Emulsified wastewater filtering system

Abstract

The invention discloses an emulsified wastewater filtering system, which utilizes the characteristic of high oil stain resistance of graphene materials in an emulsified oil filtering film module containing graphene and a biological reaction module containing graphene to improve the separation efficiency of emulsified oil. Wherein the graphene weight percentage of the graphene hollow membrane tube is not less than 50%.

Description

Technical Field

[0001] The present invention provides a wastewater filtration system. More specifically, the present invention provides a system that can filter emulsified oil and water in oily wastewater, and can achieve the purpose of recovering and reusing oil and water without adding additional chemicals. Background Art

[0002] Common oily wastewater mainly occurs in offshore crude oil leakage and large amounts of oily wastewater generated during industrial production. According to statistics, about 500 to 10,000 tons of oil flow into the ocean through various channels each year, which not only seriously pollutes the ecological environment, but also causes harm to human health. Therefore, the oil-water separation problem has always been regarded as one of the important issues in water treatment.

[0003] The current oil-water separation technology will select the appropriate separation method according to the type and state of the oil (floating oil, dispersed oil, emulsified oil, dissolved oil). Common methods include: gravity sedimentation, centrifugal separation, air flotation, coarse particle method, medium filtration, chemical coagulation, membrane filtration, etc. Generally speaking, since the particle size of floating oil and dispersed oil is large and has a high sedimentation rate, the traditional mechanical separation method (such as gravity sedimentation) can achieve the effect of oil-water separation. Similar methods are often used in the pretreatment stage of oil-water separation. However, under such a treatment system, there will still be a lot of emulsified oil with a particle size of less than 10 microns remaining in the water body. At this time, various forms of membranes can be used to separate the emulsified oil. At present, micron filter membranes (MF) and ultrafiltration membranes (UF) are mainly used for separation. Of course, more expensive nanofiltration membranes (NF) and reverse osmosis membranes (RO) are also used to separate emulsified oil.

[0004] It is true that membrane separation technologies, whether reverse osmosis membrane, micron filter membrane or ultrafiltration membrane, are all very effective in separating tiny emulsified oil droplets, and have the advantages of low energy consumption, high modularity, portability, and no need to add additional chemical agents. However, after a certain period of use, oil droplets and grease will remain in the pores of these existing membranes, resulting in an irreversible reduction in water flux, and grease will form a flaky barrier layer on the membrane, forming a pollution layer that is very difficult to remove. In fact, for reverse osmosis membranes, their tolerance for oily wastewater is very low, and the oil droplets and grease remaining on the membrane will cause the membrane to degrade and destroy the structure of the reverse osmosis membrane.

[0005] In view of the difficulties encountered by the above-mentioned prior art, in order to overcome the above-mentioned shortcomings, the oil resistance of the membrane must be improved. Therefore, the present invention discloses an emulsified wastewater filtration system that uses a filtration membrane with high oil resistance to achieve the purpose of high filtration efficiency. Summary of the invention

[0006] In view of the above, the present invention provides an emulsified wastewater filtration system, which utilizes the high oil resistance of the graphene material in the emulsified oil filtration membrane module containing graphene and the bioreactor module containing graphene to improve the separation efficiency of the emulsified oil.

[0007] In view of the above, the present invention provides an emulsified wastewater filtration system, which utilizes a multi-stage water treatment method in an emulsified oil filtration membrane module containing graphene and a biological reaction module containing graphene to further reduce the biological oxygen demand in the oily wastewater after effectively reducing the emulsified oil content.

[0008] The present invention provides an emulsified wastewater filtration system for filtering oily wastewater, wherein the emulsified wastewater filtration system comprises an oil-water separation unit, an emulsified oil separation unit and a biological reaction unit. The oil-water separation unit comprises at least one separation tank body, at least one raw wastewater input end, at least one wastewater output end and at least one floating oil recovery end. The oily wastewater enters the separation tank body from the raw wastewater input end, and the oily wastewater is separated in the separation tank body based on the different specific gravities of oil and water. The oil floats and is recovered by the floating oil recovery end, and the remaining water containing the emulsified oil is discharged from the wastewater output end; the emulsified oil separation unit comprises at least one emulsified oil separation tank body, in which at least one emulsified oil filtration membrane module containing graphene is arranged, and the emulsified oil filtration membrane module containing graphene is composed of a plurality of graphene hollow membrane tubes, and the surface of the graphene hollow membrane tubes The invention has a plurality of nanopores, and the water containing emulsified oil enters the emulsified oil separation tank body through the wastewater output end, passes through the emulsified oil filtration membrane module containing graphene, and is discharged from the emulsified oil separation tank body; the biological reaction unit comprises at least one reaction tank body, and at least one biological reaction module containing graphene is arranged inside the reaction tank body, after the reaction tank body receives the water discharged from the emulsified oil separation tank, the water passes through the biological reaction module containing graphene, and is discharged from the biological reaction unit; wherein the weight percentage of graphene in the graphene hollow membrane tube is not less than 50%, and the biological reaction module containing graphene comprises at least one of a film, a foam, and a hollow membrane tube.

[0009] In one embodiment of the present invention, the emulsified oil filtration membrane module containing graphene is in the shape of a curtain sheet.

[0010] In one embodiment of the present invention, the emulsified oil filtration membrane module containing graphene is cylindrical.

[0011] In one embodiment of the present invention, an aeration unit may be selectively provided in the emulsified oil separation unit and the biological reaction unit. The aeration unit is provided correspondingly to the emulsified oil filtration membrane module containing graphene in the emulsified oil separation unit, and the aeration unit is provided correspondingly to the biological reaction module containing graphene in the biochemical reaction unit.

[0012] In one embodiment of the present invention, the aeration unit includes at least one blower and at least one pipe body, the blower is connected to the air duct and transmits gas to the bottom of the emulsified oil separation tank of the emulsified oil separation unit through the pipe body, and the blower is connected to the air duct and transmits gas to the bottom of the reaction tank of the biological reaction unit through the pipe body.

[0013] In one embodiment of the present invention, an overflow pipe is further provided on the top of the emulsified oil separation tank body of the emulsified oil separation unit and connected to the separation tank body of the oil-water separation unit.

[0014] In one embodiment of the present invention, the emulsified wastewater filtration system further includes a backwash tank, which is connected to the emulsified oil separation tank of the emulsified oil separation unit by a pump, and the water output by the emulsified oil separation tank is transmitted to the backwash tank by the pump, and can be guided back to the emulsified oil separation tank by the pump for cleaning.

[0015] These and other components, steps, features, benefits and advantages of the present invention will now become apparent through a review of the following detailed description of illustrative embodiments, the accompanying drawings and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the accompanying drawings, in which:

[0017] Figure 1 It is a schematic diagram of the overall structure of the emulsified wastewater filtration system of the present invention.

[0018] Figure 2 It is a schematic diagram of the graphene hollow membrane tube structure in the graphene-containing emulsified oil filtration membrane module of the present invention.

[0019] Description of Figure Numbers

[0020] 1-oil-water separation unit; 11-separation tank body; 12-raw wastewater input end; 13-wastewater output end; 14-floating oil recovery end; 15-conductor body; 2-emulsified oil separation unit; 21-emulsified oil separation tank body; 22-emulsified oil filtration membrane module containing graphene; 221-graphene hollow membrane tube; 222-nanopore; 3-bioreactor unit; 31-reaction tank body; 32-bioreactor module containing graphene; 4-aeration unit; 41-blower; 42-tube body; P-pump; 5-backwash tank body. DETAILED DESCRIPTION

[0021] Before the present invention is described in detail, it should be noted that in the following description, similar components are represented by the same reference numerals. In addition, the shapes, sizes, thicknesses, angles and other related parameters of the components in the drawings are not drawn according to scale. The simplification is intended only for the convenience of clear description.

[0022] First, see Figure 1 The overall structure diagram of the emulsified wastewater filtration system of the present invention is as follows. The emulsified wastewater filtration system of the present invention comprises an oil-water separation unit 1 , an emulsified oil separation unit 2 and a biological reaction unit 3 .

[0023] The oil-water separation unit 1 has at least one separation tank body 11, at least one raw wastewater input end 12, at least one wastewater output end 13 and at least one floating oil recovery end 14. The oily wastewater enters the separation tank body 11 from the raw wastewater input end 12, and a guide body 15 is provided in the separation tank body 11 to guide the oil to float upward. The oily wastewater is separated in the separation tank body 11 based on the different specific gravities of oil and water. The oil floats and is recovered by the floating oil recovery end 14, and the remaining water containing emulsified oil is discharged from the wastewater output end 13; the emulsified oil separation unit 2 includes at least one emulsified oil separation tank body 21, in which at least one emulsified oil filtration membrane module 22 containing graphene is arranged. The emulsified oil filtration membrane module 22 containing graphene is composed of a plurality of graphene hollow membrane tubes 221. The surface of the graphene hollow membrane tube 221 has a plurality of nanopores 222. The water containing emulsified oil entering the emulsified oil separation tank body 21 through the wastewater output end 13 passes through the emulsified oil filtration membrane module 22 containing graphene and is discharged from the emulsified oil separation tank body 21. The biological reaction unit 3 includes at least one reaction tank body 31, and at least one biological reaction module 32 containing graphene is arranged inside the reaction tank body 31. After receiving the water discharged from the emulsified oil separation tank 21, the water passes through the biological reaction module 32 containing graphene and is discharged from the biological reaction unit 3. Among them, the weight percentage of graphene in the graphene hollow membrane tube 221 is not less than 50%, and the biological reaction module 32 containing graphene includes at least one of a film, a foam, and a hollow membrane tube.

[0024] The emulsified oil filtration membrane module 22 containing graphene is in the shape of a curtain sheet or a cylinder. This embodiment takes the curtain sheet shape as an example. The single curtain sheet structure of the emulsified oil filtration membrane module 22 containing graphene is as follows: Figure 2 shown.

[0025] In this way, in the operation and use of the present invention, the oil-containing wastewater first directly forms a separation state of oil and water layers by virtue of the different specific gravities of oil and water. The oil floating on the surface of the separation tank body 11 can be directly recovered through the floating oil recovery end 14, and the remaining wastewater still containing emulsified oil is led out to the emulsified oil separation tank body 21 of the emulsified oil separation unit 2 through the wastewater output end 13 of the separation tank body 11. After the wastewater containing emulsified oil enters the emulsified oil separation tank body 21 and is relatively static, the aeration unit 4 (including the blower 41 and the pipe body 42) disposed near the bottom of the emulsified oil separation tank body 21 provides appropriate gas to appropriately increase the fluidity of the emulsified oil wastewater, but still mainly at a flow rate that is not too fast, so that the emulsified oil wastewater can increase the contact probability with the emulsified oil filtration membrane module 22 containing graphene by increasing a little fluidity. Therefore, the emulsified oil wastewater will flow through the emulsified oil filtration membrane module containing graphene. After the graphene hollow membrane tube 221 of 22, the emulsified oil wastewater passes through the nanopores 222 on the surface of the graphene hollow membrane tube 221, and the impurities in the emulsified oil wastewater will be filtered out by the nanopores 222. In other words, through the excellent emulsified oil separation effect of the graphene material on the emulsified oil, wastewater with a relatively low content of emulsified oil can be obtained. At the same time, the large number of fine bubbles produced by the aeration unit 4 can also prevent the emulsified oil, impurities, etc. from adhering to the surface of the graphene hollow membrane tube 221, which also has a positive effect on the service life of the emulsified oil filtration membrane module 22 containing graphene. Finally, after the treated emulsified oil wastewater enters the biochemical reaction unit 3, the content of the emulsified oil is reduced again by using the biological reaction module 32 containing graphene, and the biological reaction module 32 containing graphene is further used to reduce the biological oxygen content to meet the discharge standard.

[0026] In order to achieve a more complete filtering effect, in some applications, an overflow pipe (not shown) can be set on the top of the emulsified oil separation tank body and connected to the separation tank body of the oil-water separation unit, so that part of the oily wastewater suspended on the top of the emulsified oil separation tank body can flow back to the separation tank body of the oil-water separation unit for further separation.

[0027] Furthermore, in other applications, the emulsified wastewater filtration system described in the present invention may further include a backwash tank 5, which is connected to the emulsified oil separation tank 21 of the emulsified oil separation unit 2 via a pump P, and the wastewater output by the emulsified oil separation tank 21 is transmitted to the backwash tank 5 via the pump P, and can be guided back from the backwash tank 5 to the emulsified oil separation tank 21 via the pump P for cleaning.

[0028] It must be noted that the above embodiments are only preferred embodiments of the present invention, and those skilled in the art may make other changes within the spirit of the present invention. These changes made according to the spirit of the present invention should be included in the scope of protection claimed by the present invention.

Claims

1. An emulsified wastewater filtration system for filtering oily wastewater, characterized in that: The emulsified wastewater filtration system includes: An oil-water separation unit, comprising at least one separation tank, at least one raw wastewater input end, at least one wastewater output end and at least one floating oil recovery end, wherein the oily wastewater enters the separation tank from the raw wastewater input end, and the oily wastewater is separated in the separation tank based on the different specific gravities of oil and water, the oil floats and is recovered by the floating oil recovery end, and the remaining water containing emulsified oil is discharged from the wastewater output end; An emulsified oil separation unit, comprising at least one emulsified oil separation tank body, and at least one graphene-containing emulsified oil filtration membrane module is arranged inside the emulsified oil filtration membrane module, the graphene-containing emulsified oil filtration membrane module is composed of a plurality of graphene hollow membrane tubes, and the surface of the graphene hollow membrane tube has a plurality of nanopores, and the emulsified oil-containing water entering the emulsified oil separation tank body through the wastewater output end passes through the graphene-containing emulsified oil filtration membrane module and is discharged from the emulsified oil separation tank body; and A bioreactor unit, comprising at least one reaction tank body, and at least one bioreactor module containing graphene is arranged inside the reaction tank body, after receiving the water discharged from the emulsified oil separation tank, the water passes through the bioreactor module containing graphene and is discharged from the bioreactor unit; The weight percentage of graphene in the graphene hollow membrane tube is not less than 50%, and the bioreactor module containing graphene comprises at least one of a film, a foam and a hollow membrane tube.

2. The emulsified wastewater filtration system according to claim 1, characterized in that: The graphene-containing emulsified oil filtration membrane module is in the shape of a curtain sheet.

3. The emulsified wastewater filtration system according to claim 1, characterized in that: The graphene-containing emulsified oil filtration membrane module is cylindrical.

4. The emulsified wastewater filtration system according to claim 1, characterized in that: The emulsified oil separation unit and the biological reaction unit can be selectively provided with an aeration unit, and the aeration unit is provided correspondingly to the emulsified oil filtration membrane module containing graphene in the emulsified oil separation unit, and the aeration unit is provided correspondingly to the biological reaction module containing graphene in the biochemical reaction unit.

5. The emulsified wastewater filtration system according to claim 1, characterized in that: The aeration unit includes at least one blower and at least one pipe body. The blower is connected to the air duct and transmits gas to the bottom of the emulsified oil separation tank of the emulsified oil separation unit through the pipe body. The blower is connected to the air duct and transmits gas to the bottom of the reaction tank of the biological reaction unit through the pipe body.

6. The emulsified wastewater filtration system according to claim 1, characterized in that: An overflow pipe is further arranged on the top of the emulsified oil separation tank body of the emulsified oil separation unit and is connected to the separation tank body of the oil-water separation unit.

7. The emulsified wastewater filtration system according to claim 1, characterized in that: The separation tank of the oil-water separation unit further has at least one guiding body to guide the oil to float upward.

8. The emulsified wastewater filtration system according to claim 1, characterized in that: It further comprises a backwash tank body, which is connected to the emulsified oil separation tank body of the emulsified oil separation unit by a pump. The water outputted by the emulsified oil separation tank body is transmitted to the backwash tank body by the pump, and can be guided back into the emulsified oil separation tank body by the pump for cleaning.

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