A resin column regeneration wastewater recycling system

Abstract

The utility model discloses a resin tower regenerative wastewater recycling system, including alkaline wastewater container and acidic wastewater container, alkaline wastewater container and acidic wastewater container are connected with the regenerative wastewater export of resin tower through first pipeline and second pipeline respectively, and first pipeline and second pipeline are installed with first valve and second valve respectively, still include neutralization treatment container, alkaline wastewater container is connected with neutralization treatment container through third pipeline, and acidic wastewater container is connected with neutralization treatment container through fourth pipeline, and neutralization treatment container is connected with the alkaline outlet pipeline still, and the alkaline outlet pipeline is used for inputting potassium hydroxide solution to neutralization treatment container, and the solution handled in neutralization treatment container is used for resin tower recycling. The utility model discloses through the neutralization of alkaline wastewater and acidic wastewater and access neutralization treatment container, add alkaline solution to neutralization treatment container through the alkaline outlet pipeline simultaneously, has improved the neutralization effect, makes alkaline wastewater and acidic wastewater can all be recycled.

Description

Technical Field

[0001] This utility model relates to the field of chlor-alkali chemical production technology, and in particular to a resin tower regeneration wastewater reuse system. Background Technology

[0002] In the chlor-alkali industry, resin tower regeneration wastewater treatment typically involves reusing alkaline wastewater and discharging acidic wastewater. However, in actual production, a portion of the water consumed after electrolysis in the electrolyzer is recycled through the resin tower regeneration alkaline wastewater. To achieve water balance, additional production water is usually required. Taking our company's 35,000 tons / year potassium hydroxide plant as an example, approximately 35-40 m³ of water needs to be added to the brine system daily. The resin tower is regenerated every two days, producing approximately 61.6 tons of wastewater each time, including 38.5 tons of alkaline recycled water and 23.1 tons of acidic wastewater discharged. During regeneration, hydrochloric acid enters the resin tower and neutralizes with the alkaline wastewater, producing approximately 1.1 tons of potassium chloride. Treating this acidic wastewater requires approximately 0.9 tons of 32% sodium hydroxide for neutralization before discharge. Based on these calculations, treating approximately 4,158 tons of regenerated acidic wastewater annually requires approximately 162 tons of 32% sodium hydroxide, and the associated waste of approximately 200 tons of potassium chloride is wasted. Therefore, we propose a resin tower regeneration wastewater reuse system according to this application.

[0003] A search revealed Chinese patent document CN213202484U, published on May 14, 2021, which discloses a resin tower regeneration wastewater treatment device. The device includes an acidic wastewater tank for receiving acidic wastewater from the resin tower, an alkaline wastewater tank for receiving alkaline wastewater from the resin tower, and a water inlet tank and a circulation pump connected to the alkaline wastewater tank. The circulation pump leads to a salting tank. The acidic and alkaline wastewater tanks are separated by a partition that divides a large reaction tank into left and right sides. The partition has an overflow port at the top, which allows alkaline wastewater to overflow into the acidic wastewater tank for acid-base neutralization. Its advantages are: alkaline wastewater can be recycled to the salt treatment tank via a water inlet tank and a circulating pump, and overflows into the acidic wastewater tank for acid-base neutralization, improving the utilization rate of regenerated water from the resin tower. Acidic wastewater is discharged after neutralization with alkaline wastewater, reducing environmental pollution. Its disadvantages are: firstly, no neutralization treatment tank is set up. In actual application, wastewater in the alkaline wastewater tank can flow from the overflow outlet into the acidic wastewater tank. Similarly, wastewater in the acidic wastewater tank may also flow from the overflow outlet into the alkaline wastewater tank, making it possible for acidic wastewater to be transported to the salt treatment tank pipeline; secondly, relying solely on the neutralization of alkaline and acidic wastewater is insufficient because the concentration of alkaline wastewater is relatively low. Utility Model Content

[0004] The purpose of this invention is to provide a resin tower regeneration wastewater reuse system. By connecting alkaline and acidic wastewater into a neutralization treatment container for neutralization, and simultaneously adding an alkaline solution into the neutralization treatment container through an alkali outlet pipe, the neutralization effect is improved, enabling both alkaline and acidic wastewater to be reused.

[0005] To achieve the above objectives, this utility model provides a resin tower regeneration wastewater reuse system, including an alkaline wastewater container and an acidic wastewater container. The alkaline wastewater container and the acidic wastewater container are respectively connected to the regeneration wastewater outlet of the resin tower through a first pipe and a second pipe. A first valve and a second valve are respectively installed on the first pipe and the second pipe. The system also includes a neutralization treatment container. The alkaline wastewater container is connected to the neutralization treatment container through a third pipe to discharge alkaline wastewater into the neutralization treatment container. The acidic wastewater container is connected to the neutralization treatment container through a fourth pipe to discharge acidic wastewater into the neutralization treatment container. The neutralization treatment container is also connected to an alkali outlet pipe for introducing potassium hydroxide solution into the neutralization treatment container. The treated solution in the neutralization treatment container is reused.

[0006] It also includes an alkaline solution container, and an alkali outlet pipe connecting the alkaline solution container and the neutralization treatment container.

[0007] The alkali outlet pipeline is equipped with a third valve and a first flow meter.

[0008] It also includes a water distribution tank, and the neutralization treatment container is connected to the water distribution tank through a fifth pipe. A sixth pipe for reuse is installed on the water distribution tank, a first circulation pump is installed on the fifth pipe, and a second circulation pump is installed on the sixth pipe.

[0009] The alkaline wastewater container is also equipped with a first circulation pipe, which is connected to a third pipe. A fourth valve is installed on the third pipe at the end near the first circulation pipe, and a fifth valve is installed on the first circulation pipe. A first pH meter is also installed on the first circulation pipe, and a third circulation pump is installed on the third pipe upstream of the first circulation pipe.

[0010] The acidic wastewater container is also equipped with a second circulation pipe, which is connected to a fourth pipe. A sixth valve is installed on the fourth pipe at one end near the second circulation pipe, and a seventh valve is installed on the second circulation pipe. A second pH meter is also installed on the second circulation pipe, and a fourth circulation pump is installed on the fourth pipe upstream of the second circulation pipe.

[0011] The neutralization treatment container is also equipped with a third circulation pipe, which is connected to a fifth pipe. An eighth valve is installed on the fifth pipe at one end near the third circulation pipe. A ninth valve is installed on the third circulation pipe. A third pH meter is also installed on the third circulation pipe. The first circulation pump is located upstream of the third circulation pipe.

[0012] A second flow meter is also installed on the third pipe.

[0013] A third flow meter is also installed on the fourth pipe.

[0014] Compared with the prior art, this utility model has the following technical effects:

[0015] This invention improves the neutralization effect by connecting alkaline and acidic wastewater into a neutralization treatment container for neutralization, and simultaneously adding potassium hydroxide solution into the neutralization treatment container through an alkali outlet pipe, thus enabling the reuse of both alkaline and acidic wastewater. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure label:

[0019] Resin Tower 10;

[0020] Alkaline wastewater container 20, first pipe 21, first valve 22, third pipe 23, fourth valve 24, third circulation pump 25, first circulation pipe 26, fifth valve 27, first pH meter 28, second flow meter 29;

[0021] Acidic wastewater container 30, second pipe 31, second valve 32, fourth pipe 33, sixth valve 34, fourth circulation pump 35, second circulation pipe 36, seventh valve 37, second pH meter 38, third flow meter 39;

[0022] Neutralization treatment container 40, alkali outlet pipe 41, third valve 42, first flow meter 43, fifth pipe 44, eighth valve 45, first circulation pump 46, third circulation pipe 47, ninth valve 48, third pH meter 49;

[0023] Water distribution tank 50, sixth pipeline 51, second circulation pump 52;

[0024] Container 60 for alkaline solutions. Detailed Implementation

[0025] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0026] Example 1:

[0027] See Figure 1 A resin tower regeneration wastewater reuse system includes an alkaline wastewater container 20 and an acidic wastewater container 30. The alkaline wastewater container 20 and the acidic wastewater container 30 are respectively connected to the regeneration wastewater outlet of the resin tower 10 through a first pipe 21 and a second pipe 31. A first valve 22 and a second valve 32 are respectively installed on the first pipe 21 and the second pipe 31. The system also includes a neutralization treatment container 40. The alkaline wastewater container 20 is connected to the neutralization treatment container 40 through a third pipe 23 to discharge alkaline wastewater into the neutralization treatment container 40. The acidic wastewater container 30 is connected to the neutralization treatment container 40 through a fourth pipe 33 to discharge acidic wastewater into the neutralization treatment container 40. The neutralization treatment container 40 is also connected to an alkali outlet pipe 41, which is used to introduce potassium hydroxide solution into the neutralization treatment container 40. The treated solution in the neutralization treatment container 40 is used for primary brine salting and reuse.

[0028] This invention improves the neutralization effect by connecting alkaline and acidic wastewater into a neutralization treatment container 40 for neutralization, and simultaneously adding potassium hydroxide solution into the neutralization treatment container 40 through an alkali outlet pipe 41, thus enabling the reuse of both alkaline and acidic wastewater.

[0029] Furthermore, it also includes an alkaline solution container 60, which is used to hold alkaline solutions.

[0030] Specifically, the alkali outlet pipe 41 is connected to the alkaline solution container 60 and the neutralization treatment container 40.

[0031] In this embodiment, the alkaline solution is a potassium hydroxide solution.

[0032] To facilitate the addition of alkaline solution, a third valve 42 and a first flow meter 43 are installed on the alkali outlet pipe 41. Of course, a water pump can also be installed on the alkali outlet pipe 41.

[0033] Furthermore, it also includes a water mixing tank 50, which is used to hold the neutralized solution.

[0034] Specifically, the neutralization treatment container 40 is connected to the water distribution tank 50 via a fifth pipe 44. A sixth pipe 51 for reuse is installed on the water distribution tank 50. A first circulation pump 46 is installed on the fifth pipe 44, and a second circulation pump 52 is installed on the sixth pipe 51. The first circulation pump 46 pumps the solution in the neutralization treatment container 40 to the water distribution tank 50, and the second circulation pump 52 pumps the solution in the water distribution tank 50 back for reuse.

[0035] To make the alkaline wastewater in the alkaline wastewater container 20 more uniform, a first circulation pipe 26 is also installed on the alkaline wastewater container 20. The first circulation pipe 26 is connected to the third pipe 23. A fourth valve 24 is installed on the third pipe 23 near the end of the first circulation pipe 26. A fifth valve 27 is installed on the first circulation pipe 26. A first pH meter 28 is also installed on the first circulation pipe 26. A third circulation pump 25 is also installed on the third pipe 23 upstream of the first circulation pipe 26.

[0036] Before the alkaline wastewater is pumped to the neutralization treatment container 40, the fourth valve 24 is closed and the fifth valve 27 is opened. The wastewater is then circulated by the third circulation pump 25 to prevent sedimentation in the alkaline wastewater container 20 and to ensure a more uniform alkaline wastewater concentration. Afterwards, the fifth valve 27 is closed and the fourth valve 24 is opened, allowing the alkaline wastewater to be pumped into the neutralization treatment container 40 via the third circulation pump 25. The first pH meter 28 is used to measure the pH value of the alkaline wastewater.

[0037] The acidic wastewater container 30 is also equipped with a second circulation pipe 36, which is connected to the fourth pipe 33. A sixth valve 34 is installed on the fourth pipe 33 at the end near the second circulation pipe 36. A seventh valve 37 is installed on the second circulation pipe 36. A second pH meter 38 is also installed on the second circulation pipe 36. A fourth circulation pump 35 is also installed on the fourth pipe 33 upstream of the second circulation pipe 36.

[0038] Before the acidic wastewater is pumped to the neutralization treatment container 40, the sixth valve 34 is closed and the seventh valve 37 is opened. The wastewater is then circulated using the fourth circulation pump 35 to prevent sedimentation in the acidic wastewater container 30 and to ensure a more uniform flow. Afterwards, the seventh valve 37 is closed and the sixth valve 34 is opened, allowing the acidic wastewater to be pumped into the neutralization treatment container 40 via the fourth circulation pump 35. The second pH meter 38 is used to measure the pH value of the acidic wastewater.

[0039] Similarly, a third circulation pipe 47 is also installed on the neutralization treatment container 40. The third circulation pipe 47 is connected to the fifth pipe 44. An eighth valve 45 is installed on the fifth pipe 44 at one end near the third circulation pipe 47. A ninth valve 48 is installed on the third circulation pipe 47. A third pH meter 49 is also installed on the third circulation pipe 47. The first circulation pump 46 is located upstream of the third circulation pipe 47.

[0040] Before the neutralized solution in the neutralization treatment container 40 is pumped to the distribution tank 50, the eighth valve 45 is closed and the ninth valve 48 is opened. The solution is then circulated by the first circulation pump 46 to improve the mixing effect during neutralization. After the neutralization process is complete, the ninth valve 48 is closed and the eighth valve 45 is opened, allowing the acidic wastewater to be pumped into the neutralization distribution tank 50 via the first circulation pump 46. The third pH meter 49 is used to determine the pH value of the neutralized solution.

[0041] Furthermore, a second flow meter 29 is installed on the third pipe 23, and a third flow meter 39 is installed on the fourth pipe 33, in order to measure the flow rate of the solution in the pipes and to calculate the amount added.

[0042] The method of use or principle of this utility model:

[0043] See Figure 1 When in use, the resin tower 10 is cut off for regeneration. Pure water enters from the top of the resin tower 10, the first valve 22 is opened, the second valve 32 is closed, and the solution enters the alkaline wastewater container 20. The pure water flow rate is 12 m³ / h, the replacement time is 1 hour, and the running time will replace the potassium chloride in the resin tower 10.

[0044] Acid washing begins by simultaneously introducing pure water and 31% hydrochloric acid from the top of the column at a flow rate of 5.51 m³ / h + 1.4 m³ / h. First valve 22 is closed, and second valve 32 is opened. The hydrochloric acid competes with the metal ions adsorbed on the resin for binding sites. According to the law of mass action, the reaction proceeds in the reverse direction, and the metal ions are displaced by H⁺, subsequently being collected in acidic wastewater container 30. Afterward, the hydrochloric acid in the column is completely replaced with pure water, which is then collected in the acidic wastewater tank.

[0045] Throughout the process, during acid washing, the potassium chloride residue in the resin tower 10 contains chlorate, which reacts with hydrochloric acid to generate chlorine gas. This chlorine gas easily causes an odor when it enters the acidic wastewater tank, so the acidic wastewater tank is usually sealed. First, the alkaline wastewater in the alkaline wastewater container 20 is pumped into the neutralization treatment container 40. After pumping, when the pH in the neutralization treatment container 40 becomes strongly alkaline, the fourth circulation pump 35 is started to pump acidic wastewater into the neutralization treatment container 40. The fourth pipe 33 is inserted into the bottom of the neutralization treatment container 40 to prevent chlorine gas from overflowing. At the same time, 30% potassium hydroxide is added according to calculation to adjust the entire wastewater to neutral, and then it is pumped into the distribution tank 50 through the first circulation pump 46.

[0046] Specific calculation formula: The pH was determined by titration in the laboratory. The acid content in the acid washing step was 9.85 Kmol / m³, and the alkali content in the alkaline washing step was 6.91 Kmol / m³. The acid washing flow rate was 1.05 m³ and the alkaline washing flow rate was 1.04 m³.

[0047] Total acid content during pickling: M(H) + =1.05 * 9.85 = 10.34 Kmol.

[0048] Total alkalinity in alkaline washing: M(OH) + =1.04 * 6.91 = 7.19 Kmol.

[0049] M(H + )-M(OH+ =3.15Kmol (remaining acid amount) If adjusted to neutral, then calculate based on adding 30% potassium hydroxide: 3.15Kmol / 6.19Kmol / m³ = 0.46m³.

Claims

1. A resin tower regeneration wastewater reuse system, comprising an alkaline wastewater container (20) and an acidic wastewater container (30), wherein the alkaline wastewater container (20) and the acidic wastewater container (30) are respectively connected to the regeneration wastewater outlet of the resin tower (10) via a first pipe (21) and a second pipe (31), and a first valve (22) and a second valve (32) are respectively installed on the first pipe (21) and the second pipe (31), characterized in that: It also includes a neutralization treatment container (40), an alkaline wastewater container (20) connected to the neutralization treatment container (40) through a third pipe (23) to discharge alkaline wastewater into the neutralization treatment container (40), an acidic wastewater container (30) connected to the neutralization treatment container (40) through a fourth pipe (33) to discharge acidic wastewater into the neutralization treatment container (40), and the neutralization treatment container (40) is also connected to an alkali outlet pipe (41) for inputting potassium hydroxide solution into the neutralization treatment container (40), and the treated solution in the neutralization treatment container (40) is used for reuse.

2. The resin tower regeneration wastewater reuse system according to claim 1, characterized in that: It also includes an alkaline solution container (60) and an alkali outlet pipe (41) connecting the alkaline solution container (60) and the neutralization treatment container (40).

3. A resin tower regeneration wastewater reuse system according to claim 1 or 2, characterized in that: A third valve (42) and a first flow meter (43) are installed on the alkali outlet pipeline (41).

4. The resin tower regeneration wastewater reuse system according to claim 1, characterized in that: It also includes a water distribution tank (50), the neutralization treatment container (40) is connected to the water distribution tank (50) through a fifth pipe (44), a sixth pipe (51) for reuse is installed on the water distribution tank (50), a first circulation pump (46) is installed on the fifth pipe (44), and a second circulation pump (52) is installed on the sixth pipe (51).

5. The resin tower regeneration wastewater reuse system according to claim 1, characterized in that: The alkaline wastewater container (20) is also equipped with a first circulation pipe (26), which is connected to a third pipe (23). A fourth valve (24) is installed on the third pipe (23) at one end near the first circulation pipe (26), and a fifth valve (27) is installed on the first circulation pipe (26). A first pH meter (28) is also installed on the first circulation pipe (26). A third circulation pump (25) is also installed on the third pipe (23) upstream of the first circulation pipe (26).

6. The resin tower regeneration wastewater reuse system according to claim 1, characterized in that: The acidic wastewater container (30) is also equipped with a second circulation pipe (36), which is connected to a fourth pipe (33). A sixth valve (34) is installed on the fourth pipe (33) at one end near the second circulation pipe (36), and a seventh valve (37) is installed on the second circulation pipe (36). A second pH meter (38) is also installed on the second circulation pipe (36). A fourth circulation pump (35) is also installed on the fourth pipe (33) upstream of the second circulation pipe (36).

7. A resin tower regeneration wastewater reuse system according to claim 4, characterized in that: The neutralization treatment container (40) is also equipped with a third circulation pipe (47), which is connected to the fifth pipe (44). An eighth valve (45) is installed on the fifth pipe (44) at one end near the third circulation pipe (47). A ninth valve (48) is installed on the third circulation pipe (47). A third pH meter (49) is also installed on the third circulation pipe (47). The first circulation pump (46) is located upstream of the third circulation pipe (47).

8. A resin tower regeneration wastewater reuse system according to claim 1 or 5, characterized in that: A second flow meter (29) is also installed on the third pipe (23).

9. A resin tower regeneration wastewater reuse system according to claim 1 or 6, characterized in that: A third flow meter (39) is also installed on the fourth pipe (33).

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