Wastewater treatment device

Abstract

The utility model provides a wastewater treatment device which comprises a wastewater feeding pump, an extraction agent feeding pump, an extraction tower, an extraction recovery tower and a backflow loop, and the wastewater feeding pump and the extraction agent feeding pump are connected with the upper middle portion and the lower middle portion of the extraction tower respectively and used for conveying wastewater and an extraction agent to the extraction tower; the extraction tower is used for extracting the wastewater through an extraction agent to generate an extraction phase and a water phase from top to bottom; the extraction recovery tower is connected with the top end of the extraction tower and is used for collecting the extraction phase in the extraction tower and treating the extraction phase to obtain an extraction agent positioned at the top of the tower and residues containing aromatic hydrocarbon oil at the bottom of the tower; the reflux loop is connected with the middle lower part of the extraction tower and the top of the extraction recovery tower and is used for conveying the extraction agent positioned at the top of the extraction recovery tower back to the extraction tower. According to the method, the wastewater treatment cost is reduced, secondary pollutants are not generated in the treatment process, byproducts can be generated, and certain economic benefits are generated.

Description

Technical Field

[0001] This application relates to the field of waste lubricating oil recycling technology, specifically to a wastewater treatment device. Background Technology

[0002] Waste lubricating oil is lubricating oil that has been used in various machines and equipment, and whose physicochemical properties have reached the point where it needs to be replaced due to oxidation, thermal decomposition, and contamination by impurities. During use and collection for recycling, waste lubricating oil becomes contaminated with water, forming emulsions. In the regeneration process of waste lubricating oil, the water needs to be removed by distillation. Due to factors such as the presence of ineffective additives in the lubricating oil, water, ineffective additives, and low-boiling-point aromatics are distilled off together during the dehydration process. This results in the distillate containing a large amount of soluble aromatics and sulfur compounds, with a high COD (chemical oxygen demand) and a foul odor, and a sulfur content exceeding 3000 ppm.

[0003] Conventional water treatment methods, such as SBR, MBR, biological treatment, Fenton oxidation, and high-pressure oxidation, are ineffective in treating distillate water. Currently available treatment methods include incineration and secondary distillation. However, these two methods are not only costly but also generate secondary pollutants. Summary of the Invention

[0004] This application proposes a wastewater treatment device that solves the problems of high wastewater treatment costs and secondary pollutant generation in the prior art. This application can not only reduce wastewater treatment costs and generate secondary pollutants during the treatment process, but also generate by-products, resulting in certain economic benefits.

[0005] This application provides a wastewater treatment device, including: a wastewater feed pump, an extractant feed pump, an extraction tower, an extraction recovery tower, and a reflux loop.

[0006] The wastewater feed pump is connected to the upper middle part of the extraction tower and is used to supply wastewater to the extraction tower; the extractant feed pump is connected to the lower middle part of the extraction tower and is used to supply extractant to the extraction tower; the extraction tower is used to extract the wastewater with the extractant to generate an extract phase and an aqueous phase from top to bottom; the extraction recovery tower is connected to the top of the extraction tower and is used to collect the extract phase in the extraction tower and to process the extract phase to obtain the extractant at the top of the tower and the residue containing aromatic oil at the bottom of the tower; the reflux loop is connected to the lower middle part of the extraction tower and the top of the extraction recovery tower and is used to transport the extractant at the top of the extraction recovery tower back to the extraction tower.

[0007] Specifically, the wastewater treatment device further includes a first intermediate tank, which is connected to the bottom of the extraction tower and is used to collect the aqueous phase in the extraction tower.

[0008] Specifically, a chemical oxygen demand (COD) analyzer is installed in the first intermediate tank, and the COD analyzer is used to detect the COD content of the aqueous phase in the first intermediate tank.

[0009] Specifically, the wastewater treatment device further includes an aqueous phase treatment component, which is used to perform anaerobic treatment on the aqueous phase in the first intermediate tank.

[0010] Specifically, the wastewater treatment device further includes a distillation assembly for distilling the extract phase in the extraction recovery tower.

[0011] Specifically, the wastewater treatment device further includes a second intermediate tank, which is connected to the bottom of the extraction and recovery tower and is used to collect the residue containing aromatic oil at the bottom of the extraction and recovery tower.

[0012] Specifically, the extraction tower and the extraction recovery tower are equipped with regulating pumps, which are used to control the flow rate of the extract phase flowing from the extraction tower to the extraction recovery tower.

[0013] Compared with existing technologies, in this application, wastewater enters the upper part of the extraction tower via a wastewater feed pump, while the extractant enters the lower part via an extractant feed pump. The wastewater and extractant are mixed and extracted by gravity difference, forming an extract phase and an aqueous phase. The aqueous phase is located at the bottom of the extraction tower and can be discharged from the bottom, allowing it to enter a biochemical system for further treatment. The extract phase is located at the top of the extraction tower and is transported to an extraction recovery tower for further processing to obtain aromatic oil. The aromatic oil, a byproduct, can be further sold and applied, generating certain economic benefits. A reflux loop is set up to return the extractant to the extraction tower, allowing the extractant in the extract phase to be recycled again in the extraction tower, reducing wastewater treatment costs. This wastewater treatment device uses extraction to treat wastewater; extraction does not produce secondary pollutants, only a small amount of concentrated residue. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a wastewater treatment device in an embodiment of this application. Detailed Implementation

[0016] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0017] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0019] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0020] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0021] like Figure 1 As shown, this embodiment provides a wastewater treatment device for phase separation treatment of aromatic hydrocarbons and sulfur-containing compounds in wastewater, extracting both aromatic hydrocarbons and sulfur-containing compounds in the wastewater into an extractant, including: a wastewater feed pump 10, an extractant feed pump 11, an extraction tower 12, an extraction recovery tower 13, and a reflux loop 14.

[0022] Wastewater feed pump 10 is connected to the upper middle part of extraction tower 12 and is used to transport wastewater from the top of extraction tower 12 to extraction tower 12.

[0023] The extractant feed pump 11 is connected to the lower middle part of the extraction column 12 and is used to deliver the extractant from the bottom of the extraction column 12 to the extraction column 12.

[0024] Extraction tower 12 is used to extract wastewater using an extractant. The extraction tower 12 is a vertical cylindrical body that provides contact space for the extractant and wastewater. Liquid inlets are provided at the top and bottom of the extraction tower 12 to ensure uniform distribution of the light and heavy phases. In this embodiment, the liquid inlet at the top of the extraction tower 12 is connected to the wastewater feed pump 10, and the liquid inlet at the bottom of the extraction tower 12 is connected to the extractant feed pump 11. The extraction tower 12 is equipped with packing, sieve plates, or rotating discs to increase the contact area between the light and heavy phases and promote mass transfer.

[0025] Extraction recovery tower 13 is connected to the top of extraction tower 12 and is used to collect the extract phase in extraction tower 12. Extraction recovery tower 13 is used to process the collected extract phase to obtain the extractant at the top of the tower and the residue containing aromatic oil at the bottom of the tower.

[0026] The reflux loop 14 is located between the extraction recovery tower 13 and the extraction tower 12, connecting the top of the extraction recovery tower 13 and the middle and lower part of the extraction tower 12. The reflux loop 14 is used to transfer the extractant at the top of the extraction recovery tower 13 back to the extraction tower 12, and the extractant re-enters the extraction tower 12 to extract the wastewater.

[0027] Wastewater feed pump 10 draws wastewater and delivers it into extraction tower 12 through the liquid inlet at the top of the tower. Extractant feed pump 11 draws extractant and delivers it into extraction tower 12 through the liquid inlet at the bottom of the tower. The extractant is propylene glycol methyl ether acetate and n-butanol in a ratio of 1:0.3–0.7. The ratio of extractant to wastewater is 0.2–0.5:1. Wastewater and extractant are mixed and extracted by gravity difference. The extract extracts water-soluble aromatics and sulfur-containing compounds from the wastewater, reducing the COD (chemical oxygen demand) of the aqueous phase. The small amount of extractant remaining in the aqueous phase does not affect it under biochemical treatment. After extraction, an extract phase and an aqueous phase are formed from top to bottom in extraction tower 12. The aqueous phase can be removed for use. Extraction recovery tower 13 is connected to the top of extraction tower 12 and collects the extract phase located at the top of extraction tower 12. The extraction recovery tower 13 further processes the collected extract phase, yielding the extractant at the top and a residue containing aromatic oil at the bottom. The extractant in the extraction recovery tower 13 is then returned to the extraction tower from the top via reflux loop 14, where it is reused for wastewater extraction. The remaining residue in the extraction recovery tower 13 undergoes further processing, such as acid-base neutralization with an alkaline compound, to obtain aromatic oil. The aromatic oil can then be further marketed and used.

[0028] In this embodiment, wastewater enters the upper part of the extraction tower via a wastewater feed pump, while the extractant enters the lower part via an extractant feed pump. The wastewater and extractant are mixed and extracted by gravity difference, forming an extract phase and an aqueous phase. The aqueous phase, located at the bottom of the extraction tower, can be discharged from the bottom and can then enter a biochemical system for further treatment. The extract phase, located at the top of the extraction tower, is transported to an extraction recovery tower for further processing to obtain aromatic oil. The aromatic oil, a byproduct, can be further sold and applied, generating certain economic benefits. A reflux loop is set up to return the extractant to the extraction tower, allowing the extractant in the extract phase to be recycled again, reducing wastewater treatment costs. This wastewater treatment device utilizes extraction to treat wastewater; extraction does not produce secondary pollutants, only a small amount of concentrated residue.

[0029] In one embodiment, the wastewater treatment device further includes a first intermediate tank 15, which is connected to the bottom of the extraction tower 12 and is used to collect the aqueous phase located at the bottom of the extraction tower 12 after extraction. After collecting the aqueous phase in the extraction tower 12, the first intermediate tank 15 can accurately detect the actual condition of the aqueous phase and further process it according to the actual condition. The resulting aqueous phase does not contain soluble aromatic hydrocarbons or sulfur-containing compounds, and has a low COD. After further processing in the first intermediate tank 15, the aqueous phase can be directly subjected to biochemical treatment.

[0030] In one embodiment, a chemical oxygen demand (COD) analyzer is installed in the first intermediate tank 15 to detect the COD content of the aqueous phase in the wastewater intermediate tank 15. The COD analyzer monitors the COD content of the aqueous phase in the first intermediate tank 15 in real time to ensure that the COD of the aqueous phase in the first intermediate tank 15 meets the standards of the next treatment equipment or the next process.

[0031] In one embodiment, the wastewater treatment apparatus further includes an aqueous phase treatment component for anaerobic treatment of the aqueous phase in the first intermediate tank. In one embodiment, when the chemical oxygen demand (COD) analyzer detects that the COD of the aqueous phase in the first intermediate tank 15 is too high, the aqueous phase treatment component performs anaerobic treatment on the aqueous phase, thereby reducing the COD of the aqueous phase to meet the required standard.

[0032] In one embodiment, the wastewater treatment apparatus further includes a distillation assembly for distilling the extract phase in the extraction recovery tower 13. After distillation, the extractant evaporates, concentrates at the top of the extraction recovery tower 13, and returns to the extraction tower 12 through a reflux loop. The extractant is reused, reducing the wastewater treatment cost.

[0033] In one embodiment, the wastewater treatment apparatus further includes a second intermediate tank 16, which is connected to the bottom of the extraction and recovery tower 13. The second intermediate tank 16 is used to collect the residue containing aromatic oil at the bottom of the extraction and recovery tower. In one embodiment, the residue can be treated in the extraction and recovery tower 13 to obtain aromatic oil, or the residue can be further treated in the second intermediate tank 16 to obtain aromatic oil.

[0034] In one embodiment, a regulating pump 17 is installed between the extraction tower 12 and the extraction recovery tower 13. The regulating pump 17 controls the flow rate of the extractant phase from the extraction tower 12 to the extraction recovery tower 13. When the extraction operation in the extraction tower 12 is not completely completed, the regulating pump 17 adjusts the flow rate to 0 to prevent non-extractable phase from entering the extraction recovery tower 13. When the extraction operation in the extraction tower 12 is completely completed, the regulating pump 17 increases the flow rate, allowing the extractant phase from the extraction tower 12 to quickly enter the extraction recovery tower 13. When the residual amount in the extraction tower 12 is small, the regulating pump 17 decreases the flow rate, allowing the extractant phase from the extraction tower 12 to slowly enter the extraction recovery tower 13. The flow rate is gradually decreased by the regulating pump 17 until the flow rate is 0 and all the extractant phase in the extraction tower 12 enters the extraction recovery tower 13. This prevents the aqueous phase from entering the extraction recovery tower 13 or the extractant phase from remaining in the extraction tower 12.

[0035] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A wastewater treatment device, characterized in that, include: Wastewater feed pump, extractant feed pump, extraction tower, extraction recovery tower, and reflux loop. The wastewater feed pump is connected to the upper middle part of the extraction tower and is used to transport wastewater to the extraction tower. The extractant feed pump is connected to the lower middle part of the extraction tower and is used to deliver the extractant to the extraction tower; The extraction tower is used to extract the wastewater with an extractant to generate an extract phase and an aqueous phase from top to bottom; The extraction recovery tower is connected to the top of the extraction tower and is used to collect the extract phase in the extraction tower and to process the extract phase to obtain the extractant at the top of the tower and the residue containing aromatic oil at the bottom of the tower. The reflux loop connects the lower middle part of the extraction tower and the top of the extraction recovery tower, and is used to transport the extractant located at the top of the extraction recovery tower back into the extraction tower.

2. The wastewater treatment device according to claim 1, characterized in that, The wastewater treatment device also includes a first intermediate tank, which is connected to the bottom of the extraction tower and is used to collect the aqueous phase in the extraction tower.

3. The wastewater treatment device according to claim 2, characterized in that, A chemical oxygen demand (COD) analyzer is installed in the first intermediate tank, and the COD analyzer is used to detect the COD content of the aqueous phase in the first intermediate tank.

4. The wastewater treatment device according to claim 2, characterized in that, The wastewater treatment device further includes an aqueous phase treatment component, which is used to perform anaerobic treatment on the aqueous phase in the first intermediate tank.

5. The wastewater treatment device according to claim 1, characterized in that, The wastewater treatment device also includes a distillation assembly, which is used to distill the extract phase in the extraction recovery tower.

6. The wastewater treatment device according to claim 1, characterized in that, The wastewater treatment device also includes a second intermediate tank, which is connected to the bottom of the extraction and recovery tower and is used to collect the residue containing aromatic oil at the bottom of the extraction and recovery tower.

7. The wastewater treatment device according to claim 1, characterized in that, The extraction tower and the extraction recovery tower are equipped with regulating pumps, which are used to control the flow rate of the extract phase from the extraction tower to the extraction recovery tower.

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