A sewage treatment process and apparatus

Abstract

The application relates to the technical field of sewage treatment, in particular to a sewage treatment process and device, in particular to a nucleation granulation-ozone integration type water treatment process and device for synchronously removing metal ions and organic matters in sewage. The sewage treatment device provided by the application can effectively remove the metal ions and the organic matters in the sewage, has high treatment efficiency and stable effect, does not produce chemical sludge, saves the chemical sludge treatment device, has small device area and low cost, and has important significance in the field of sewage treatment.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a wastewater treatment process and apparatus, specifically to an integrated water treatment process and apparatus for the simultaneous removal of metal ions and organic matter from wastewater by nucleation granulation and ozonation. Background Technology

[0002] Chemical precipitation is a commonly used method for removing metal ions from wastewater. It utilizes alkaline agents to react with metal ions to form precipitates, which are then removed through solid-liquid separation. However, conventional solid-liquid separation relies on physical sedimentation, which typically requires long settling times and a large land area, and generates significant amounts of chemical sludge. Furthermore, traditional chemical precipitation has limited effectiveness in removing organic matter from water.

[0003] Therefore, a wastewater treatment process and device are proposed for the efficient removal of metal ions and organic matter from wastewater. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a wastewater treatment process and apparatus, particularly an integrated nuclear crystal granulation-ozonation water treatment process and apparatus for the simultaneous removal of metal ions and organic matter from wastewater. Using the wastewater treatment apparatus provided by this invention, metal ions and organic matter can be effectively removed from wastewater, with high treatment efficiency and stable results. Furthermore, it does not produce chemical sludge, eliminating the need for chemical sludge treatment equipment. The apparatus also has a small footprint and low cost, making it of significant importance in the field of wastewater treatment.

[0005] In a first aspect, the present invention provides a wastewater treatment device, the treatment device comprising a wastewater tank, a seed crystal tank, a first reagent tank, a reaction tank, an ozone generator, a scum collection tank, and a clean water tank;

[0006] The reaction vessel includes an inner cylinder, an outer cylinder, an aeration device, and an exhaust pipe; the exhaust pipe is located below the outer cylinder, the inner cylinder is located inside the outer cylinder, the top of the inner cylinder is an open structure, the bottom of the inner cylinder is connected to the bottom of the outer cylinder, and an aeration device is provided at the bottom of both the inner and outer cylinders.

[0007] The wastewater tank, seed crystal tank, and first reagent tank are respectively connected to the inner cylinder via pipes;

[0008] The ozone generator is connected to the aeration device via a pipe;

[0009] The scum collection box and the clear water box are respectively connected to the outer cylinder through pipes.

[0010] The wastewater treatment device provided by this invention is an integrated water treatment device for nucleogranulation and ozonation. Using this device, wastewater treatment can effectively remove metal ions and organic matter, with high treatment efficiency and stable results. It does not produce chemical sludge, eliminating the need for a separate chemical sludge treatment device. The device also has a small footprint and low cost. Specifically:

[0011] The wastewater treatment device provided by this invention adds seed crystals to the inner cylinder for nucleation and granulation, which promotes the dense growth of precipitates on the surface of the seed crystals to achieve floc densification, thereby efficiently removing metal ions and avoiding the generation of chemical sludge. At the same time, aeration devices are installed at the bottom of both the inner and outer cylinders to introduce ozone. On the one hand, the growth of crystals is regulated by physical action, and on the other hand, the ozone reacts with the first reagent to enhance the removal of organic matter, thereby achieving efficient removal of metal ions and organic matter in wastewater. It can also save the dosage of reagents required for the ozonation process, thus saving costs.

[0012] As a preferred embodiment of the present invention, the inner cylinder and the outer cylinder are coaxially arranged.

[0013] As a preferred embodiment of the present invention, the diameter of the upper end of the inner cylinder is larger than the diameter of the lower end. This arrangement can ensure that the seeds and precipitates inside the inner cylinder are not washed into the outer cylinder.

[0014] As a preferred embodiment of the present invention, the wastewater tank, the seed crystal tank, and the first reagent tank are respectively connected to the bottom of the inner cylinder through pipes. This arrangement ensures that the wastewater can fully contact and react with the seed crystals and the first reagent after entering the bottom of the inner cylinder.

[0015] As a preferred embodiment of the present invention, the scum collection box and the clear water box are respectively connected to the upper side of the outer cylinder via pipes.

[0016] As a preferred embodiment of the present invention, the connection position between the scum collection box and the outer cylinder is higher than the connection position between the clear water tank and the outer cylinder, that is, the position of the scum discharge outlet on the outer cylinder is higher than the position of the water outlet, so as to remove the scum generated during the ozone flotation process and ensure that the effluent and scum are completely separated.

[0017] As a preferred embodiment of the present invention, the processing device further includes a second reagent tank, which is connected to the outer cylinder via a pipe.

[0018] As a preferred embodiment of the present invention, the second reagent tank is connected to the lower side of the outer cylinder via a pipe.

[0019] As a preferred embodiment of the present invention, the second reagent tank contains a second reagent, which is selected from oxidants, coagulants or catalysts, and can work synergistically with ozone to remove organic matter, thereby further improving the removal effect of organic matter.

[0020] As a preferred embodiment of the present invention, the oxidant is selected from any one or more of ozone, hydrogen peroxide, or peracetic acid, and the dosage of the oxidant is 200-2000 mg / L, such as 200 mg / L, 500 mg / L, 1000 mg / L, 1500 mg / L, 2000 mg / L, etc.

[0021] As a preferred embodiment of the present invention, the coagulant is selected from any one or more of aluminum chloride, ferric chloride, polyaluminum chloride, or polyferric chloride, and the dosage of the coagulant is 200-1000 mg / L, such as 200 mg / L, 400 mg / L, 600 mg / L, 800 mg / L, 1000 mg / L, etc.

[0022] As a preferred embodiment of the present invention, the catalyst is selected from any one or more of ceramsite, activated carbon, or activated alumina, and the dosage of the catalyst is 100-500 mg / L, such as 100 mg / L, 200 mg / L, 300 mg / L, 400 mg / L, 500 mg / L, etc.

[0023] As a preferred technical solution of the present invention, the processing device further includes a crystal collection box, which is connected to the bottom of the inner cylinder through a pipe. The crystal collection box is used to periodically collect the grown crystal seeds that have settled at the bottom of the inner cylinder, and new crystal seeds are replenished by the seed box. It is understood that a valve is provided at the bottom of the inner cylinder. When it is necessary to discharge the crystal seeds, the valve is opened, and the valve is closed during the operation of the device.

[0024] As a preferred embodiment of the present invention, the processing device further includes an exhaust gas treatment system, which is connected to the top of the reaction tank via a pipeline.

[0025] As a preferred embodiment of the present invention, the seed box is provided with seed crystals, which include natural minerals and / or synthetic materials.

[0026] The natural minerals include garnet, dolomite, brucite, quartz sand, etc., and the synthetic materials include resin, oxides, metal particles, etc.

[0027] As a preferred embodiment of the present invention, the first reagent box contains a first reagent, which is an alkaline reagent, preferably any one or more of sodium hydroxide, sodium carbonate, or calcium hydroxide.

[0028] Metal ions in wastewater can react with alkaline agents to form precipitates that adhere to the surface of seed crystals. Under the regulation of hydraulics and ozone gas, they form dense crystals that, after growing to a certain size, sink to the bottom of the inner cylinder and are periodically removed, thus achieving the removal of metal ions.

[0029] Secondly, the present invention provides a wastewater treatment process, wherein the wastewater treatment process is carried out using the wastewater treatment device described in the first aspect, and the steps are as follows:

[0030] Wastewater enters the bottom of the inner cylinder of the reaction tank from the wastewater tank. Seeds and the first reagent are added from the seed tank and the first reagent tank, respectively. At the same time, the ozone generator is turned on, and ozone is introduced by the aeration device. Then, the wastewater enters the outer cylinder from the top of the inner cylinder. After staying for a period of time, the scum is discharged into the scum collection tank, and the effluent is discharged into the clear water tank.

[0031] The wastewater treatment process of this invention utilizes the wastewater treatment device described in the first aspect. In the reaction tank, the seed crystals are suspended by hydraulic action. Metal ions in the water react with the first reagent to form insoluble substances, which then precipitate on the surface of the seed crystals. Organic matter is degraded by the action of ozone, thereby achieving efficient removal of metal ions and organic matter from the wastewater. The wastewater treatment effect is highly efficient and stable.

[0032] As a preferred technical solution of the present invention, the treatment process is as follows: wastewater enters the bottom of the inner cylinder of the reaction tank from the wastewater tank, and seed crystals and the first reagent are added from the seed crystal tank and the first reagent tank respectively. At the same time, the ozone generator is turned on and ozone is introduced by the aeration device. Then, the wastewater enters the outer cylinder from the top of the inner cylinder, and the second reagent is added from the second reagent tank. After staying for a period of time, the scum is discharged into the scum collection tank, and the effluent is discharged into the clear water tank.

[0033] As a preferred embodiment of the present invention, the upward flow velocity of the sewage in the inner cylinder is 50-120 m / h, for example, 50 m / h, 80 m / h, 100 m / h, 120 m / h, etc.

[0034] As a preferred embodiment of the present invention, the hydraulic retention time of the wastewater in the outer cylinder is 10-120 min, such as 10 min, 30 min, 60 min, 90 min, 120 min, etc.

[0035] As a preferred embodiment of the present invention, the amount of seed crystals used is 0.1-0.5 mg seed crystals / mg metal ions, that is, the amount of seed crystals used per mg of metal ions is 0.1-0.5 mg, for example 0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, etc.

[0036] As a preferred embodiment of the present invention, the ozone aeration rate is 200-2000 mg / min, such as 200 mg / min, 500 mg / min, 1000 mg / min, 1500 mg / min, 2000 mg / min, etc.

[0037] As a preferred embodiment of the present invention, the dosage of the first agent is 100-1000 mg / L, that is, the dosage of the first agent in each liter of water is 100-1000 mg / L, such as 100 mg / L, 200 mg / L, 400 mg / L, 600 mg / L, 800 mg / L, 1000 mg / L, etc.

[0038] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art:

[0039] The wastewater treatment device provided by this invention can effectively remove metal ions and organic matter from wastewater, with high treatment efficiency and stable results. It does not produce chemical sludge, eliminating the need for chemical sludge treatment equipment. The device has a small footprint and low cost, and is of great significance in the field of wastewater treatment. Attached Figure Description

[0040] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This refers to the wastewater treatment device described in Embodiment 4 of the present invention;

[0043] Among them, 1-sewage tank; 2-seed crystal tank; 3-first reagent tank; 4-reaction vessel; 5-ozone generator; 6-scum collection tank; 7-clean water tank; 8-second reagent tank; 9-crystal collection tank; 10-exhaust gas treatment system;

[0044] 41-Inner cylinder; 42-Outer cylinder; 43-Aeration device; 44-Drain pipe. Detailed Implementation

[0045] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0046] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0047] Example 1

[0048] This embodiment provides a wastewater treatment device and a wastewater treatment process. The wastewater treatment device includes a wastewater tank 1, a seed crystal tank 2, a first reagent tank 3, a reaction tank 4, an ozone generator 5, a scum collection tank 6, a clear water tank 7, a crystal collection tank 9, and an exhaust gas treatment system 10.

[0049] The reaction tank 4 includes an inner cylinder 41, an outer cylinder 42, an aeration device 43, and an exhaust pipe 44. The exhaust pipe 44 is located below the outer cylinder 42 and is used for maintenance of the treatment device. The inner cylinder 41 is located inside the outer cylinder 42 and is coaxially arranged with the outer cylinder 42. The height of the inner cylinder 41 is less than that of the outer cylinder 42. The top of the inner cylinder 41 is an open structure, and the bottom of the inner cylinder 41 is connected to the bottom of the outer cylinder 42. An aeration device 43 is provided at the bottom of both the inner cylinder 41 and the outer cylinder 42.

[0050] The wastewater tank 1, the seed crystal tank 2, and the first reagent tank 3 are respectively connected to the bottom of the inner cylinder 41 via pipes;

[0051] The ozone generator 5 is connected to the aeration device 43 via a pipe;

[0052] The scum collection box 6 and the clear water box 7 are respectively connected to the upper side of the outer cylinder 42 via pipes;

[0053] The crystal collection box 9 is connected to the bottom of the inner cylinder 41 via a pipe;

[0054] The exhaust gas treatment system 10 is connected to the top of the reaction tank 4 via a pipe;

[0055] The seed box 2 contains seed dolomite, and the first reagent box 3 contains sodium carbonate.

[0056] The wastewater treatment process is carried out using the aforementioned wastewater treatment device and specifically includes the following steps:

[0057] Before the wastewater enters the device, seed crystals are introduced into the inner cylinder 41 through the seed crystal box 2. The process stops when the seed crystals reach a certain height. Then, the original wastewater enters the lower part of the inner cylinder 41 through the wastewater box 1. At the same time, the first reagent (sodium carbonate) enters the inner cylinder 41 from the first reagent box 3. The dosage of the first reagent is 1000 mg / L of water. The ozone generator 5 is turned on, and ozone is introduced through the aeration device 43 at a rate of 1000 mg / min. The upward flow velocity of the wastewater in the inner cylinder 41 is controlled at 80 m / h. Metal ions in the water react with the alkaline reagent to form precipitates that adhere to the surface of the seed crystals. Under the regulation of hydraulics and ozone gas, dense crystals are formed. When the wastewater flows to the top of the inner cylinder 41, the flow velocity decreases due to the increased pipe diameter, making it easier for insoluble substances to settle and preventing them from being carried out of the inner cylinder 41 by the water flow. At the same time, due to the effect of ozone, organic matter in the water can be oxidized and modified. Subsequently, wastewater enters the outer cylinder 42 from the top of the inner cylinder 41. The hydraulic residence time of the wastewater in the outer cylinder 42 is controlled to be 60 minutes. Ozone continues to be introduced into the outer cylinder 42 to enhance the oxidation and removal of organic matter. After nucleation granulation and ozonation treatment, metal ions and organic matter in the water are effectively removed. The clean water is discharged from the top of the reaction tank 4 into the clean water tank 7. If scum is generated, it is discharged into the scum collection tank 6. As the crystals in the inner cylinder 41 continue to grow, the grown crystals are periodically discharged into the crystal collection tank 9, and new crystal seeds are replenished by the seed tank 2. The test showed that the calcium ion content in the clean water decreased from 1000 mg / L to 36 mg / L, and the organic matter content decreased from 500 mg COD / L to 37 mg COD / L.

[0058] Example 2

[0059] This embodiment provides a wastewater treatment device and a wastewater treatment process. The wastewater treatment device and process are the same as in Embodiment 1. The difference is that in this embodiment, the upward flow velocity of the wastewater in the inner cylinder 41 is 120 m / h, and the hydraulic retention time of the wastewater in the outer cylinder 42 is 120 min. Testing revealed that the calcium ion content in the purified water decreased from 1000 mg / L to 152 mg / L, and the organic matter content decreased from 500 mg COD / L to 15 mg COD / L.

[0060] Example 3

[0061] This embodiment provides a wastewater treatment device and a wastewater treatment process. The wastewater treatment device and process are the same as in Embodiment 1. The difference is that in this embodiment, the upward flow velocity of the wastewater in the inner cylinder 41 is 50 m / h, and the hydraulic retention time of the wastewater in the outer cylinder 42 is 10 min. Testing revealed that the calcium ion content in the purified water decreased from 1000 mg / L to 22 mg / L, and the organic matter content decreased from 500 mg COD / L to 215 mg COD / L.

[0062] Example 4

[0063] This embodiment provides a wastewater treatment device and a wastewater treatment process. The wastewater treatment device is the same as that in Embodiment 1, except that the wastewater treatment device in this embodiment further includes a second reagent tank 8 containing polyaluminum chloride. The second reagent tank 8 is connected to the outer cylinder 42 via a pipe, as detailed below. Figure 1 As shown.

[0064] The wastewater treatment process is the same as in Example 1, except that in this example, when the wastewater enters the outer cylinder 42 from the top of the inner cylinder 41, polyaluminum chloride is added to the outer cylinder 42 through the second reagent tank 8 at a dosage of 600 mg / L, further enhancing the removal effect of organic matter. Testing revealed that the calcium ion content in the purified water decreased from 1000 mg / L to 12 mg / L, and the organic matter content decreased from 500 mg COD / L to 35 mg COD / L.

[0065] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0066] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wastewater treatment device, characterized in that, The treatment device includes a sewage tank (1), a seed crystal tank (2), a first reagent tank (3), a reaction vessel (4), an ozone generator (5), a scum collection tank (6), and a clean water tank (7). The reaction tank (4) includes an inner cylinder (41), an outer cylinder (42), an aeration device (43), and an exhaust pipe (44); the exhaust pipe (44) is located below the outer cylinder (42), the inner cylinder (41) is located inside the outer cylinder (42), the top of the inner cylinder (41) is an open structure, the bottom of the inner cylinder (41) is connected to the bottom of the outer cylinder (42), and an aeration device (43) is provided at the bottom of both the inner cylinder (41) and the outer cylinder (42). The wastewater tank (1), the seed tank (2) and the first reagent tank (3) are respectively connected to the inner cylinder (41) through pipes; The ozone generator (5) is connected to the aeration device (43) via a pipe; The scum collection box (6) and the clear water box (7) are respectively connected to the outer cylinder (42) through pipes; The seed box (2) is provided with seed crystals, which include natural minerals and / or synthetic materials; The diameter of the upper end of the inner cylinder (41) is larger than the diameter of the lower end; The processing device further includes a second reagent tank (8), which is connected to the outer cylinder (42) via a pipe; the second reagent tank (8) contains a second reagent, which is selected from a coagulant or a catalyst; The first reagent box (3) contains a first reagent, which is selected from any one or more of sodium hydroxide, sodium carbonate or calcium hydroxide.

2. The wastewater treatment device according to claim 1, characterized in that, The inner cylinder (41) and the outer cylinder (42) are coaxially arranged.

3. The wastewater treatment device according to claim 1 or 2, characterized in that, The wastewater tank (1), seed tank (2) and first reagent tank (3) are respectively connected to the bottom of the inner cylinder (41) through pipes.

4. The wastewater treatment device according to claim 1 or 2, characterized in that, The scum collection box (6) and the clear water box (7) are respectively connected to the upper side of the outer cylinder (42) through pipes.

5. The wastewater treatment device according to claim 4, characterized in that, The connection position between the scum collection box (6) and the outer cylinder (42) is higher than the connection position between the clear water tank (7) and the outer cylinder (42).

6. The wastewater treatment apparatus according to claim 1 or 2, characterized in that, The processing device also includes a crystal collection box (9), which is connected to the bottom of the inner cylinder (41) via a pipe.

7. The wastewater treatment apparatus according to claim 1 or 2, characterized in that, The processing device also includes an exhaust gas treatment system (10), which is connected to the top of the reaction vessel (4) via a pipe.

8. A wastewater treatment process, characterized in that, The wastewater treatment process is carried out using the wastewater treatment device according to any one of claims 1-7, and the steps are as follows: Wastewater enters the bottom of the inner cylinder (41) of the reaction tank (4) from the wastewater tank (1). Seeds and the first reagent are added from the seed tank (2) and the first reagent tank (3) respectively. At the same time, the ozone generator (5) is turned on and ozone is introduced by the aeration device (43). Then the wastewater enters the outer cylinder (42) from the top of the inner cylinder (41). After staying for a period of time, the scum is discharged into the scum collection tank (6) and the effluent is discharged into the clear water tank (7).

9. The wastewater treatment process according to claim 8, characterized in that, The upward flow velocity of the wastewater in the inner cylinder (41) is 50-120 m / h; And / or, the hydraulic retention time of the wastewater in the outer cylinder (42) is 10-120 min.

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