclone diameter used in this invention for the aforementioned solid particles in the tens of micrometers range is preferably 5-50 mm.

[0055] Optionally, the median particle size of the solid particles is 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm.

[0056] In this embodiment, one floating column 120 is paired with one hydrocyclone 130. However, depending on the throughput and the particle type used, multiple floating columns 120 can be paired with one hydrocyclone 130, or one floating column 120 can be paired with multiple hydrocyclones 130, thereby making it easier to achieve high throughput or fine-grained operation.

[0057] Compared to existing technologies, this invention is applicable to the separation and collection of hazardous chemicals, especially in the field of oil-water separation. By dispersing oil droplets in water, it solves the problem that the separation medium in traditional air flotation methods cannot be recycled after separation. In other words, this invention replaces air bubbles in the traditional air flotation process with solid particles (low density), thereby not only improving the efficiency and quality of oil-water separation but also enabling the reuse of the solid particles used in the separation. Therefore, this invention effectively avoids resource waste and has promising application prospects.

[0058] In one embodiment, such as Figure 1 As shown, a liquid distributor 125 is provided inside the upper float column 120. In this invention, when the oil-water mixture enters the upper float column 120 through the liquid inlet pipe 121, the oil-water mixture can achieve an even distribution of the liquid intake under the action of the liquid distributor 125, thereby effectively avoiding the situation where the water flow forms streams that disturb the light flocs adhering to the solid particles and the oil phase.

[0059] In one embodiment, such as Figure 1As shown, the liquid distributor 125 includes a plurality of liquid inlet discs 126 arranged at intervals along the axial direction. Preferably, the outer peripheral surface of each liquid inlet disc 126 forms a sealed connection with the inner peripheral surface of the upper float 120, thereby ensuring that the oil-water mixture can only flow upward through the liquid inlet disc 126, so as to achieve the purpose of evenly distributing the liquid inlet volume of the oil-water mixture.

[0060] In other embodiments, the liquid distributor 125 may also be provided with only one liquid inlet plate 126, which only needs to ensure that the injected oil-water mixture does not flow in streams.

[0061] In one embodiment, such as Figure 1 As shown, a plurality of through holes 127 are provided on the liquid inlet plate 126. Preferably, the through holes 127 are configured as small circular holes, and the diameter of the through holes 127 is smaller than the particle size of the solid particles, thereby allowing reusable solid particles to pass through.

[0062] In this invention, the diameter of the through hole 127 is in the range of 3 to 20 mm. When the diameter of the through hole 127 is 3 mm, 10 mm and 20 mm, the oil-water separator 100 can have a better working state.

[0063] In a preferred embodiment, a plurality of through holes 127 are arranged in an equilateral triangle on the inlet plate 126. It is easy to understand that the purpose is to enable the oil-water mixture to be evenly distributed in the radial direction, thereby effectively avoiding the disturbance caused by water flowing in streams to the mixing of solid particles and oil phase (forming light flocs).

[0064] According to the present invention, such as Figure 1 As shown, the separation mechanism also includes a drain pipe 124 disposed on the upper float 120. Preferably, the drain pipe 124 is axially positioned between the injection pipe 122 and the oil discharge pipe 123. In this invention, the phase discharged through the drain pipe 124 is the aqueous phase.

[0065] Preferably, because the solid particles can adhere to the oil phase (oil droplets) in the oil-water mixture during the floating process, they form a light flocculent adherent that floats on the surface of the liquid phase to form an adherent layer. Therefore, in this way, the oil phase in the oil-water mixture can be fully promoted to rise and float on the surface of the liquid phase, thereby allowing the water phase treated by the solid particles to be discharged through the drain pipe 124.

[0066] In one embodiment of the present invention, the inlet pipe 121 is disposed at the lower end face of the upper float 120. Therefore, the fluid entering the upper float 120 through the inlet pipe 121 flows from the bottom of the upper float 120 to the top of the upper float 120.

[0067] In this way, on the one hand, the solid particles in the rising process can more easily contact more oil phase, so as to produce adhesion to form light floc adhesion and eventually float on the surface of the liquid phase, so as to further improve the quality and efficiency of oil-water separation; on the other hand, the oil-water mixture can pass through the liquid inlet distributor 125 completely, so as to ensure that the oil-water mixture can achieve the purpose of average distribution of liquid amount, so as to effectively avoid the disturbance of the water flow to the mixing of solid particles and oil phase (forming light floc adhesion).

[0068] In one embodiment, pumps are arranged on the liquid inlet pipe 121, the oil outlet pipe 123 and the water outlet pipe 124, such as a liquid inlet pump 151 arranged on the liquid inlet pipe 121, an oil phase oil outlet pump 152 arranged on the oil outlet pipe 123, and a water phase water outlet pump 153 arranged on the water outlet pipe 124.

[0069] According to the present application, the separation mechanism further comprises a partitioning member arranged in the floating column 120. Preferably, the partitioning member is arranged outside the water outlet pipe 124 and can guide the flow direction of the solid particles. In other words, since the solid particles have a low density, they will perform an upward movement after being put into the floating column 120, and the partitioning member can effectively prevent the solid particles from flowing to the water outlet pipe 124, so as to further avoid the situation that the solid particles are discharged through the water outlet pipe 124.

[0070] In the present application, when the liquid phase fills the floating column 120, the water outlet pipe 124 should be opened, and in order to maintain the liquid level of the floating column 120 stable, the flow rate of the water phase water outlet pump 153 should be equal to the sum of the flow rates of the liquid inlet pump 151 and the liquid outlet port 132 of the hydrocyclone 130. In addition, the water outlet pipe 124 of the floating column 120 is connected to the sewage tank 110, so that after the oil-water separation device 100 is stably operated, the sewage in the tank can be recycled and deoiled until the oil content in the water is reduced to the required concentration.

[0071] In one embodiment, as shown in Figure 1 The partitioning member comprises a first partitioning plate 141 fixed to the inner wall of the floating column 120, and a second partitioning plate 142 arranged above the first partitioning plate 141. Preferably, the first partitioning plate 141 is arranged obliquely, and the extension direction of the first partitioning plate 141 forms an angle of 10°-80° with the horizontal direction, so as to effectively reduce the resistance of the upward flow of the liquid phase in the floating column 120.

[0072] Preferably, the total height of the partitioning member is 2-8 times the pipe diameter of the water outlet pipe 124, and the upper edge of the second partitioning plate 142 is located at 0.5-6 times the pipe diameter above the upper edge of the water outlet pipe 124. Based on the above ratio data, the present application has the following preferred embodiments.

[0073] For example, when the extending direction of the first partition plate 141 forms an angle of 10° with the horizontal direction, the total height of the partition member is 2 times the pipe diameter of the drain pipe 124;

[0074] When the extending direction of the first partition plate 141 forms an angle of 45° with the horizontal direction, the total height of the partition member is 2 times the pipe diameter of the drain pipe 124, and the upper edge of the second partition plate 142 is at 0.5 times the upper edge of the drain pipe 124;

[0075] When the total height of the partition member is 4 times the pipe diameter of the drain pipe 124, the upper edge of the second partition plate 142 is at 1.5 times the upper edge of the drain pipe 124;

[0076] When the extending direction of the first partition plate 141 forms an angle of 80° with the horizontal direction, the total height of the partition member is 8 times the pipe diameter of the drain pipe 124, and the upper edge of the second partition plate 142 is at 2 times the upper edge of the drain pipe 124;

[0077] When the extending direction of the first partition plate 141 forms an angle of 80° with the horizontal direction, the total height of the partition member is 8 times the pipe diameter of the drain pipe 124, and the upper edge of the second partition plate 142 is at 6 times the upper edge of the drain pipe 124.

[0078] In the present application, the hydrocyclone 130 has the following preferred embodiments.

[0079] For example, when the diameter of the hydrocyclone 130 is 100 mm, the inlet diameter, the overflow port 131 diameter, and the drain port 132 diameter are respectively 0.1, 0.3 and 0.2 times the diameter of the hydrocyclone 130;

[0080] When the diameter of the hydrocyclone 130 is 50 mm, the diameter of the overflow port 131 is 1.2 times the diameter of the drain port 132, and the hydrocyclones 130 are arranged in parallel by 3;

[0081] When the diameter of the hydrocyclone 130 is 10 mm, the diameter of the overflow port 131 is 2 times the diameter of the drain port 132, and the hydrocyclones 130 are arranged in parallel by 10;

[0082] When the diameter of the hydrocyclone 130 is 10 mm, the diameter of the overflow port 131 is 2 times the diameter of the drain port 132, and the hydrocyclones 130 are arranged in parallel by 30.

[0083] As shown in FIG. 2, according to the second aspect of the present application, there is provided a method for separating an oil phase by using the oil-water separation device 100 as described above, comprising the following steps: Figure 1

[0084] ​Step one: connect the sewage tank 110 with the liquid inlet pipe 121, and pump the oil-water mixture into the up-floating column 120 through the liquid inlet pump 151, and the oil-water mixture rises in the up-floating column 120 through the liquid inlet distributor 125.

[0085] Preferably, the oil-water mixture can be evenly distributed under the action of the liquid inlet distributor 125, so as to effectively avoid the disturbance of the water flow to the light flocculation adherent formed by the solid particles and the oil phase. In this step, the oil-water mixture needs to continue to the position 10 cm away from the top of the up-floating column 120.

[0086] Step two: inject the solid particles into the up-floating column 120 through the injection pipe 122.

[0087] In the present application, since the solid particles have a low density, they will be in an upward state after being injected into the up-floating column 120. In the process of rising, the solid particles and the oil phase in the oil-water mixture produce an adhering effect, thereby forming a light flocculation adherent and floating on the surface of the liquid phase to form an adherent layer.

[0088] Preferably, since the oil droplets in the oil-water mixture have a negative charge, the present application performs cationic surface coating on the surface of the solid particles, so as to make the solid particles have a positive charge, thereby enhancing the adhesion between the solid particles and the oil droplets through electrostatic adsorption, to further improve the effect and quality of oil-water separation.

[0089] In the present application, the solid particles have a non-smooth surface and sharp burrs on the surface, so as to facilitate the solid particles to collide and adhere with the oil droplets, to further promote the rupture of the water film outside the two (solid particles and oil droplets), thereby increasing the adhesion probability between the solid particles and the oil droplets, to further improve the effect and quality of oil-water separation.

[0090] Step three: open the oil discharge pipe 123 and suck the light flocculation adherent into the hydrocyclone 130 through the oil phase oil pump 152 to separate the oil phase from the solid particles, and at the same time, open the water discharge pipe 124 and suck the water phase treated by the solid particles into the sewage tank 110 through the water phase water pump 153.

[0091] Preferably, in this step, the flow rate of the liquid inlet pipe 121 should be the sum of the flow rates of the water discharge pipe 124 and the oil discharge pipe 123, so as to ensure that the liquid level of the up-floating column 120 is always in a stable state.

[0092] It is worth noting that the oil discharge pipe 123 should always be within the range of the adherent layer in terms of vertical height, so as to ensure that the fluid discharged through the oil discharge pipe 123 does not contain water, to further improve the effect and quality of oil-water separation.

[0093] Step four: the light floc adhering body entering into the hydrocyclone 130 is separated in the hydrocyclone 130 due to the centrifugal force, and since the density of the solid particles is still less than that of the oil phase, the oil phase is as a heavy phase and is thrown to the wall of the cone section of the hydrocyclone 130, thereby being discharged to an external collector (not shown) through the liquid outlet 132; and the solid particles are as a light phase and flow out of the overflow outlet 131 and re-enter the liquid inlet pipe 121 to enter the up-floating column 120 again and participate in the next oil-water separation work, so that the solid particles have a recycling effect.

[0094] The first embodiment of the present application is described below, which is based on the first layout structure of the present application.

[0095] Step one: the sewage pool 110 is connected with the liquid inlet pipe 121, and the oil-water mixture is pumped into the up-floating column 120 through the liquid inlet pump 151, and the oil-water mixture rises in the up-floating column 120 through the liquid inlet distributor 125 until the liquid surface in the up-floating column 120 is 10 cm from the top.

[0096] Step two: the solid particles are injected into the up-floating column 120 through the injection pipe 122. The solid particles produce an adhering effect with the oil phase in the oil-water mixture in the rising process, thereby forming light floc adhering bodies and floating on the surface of the liquid phase to form an adhering body layer.

[0097] In this embodiment, the solid particles can use hollow glass microbeads (the particle size is 20 μm, and the single particle density is 300 kg / m 3 ).

[0098] Step three: the oil outlet pipe 123 is opened, and the light floc adhering bodies are sucked into the hydrocyclone 130 through the oil phase oil outlet pump 152 to separate the oil phase from the solid particles, and at the same time, the water outlet pipe 124 is opened, and the water phase treated by the solid particles is sucked into the sewage pool 110 through the water phase water outlet pump 153.

[0099] Step four: the light floc adhering bodies are separated through the hydrocyclone 130, the separated oil droplets (heavy phase) are discharged to an external collector through the liquid outlet 132, and the separated solid particles (light phase) flow out of the overflow outlet 131 and re-enter the liquid inlet pipe 121 to enter the up-floating column 120 again and participate in the next oil-water separation work.

[0100] In this embodiment, the diameter of the hydrocyclone 130 is 30 mm, and the inlet diameter, the overflow outlet 131 diameter and the liquid outlet 132 diameter are 5 mm, 3 mm and 3 mm, respectively.

[0101] The second layout structure of the present application is described below with reference to the accompanying drawings Figure 2 , and repeated contents will not be described herein.

[0102] As Figure 2 shown, the present application provides an oil-water separation device 200, which comprises a sewage pool 210 containing oil-water mixture and a separation mechanism. In the present application, the separation mechanism is connected with the sewage pool 210 through a liquid inlet pipe 211.

[0103] In one embodiment, as Figure 2 shown, the separation mechanism comprises a first floating column 220 and a second floating column 230 arranged in parallel. Preferably, a first injection pipe 221 and a first oil outlet pipe 222 are arranged on the first floating column 220; a second injection pipe 231 and a second oil outlet pipe 232 are arranged on the second floating column 230. Preferably, the first oil outlet pipe 222 is above the first injection pipe 221, and the second oil outlet pipe 232 is above the second injection pipe 231.

[0104] In the present application, solid particles can be respectively injected into the first floating column 220 and the second floating column 230 through the first injection pipe 221 and the second injection pipe 231. Preferably, since the solid particles have a low density, they will be in an upward state after being injected into the floating column.

[0105] In the process of rising, the solid particles will adhere to the oil phase (oil droplets) in the oil-water mixture (i.e. by collision to break the water film of both to achieve the effect of adhesion), thereby forming light floc adherent and floating on the surface of the liquid phase to form an adherent layer. Preferably, the adherent layer can be discharged into the buffer tank 250 through the first oil outlet pipe 222 and the second oil outlet pipe 232, which helps subsequent separation and recovery of oil.

[0106] In one embodiment of the present application, the first floating column 220 and the second floating column 230 are both configured as hollow vertical structures, and the cross-sectional area of the floating column is any one of a circle and a square. In this way, sufficient rising space can be provided for the solid particles, which effectively increases the adhesion probability between the solid particles and the oil droplets, thereby improving the effect and quality of oil-water separation.

[0107] According to the present application, as Figure 2 shown, the oil-water separation device 200 further comprises a hydrocyclone 240. Preferably, the hydrocyclone 240 is connected with the buffer tank 250, and a liquid outlet pump 264 is arranged between the hydrocyclone 240 and the buffer tank 250, so that the adherent layer from the floating column can be more easily received.

[0108] In the present application, the top end of the hydrocyclone 240 is connected with the buffer tank 250 through the overflow port 241, and the bottom end of the hydrocyclone 240 is provided with the liquid discharge port 242. Preferably, the light-floc adhesion body can realize the separation of the solid particles and the oil phase under the action of the hydrocyclone 240, and the separated solid particles will re-enter the up-floating column through the overflow port 241 and the liquid inlet pipe 211 to realize the function of repeated use, while the separated oil phase is discharged through the liquid discharge port 242 for recycling and collection.

[0109] In one embodiment, as shown in FIG. 2, the first up-floating column 220 and the second up-floating column 230 are both provided with a liquid inlet distributor 224. In the present application, when the oil-water mixture enters the up-floating column (i.e. the first up-floating column 220 and the second up-floating column 230) through the liquid inlet pipe 211, the oil-water mixture can realize the average distribution of the liquid inlet amount under the action of the liquid inlet distributor 224, so as to effectively avoid the disturbance to the light-floc adhesion body formed by the solid particles and the oil phase due to the water flow. Figure 2

[0110] According to the present application, as shown in FIG. 2, the separation mechanism further comprises a first drain pipe 223 and a second drain pipe 233 respectively arranged on the first up-floating column 220 and the second up-floating column 230. Preferably, the first drain pipe 223 is below the first injection pipe 221 in the axial direction; the second drain pipe 233 is below the second injection pipe 231 in the axial direction. In the present application, the water phase is discharged through the drain pipe (the first drain pipe 223 and the second drain pipe 233). Figure 2 Preferably, since the solid particles can produce adhesion with the oil phase (oil droplets) in the oil-water mixture during the up-floating process, the light-floc adhesion body is formed and floats on the surface layer of the liquid phase to form an adhesion body layer. Therefore, in this way, the oil phase in the oil-water mixture can be fully lifted and floated on the surface layer of the liquid phase, so that the water phase treated by the solid particles can be discharged through the drain pipe (the first drain pipe 223 and the second drain pipe 233).

[0111] In one embodiment of the present application, the liquid inlet pipe 211 is arranged at the lower end surface of the up-floating column (the first up-floating column 220 and the second up-floating column 230). Therefore, the flow direction of the fluid entering the up-floating column through the liquid inlet pipe 211 is from the bottom to the top.

[0112]

[0113] ​​In this way, on the one hand, the solid particles in the ascending process can more easily contact more oil phase, so as to produce adhesion to form light floc adhesion and eventually float on the surface of the liquid phase, so as to further improve the quality and efficiency of oil-water separation; on the other hand, the oil-water mixture can pass through the liquid inlet distributor 224, so as to ensure that the oil-water mixture can achieve the purpose of average distribution of liquid inlet amount, so as to effectively avoid the disturbance of the water flow to the mixing of solid particles and oil phase (forming light floc adhesion).

[0114] In one embodiment, as shown in FIG. 2, a liquid inlet pump 261 is arranged on the liquid inlet pipe 211; an oil phase outlet pump 262 is arranged on the first oil outlet pipe 222 and the second oil outlet pipe 232; and a water phase outlet pump is arranged on the first water outlet pipe 223 and the second water outlet pipe 233. Figure 2

[0115] According to the present application, the separation mechanism further comprises a partitioning member arranged in the floating column (the first floating column 220 and the second floating column 230). Preferably, the partitioning member is arranged outside the water outlet pipe (the first water outlet pipe 223 and the second water outlet pipe 233) and can guide the flow direction of the solid particles. In other words, since the solid particles have a low density, they will perform an ascending movement after being put into the floating column, and the partitioning member can effectively prevent the solid particles from flowing to the water outlet pipe, so as to further avoid the situation that the solid particles are discharged through the water outlet pipe.

[0116] In the present application, when the liquid phase fills the floating column (the first floating column 220 and the second floating column 230), the water outlet pipe (the first water outlet pipe 223 and the second water outlet pipe 233) should be opened respectively, and in order to maintain the liquid level of the floating column stable, the flow rate of the water phase outlet pump should be equal to the sum of the flow rates of the liquid inlet pump 211 and the liquid outlet 242 of the hydrocyclone 240. In addition, the water outlet pipe of the floating column is connected with the sewage pool 210, so that after the oil-water separation device 200 is stably operated, the circulating and reciprocating oil removal operation of the sewage in the pool can be realized, until the oil content in the water is reduced to the required concentration.

[0117] As shown in FIG. 2, the present application provides a method for separating oil phase by using the oil-water separation device 200 as described above, which comprises the following steps: Figure 2

[0118] Step one: connecting the sewage pool 210 with the liquid inlet pipe 211, and pumping the oil-water mixture into the first floating column 220 and the second floating column 230 through the liquid inlet pump 261 respectively, and the oil-water mixture rises in the floating column through the liquid inlet distributor 224.

[0119] ​​Preferably, the oil-water mixture can achieve an average distribution of liquid under the action of the liquid inlet distributor 224, so as to effectively avoid the disturbance of the water flow to the light floc adherent formed by the solid particles and the oil phase. In this step, the oil-water mixture needs to continue to the liquid level distance of 10 cm from the top of the floating column.

[0120] Step two: inject solid particles into the first floating column 220 and the second floating column 230 through the first injection pipe 221 and the second injection pipe 231 respectively.

[0121] In the present application, since the solid particles have a low density, they will be in an upward state after being injected into the floating column. In the process of rising, the solid particles and the oil phase in the oil-water mixture produce an adhering effect, thereby forming a light floc adherent and floating on the surface of the liquid phase to form an adherent layer.

[0122] Preferably, since the oil droplets in the oil-water mixture have a negative charge, the present application performs cationic surface coating on the surface of the solid particles, so as to make the solid particles have a positive charge, thereby enhancing the adhesion between the solid particles and the oil droplets through electrostatic adsorption, to further improve the effect and quality of oil-water separation.

[0123] In the present application, the solid particles have a non-smooth surface and sharp burrs on the surface, so as to facilitate the solid particles to collide and adhere with the oil droplets more easily, to further promote the rupture of the water film outside the two (solid particles and oil droplets), thereby increasing the adhesion probability between the solid particles and the oil droplets, to further improve the effect and quality of oil-water separation.

[0124] Step three: open the first oil discharge pipe 222 and the second oil discharge pipe 232 respectively, and collect the light floc adherent in the oil phase buffer tank 250 through the oil phase oil pump 262, and then pump it into the hydrocyclone 240 for oil phase and solid particle separation, at the same time, open the first water discharge pipe 223 and the second water discharge pipe 233 respectively and pump the water phase treated by the solid particles to the sewage tank 210 through the water phase water pump.

[0125] Preferably, in this step, the flow rate of the liquid inlet pipe 211 should be the sum of the flow rates of the water discharge pipe (the first water discharge pipe 223 and the second water discharge pipe 233) and the oil discharge pipe (the first oil discharge pipe 222 and the second oil discharge pipe 232), so as to ensure that the liquid level of the floating column is always in a stable state.

[0126] It is worth noting that the oil discharge pipe should always be within the range of the adherent layer in terms of vertical height, so as to ensure that the fluid discharged through the oil discharge pipe does not contain water, to further improve the effect and quality of oil-water separation.

[0127] Step four: the light floc adhering body entering into the hydrocyclone 240 is separated in the hydrocyclone 240 due to the centrifugal force, and since the density of the solid particles is still less than that of the oil phase, the oil phase is as a heavy phase and is thrown to the wall of the cone section of the hydrocyclone 240 and then is discharged to an external collector (not shown) through the liquid outlet 242; and the solid particles are as a light phase and flow out from the overflow outlet 241 and then are re-collected into the liquid inlet pipe 211 to enter the floatation column again and participate in the next oil-water separation work, so that the solid particles have the function of recycling.

[0128] The second embodiment of the present application is introduced below, which is based on the second layout structure of the present application.

[0129] Step one: the sewage pool 210 is connected with the liquid inlet pipe 211, and the oil-water mixture is pumped into the first floatation column 220 and the second floatation column 230 through the liquid inlet pump 261, and the oil-water mixture is raised in the floatation column through the liquid inlet distributor 224 until the liquid surface is at a position 10 cm from the top of the floatation column.

[0130] Step two: the solid particles are respectively injected into the first floatation column 220 and the second floatation column 230 through the first injection pipe 221 and the second injection pipe 231. The solid particles have the adhering effect with the oil phase in the oil-water mixture in the process of rising, so that the light floc adhering body is formed and floats on the surface of the liquid phase to form the adhering body layer.

[0131] In the embodiment, the solid particles can use hollow glass beads (the particle size is 30 μm, and the single particle density is 200 kg / m 3 ).

[0132] Step three: the first oil discharge pipe 222 and the second oil discharge pipe 232 are respectively opened, and the light floc adhering body is collected in the buffer tank 250 through the oil phase oil outlet pump 262, and then is pumped into the hydrocyclone 240 to separate the oil phase from the solid particles, at the same time, the first water discharge pipe 223 and the second water discharge pipe 233 are respectively opened, and the water phase treated by the solid particles is pumped into the sewage pool 210 through the water phase water outlet pump.

[0133] Step four: the light floc adhering body is separated through the hydrocyclone 240, the separated oil droplets (heavy phase) are discharged to the external collector through the liquid outlet 242, and the separated solid particles (light phase) flow out from the overflow outlet 241 and are re-collected into the liquid inlet pipe 211 to enter the first floatation column 220 and the second floatation column 230 again and participate in the next oil-water separation work.

[0134] In the embodiment, the diameter of the hydrocyclone 130 is 30 mm, the inlet diameter, the overflow outlet 131 diameter and the liquid outlet 132 diameter are respectively 5 mm, 3 mm and 3 mm.

[0135] The preparation method of the solid particles in the present application is described as follows, including the following steps:

[0136] 1) surface roughening treatment is performed on the solid particles to obtain rough solid particles;

[0137] 2) positive charges are introduced on the surface of the rough solid particles to obtain the particle adsorbent.

[0138] In the present application, the purpose of surface roughening treatment on the solid particles is to increase the surface roughness thereof, and preferably to generate sharp burrs on the surface of the solid particles through surface roughening treatment, so as to be able to quickly pierce the liquid film between the adsorbing particles and oil droplets, accelerate the liquid film drainage process, and further increase the adhesion probability of the particle adsorbent and oil droplets on the basis of electrostatic adsorption. In order to generate the sharp burrs on the surface of the solid particles, the present application provides the following embodiments for the means of surface roughening treatment.

[0139] According to one specific embodiment of the present application, in step 1), the surface roughening treatment includes grinding treatment or acid etching treatment.

[0140] According to one specific embodiment of the present application, the solid particles are subjected to the grinding treatment in a mortar; or

[0141] The solid particles are subjected to the grinding treatment using double-layer friction plates.

[0142] It should be noted that the duration of the grinding treatment is determined according to the surface roughness that the solid particles need to achieve.

[0143] According to one specific embodiment of the present application, the solid particles are immersed in a strong acid for the acid etching treatment;

[0144] Preferably, the pH of the strong acid is less than 5 (for example, pH is 1, 2, 3 or 4);

[0145] Preferably, when the solid particles are hollow glass beads and / or silica particles, the strong acid is hydrofluoric acid;

[0146] Preferably, stirring is performed at a rotation speed of 10-600 r / min (for example, 10 r / min, 50 r / min, 100 r / min, 200 r / min, 300 r / min, 400 r / min, 500 r / min or 600 r / min) during the acid etching treatment, which can make the surface roughness of the solid particles more uniform.

[0147] It should be noted that the acid etching treatment time is determined according to the acidity of the strong acid used and the type of the solid particles. The stronger the acidity of the strong acid, the shorter the acid etching treatment time. Here, the acid etching treatment time of 30-240 min (e.g., 30 min, 60 min, 180 min, or 240 min) is provided for reference.

[0148] According to a specific embodiment of the present application, in step 2), the coarse solid particles are immersed in the cationic modifier, filtered, the filter residue is collected and dried to obtain the solid particles with positive charges on the surface, i.e., the particle adsorbent.

[0149] Preferably, the immersion is carried out at room temperature; and / or the immersion time is 1-24 h (e.g., 1 h, 3 h, 5 h, 10 h, 15 h, 20 h, or 24 h).

[0150] Preferably, the drying temperature is 50-80°C (e.g., 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, or 80°C).

[0151] Preferably, the stirring speed during the immersion is 60-600 r / min (e.g., 60 r / min, 100 r / min, 200 r / min, 300 r / min, 400 r / min, 500 r / min, or 600 r / min) to improve the uniformity of the immersion process and enable uniform distribution of the positive charges on the surface of the solid particles.

[0152] Preferably, the amount of the cationic modifier is sufficient to completely immerse the coarse solid particles. When the mass of the coarse solid particles increases, the amount of the cationic modifier should also be increased.

[0153] In addition, considering that the density of the particle adsorbent affects its ability to carry oil droplets to float on the oil-water mixture, thereby affecting the final oil-water separation efficiency, the present application provides the following embodiments in view of the densities of the water and oil phases.

[0154] According to a specific embodiment of the present application, the density of the solid particles is not higher than 0.3 g / cm3.

[0155] Alternatively, the density of the solid particles is 0.3 g / cm3, 0.25 g / cm3, 0.2 g / cm3, 0.15 g / cm3, 0.1 g / cm3, or 0.05 g / cm3.

[0156] According to a preferred embodiment of the present application, the density of the solid particles is not higher than 0.1 g / cm3.

[0157] Optionally, the density of the solid particles is 0.1 g / cm3, 0.09 g / cm3, 0.08 g / cm3, 0.07 g / cm3, 0.06 g / cm3, 0.05 g / cm3, 0.04 g / cm3, 0.03 g / cm3, 0.02 g / cm3, or 0.01 g / cm3.

[0158] The rougher the surface of the particle adsorbent, the more conducive to efficient adhesion after collision between the particle adsorbent and oil droplets. Considering the material of the particle adsorbent and the level of existing rough surface processing technology, to ensure that sufficient surface roughness can pierce the liquid film between the particle adsorbent and the oil droplets and accelerate the film liquid discharge process, the present application provides the following embodiments for the surface roughness of the particle adsorbent.

[0159] According to one specific embodiment of the present application, the surface roughness Ra of the solid particles is 100-600.

[0160] Optionally, the surface roughness Ra of the solid particles is 100, 200, 300, 400, 500, or 600.

[0161] According to one specific embodiment of the present application, the solid particles have a porous structure. The porous structure is conducive to reducing the density of the particle adsorbent. Specifically, the solid particles are preferably porous resin particles (such as porous ABS plastic, porous polyamide resin, or porous polyvinyl chloride resin).

[0162] The inventors have found that a smaller particle size is conducive to increasing the specific surface area of the particle adsorbent, thereby improving its adhesion performance to oil droplets. However, the particle size of the particle adsorbent is not the smaller the better. If the particle size of the particle adsorbent is too small, although it has a larger specific surface area and higher adhesion performance to oil droplets, the speed of carrying oil droplets to float in the oil-water mixture after the particle adsorbent adheres to the oil droplets will be slower, which is not conducive to oil-water separation. Therefore, it is necessary to provide an appropriate particle size range to balance the adhesion performance of the particle adsorbent to oil droplets and the floating speed of carrying oil droplets in the oil-water mixture, so as to achieve an ideal oil-water separation effect. Based on this, the present application provides the following embodiments for the particle size of the solid particles.

[0163] According to one specific embodiment of the present application, the positive charge is introduced by impregnating the solid particles with a cationic modifier.

[0164] According to one specific embodiment of the present application, the cationic modifier is a solution of a cationic polymer.

[0165] According to an embodiment of the present application, the concentration of the cationic polymer in the cationic modifier is 2-30 wt%; and / or the solvent is water.

[0166] Optionally, the concentration of the cationic polymer in the cationic modifier is 2 wt%, 10 wt%, 15 wt%, 20 wt% or 30 wt%.

[0167] According to an embodiment of the present application, the cationic polymer is cationic polyacrylamide.

[0168] Preferably, the molecular weight of the cationic polyacrylamide is 1 x 10 4 -2 x 10 7 .

[0169] Optionally, the molecular weight of the cationic polyacrylamide is 1 x 10 4 , 5 x 10 5 , 8 x 10 6 or 2 x 10 7 .

[0170] The following provides several embodiments and corresponding performance evaluation experiments to provide detailed description of the particle adsorbent and the preparation method thereof, and the oil-water separation performance, and provides application examples of the particle adsorbent in separating oil-water mixture.

[0171] Preparation of particle adsorbent

[0172] Example 1

[0173] In this embodiment, hollow glass microbeads are used as solid particles to prepare the particle adsorbent. The median particle size of the hollow glass microbeads used in this embodiment is 5 μm, and the density is 0.08 g / cm 3 . The specific preparation steps are as follows:

[0174] 1) 100 g of the above-mentioned hollow glass microbeads are placed in a mortar for grinding. After grinding, the surface roughness of the hollow glass microbeads is improved, and the surface is formed into sharp spikes to obtain rough solid particles. The surface roughness Ra is measured to be 100.

[0175] 2) The rough solid particles prepared in step 1) are transferred into a cationic polyacrylamide aqueous solution (the molecular weight of the cationic polyacrylamide is 2 x 10 7 , and the concentration is 2 wt%). A stirring paddle is used to stir at a speed of 60 r / min for 1 h to make the rough solid particles fully immersed in the cationic polyacrylamide solution, and to introduce positive charges on the surface of the rough solid particles. After immersion, the filter residue is collected and placed in a ventilated oven at 50°C for drying to obtain solid particles with positive charges, i.e. the particle adsorbent. The structural schematic diagram is as follows:Figure 3 as shown.

[0176] Example 2

[0177] In this example, silica particles are used as solid particles to prepare a particle adsorbent. The median particle size of the silica particles used in this example is 25 pm, and the density is 0.15 g / cm 3 The specific preparation steps are as follows:

[0178] 1) 100 g of the above-mentioned silica particles are placed in an aqueous hydrofluoric acid solution with a pH of 3. To avoid splashing of the acid solution, the mixture of the aqueous hydrofluoric acid solution and the silica particles is stirred at a speed of 300 r / min for 60 min under sealed conditions using a stirring paddle for sufficient acid etching treatment. After filtration, the acid-etched solid particles are separated, washed with water to remove the residual hydrofluoric acid on the surface, and then the rough solid particles are obtained. The surface roughness Ra of the rough solid particles is measured to be 200;

[0179] 2) The rough solid particles prepared in step 1) are transferred to an aqueous cationic polyacrylamide solution (in which the molecular weight of the cationic polyacrylamide is 5 x 10 5 The mixture is stirred at a speed of 200 r / min for 5 h using a stirring paddle to allow the rough solid particles to be fully immersed in the aqueous cationic polyacrylamide solution and introduce positive charges on the surface of the rough solid particles. After immersion, the filtrate is collected by filtration and placed in an environment at 65°C for ventilation and drying to obtain solid particles with positive charges on the surface, i.e. a particle adsorbent. The structural schematic diagram is as shown. Figure 3

[0180] Example 3

[0181] In this example, porous ABS plastic particles are used as solid particles to prepare a particle adsorbent. The median particle size of the porous ABS plastic particles used in this example is 50 pm, and the density is 0.3 g / cm 3 The specific preparation steps are as follows:

[0182] 1) 100 g of the above-mentioned porous ABS plastic particles are placed in a double-layer mechanical friction plate for grinding. After grinding, the surface roughness of the particles is improved to form a surface with sharp spikes, and the rough solid particles are obtained. The surface roughness Ra of the rough solid particles is measured to be 300;

[0183] 2) The rough solid particles prepared in step 1) are transferred to an aqueous cationic polyacrylamide solution (in which the molecular weight of the cationic polyacrylamide is 1 x 10 4 ​, the stirring paddle is used to stir at a speed of 400 r / min for 15 h to immerse the coarse solid particles in the cationic polyacrylamide aqueous solution, so that positive charges are introduced on the surface of the coarse solid particles; after the immersion is completed, filtration is performed, the filter residue is collected, and ventilation drying is performed at 80°C to obtain the solid particles with positive charges on the surface, i.e., the particle adsorbent, a structure diagram of which is shown in Figure 3 .

[0184] Example 4

[0185] In this example, hollow glass microbeads are used as the solid particles to prepare the particle adsorbent. Particle size analysis shows that the median particle size of the hollow glass microbeads used in this example is 50 μm, and the density is 0.1 g / cm 3 . The specific preparation steps are as follows:

[0186] 1) 100 g of the hollow glass microbeads are placed in a hydrofluoric acid aqueous solution with a pH of 2. To avoid splashing of the acid solution, the mixture of the hydrofluoric acid aqueous solution and the hollow glass microbeads is stirred at a speed of 300 r / min for 60 min for sufficient acid etching treatment under sealed conditions. Filtration is performed to separate the solid particles after acid etching treatment. After the surface residual hydrofluoric acid is washed away with water, the coarse solid particles are obtained, and the surface roughness Ra thereof is measured to be 400;

[0187] 2) The coarse solid particles prepared in step 1) are transferred to a cationic polyacrylamide aqueous solution (in which the molecular weight of the cationic polyacrylamide is 5 x 10 5 , and the concentration is 10 wt%). The stirring paddle is used to stir at a speed of 200 r / min for 10 h to immerse the coarse solid particles in the cationic polyacrylamide aqueous solution, so that positive charges are introduced on the surface of the coarse solid particles; after the immersion is completed, filtration is performed, the filter residue is collected, and ventilation drying is performed at 65°C to obtain the solid particles with positive charges on the surface, i.e., the particle adsorbent, a structure diagram of which is shown in Figure 3 .

[0188] Example 5

[0189] In this example, hollow glass microbeads are used as the solid particles to prepare the particle adsorbent. Particle size analysis shows that the median particle size of the hollow glass microbeads used in this example is 20 μm, and the density is 0.2 g / cm 3 . The specific preparation steps are as follows:

[0190] 1) 100 g of the hollow glass microspheres described above were placed in an aqueous hydrofluoric acid solution with a pH of 1. To avoid splashing of the acid solution, the mixture of the aqueous hydrofluoric acid solution and the hollow glass microspheres was stirred at a speed of 300 r / min for 60 min under sealed conditions using a stirring paddle for sufficient acid etching treatment. After filtration, the solid particles after acid etching treatment were obtained. After rinsing the surface residual hydrofluoric acid with water, the rough solid particles were obtained. The surface roughness Ra of the rough solid particles was measured to be 500;

[0191] 2) The rough solid particles prepared in step 1) were transferred to an aqueous cationic polyacrylamide solution (wherein the molecular weight of the cationic polyacrylamide was 5 x 10 5 , and the concentration was 10 wt%). The rough solid particles were stirred in the aqueous cationic polyacrylamide solution for 20 h using a stirring paddle at a speed of 200 r / min to allow the rough solid particles to be fully immersed in the aqueous cationic polyacrylamide solution and to introduce positive charges on the surface of the rough solid particles. After the immersion was completed, the filter residue was collected and placed in an environment at 65°C for ventilation drying to obtain the solid particles with positive charges on the surface, i.e. the particle adsorbent. The structural schematic diagram thereof is shown in Figure 3 .

[0192] Example 6

[0193] In this example, polyamide resin particles were used as the solid particles to prepare the particle adsorbent. The polyamide resin particles used in this example had a median particle size of 15 μm and a density of 0.2 g / cm 3 . The specific preparation steps were as follows:

[0194] 1) 100 g of the polyamide resin particles described above were placed in a mortar for grinding. After grinding, the surface roughness of the polyamide resin particles was improved to form a surface with sharp spikes to obtain the rough solid particles. The surface roughness Ra of the rough solid particles was measured to be 600.

[0195] 2) The rough solid particles prepared in step 1) were transferred to an aqueous cationic polyacrylamide solution (wherein the molecular weight of the cationic polyacrylamide was 8 x 10 6 , and the concentration was 2 wt%). The rough solid particles were stirred in the aqueous cationic polyacrylamide solution for 24 h using a stirring paddle at a speed of 600 r / min to allow the rough solid particles to be fully immersed in the aqueous cationic polyacrylamide solution and to introduce positive charges on the surface of the rough solid particles. After the immersion was completed, the filter residue was collected and placed in an environment at 50°C for ventilation drying to obtain the solid particles with positive charges on the surface, i.e. the particle adsorbent. The structural schematic diagram thereof is shown in Figure 3 .

[0196] Structural characterization of the particle adsorbent

[0197] i. Structural schematic diagram of the particle adsorbent

[0198] Figure 3The schematic diagram of the particle adsorbent provided by the present application is shown in the figure. It can be seen that the particle adsorbent provided by the present application has a rough surface with sharp burr-like rough structure, and carries positive charges on the surface of the particle adsorbent.

[0199] ⅱMorphology of the particle adsorbent under scanning electron microscope

[0200] The particle adsorbents prepared in Examples 1 to 6 were observed for morphology under scanning electron microscope, and the particle adsorbent prepared in Example 6 was taken as an example for detailed description.

[0201] Figure 4 The morphology of the particle adsorbent prepared in Example 6 under scanning electron microscope with magnification of 2000 can be seen from the figure. It can be seen that after the surface roughening treatment, the particle adsorbent has a high roughness, and is not adhered to each other. The sharp burr-like rough structure on the surface of the particle adsorbent can be observed. The particle adsorbents prepared in the other five examples can also be observed under scanning electron microscope to have similar sharp burr-like rough structure on the surface. Figure 4

[0202] ⅲMeasurement of surface potential of the particle adsorbent

[0203] The surface potential of the particle adsorbents prepared in Examples 1 to 6 was measured by using a Zeta potential meter, and the specific steps were as follows:

[0204] a. First, the Zeta potential meter was turned on and preheated for 15 minutes, and the sample cell and electrode were rinsed and reserved;

[0205] b. The particle adsorbent prepared in Example 1 was added into a container, and then deionized water was slowly added (1 g of particle adsorbent was added with 1 L of deionized water), and a suspension of the particle adsorbent was prepared by constant stirring as a sample to be measured, and the sample to be measured was confirmed to be clean and free of impurities and was reserved;

[0206] c. Then the sample to be measured was injected into the sample cell and inserted into the Zeta potential meter, and the measurement was started and the measurement data was saved;

[0207] The particle adsorbents prepared in Examples 2 to 6 were measured for Zeta potential according to steps a to c.

[0208] The measurement results of the Zeta potential of the particle adsorbent are shown in Table 1.

[0209] Table 1. Zeta potential of the surface of the particle adsorbent

[0210]

[0211] ​Comprehensively, the particle adsorbent provided by the application has positive charges on the surface and has a rough sharp burr structure, which can make the particle adsorbent adhere to the surface of oil droplets with high adhesion separation efficiency and good adhesion quality, and lay a foundation for better oil-water separation effect, based on the electrostatic adsorption between positive and negative charges and the liquid film between the adsorption particles and the oil droplets pierced by the sharp burr structure to accelerate the liquid discharge process.

[0212] Application examples of the particle adsorbent for separating oil-water mixture and evaluation of oil-water separation performance

[0213] The following will be combined with the process flow diagram shown in Figure 1 The particle adsorbents prepared by Examples 1 to 6 are respectively used for oil-water separation treatment of oil-water mixture, as application examples (specifically, Examples 7-12) of the particle adsorbent for separating oil-water mixture. At the same time, the adhesion separation efficiency of the particle adsorbent in each application example to the oil droplets in the oil-water mixture is used as a technical index to evaluate the oil-water separation performance of the particle adsorbent.

[0214] The oil-water mixtures treated in Examples 7-12 have the same composition, wherein the initial content of the oil phase is 500mg / L, and after being sheared and emulsified for 30min, they are used for Examples 7-12.

[0215] Example 7

[0216] The application example of the particle adsorbent for separating oil-water mixture is provided in this embodiment, and specifically, the particle adsorbent prepared by Example 1 is used, combined with the process flow shown in Figure 1 for oil-water separation treatment of oil-water mixture (the specific process is described above).

[0217] In this embodiment, the mass ratio of the oil-water mixture and the particle adsorbent contained in the up-floating column 120 is 1:100; the extension direction of the first isolation plate 141 forms an angle of 30° with the horizontal direction; the diameter of the hydrocyclone 130 is 30mm, and the inlet diameter, the overflow port 131 diameter and the liquid discharge port 132 diameter are 5mm, 3mm and 3mm respectively.

[0218] Example 8

[0219] The application example of the particle adsorbent for separating oil-water mixture is provided in this embodiment, and specifically, the particle adsorbent prepared by Example 2 is used, combined with the process flow shown in Figure 1 for oil-water separation treatment of oil-water mixture (the specific process is described above).

[0220] This example only replaces the granular adsorbent in Example 7 with the same mass of the granular adsorbent prepared in Example 2.

[0221] Example 9

[0222] This example provides an application example of the granular adsorbent for separating an oil-water mixture. Specifically, the granular adsorbent prepared in Example 3 is used in combination with the process flow shown in the figure (the specific process is described above in the separation method) to perform oil-water separation treatment on an oil-water mixture. Figure 1

[0223] This example only replaces the granular adsorbent in Example 7 with the same mass of the granular adsorbent prepared in Example 3.

[0224] Example 10

[0225] This example provides an application example of the granular adsorbent for separating an oil-water mixture. Specifically, the granular adsorbent prepared in Example 4 is used in combination with the process flow shown in the figure (the specific process is described above in the separation method) to perform oil-water separation treatment on an oil-water mixture. Figure 1

[0226] This example only replaces the granular adsorbent in Example 7 with the same mass of the granular adsorbent prepared in Example 4.

[0227] Example 11

[0228] This example provides an application example of the granular adsorbent for separating an oil-water mixture. Specifically, the granular adsorbent prepared in Example 5 is used in combination with the process flow shown in the figure (the specific process is described above in the separation method) to perform oil-water separation treatment on an oil-water mixture. Figure 1

[0229] This example only replaces the granular adsorbent in Example 7 with the same mass of the granular adsorbent prepared in Example 5.

[0230] Example 12

[0231] This example provides an application example of the granular adsorbent for separating an oil-water mixture. Specifically, the granular adsorbent prepared in Example 6 is used in combination with the process flow shown in the figure (the specific process is described above in the separation method) to perform oil-water separation treatment on an oil-water mixture. Figure 1

[0232] This example only replaces the granular adsorbent in Example 7 with the same mass of the granular adsorbent prepared in Example 6.

[0233] Evaluation of the oil-water separation performance of the granular adsorbent

[0234] ​​​​In the implementation of the above-mentioned embodiments 7-12, the particle adsorbent added into the floating column 120 will adhere to the oil droplets in the oil-water mixture and carry them to the surface of the liquid level of the oil-water mixture in the floating column 120, forming a light-floc adherent layer. In the implementation of embodiments 7-12, the time was counted from the completion of the step of adding the particle adsorbent into the floating column 120, and at the time points of 20 min and 40 min, respectively, the treated samples were sucked from the light-floc adherent layer in the floating column 120, the oil phase content in the treated samples was determined by the method specified in the standard “HJ 970-2018 Water Quality-Determination of Petroleum Oils-Ultraviolet Spectrophotometric Method”, and then combined with the initial content of the oil phase in the oil-water mixture, the percentage of the oil phase content in the treated sample to the initial content of the oil phase in the oil-water mixture was calculated to obtain the adhesion separation efficiency of the particle adsorbent to the oil droplets in the oil-water mixture, and the results are shown in Table 2.

[0235] Table 2. Adhesion separation efficiency of particle adsorbent to oil droplets in oil-water mixture

[0236]

[0237] From the data in Table 2, it can be seen that the adhesion separation efficiency of the particle adsorbent prepared in embodiments 1-6 to the oil droplets in the oil-water mixture is all above 68%, which has a good oil-water separation effect.

[0238] In summary, the particle adsorbent provided by the present application can replace the bubbles in the air flotation method, and is popularized in the field of oil-water separation in an oil-water mixture (such as separation of emulsified oil in sewage), and has a good application prospect.

[0239] Compared with the prior art, the present application has the following advantages:

[0240] Firstly, the present application is suitable for separation and collection of hazardous chemicals, especially in the field of oil-water separation, and solves the problem that the separation medium cannot be recycled after participating in separation in the traditional air flotation method by dispersing oil droplets in water. In other words, the present application replaces the bubbles in the traditional air flotation process with solid particles (low density), so as to not only improve the effect and quality of oil-water separation, but also realize the recycling of the solid particles used for separation, and therefore, the present application effectively avoids resource waste, and has a good application prospect.

[0241] Specifically, the light-floc-adsorbed body entering the hydrocyclone is separated due to the centrifugal force, and since the density of the solid particle is still less than that of the oil phase, the oil phase serves as a heavy phase and is thrown to the wall of the cone section of the hydrocyclone, so as to be discharged to the external collector through the liquid discharge port; and the solid particle serves as a light phase and flows out from the overflow port and reenters the liquid inlet pipe to enter the floating column again and participate in the next oil-water separation work, so that the solid particle has the recycling effect.

[0242] Secondly, the solid particles in the present application can form light flocculation adherent bodies floating on the surface of the liquid phase with the oil droplets in the oil-water mixture, so as to further reduce the density difference between the oil droplets and the water, thereby facilitating the subsequent oil-water separation work.

[0243] Specifically, on the one hand, in the process of collision with the oil droplets, the solid particles can effectively promote the rupture of the water film outside the solid particles and the oil droplets by the sharp burrs arranged on the surface of the solid particles, thereby increasing the adhesion probability between the solid particles and the oil droplets, so as to further improve the effect and quality of oil-water separation; on the other hand, in the process of adhesion of the oil droplets, the solid particles can be coated with a cationic coating on the surface, so as to make the solid particles have a positive charge to more easily produce an electrostatic adsorption effect with the oil droplets, thereby enhancing the adhesion between the solid particles and the oil droplets, so as to further improve the effect and quality of oil-water separation.

[0244] The above is only the preferred embodiment of the present application, but the protection scope of the present application is not limited thereto. Those skilled in the art can easily make changes or variations within the scope of the present application, and such changes or variations should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An oil-water separation device, comprising: A wastewater tank (110) containing an oil-water mixture, and A separation mechanism connected to the wastewater tank (110) via an inlet pipe (121) includes at least one floating column (120), an injection pipe disposed on the floating column (120) for discharging solid particles, and an oil discharge pipe disposed above the injection pipe. The solid particles can form a light, flocculent adherent body that floats on the surface of the liquid phase with the oil phase in the oil-water mixture.

2. The oil-water separation device according to claim 1, characterized in that, The oil-water separation device further includes a hydrocyclone (130) connected to the oil drain pipe and used to receive the light flocculent adhering body. The hydrocyclone (130) is connected to the liquid inlet pipe (121) through an overflow port (131), and a liquid outlet (132) is provided at the bottom end of the hydrocyclone (130). The light flocs can be separated in the hydrocyclone (130), and the separated solid particles re-enter the upper float (120) through the overflow port (131) and the liquid inlet pipe (121), and the separated oil phase is discharged through the drain port (132).

3. The oil-water separation device according to claim 2, characterized in that, The fixed particles are constructed of at least one of hollow glass microspheres, silica particles, and solid resin particles. The fixed particles have a non-smooth surface and are provided with a plurality of spaced burrs on the surface of the fixed particles.

4. The oil-water separation device according to claim 3, characterized in that, The density of the stationary particles is lower than that of the aqueous phase and the oil phase, and a cationic coating is provided on the surface of the stationary particles for electrostatic adsorption with the oil phase.

5. The oil-water separation device according to claim 4, characterized in that, The upper float (120) is provided with a liquid inlet distributor (125) for evenly distributing the liquid inlet volume. The liquid inlet distributor (125) includes a plurality of liquid inlet trays (126) arranged axially at intervals and forming a sealed connection with the upper float (120). The liquid inlet plate (126) is provided with a plurality of through holes (127) that allow the solid particles to pass through, and the through holes (127) are arranged in an equilateral triangle on the liquid inlet plate (126).

6. The oil-water separation device according to claim 5, characterized in that, The separation mechanism also includes a drain pipe disposed on the upper float (120) and located below the oil drain pipe.

7. The oil-water separation device according to claim 6, characterized in that, The liquid inlet pipe (121) is located at the lower end face of the upper float (120), and a pump body is provided on the liquid inlet pipe (121), the drain pipe and the oil drain pipe.

8. The oil-water separation device according to claim 7, characterized in that, The separation mechanism further includes a separator disposed inside the upper float (120) for guiding the solid particles. The separator covers the drain pipe and includes a first separator plate (141) fixed to the inner wall of the upper float (120) and a second separator plate (142) disposed above the first separator plate (141).

9. The oil-water separation device according to claim 8, characterized in that, The first isolation plate (141) is arranged at an angle, and the extension direction of the first isolation plate (141) forms an angle of 10° to 80° with the horizontal direction.

10. The oil-water separation device according to claim 9, characterized in that, The total height of the isolation element is 2 to 8 times the diameter of the drain pipe, and the upper edge of the second isolation plate (142) is located 0.5 to 6 times the diameter above the upper edge of the drain pipe.

11. The oil-water separation device according to claim 10, characterized in that, The cross-sectional area of ​​the upper floating column (120) is either circular or square.

12. A method for separating an oil phase using an oil-water separation apparatus according to any one of claims 1 to 11, comprising the following steps: S1. The oil-water mixture is pumped into the upper float column (120) through the pump body; S2. The solid particles are injected through the injection pipe. The solid particles can form a light flocculent body floating on the surface of the liquid phase with the oil phase in the oil-water mixture, and are transported to the hydrocyclone (130) through the oil discharge pipe. S3. The light flocs are separated by the hydrocyclone (130). The separated solid particles re-enter the upper float (120) through the overflow port (131) and the liquid inlet pipe (121). The separated oil phase is discharged through the drain port (132).

Images