Dye intermediate production wastewater treatment device

Abstract

The utility model provides a dye intermediate production wastewater treatment device and relates to the technical field of water treatment. The dye intermediate production wastewater treatment device comprises an adjusting tank, a filtering device, a first-stage reverse osmosis device, a second-stage reverse osmosis device, a third-stage reverse osmosis device, a first oxidation treatment device, a biological aerated filter, a second oxidation treatment device and an MVR evaporative crystallization device. Wherein the regulating tank keeps the water quality of wastewater stable; the filtering device is used for removing suspended matters in the wastewater; the reverse osmosis device is used for carrying out membrane separation treatment on the dye intermediate wastewater to remove most organic matters and reduce the treatment energy consumption of the second oxidation treatment device; the first oxidation treatment device and the biological aerated filter are used for removing small molecular organic matters in reverse osmosis produced water to meet the recycling requirement; the second oxidation treatment device is used for degrading and oxidizing the dye intermediate production wastewater; and the MVR evaporative crystallization device is used for crystallizing and separating out ammonium sulfate in the degraded and oxidized wastewater.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment, in particular to a treatment device for wastewater produced in the production of dye intermediates. Background Art

[0002] Dye intermediates refer to the chemical precursors for the production of organic dyes and are also important chemical raw materials. They are mainly classified into four categories: benzene-based intermediates, toluene-based intermediates, naphthalene-based intermediates, and anthraquinone-based intermediates. Among them, benzene-based, naphthalene-based, and anthraquinone-based dye intermediates cover more than about 95% of the dye intermediate products, and benzene-based and naphthalene-based products account for 50% and 26% respectively. Due to the variety of dyes and dye intermediates and the complex production processes, the components of pollutants in their wastewater are complex, with high concentrations and high biological toxicity, making it difficult to be directly degraded by microorganisms. With the changing demand for dyes and the rapid development of technology, newly developed dye and dye intermediate products will increasingly tend to be more complex and stable in structure, which will further increase the difficulty of treating their production wastewater.

[0003] In view of this, the present utility model is specifically proposed. Content of the Utility Model

[0004] The purpose of the present utility model is to provide a treatment device for wastewater produced in the production of dye intermediates to solve the above-mentioned wastewater treatment problem.

[0005] In order to achieve the above purposes, the following technical solutions are specifically adopted:

[0006] In the first aspect, the present utility model provides a treatment device for wastewater produced in the production of dye intermediates, including: an adjustment tank, a filtration device, a first-stage reverse osmosis device (first-stage RO), a second-stage reverse osmosis device (second-stage RO), a third-stage reverse osmosis device (third-stage RO), a first oxidation treatment device, an aerated biological filter, a second oxidation treatment device, and an MVR evaporation crystallization device;

[0007] The adjustment tank is used for collecting wastewater and homogenizing the wastewater;

[0008] The filtration device is connected to the adjustment tank and is used for removing suspended solids in the wastewater;

[0009] The water inlet tank of the first-stage reverse osmosis device is connected to the water production port of the filtration device, and an acid dosing port is further provided on the water inlet tank of the first-stage reverse osmosis device for adjusting the pH of the wastewater in the water inlet tank to 8.5 - 9.5;

[0010] The water inlet tank of the second-stage reverse osmosis device is connected to the water production port of the first-stage reverse osmosis device, and an acid dosing port is further provided on the water inlet tank of the second-stage reverse osmosis device for adjusting the pH of the wastewater in the water inlet tank to 6 - 7; the concentrated water port of the second-stage reverse osmosis device is connected to the water inlet tank of the first-stage reverse osmosis device;

[0011] The water inlet of the third-stage reverse osmosis device is communicated with the water production outlet of the second-stage reverse osmosis device, and the concentrated water outlet of the third-stage reverse osmosis device is communicated with the water inlet tank of the second-stage reverse osmosis device;

[0012] The first oxidation treatment device is used for oxidizing the wastewater. The water inlet of the first oxidation treatment device is communicated with the water production outlet of the third-stage reverse osmosis device, and the water outlet of the first oxidation treatment device is communicated with the water inlet of the biological aerated filter. The first oxidation treatment device and the biological aerated filter are mainly used to remove COD in the wastewater;

[0013] The water inlet of the second oxidation treatment device is communicated with the concentrated water outlet of the first-stage reverse osmosis device, and is used for degrading and oxidizing the dye intermediate in the concentrated liquid;

[0014] The water inlet of the MVR evaporation crystallization device is communicated with the water outlet of the second oxidation treatment device, and is used for evaporating and crystallizing the concentrated liquid. The condensed water outlet of the MVR evaporation crystallization device is communicated with the water inlet tank of the second-stage reverse osmosis device.

[0015] As a further technical solution, along the wastewater treatment direction, the filtration device includes a sand filtration device and an ultrafiltration device that are sequentially communicated.

[0016] As a further technical solution, the ultrafiltration device is a tubular ultrafiltration device;

[0017] The cut-off molecular weight of the filter membrane of the ultrafiltration device is 10,000 Da.

[0018] As a further technical solution, it further includes a plate and frame filtration device. The water inlet of the plate and frame filtration device is respectively communicated with the sand filtration device and the ultrafiltration device, and is used for filtering the backwash water of the sand filtration device and the ultrafiltration device; the water outlet of the plate and frame filtration device is communicated with the adjustment tank, and is used for returning the filtrate to the adjustment tank.

[0019] As a further technical solution, the recovery rate of the first-stage reverse osmosis device is 70%-80%;

[0020] The recovery rate of the second-stage reverse osmosis device is 80%-85%;

[0021] The recovery rate of the third-stage reverse osmosis device is 90%-95%.

[0022] As a further technical solution, the acid includes sulfuric acid.

[0023] As a further technical solution, the first oxidation treatment device is an ozone oxidation treatment device.

[0024] As a further technical solution, the second oxidation treatment device is a wet catalytic oxidation device.

[0025] As a further technical solution, the catalyst for the oxidation treatment in the wet catalytic oxidation device is a copper salt.

[0026] Compared with the prior art, the present utility model has the following beneficial effects:

[0027] The treatment device for the wastewater from the production of dye intermediates provided by the present utility model collects the wastewater from dye intermediates through an adjustment tank and homogenizes the wastewater, so as to make the water quality of the wastewater discharged from the adjustment tank stable; removes the suspended solids in the wastewater through a filtering device; performs membrane separation treatment on the wastewater from dye intermediates through a reverse osmosis device, thereby reducing the treatment energy consumption of the second oxidation treatment device and achieving the effect of low-carbon environmental protection; removes the small-molecule organic matters in the reverse osmosis product water through the first oxidation treatment device and the biological aerated filter to meet the reuse requirements (COD ≤ 50 ppm); degrades and oxidizes the wastewater from the production of dye intermediates through the second oxidation treatment device, converts the macromolecule organic matters into small-molecule organic matters, and converts the small-molecule organic matters into carbon dioxide and water, thereby improving the utilization rate of the wastewater and reducing the harmfulness of the wastewater from dye intermediates; crystallizes out ammonium sulfate in the wastewater from dye intermediates after degradation and oxidation through an MVR evaporation crystallization device. Description of the Drawings

[0028] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is the treatment device for the wastewater from the production of dye intermediates provided in Embodiment 1 of the present utility model;

[0030] Figure 2 It is the treatment device for the wastewater from the production of dye intermediates provided in Embodiment 2 of the present utility model.

[0031] Icons: 1 - adjustment tank; 2 - filtering device; 21 - sand filtering device; 22 - ultrafiltration device; 3 - first-stage reverse osmosis device; 4 - second oxidation treatment device; 5 - MVR evaporation crystallization device; 6 - second-stage reverse osmosis device; 7 - third-stage reverse osmosis device; 8 - first oxidation treatment device; 9 - biological aerated filter; 10 - plate and frame filtering device. Detailed Embodiments

[0032] The embodiments of the present utility model will be described in detail below in combination with the embodiments and examples. However, those skilled in the art will understand that the following embodiments and examples are only used to illustrate the present utility model and should not be regarded as limiting the scope of the present utility model. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0033] It should be noted that in this solution, the produced water refers to the water with low impurity content after being treated by the treatment device.

[0034] In a first aspect, the present utility model provides a treatment device for dye intermediate production wastewater, including: an adjustment tank 1, a filtration device 2, a first-stage reverse osmosis device 3, a second-stage reverse osmosis device 6, a third-stage reverse osmosis device 7, a first oxidation treatment device 8, an aerated biological filter 9, a second oxidation treatment device 4, and an MVR evaporation crystallization device 5;

[0035] The adjustment tank 1 is used to collect wastewater and perform homogenization treatment on the wastewater;

[0036] The filtration device 2 is connected to the adjustment tank 1 and is used to remove suspended solids in the wastewater;

[0037] The water inlet tank of the first-stage reverse osmosis device 3 is connected to the water production outlet of the filtration device 2, and an acid dosing port is also provided on the water inlet tank of the first-stage reverse osmosis device 3 for adjusting the pH of the wastewater in the water inlet tank to 8.5 - 9.5;

[0038] The water inlet tank of the second-stage reverse osmosis device 6 is connected to the water production outlet of the first-stage reverse osmosis device 3, and an acid dosing port is also provided on the water inlet tank of the second-stage reverse osmosis device 6 for adjusting the pH of the wastewater in the water inlet tank to 6 - 7; the concentrated water outlet of the second-stage reverse osmosis device 6 is connected to the water inlet tank of the first-stage reverse osmosis device 3;

[0039] The water inlet of the third-stage reverse osmosis device 7 is connected to the water production outlet of the second-stage reverse osmosis device 6, and the concentrated water outlet of the third-stage reverse osmosis device 7 is connected to the water inlet tank of the second-stage reverse osmosis device 6;

[0040] The first oxidation treatment device 8 is used to perform oxidation treatment on the wastewater. The water inlet of the first oxidation treatment device 8 is connected to the water production outlet of the third-stage reverse osmosis device 7, and the water outlet of the first oxidation treatment device 8 is connected to the water inlet of the aerated biological filter 9. The first oxidation treatment device 8 and the aerated biological filter 9 are mainly used to remove COD in the wastewater;

[0041] The water inlet of the second oxidation treatment device 4 is connected to the concentrated water outlet of the first-stage reverse osmosis device 3 and is used to perform degradation and oxidation treatment on the dye intermediate in the concentrated liquid;

[0042] The water inlet of the MVR evaporation crystallization device 5 is connected to the water outlet of the second oxidation treatment device 4 and is used for performing evaporation crystallization treatment on the concentrated liquid. The condensed water outlet of the MVR evaporation crystallization device 5 is connected to the water inlet tank of the second-stage reverse osmosis device 6.

[0043] The steps of treating the dye intermediate production wastewater by the treatment device of the present utility model are as follows:

[0044] (1) The wastewater generated is collected by the regulating tank 1 and, after being filtered by the filtering device 2, the particulate suspended matters are removed to meet the water inlet requirements of reverse osmosis; then it enters the reverse osmosis device for treatment. During the reverse osmosis treatment process, most of the organic matters and ammonia nitrogen are retained in the concentrated liquid by the membrane, while some small molecular organic matters pass through the reverse osmosis membrane and exist in the reverse osmosis product water. The reverse osmosis device includes a three-stage reverse osmosis device. The product water of the first-stage reverse osmosis device 3 serves as the water inlet of the second-stage reverse osmosis device 6, the product water of the second-stage reverse osmosis device 6 serves as the water inlet of the third-stage reverse osmosis device 7, the concentrated liquid of the second-stage reverse osmosis device 6 is returned to the water inlet tank of the first-stage reverse osmosis device 3, and the concentrated liquid of the third-stage reverse osmosis device 7 is returned to the water inlet tank of the second-stage reverse osmosis device 6.

[0045] (2) After the dye intermediate wastewater is treated by reverse osmosis, the reverse osmosis product water still contains organic matters with relatively small molecular weights. These organic matters are removed by the first oxidation treatment device 8 and the biological aerated filter 9 to meet the reuse requirements (COD ≤ 50 ppm).

[0046] (3) The concentrated liquid of the first-stage reverse osmosis device 3 enters the second oxidation treatment device 4. The second oxidation treatment device 4 performs degradation and oxidation treatment on the dye intermediate production wastewater, converting macromolecular organic matters into small molecular organic matters, and the small molecular organic matters into carbon dioxide and water;

[0047] (4) After the concentrated liquid removes most of the organic matters through the second oxidation treatment device 4, the effluent enters the MVR evaporation crystallization device 5, crystallizes into salts and is transported out, and the condensed water enters the water inlet tank of the second-stage reverse osmosis device for treatment.

[0048] In some alternative embodiments, along the wastewater treatment direction, the filtering device 2 includes a sand filtering device 21 and an ultrafiltration device 22 that are connected in sequence.

[0049] Among them, the sand filtering device 21 is used to remove large particulate suspended matters in the wastewater, and the ultrafiltration device 22 is used to remove small particulate suspended matters in the wastewater.

[0050] In some alternative embodiments, the ultrafiltration device 22 is a tubular ultrafiltration device;

[0051] The cut-off molecular weight of the filter membrane of the ultrafiltration device 22 is 10,000 Da.

[0052] In some alternative embodiments, a plate-and-frame filter device 10 is further included. The water inlets of the plate-and-frame filter device 10 are respectively communicated with the sand filter device 21 and the ultrafiltration device 22, and are used for filtering and treating the backwash water of the sand filter device 21 and the ultrafiltration device 22; the water outlet of the plate-and-frame filter device 10 is communicated with the regulation tank 1 and is used for returning the filtrate to the regulation tank 1.

[0053] In some alternative embodiments, the material of the reverse osmosis membrane is polyamide.

[0054] In some alternative embodiments, the operating pressure of the first-stage reverse osmosis device 3 is 40 - 50 bar, the temperature is 15 - 40 °C, and the recovery rate is 70% - 80%;

[0055] The operating pressure of the second-stage reverse osmosis device 6 is 15 - 20 bar, the temperature is 15 - 40 °C, and the recovery rate is 80% - 85%;

[0056] The operating pressure of the third-stage reverse osmosis device 7 is 5 - 10 bar, the temperature is 15 - 40 °C, and the recovery rate is 90% - 95%.

[0057] In some alternative embodiments, the acid includes sulfuric acid. Through research by the inventor, it is found that adjusting the pH of the wastewater to 8.5 - 9.5 with sulfuric acid helps to remove COD during the first reverse osmosis process. Adjusting the pH of the wastewater to 6 - 7 with sulfuric acid helps to remove ammonia nitrogen during the second reverse osmosis process. And the salt in the wastewater is mainly ammonium sulfate. Therefore, it is preferred to use sulfuric acid to adjust the pH of the wastewater to avoid the introduction of other impurity ions.

[0058] In some alternative embodiments, the first oxidation treatment device 8 is an ozone oxidation treatment device.

[0059] In some alternative embodiments, the second oxidation treatment device 4 is a wet catalytic oxidation device.

[0060] In some alternative embodiments, the catalyst for the oxidation treatment in the wet catalytic oxidation device is a copper salt, and preferably, a copper salt catalyst of one ten-thousandth of the water inflow of the wet catalytic oxidation device is added.

[0061] In some alternative embodiments, the air pressure for catalytic degradation in the wet catalytic oxidation device is 5 Mpa - 8 Mpa, the degradation temperature is 160 °C - 200 °C, and the degradation time is 6 - 10 hours.

[0062] The present utility model will be further described below through specific embodiments. However, it should be understood that these embodiments are only used for more detailed description and should not be construed as limiting the present utility model in any form.

[0063] Example 1

[0064] A treatment device for wastewater produced in the production of dye intermediates, as Figure 1 shown, comprising: a regulating tank 1, a filtering device 2, a first-stage reverse osmosis device 3, a second-stage reverse osmosis device 6, a third-stage reverse osmosis device 7, a first oxidation treatment device 8, a biological aerated filter 9, a second oxidation treatment device 4, and an MVR evaporation crystallization device 5;

[0065] The regulating tank 1 is used for collecting wastewater and homogenizing the wastewater;

[0066] The filtering device 2 includes a sand filtering device 21 and an ultrafiltration device 22 which are connected in sequence; the sand filtering device 21 is connected to the regulating tank 1 and is used for removing large-particle suspended matters in the wastewater; the ultrafiltration device 22 is a tubular ultrafiltration device, and the cut-off molecular weight of its filter membrane is 10,000 Da, which is used for removing small-particle suspended matters in the wastewater.

[0067] The water inlet tank of the first-stage reverse osmosis device 3 is connected to the water production port of the filtering device 2, and a sulfuric acid dosing port is further arranged on the water inlet tank of the first-stage reverse osmosis device 3 for adjusting the pH of the wastewater in the water inlet tank to 8.5 - 9.5;

[0068] The water inlet tank of the second-stage reverse osmosis device 6 is connected to the water production port of the first-stage reverse osmosis device 3, and a sulfuric acid dosing port is further arranged on the water inlet tank of the second-stage reverse osmosis device 6 for adjusting the pH of the wastewater in the water inlet tank to 6 - 7; the concentrated water port of the second-stage reverse osmosis device 6 is connected to the water inlet tank of the first-stage reverse osmosis device 3;

[0069] The water inlet of the third-stage reverse osmosis device 7 is connected to the water production port of the second-stage reverse osmosis device 6, and the concentrated water port of the third-stage reverse osmosis device 7 is connected to the water inlet tank of the second-stage reverse osmosis device 6;

[0070] The first oxidation treatment device 8 is an ozone oxidation treatment device for oxidizing the wastewater. The water inlet of the first oxidation treatment device 8 is connected to the water production port of the third-stage reverse osmosis device 7, and the water outlet of the first oxidation treatment device 8 is connected to the water inlet of the biological aerated filter 9. The first oxidation treatment device 8 and the biological aerated filter 9 are mainly used for removing COD in the wastewater;

[0071] The second oxidation treatment device 4 is a wet catalytic oxidation device which uses copper salt as a catalyst. Its water inlet is connected to the concentrated water port of the first-stage reverse osmosis device 3 and is used for degrading and oxidizing the dye intermediate in the concentrated liquid;

[0072] The water inlet of the MVR evaporation crystallization device 5 is communicated with the water outlet of the second oxidation treatment device 4 for performing evaporation crystallization treatment on the concentrated liquid. The condensed water outlet of the MVR evaporation crystallization device 5 is communicated with the water inlet tank of the second-stage reverse osmosis device 6 for flowing the condensed water to the water inlet tank of the second-stage reverse osmosis device 6.

[0073] The steps for the treatment device of the present utility model to treat the wastewater from dye intermediate production are as follows:

[0074] 1. The wastewater generated is collected in the regulating tank 1 and, after being sequentially treated by the sand filtration device 21 and the ultrafiltration device 22, flows to the water inlet tank of the first-stage reverse osmosis device 3. Sulfuric acid is added to adjust the pH to 8.5 - 9.5, and then the first reverse osmosis treatment is carried out. The treated wastewater flows out from the water production outlet of the first-stage reverse osmosis device 3, and then flows to the water inlet tank of the second-stage reverse osmosis device 6. Sulfuric acid is added to adjust the pH to 6 - 7, and then the second reverse osmosis treatment is carried out. The concentrated water after treatment flows back to the water inlet tank of the first-stage reverse osmosis device 3, and the produced water flows out from the water production outlet of the second-stage reverse osmosis device 6. Then it flows to the third-stage reverse osmosis device 7 for the third reverse osmosis treatment. The concentrated water after treatment flows back to the water inlet tank of the second-stage reverse osmosis device 6, and the produced water flows out from the water production outlet of the third-stage reverse osmosis device 7. Then it successively passes through the first oxidation treatment device 8 and the biological aerated filter 9 to meet the reuse requirements (COD ≤ 50 ppm).

[0075] Among them, the operating pressure of the first-stage reverse osmosis device 3 is 48 bar, the temperature is 25 °C, and the recovery rate is 75%; the operating pressure of the second-stage reverse osmosis device 6 is 17 bar, the temperature is 25 °C, and the recovery rate is 85%; the operating pressure of the third-stage reverse osmosis device 7 is 6 bar, the temperature is 25 °C, and the recovery rate is 90%.

[0076] 2. The concentrated water after the first reverse osmosis treatment flows from the concentrated water outlet of the first-stage reverse osmosis device 3 to the second oxidation treatment device 4. The second oxidation treatment device 4 conducts degradation and oxidation treatment on the wastewater from dye intermediate production, converting macromolecular organic substances into small-molecular organic substances, and the small-molecular organic substances into carbon dioxide and water. Then it enters the MVR evaporation crystallization device 5 for evaporation crystallization treatment. The crystallized salt is transported out, and the condensed water enters the water inlet tank of the second-stage reverse osmosis device 6.

[0077] Among them, the air pressure for catalytic degradation in the wet catalytic oxidation device is 5 Mpa - 8 Mpa, the degradation temperature is 160 °C - 200 °C, and the degradation time is 6 - 10 hours.

[0078] Example 2

[0079] A treatment device for wastewater from dye intermediate production, such as Figure 2As shown in the figure, it includes: an adjustment tank 1, a filtration device 2, a first-stage reverse osmosis device 3, a second-stage reverse osmosis device 6, a third-stage reverse osmosis device 7, a first oxidation treatment device 8, an aerated biological filter 9, a second oxidation treatment device 4, an MVR evaporation crystallization device 5, and a plate-and-frame filtration device 10;

[0080] The adjustment tank 1 is used to collect wastewater and homogenize the wastewater;

[0081] The filtration device 2 includes a sand filtration device 21 and an ultrafiltration device 22 connected in sequence; the sand filtration device 21 is connected to the adjustment tank 1 and is used to remove large particulate suspensions in the wastewater; the ultrafiltration device 22 is a tubular ultrafiltration device, and the cut-off molecular weight of its filter membrane is 10,000 Da, which is used to remove small particulate suspensions in the wastewater.

[0082] The water inlet tank of the first-stage reverse osmosis device 3 is connected to the water production outlet of the filtration device 2. A sulfuric acid dosing port is also provided in the water inlet tank of the first-stage reverse osmosis device 3 to adjust the pH of the wastewater in the water inlet tank to 8.5 - 9.5;

[0083] The water inlet tank of the second-stage reverse osmosis device 6 is connected to the water production outlet of the first-stage reverse osmosis device 3. A sulfuric acid dosing port is also provided in the water inlet tank of the second-stage reverse osmosis device 6 to adjust the pH of the wastewater in the water inlet tank to 6 - 7; the concentrated water outlet of the second-stage reverse osmosis device 6 is connected to the water inlet tank of the first-stage reverse osmosis device 3;

[0084] The water inlet of the third-stage reverse osmosis device 7 is connected to the water production outlet of the second-stage reverse osmosis device 6, and the concentrated water outlet of the third-stage reverse osmosis device 7 is connected to the water inlet tank of the second-stage reverse osmosis device 6;

[0085] The first oxidation treatment device 8 is an ozone oxidation treatment device used to oxidize the wastewater. The water inlet of the first oxidation treatment device 8 is connected to the water production outlet of the third-stage reverse osmosis device 7, and the water outlet of the first oxidation treatment device 8 is connected to the water inlet of the aerated biological filter 9. The first oxidation treatment device 8 and the aerated biological filter 9 are mainly used to remove COD in the wastewater;

[0086] The second oxidation treatment device 4 is a wet catalytic oxidation device. This device uses copper salt as a catalyst, and its water inlet is connected to the concentrated water outlet of the first-stage reverse osmosis device 3, and is used to degrade and oxidize the dye intermediate in the concentrated liquid;

[0087] The water inlet of the MVR evaporation crystallization device 5 is connected to the water outlet of the second oxidation treatment device 4 and is used to perform evaporation crystallization treatment on the concentrated liquid. The condensed water outlet of the MVR evaporation crystallization device 5 is connected to the water inlet tank of the second-stage reverse osmosis device 6 to flow the condensed water to the water inlet tank of the second-stage reverse osmosis device 6.

[0088] The water inlets of the plate and frame filtering device 10 are respectively communicated with the sand filtering device 21 and the ultrafiltration device 22, and are used for filtering the backwash water of the sand filtering device 21 and the ultrafiltration device 22; the water outlet of the plate and frame filtering device 10 is communicated with the regulating tank 1, and is used for returning the filtrate to the regulating tank 1.

[0089] The steps of treating the dye intermediate production wastewater by the treatment device of the utility model are as follows:

[0090] 1. The wastewater generated is collected in the regulating tank 1, and after being treated by the sand filtering device 21 and the ultrafiltration device 22 in sequence, it flows to the water inlet tank of the first-stage reverse osmosis device 3. Sulfuric acid is added to adjust the pH to 8.5 - 9.5, and then the first reverse osmosis treatment is carried out. The treated wastewater flows out from the water production outlet of the first-stage reverse osmosis device 3, and then flows to the water inlet tank of the second-stage reverse osmosis device 6. Sulfuric acid is added to adjust the pH to 6 - 7, and then the second reverse osmosis treatment is carried out. The concentrated water after treatment is returned to the water inlet tank of the first-stage reverse osmosis device 3, and the produced water flows out from the water production outlet of the second-stage reverse osmosis device 6, and then flows to the third-stage reverse osmosis device 7 for the third reverse osmosis treatment. The concentrated water after treatment is returned to the water inlet tank of the second-stage reverse osmosis device 6, and the produced water flows out from the water production outlet of the third-stage reverse osmosis device 7, and then passes through the first oxidation treatment device 8 and the biological aerated filter 9 in sequence to meet the reuse requirements (COD ≤ 50 ppm).

[0091] Among them, the operating pressure of the first-stage reverse osmosis device 3 is 44 bar, the temperature is 27 °C, and the recovery rate is 70%; the operating pressure of the second-stage reverse osmosis device 6 is 20 bar, the temperature is 30 °C, and the recovery rate is 80%; the operating pressure of the third-stage reverse osmosis device 7 is 7 bar, the temperature is 28 °C, and the recovery rate is 92%.

[0092] 2. The concentrated water after the first reverse osmosis treatment flows from the concentrated water outlet of the first-stage reverse osmosis device 3 to the second oxidation treatment device 4. The second oxidation treatment device 4 carries out degradation and oxidation treatment on the dye intermediate production wastewater, converting macromolecular organic substances into small molecular organic substances, and the small molecular organic substances into carbon dioxide and water; then it enters the MVR evaporation crystallization device 5 for evaporation crystallization treatment. The crystallized salt is transported out, and the condensed water enters the water inlet tank of the second-stage reverse osmosis device 6.

[0093] Among them, the air pressure for catalytic degradation of the wet catalytic oxidation device is 5 Mpa - 8 Mpa, the degradation temperature is 160 °C - 200 °C, and the degradation time is 6 - 10 hours.

[0094] 3. The backwash water of the sand filtering device 21 and the ultrafiltration device 22 flows to the plate and frame filtering device 10 for plate and frame filtration. The filtered water is returned to the regulating tank 1, and the filter cake is transported out.

[0095] The treatment device provided in Embodiment 2 was used to treat the wastewater from dye intermediate production. The water quality of the influent and effluent of the three reverse osmosis devices was recorded respectively. The results are shown in Table 1. It can be seen from the table that the device has achieved good treatment of the wastewater from dye intermediate production.

[0096] Table 1

[0097]

[0098] In addition, in order to prove the effect of adjusting the pH of the influent of the first-stage reverse osmosis device, a comparative example without pH adjustment was set for the influent of the first-stage reverse osmosis device. The difference between this comparative example and Embodiment 2 is only that the pH of the influent of the first-stage reverse osmosis device is not adjusted. The detection results of the influent water production of the first-stage reverse osmosis device in the comparative example are shown in Table 2. It can be seen that the removal rate of COD by the first-stage reverse osmosis device in Embodiment 2 is 96%, while the removal rate of COD by the first-stage reverse osmosis device in the comparative example is 92%, which is much lower than that in Embodiment 2. It can be seen that adjusting the pH of the influent of the first-stage reverse osmosis device to 9 can further improve the removal effect of COD.

[0099] Table 2

[0100]

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A treatment device for wastewater from the production of a dye intermediate, characterized in that, Including: A regulating tank (1), a filtering device (2), a first-stage reverse osmosis device (3), a second-stage reverse osmosis device (6), a third-stage reverse osmosis device (7), a first oxidation treatment device (8), an aerated biological filter (9), a second oxidation treatment device (4), and an MVR evaporation crystallization device (5); The regulating tank (1) is used for collecting wastewater and homogenizing the wastewater; The filtering device (2) is connected to the regulating tank (1) and is used for removing suspended solids in the wastewater; The water inlet tank of the first-stage reverse osmosis device (3) is connected to the water outlet of the filtering device (2), and an acid dosing port is also provided on the water inlet tank of the first-stage reverse osmosis device (3) for adjusting the pH of the wastewater in the water inlet tank to 8.5 - 9.5; The water inlet tank of the second-stage reverse osmosis device (6) is connected to the water outlet of the first-stage reverse osmosis device (3), and an acid dosing port is also provided on the water inlet tank of the second-stage reverse osmosis device (6) for adjusting the pH of the wastewater in the water inlet tank to 6 - 7; the concentrated water outlet of the second-stage reverse osmosis device (6) is connected to the water inlet tank of the first-stage reverse osmosis device (3); The water inlet of the third-stage reverse osmosis device (7) is connected to the water outlet of the second-stage reverse osmosis device (6), and the concentrated water outlet of the third-stage reverse osmosis device (7) is connected to the water inlet tank of the second-stage reverse osmosis device (6); The first oxidation treatment device (8) is used for oxidizing the wastewater. The water inlet of the first oxidation treatment device (8) is connected to the water outlet of the third-stage reverse osmosis device (7), and the water outlet of the first oxidation treatment device (8) is connected to the water inlet of the aerated biological filter (9). The first oxidation treatment device (8) and the aerated biological filter (9) are mainly used for removing COD in the wastewater; The water inlet of the second oxidation treatment device (4) is connected to the concentrated water outlet of the first-stage reverse osmosis device (3) and is used for degrading and oxidizing the dye intermediate in the concentrated liquid; The water inlet of the MVR evaporation crystallization device (5) is connected to the water outlet of the second oxidation treatment device (4) and is used for evaporating and crystallizing the concentrated liquid. The condensed water outlet of the MVR evaporation crystallization device (5) is connected to the water inlet tank of the second-stage reverse osmosis device (6).

2. The processing device according to claim 1, wherein Along the wastewater treatment direction, the filtering device (2) includes a sand filtering device (21) and an ultrafiltration device (22) connected in sequence.

3. The processing device according to claim 2, characterized in that, The ultrafiltration device (22) is a tubular ultrafiltration device; The cut-off molecular weight of the filter membrane of the ultrafiltration device (22) is 10,000 Da.

4. The processing device according to claim 2 or 3, characterized in that It further includes a plate and frame filtering device (10). The water inlet of the plate and frame filtering device (10) is respectively connected to the sand filtering device (21) and the ultrafiltration device (22) and is used for filtering the backwash water of the sand filtering device (21) and the ultrafiltration device (22); the water outlet of the plate and frame filtering device (10) is connected to the regulating tank (1) for returning the filtrate to the regulating tank (1).

5. The processing device according to claim 1, characterized in that The recovery rate of the first-stage reverse osmosis device (3) is 70% - 80%; The recovery rate of the second-stage reverse osmosis device (6) is 80% - 85%; The recovery rate of the third-stage reverse osmosis device (7) is 90% - 95%.

6. The processing device according to claim 1, characterized in that, The acid includes sulfuric acid.

7. The processing device according to claim 1, characterized in that, The first oxidation treatment device (8) is an ozone oxidation treatment device.

8. The processing device according to claim 1, characterized in that The second oxidation treatment device (4) is a wet catalytic oxidation device.

9. The processing device according to claim 8, wherein The catalyst for the oxidation treatment in the wet catalytic oxidation device is a copper salt.

Images