阅读说明：本技术 一种聚丙烯聚结纤维的制备方法及应用 (Preparation method and application of polypropylene coalescent fibers ) 是由 杨丽 奚振宇 李宇 于 2019-08-22 设计创作，主要内容包括：本发明公开了一种聚结纤维的制备方法及由该方法制备的聚结纤维,包括以下步骤：S1.对包含聚丙烯树脂和稀释剂的混合物进行熔融处理,得到纺丝液；S2.对所述纺丝液进行挤出处理；S3.对所述步骤S2得到的纺丝液进行纺丝处理,得到初生纤维；S4.使所述初生纤维在空气中暴露5-30s,使稀释剂挥发；S5.对步骤S4得到的初生纤维进行冷却处理,得到纤维长丝；S6.对步骤S5得到的纤维长丝进行萃取处理,制得所述聚丙烯聚结纤维。本发明方法工艺简便,生产路径短,制备的聚结纤维孔径适中、机械强度高、分离性能优良,应用于处理含油污水中,对污水的除油效率高。(The invention discloses a preparation method of coalescent fiber and the coalescent fiber prepared by the method, which comprises the following steps: s1, carrying out melting treatment on a mixture containing polypropylene resin and a diluent to obtain a spinning solution; s2, extruding the spinning solution; s3, spinning the spinning solution obtained in the step S2 to obtain nascent fibers; s4, exposing the nascent fiber in the air for 5-30s to volatilize the diluent; s5, cooling the nascent fiber obtained in the step S4 to obtain a fiber filament; s6, extracting the fiber filaments obtained in the step S5 to obtain the polypropylene coalescent fiber. The method has the advantages of simple process, short production path, moderate aperture of the prepared coalescent fiber, high mechanical strength, excellent separation performance, application to the treatment of oily sewage and high oil removal efficiency of sewage.)

1. A preparation method of polypropylene coalesced fiber comprises the following steps:

s1, carrying out melting treatment on a mixture containing polypropylene resin and a diluent to obtain a spinning solution;

s2, extruding the spinning solution;

s3, spinning the spinning solution obtained in the step S2 to obtain nascent fibers;

s4, exposing the nascent fiber in the air for 5-30s to volatilize the diluent;

s5, cooling the nascent fiber obtained in the step S4 to obtain a fiber filament;

s6, extracting the fiber filaments obtained in the step S5 to obtain the polypropylene coalescent fiber.

2. The production method according to claim 1, wherein the mass ratio of the polypropylene resin to the diluent is (20-95): (5-80), preferably (45-85): (15-55); and/or the diluent comprises vegetable oil and/or phthalate ester compounds.

3. The method as claimed in claim 1 or 2, wherein the melting treatment is carried out at a temperature of 175 ℃ and a temperature of 230 ℃ for a period of 0.5 to 3 hours.

4. The production method according to any one of claims 1 to 3, wherein the spinning solution is subjected to an extrusion treatment by a screw extruder in the step S2; and/or the processing temperature of the screw extruder is 175-230 ℃, and the pressure is 0.5-3 MPa.

5. The production method according to any one of claims 1 to 4, wherein the spinning process in step S3 includes: conveying the spinning solution to a spinning nozzle, and extruding through the spinning nozzle to obtain nascent fiber; and/or the spinneret has an aperture of 0.1-5mm, preferably 1-2.5mm, at a temperature of 140-.

6. The production method according to any one of claims 1 to 5, wherein the as-spun fiber is subjected to a cooling treatment by passing through at least three stages of coagulation baths in the step S5; preferably, the as-spun fiber is first cooled through a primary coagulation bath at 80-100 ℃, then through a secondary coagulation bath at 40-60 ℃, and finally through a tertiary bath at 0-10 ℃ to produce the fiber filament.

7. The production method according to any one of claims 1 to 6, wherein the medium of the primary coagulation bath includes at least one of vegetable oil, phthalate-based compound and triacetin-based compound; and/or the medium of the secondary coagulation bath comprises an aqueous solution of a surfactant and/or a polyol; and/or the medium of the tertiary coagulation bath is deionized water.

8. The production method according to any one of claims 1 to 7, wherein the step S6 includes: putting the fiber filaments obtained in the step S5 into an extracting agent for extraction or a plurality of extracting agents for extraction, wherein the extraction time is 3-48 h; and/or the extractant is selected from a ketone, an alcohol or an alkane.

9. Surface-porogenic coalesced fibers prepared according to the method of any one of claims 1 to 8 having a diameter of 0.1 to 5mm, the specific surface area is 18.1-28.6m²/g。

10. Use of polypropylene coalescent fibers prepared according to any one of claims 1 to 8 or the polypropylene coalescent fibers of claim 9 for treating oily wastewater comprising passing the oily wastewater through the polypropylene coalescent fibers to separate the oil phase and the aqueous phase therein.

11. An apparatus for treating oily sewage, comprising:

a liquid storage tank for storing oily sewage;

a coalescer connected to the liquid tank and filled with the polypropylene coalesced fiber prepared according to the method of any one of claims 1 to 8 or the polypropylene coalesced fiber of claim 9 for receiving the oily sewage from the liquid tank and treating the same to separate an oil phase and a water phase therein;

a water production tank connected to said coalescer for receiving the aqueous phase from said coalescer;

an oil collection tank connected to the coalescer for receiving the oil phase from the coalescer.

Technical Field

The invention relates to a preparation method of polypropylene coalescent fiber, a polypropylene coalescent fiber material prepared by the method, application of the polypropylene coalescent fiber material in treating oily sewage, and a device for treating the oily sewage, belonging to the technical field of water treatment.

Background

Oil pollution, a common pollution, is extremely harmful to environmental protection and ecological balance. The range of producing the oily sewage is wide, and the oily sewage is produced in the processes of petroleum exploitation, petroleum refining, petrochemical industry, oil storage and transportation and the like. The oil-containing sewage in China has extremely high yield, more than 30 hundred million tons of oil-containing sewage are generated every year in oil fields and oil refining industries, the oil-containing sewage is one of the industrial waste water which is difficult to treat at present, and along with the requirement on environmental protection and the gradual strictness of energy conservation and consumption reduction, the oil concentration of the discharged sewage specified in the comprehensive sewage discharge standard (GB 8978-.

The coalescence-separation method is a physical oil-removing method, integrates gravity separation and coalescence technologies, and utilizes the characteristic of oil-water density difference to realize the separation process. The coalescence separator has the advantages of low power consumption, high separation efficiency, large operation elasticity and the like, when oily sewage passes through the coalescence separator, oil drops interact with the coalescence material, due to lipophilicity of the surface of the material, the oil drops and the surface of the material form a continuous oil film with a certain thickness, when subsequent oil drops pass through the surface, a liquid-sandwiched layer is formed between the oil drops and the film, the liquid film of the liquid drops is gradually deformed and thinned in the liquid discharging process, the liquid film is broken when reaching a critical value, the two liquid drops are fused and grow up, the small oil drops are gradually aggregated into large oil drops, and along with the traction force of water flow, the large oil drops break away from the adsorption of the coalescence material to realize falling and enter an oil layer under the action of buoyancy to. The technical key of the coalescence method for removing oil is a coalescence material which can be divided into a porous material, a fiber material, a granular material and the like, wherein the fiber material can be made into a material with a smaller diameter and a larger surface area, and the coalescence material has obvious oil removing effect.

The coalescence process mainly depends on the blocking and diffusion effects, and oil drops can be captured by the material under the action of Van der Waals attraction only when moving to the surface close to the material, so that the action is only carried out on the outer surface, the larger the outer surface, the higher the probability that the oil drops are close to the material and attached, the more remarkable influence of the surface area of the material on the coalescence effect of the oil drops can be realized, the surface area of the fiber material on the smooth surface can be improved by adopting methods such as reducing the diameter and the like, but the forms such as the small diameter of the coalescence material or hollow fibers and the like can cause overlarge pressure drop of a filling bed layer and difficult cleaning and regeneration, and great difficulty is caused to the actual operation, so the more ideal method is to increase the roughness of the.

Disclosure of Invention

The invention aims to provide a preparation method of polypropylene coalescent fiber, which prepares oleophylic polypropylene resin into a coalescent fiber material with a microporous structure on the surface by a thermally induced phase separation method, increases the roughness and the surface area of the surface, has simple and convenient process and short production path, and the polypropylene coalescent fiber prepared by the method has moderate aperture, high surface roughness, large specific surface area, high mechanical strength and excellent separation performance, is applied to treating oily sewage and has high oil removal efficiency on the sewage.

According to one aspect of the present invention, there is provided a method for preparing polypropylene coalesced fiber, comprising the steps of:

s1, carrying out melting treatment on a mixture containing polypropylene resin and a diluent to obtain a spinning solution;

s2, extruding the spinning solution;

s3, spinning the spinning solution obtained in the step S2 to obtain nascent fibers;

s4, exposing the nascent fiber in the air for 5-30s to volatilize the diluent;

s5, cooling the nascent fiber obtained in the step S4 to obtain a fiber filament;

s6, extracting the fiber filaments obtained in the step S5 to obtain the polypropylene coalescent fiber.

According to a preferred embodiment of the present invention, the mass ratio of the polypropylene resin to the diluent is (20-95) to (5-80), preferably (45-85) to (15-55).

The fiber prepared in the mass ratio range has good mechanical property and uniform surface pore distribution.

According to a preferred embodiment of the present invention, the polypropylene resin has a melt index of 0.2-80g/10min, and the polypropylene resin has good flowability, processability and mechanical properties in the melt index range, wherein the melt index test condition is that the temperature is 230 ℃ and the load weight is 2.16 kg.

According to a preferred embodiment of the invention, the diluent comprises vegetable oil and/or phthalate type compounds.

According to a particular embodiment of the invention, the vegetable oil is selected from at least one of peanut oil, castor oil and soybean oil, preferably soybean oil.

According to a specific embodiment of the present invention, the phthalate-based compound includes at least one of dibutyl phthalate, diamyl phthalate, diheptyl phthalate and dioctyl phthalate, preferably dibutyl phthalate and/or dioctyl phthalate.

According to a preferred embodiment of the present invention, the polypropylene resin raw material is dried at 70 to 90 ℃ for 2 to 6 hours before use, and then mixed with a diluent, preferably under nitrogen gas.

According to a preferred embodiment of the present invention, the temperature of the melting treatment is 175-230 ℃ and the time is 0.5-3 h.

According to a preferred embodiment of the present invention, the step S1 may be performed as follows: drying the polypropylene resin raw material at 70-90 ℃ for 2-6 hours, mixing the polypropylene resin raw material with a diluent in a spinning kettle with a stirring device, heating to 175-230 ℃, and stirring for 0.5-3 hours under the condition of introducing nitrogen, and uniformly mixing to obtain the spinning solution.

According to some embodiments of the present invention, the spinning solution is subjected to an extrusion process by a screw extruder in the step S2; and/or the pipeline temperature of the screw extruder is 175-230 ℃, and the head pressure is 0.5-3 MPa.

The spinning solution is directly extruded by the screw extruder, and bubbles entering the spinning nozzle are removed by utilizing the high pressure of the machine head, so that the standing and defoaming time is saved, the continuous preparation of fibers is facilitated, and the production efficiency is improved.

According to some embodiments of the present invention, the spinning process in step S3 includes: conveying the spinning solution to a spinning nozzle, and extruding through the spinning nozzle to obtain nascent fiber;

according to a preferred embodiment of the invention, the spinneret has an aperture of 0.1-5mm, preferably 1-2.5mm, and a temperature of 140-.

According to a preferred embodiment of the present invention, the step S3 may be performed as follows: filtering the spinning solution, then conveying the filtered spinning solution to a spinning nozzle by using a metering pump, and extruding the spinning solution through the spinning nozzle at a constant speed to obtain fiber filaments.

According to some embodiments of the invention, the as-spun fiber is subjected to a cooling treatment in step S5 by passing through at least three stages of coagulation baths; preferably, the as-spun fiber is first cooled through a primary coagulation bath at 80-100 ℃, then through a secondary coagulation bath at 40-60 ℃, and finally through a tertiary bath at 0-10 ℃ to produce the fiber filament.

According to a preferred embodiment of the invention, the medium of the primary coagulation bath comprises 10-100% by mass of an aqueous solution of at least one of vegetable oil, phthalate compounds and triacetin; and/or the medium of the secondary coagulating bath comprises 10-90% by mass of surfactant and/or polyhydric alcohol aqueous solution; and/or the medium of the tertiary coagulation bath is deionized water.

According to a preferred embodiment of the present invention, the vegetable oil comprises at least one of peanut oil, castor oil, soybean oil and corn oil, preferably soybean oil.

According to a preferred embodiment of the present invention, the phthalate-based compound includes at least one of dibutyl phthalate, dipentyl phthalate, diheptyl phthalate, and dioctyl phthalate, preferably dibutyl phthalate and/or dioctyl phthalate.

According to a preferred embodiment of the present invention, the surfactant comprises at least one of sodium laureth sulfate and sodium dodecylbenzenesulfonate.

According to a preferred embodiment of the present invention, the polyol comprises at least one of ethylene glycol, diethylene glycol, triethylene glycol, glycerol and polyethylene glycol.

According to the invention, as-spun fibers are cooled and solidified by three different coagulation baths, the internal stress of the fibers can be reduced to the greatest extent, the phenomena of stress cracking, buckling deformation and the like are prevented, and the mechanical and thermal properties of the coalesced fibers are improved.

The invention prepares the polypropylene coalescent fiber material with the micropore structure by selecting the types and component concentrations of the components of the coagulating bath, the temperature of the coagulating bath and the number of the stages of the coagulating bath, and the coagulating bath and the diluent are dissolved and exchanged when the nascent fiber is formed, thereby avoiding the generation of a compact skin layer and enabling the surface of the fiber to generate a large number of micropores.

According to some embodiments of the invention, the step S6 includes: and (4) putting the fiber filaments obtained in the step S5 into an extracting agent for extraction or a plurality of extracting agents for extraction.

According to a preferred embodiment of the invention, the extraction time is between 3 and 48 h.

According to a preferred embodiment of the present invention, the extractant is selected from at least one of a ketone, an alcohol and an alkane.

According to a specific embodiment of the present invention, the ketone comprises acetone.

According to a specific embodiment of the present invention, the alcohol comprises at least one of methanol, ethanol and isopropanol.

According to a particular embodiment of the invention, the alkane comprises n-hexane and/or cyclohexane.

According to some embodiments of the invention, the method further comprises the steps of:

and S7, respectively soaking the coalesced fiber by using an acid solution and an alkali solution, and cleaning and drying.

According to a preferred embodiment of the invention, the acid solution is a hydrochloric acid solution, with a concentration of 0.5 to 1 mol/L, preferably 0.5 mol/L; the alkali solution is sodium hydroxide solution, and the concentration is 0.5-1 mol/L, preferably 0.5 mol/L.

According to a preferred embodiment of the present invention, the step S7 may be performed as follows: soaking the prepared coalesced fiber in an acid solution for 5-10h, then soaking in an alkali solution for 5-10h, washing with deionized water to neutrality, then drying at 60-80 ℃ for 12-24h, and removing the moisture on the surface to obtain the coalesced fiber.

After the treatment, the pollutants on the surface of the fiber can be removed.

According to another aspect of the present invention there is also provided a surface-porogenic coalesced fiber prepared according to the above method, having a diameter of 0.1 to 5mm, preferably 1 to 2.5 mm; the specific surface area is 18.1-28.6m²/g。

According to another aspect of the present invention, there is also provided the use of the above-mentioned polypropylene coalesced fiber for treating oily sewage, comprising passing the oily sewage through the polypropylene coalesced fiber to separate an oil phase and an aqueous phase therein.

The polypropylene coalescent fiber is an oleophilic material, when oily sewage passes through the coalescent fiber, oil drops in the sewage are coalesced on the surface of the coalescent fiber due to different affinities of oil phase and water phase relative to the coalescent fiber, so that the oil drops are changed from small to large, and the enlarged oil drops float up due to smaller density, thereby further realizing the separation of the oil phase and the water phase. .

According to another aspect of the present invention, there is also provided an apparatus for treating oily sewage, comprising:

a liquid storage tank for storing oily sewage;

a coalescer connected to said tank and packed with said polypropylene coalesced fibers for receiving and treating oily sewage from said tank to separate oil and water phases therein;

a water production tank connected to said coalescer for receiving the aqueous phase from said coalescer;

an oil collection tank connected to the coalescer for receiving the oil phase from the coalescer.

According to some embodiments of the invention, the polypropylene coalesced fibers are packed in a bed of the coalescer by layered compaction at a packing ratio of 1/2.

According to a preferred embodiment of the present invention, the coalescer is provided with a sewage inlet, a water phase outlet and an oil phase outlet. In some specific embodiments, the oil phase outlet is disposed in an upper portion of the coalescer, and the water phase outlet is disposed in a sidewall of the coalescer.

According to a preferred embodiment of the invention, the apparatus further comprises a sewage tank arranged between the liquid reservoir and the coalescer, the sewage tank being provided with a sewage inlet communicating with the liquid reservoir via a pipe, a sewage outlet communicating with the inlet of the coalescer via a pipe, and a gas inlet, for receiving sewage from the liquid reservoir and conveying it to the coalescer.

According to a preferred embodiment of the present invention, the apparatus further comprises a sewage pump disposed on the pipe between the liquid tank and the sewage tank, for pumping the sewage in the liquid tank into the sewage tank.

According to a preferred embodiment of the invention, the apparatus further comprises a gas source connected to the gas inlet of the waste tank for supplying gas into the waste tank to propel waste into the coalescer. In some embodiments, the gas source is a nitrogen gas cylinder. The air source is connected with the sewage tank through a pipeline, and a pressure stabilizing valve is arranged on the pipeline.

According to a preferred embodiment of the present invention, the apparatus further comprises a flow regulating valve, a flow meter and a feed pump arranged in sequence on the pipe between the sewage tank and the coalescer.

According to a preferred embodiment of the invention, the water production tank communicates with the water phase outlet of the coalescer by means of a conduit, and the oil collection tank communicates with the oil phase outlet of the coalescer by means of a conduit.

The working process and the principle of the device for treating the oily sewage are as follows:

pumping oily sewage in a liquid storage tank into a sewage tank through a sewage pump, pumping liquid in the sewage tank into a coalescer through a feeding pump, and controlling the inflow of water to be 0.1-0.5m by adjusting a flow regulating valve³Within/h; the oil phase in the sewage is slowly attached to the surface of the coalesced fiber and then is gathered to form oil drops, the large-particle oil drops are carried away from the surface of the coalesced fiber by the water phase and enter the oil collecting tank through the oil phase outlet, and the water phase without the oil phase enters the water producing tank through the water phase outlet. Preferably, the temperature of the contaminated water is between 30 and 50 ℃.

According to another aspect of the present invention, there is provided a method for treating oily sewage using the above apparatus, comprising:

(1) the coalescent fibers are packed into the bed layer of the coalescer in a layered compaction mode, wherein the packing ratio is 1/2;

(2) pumping the oily sewage with the temperature of 30-50 ℃ in the liquid storage tank into a sewage tank through a sewage pump;

(3) opening a flow regulating valve, a flowmeter, a pressure stabilizing valve and an air source, pumping the liquid in the sewage tank into the coalescer by a feed pump, and controlling the inflow of water to be 0.1-0.5m by regulating the flow regulating valve³Within/h; the oil phase in the sewage is slowly attached to the surface of the coalesced fiberAnd the oil droplets are carried by the water phase to leave the surfaces of the coalesced fibers and enter an oil collecting tank through an oil phase outlet, and the water phase without the oil phase enters a water producing tank through a water phase outlet.

The invention has the advantages and beneficial technical effects as follows:

the polypropylene coalescent fiber material with a microporous structure is prepared by selecting the types and the component concentrations of the components of the coagulating bath, the temperature of the coagulating bath and the progression of the coagulating bath, the coagulating bath and a diluent are dissolved and exchanged during the formation of nascent fiber, the generation of a compact skin layer is avoided, a large number of micropores can be generated on the surface of the fiber, and the nascent fiber is slowly cooled by the coagulating bath at different temperatures, so that the internal stress of the fiber can be reduced to the maximum extent, the mechanical and thermal properties and the like of the polypropylene coalescent fiber material are improved, and the phenomena of stress cracking, warping deformation and the like are prevented; the spinning solution is directly extruded by the screw extruder, and bubbles entering the spinning nozzle are removed by utilizing the high pressure of the machine head, so that the standing and defoaming time is saved, the continuous preparation of fibers is facilitated, and the production efficiency is improved.

The invention prepares the polypropylene coalescent fiber material with the micropore structure by a simple and convenient process, increases the roughness and the surface area of the fiber surface structure, is beneficial to capturing oil drops by the material and converging and combining the oil drops on the surface, improves the coalescent and oil-water separation efficiency, and the filled and prepared oil-water separation equipment has compact structure, full sealing, safety and explosion resistance, realizes the treatment of oily sewage, has high treatment efficiency, can recycle the recovered dirty oil, does not generate any waste residue, and can not cause secondary pollution.

Drawings

FIG. 1 is a schematic structural view of an apparatus for treating oily sewage according to the present invention;

FIG. 2 is a surface SEM image of a polypropylene coalesced fiber of the present invention;

description of reference numerals: 1: a gas source; 2: a liquid storage tank; 3: a pressure maintaining valve; 4: a sewage pump; 5: a sewage tank; 6: a flow regulating valve; 7: a flow meter; 8: a feed pump; 9: a coalescer; 10: a water producing tank; 11: an oil collecting tank.

Detailed Description

The present invention is described below with reference to specific examples, which are not intended to limit the scope of the present invention, and those skilled in the art may make insubstantial modifications and adaptations of the present invention based on the above-described disclosure.

The starting materials used in the examples are all commercially available unless otherwise specified.

The test method comprises the following steps:

the specific surface area of the prepared fiber material is measured according to national standard GB/T19587-.

The oil content in the water is measured according to the national standard GB/T16488 and 1996 determination of water quality petroleum and animal and vegetable oil;

the oil removal rate was calculated as follows:

in the formula, C₀Represents the oil content of the oily sewage in the sewage tank, mg/L;

c represents the oil content of the water phase in the water production tank, mg/L.

As shown in fig. 1, the apparatus for treating oily sewage of the present invention comprises an air source 1, a liquid storage tank 2, a pressure-stabilizing valve 3, a sewage pump 4, a sewage tank 5, a flow rate regulating valve 6, a flow meter 7, a feed pump 8, a coalescer 9, a water production tank 10 and a oil collection tank 11.

Wherein, the liquid storage tank 2 is used for storing oily sewage, the temperature of the sewage is 30-50 ℃, and the sewage is sequentially connected with a sewage pump 4 through a pipeline; the sewage pump 4 is connected with a sewage inlet of the sewage tank 5 through a pipeline and is used for pumping the oily sewage in the liquid storage tank 2 into the sewage tank 5. The gas source 1 is connected with a gas inlet of a sewage tank 5 through a pipeline, a pressure stabilizing valve 3 is arranged on the pipeline, and in the embodiment of the invention, the gas source 1 is preferably a nitrogen cylinder. The sewage outlet of the sewage tank 5 is connected with a feed pump 8 through a pipeline, a flow regulating valve 6 and a flow meter 7 are sequentially arranged on the pipeline, and the feed pump is connected with the inlet of a coalescer 9 through a pipeline and is used for pumping the sewage in the sewage tank 5 into the coalescer 9 for treatment. The coalescer 9 is filled with coalescing fibers to treat the wastewater and separate the oil phase from the water phase. The coalescer comprises an oil phase outlet and a water phase outlet, the oil phase outlet is connected with the oil collecting tank 11 through a pipeline, and the water phase outlet is connected with the water producing tank 10 through a pipeline.

Examples 1 to 27 and comparative examples 1 to 11

(1) Adding the polypropylene master batch into a spinning kettle with a stirring device, mixing the polypropylene master batch with a diluent in proportion, heating the mixture to a certain temperature for melting, and stirring the mixture for a period of time under the condition of introducing nitrogen to obtain a spinning solution.

(2) The spinning solution is filtered by a filter screen and then extruded by a screw extruder.

(3) The extruded spinning solution is fed to a spinneret using a metering pump, and then extruded at a constant rate into a nascent fiber.

(4) Exposing the nascent fiber to air for 5-30 s; then cooled by a three-stage coagulation bath, and then a traction wheel is used for winding and collecting coalesced fiber filaments.

(5) The fiber filament is put into an extracting agent for extraction for a period of time to obtain the coalescent fiber.

(6) The prepared coalesced fiber is soaked in HCI solution of 0.5mol/L for a period of time, then soaked in NaOH solution of 0.5mol/L for a period of time, washed to be neutral by deionized water, dried in an oven and removed of water adsorbed on the surface.

The data of each step are shown in Table 1.

TABLE 1

Examples 28 to 58 and comparative examples 12 to 23

The device shown in figure 1 is adopted to treat oily wastewater of a certain refinery, the pH of the wastewater is 7.0, and the oil content is 1526 mg/L.

(1) The coalesced fibers prepared in examples 1 to 27 and comparative examples 1 to 11 were packed in layers in the bed of the coalescer at a packing ratio of 1/2;

(2) pumping the oily sewage with the temperature of 30-50 ℃ in the liquid storage tank into a sewage tank through a sewage pump;

(3) opening a flow regulating valve, a flowmeter, a pressure stabilizing valve and an air source, pumping the liquid in the sewage tank into the coalescer by a feed pump, and controlling the inflow of water to be 0.1-0.5m by regulating the flow regulating valve³/h。

And measuring data after the operation is stable, and calculating to obtain the oil removal rate.

The data for each example and comparative example are shown in table 2.

TABLE 2

Any numerical value mentioned in this specification, if there is only a two unit interval between any lowest value and any highest value, includes all values from the lowest value to the highest value incremented by one unit at a time. For example, if it is stated that the amount of a component, or a value of a process variable such as temperature, pressure, time, etc., is 50 to 90, it is meant in this specification that values of 51 to 89, 52 to 88 … …, and 69 to 71, and 70 to 71, etc., are specifically enumerated. For non-integer values, units of 0.1, 0.01, 0.001, or 0.0001 may be considered as appropriate. These are only some specifically named examples. In a similar manner, all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be disclosed in this application.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.