Apparatus and method for synergistically treating sulfite and acid gases in wastewater

Abstract

The application discloses a device and method for cooperatively treating sulfite and acid gas in wastewater, and belongs to the field of wastewater treatment. The application treats the sulfite by combining air with micro-nano bubble aeration technology, reduces COD in the wastewater, and reduces the load of a subsequent system. Meanwhile, the acid gas in the wastewater is discharged through heating and deacidification treatment, so that the corrosion to subsequent pipeline equipment is reduced, new pollutants are not generated, and clean and efficient treatment is realized.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment, and more specifically, relates to an apparatus and method for the synergistic treatment of sulfites and acidic gases in wastewater. Background Technology

[0002] With rapid global economic development and increasing fossil fuel consumption, SO2 emissions from industrial production are constantly rising, leading to a series of environmental problems such as acid rain. Statistics show that over 200 SO2 control methods exist, with most employing post-combustion flue gas desulfurization (FGD) processes. Currently, wet limestone / gypsum FGD is the mainstream FGD process. In wet FGD systems, alkaline substances meet with flue gas in a spray tower. Sulfur dioxide in the flue gas dissolves in water, forming a dilute acid solution, which then neutralizes the alkaline substances dissolved in the water. The resulting sulfites and sulfates precipitate from the aqueous solution. The precipitation depends on the relative solubility of the different salts in the solution, but it is certain that some sulfites and sulfates will dissolve in the water, increasing the COD concentration. Simultaneously, the wet FGD reaction produces a certain amount of acidic gases, mainly carbon dioxide and a small amount of unreacted sulfur dioxide. These acidic gases corrode subsequent treatment equipment and pipelines, reducing their service life and increasing maintenance costs.

[0003] Resin technology is now widely used in the treatment of petrochemical wastewater. Resin performance is a major factor affecting wastewater treatment. However, based on practical engineering experience and results from pilot-scale experiments, a high COD concentration in wastewater can negatively impact the resin, leading to a decline in its performance after desorption. COD competes with resin adsorption; therefore, reducing the COD concentration can effectively maintain the performance of the resin desorption system. Summary of the Invention

[0004] 1. The problem to be solved

[0005] To address the issue that sulfites generated during existing desulfurization processes significantly increase the COD of wastewater, affecting the normal operation of subsequent processes such as resin adsorption, this invention provides a device and method for the synergistic treatment of sulfites and acidic gases in wastewater. This invention combines air and micro / nano bubble aeration technology to treat sulfites, reducing COD in the wastewater and lowering the load on subsequent systems. Simultaneously, through heating and deacidification, acidic gases are discharged from the wastewater, reducing corrosion of downstream pipelines and equipment while preventing the generation of new pollutants, achieving clean and efficient treatment.

[0006] 2. Technical Solution

[0007] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0008] The present invention discloses an apparatus for synergistic treatment of sulfites and acidic gases in wastewater, comprising a tower body, wherein an inlet is provided at the upper part of the tower body, an outlet is provided at the lower part of the tower body, and an aeration unit and a deacidification unit are provided inside the tower body.

[0009] The aeration unit includes an air inlet, an aeration main pipe, and an aeration branch pipe. The air inlet is located between the water inlet and the water outlet. The aeration main pipe is connected to the air inlet, and the aeration branch pipe is connected to the aeration main pipe. It is used to aerate the wastewater with micro-nano bubbles.

[0010] The deacidification unit includes heating pipes, trays, packing layer and air outlet, and is used to heat and deacidify wastewater. The heating pipes are located at the bottom of the tower body, the trays are staggered in the upper part of the tower body, the packing layer is located at the top of the tower body, and the air outlet is located at the top of the tower body. The packing layer and the air outlet are connected.

[0011] Preferably, the number of trays is 5 to 15, and the spacing between the trays is 50 to 150 cm.

[0012] Preferably, one end of the tray is fixed to the inner wall of the tower body, and the other end of the tray does not contact the inner wall of the tower body. A baffle is provided at the end of the tray that does not contact the inner wall of the tower body.

[0013] Preferably, the height of the packing layer is 20-100cm, and the packing structure is one or more of the following: rectangular, circular, and triangular.

[0014] Preferably, the filler is made of 304, 316, PP, or ABS material.

[0015] Preferably, a foam destroyer is provided on the air outlet.

[0016] Preferably, a cleaning water inlet is provided at the top of the tower body for cleaning the interior of the tower body.

[0017] Preferably, a temperature gauge and a pressure gauge are provided at the top of the tower body.

[0018] Preferably, the aeration unit further includes a blower and a pressure regulating valve located outside the tower body. The air inlet is connected to the blower through a pipe, and a pressure regulating valve is installed on the pipe connecting the air inlet and the blower.

[0019] More preferably, the apparatus for synergistic treatment of sulfites and acidic gases in wastewater according to the present invention further includes an online monitoring unit and a condensate recovery unit. The online monitoring unit includes a temperature probe and a control system. The temperature probe is located inside the tower body and is connected to the control system. The condensate recovery unit is located outside the tower body and is connected to the gas outlet.

[0020] Preferably, when the apparatus for co-treating sulfites and acidic gases in wastewater according to the present invention is located in a northern region with low winter temperatures, it should also include a heat preservation device, which is located around the tower body and the pipeline.

[0021] Preferably, the online monitoring unit further includes a DO probe for detecting dissolved oxygen in the wastewater.

[0022] The present invention discloses a method for synergistically treating sulfites and acidic gases in wastewater, comprising: wastewater entering the tower body through the inlet, flowing through the tray to the aeration unit, opening the air inlet to aerate the wastewater with micro-nano bubbles, simultaneously opening the heated return water inlet to heat the wastewater through the heating pipe, using the deacidification unit to deacidify, synergistically removing sulfites and acidic gases from the wastewater, the acidic gases being discharged from the air outlet at the top of the tower body, and the treated wastewater being discharged from the outlet.

[0023] Preferably, the treatment time for simultaneously aerating the wastewater with micro-nano bubbles and heating to remove acid is 30–90 min.

[0024] Preferably, the diameter of the air micro-nano bubble aeration is 10 nm to 10 μm, and the heating temperature is 80 °C to 140 °C.

[0025] 3. Beneficial effects

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) The present invention provides a device for synergistic treatment of sulfites and acidic gases in wastewater. By setting up an aeration unit and a deacidification unit, the device combines aeration and desalination with deacidification. It adopts air micro-nano bubble aeration technology, which utilizes the synergistic effect of micro-nano bubbles and air to efficiently treat wastewater and reduce COD in the wastewater. At the same time, it removes acidic gases from the wastewater by using a simplified heating deacidification structure.

[0028] (2) The device for co-treating sulfites and acidic gases in wastewater according to the present invention adopts a condensate recovery unit to collect steam condensate for reuse, thereby realizing resource reuse and reducing operating input and resource consumption.

[0029] (3) The present invention provides a method for synergistic treatment of sulfites and acidic gases in wastewater. Air is selected for aeration. Air has strong oxidizing properties and a good ability to remove COD. It has the advantages of high efficiency in the treatment process and does not produce carcinogenic substances such as trihalomethanes. It does not burden subsequent treatment and is a good cleaning agent with the advantages of energy saving, low consumption and environmental protection. Attached Figure Description

[0030] Figure 1This is a schematic diagram of the structure of an apparatus for the synergistic treatment of sulfites and acidic gases in wastewater according to the present invention;

[0031] In the picture:

[0032] 100. Tower body; 101. Water inlet; 102. Water outlet; 103. Cleaning water inlet;

[0033] 104. Movable tower gate; 210. Air inlet; 220. Main aeration pipe; 230. Branch aeration pipe;

[0034] 310. Heating element; 320. Tray; 330. Packing layer; 340. Gas outlet;

[0035] 350, baffle; 360, foam destroyer; 370, thermometer; 380, pressure gauge. Detailed Implementation

[0036] The present invention will be further described below with reference to specific embodiments.

[0037] like Figure 1 As shown, the present invention provides an apparatus for the synergistic treatment of sulfites and acidic gases in wastewater, comprising a tower body 100, wherein an inlet 101 is provided at the upper part of the tower body 100, an outlet 102 is provided at the lower part of the tower body 100, and an aeration unit and a deacidification unit are provided inside the tower body 100.

[0038] The aeration unit includes an air inlet 210, an aeration main pipe 220, and an aeration branch pipe 230. The air inlet 210 is located between the water inlet 101 and the water outlet 102, and is parallel to the aeration main pipe 220 and connected to the air inlet 210. The aeration branch pipe 230 is perpendicular to the aeration main pipe 220 and connected to the aeration main pipe 220. It is used for aeration of wastewater with air micro-nano bubbles. It should be noted that the present invention combines air aeration with micro-nano bubble technology. The diameter of the air micro-nano bubbles is 10nm to 10μm, which can efficiently treat wastewater and reduce COD in the wastewater.

[0039] The deacidification unit includes a heating pipe 310, a tray 320, a packing layer 330, and an air outlet 340, and is used to heat and deacidify wastewater. The heating pipe 310 is located at the bottom of the tower body 100, and heated return water is supplied to the heating pipe 310 through a heated return water inlet to heat the wastewater in the tower body 100 while it is being aerated.

[0040] It should be noted that multiple trays 320 are staggered within the upper tower body 100. One end of each tray 320 is fixed to the inner wall of the tower body 100, while the other end of the tray 320 does not contact the inner wall of the tower body 100. A baffle 350 is installed at the end of the tray 320 that does not contact the inner wall of the tower body 100. This structure not only guides the wastewater downwards to the bottom of the tower body 100, but also acts as a gas-liquid separator, guiding the acidic gases removed during deacidification to the outlet 340 at the top of the tower body 100 for discharge. The number of trays 320 is preferably 5 to 15, and the spacing between the trays 320 is 50 to 150 cm.

[0041] A packing layer 330 is disposed at the top of the tower body 100, and an outlet 340 is disposed at the top of the tower body 100, with the packing layer 330 and the outlet 340 connected. The height of the packing layer 330 is 20-100cm, and the packing structure is one or more of rectangular, circular, and triangular shapes. The packing material is 304, 316, PP, or ABS. A foam destroyer 360 is provided on the outlet 340 to destroy the foam carried up by the removed acidic gas.

[0042] In addition, the top of the tower body 100 is provided with a cleaning water inlet 103 for cleaning the inside of the tower body, which helps to extend the service life of the equipment; and the top of the tower body 100 is provided with a temperature gauge 370 and a pressure gauge 380, and the bottom of the tower body 100 is provided with a movable tower door 104 for regular inspection and maintenance of the aeration unit when the machine is stopped.

[0043] In another preferred embodiment, the apparatus for co-treating sulfite and acidic gases in wastewater according to the present invention further includes an online monitoring unit and a condensate recovery unit. The online monitoring unit includes a temperature probe and a control system. The temperature probe is located inside the tower body 100 and is connected to the control system. The condensate recovery unit is located outside the tower body 100 and is connected to the gas outlet 340. When the apparatus for co-treating sulfite and acidic gases in wastewater according to the present invention is located in a northern region with low winter temperatures, it should also include a heat insulation device located around the tower body and pipelines.

[0044] The present invention discloses a method for synergistically treating sulfites and acidic gases in wastewater, comprising the following steps:

[0045] The wastewater to be treated enters the tower body 100 through inlet 101 via a booster pump. After a brief stay on the tray 320, it flows to the aeration unit. Air inlet 210 is opened, allowing air to enter the main aeration pipe 220 and be ejected through the aeration holes on the branch pipes 230, thus aerating the wastewater with micro- and nano-bubbles. Due to the oxidizing properties of nano-air, sulfites are oxidized to sulfates, resulting in a significant removal of sulfites from the wastewater and a marked decrease in COD. Simultaneously, the heated return water inlet is opened, heating the wastewater through heating pipe 310. Acidic gases in the wastewater are discharged from the water body. The deacidification unit further removes sulfites and acidic gases from the wastewater. The acidic gases are discharged from the outlet 340 at the top of the tower body 100, and the treated wastewater is discharged from the outlet 102. It should be noted that the treatment time for wastewater to undergo simultaneous air micro-nano bubble aeration and heating deacidification is 30 to 90 minutes; the diameter of the air micro-nano bubble aeration bubbles is 10 nm to 10 μm, and the heating temperature is 80℃ to 140℃.

[0046] Example 1

[0047] This embodiment provides a method for the synergistic treatment of sulfites and acidic gases in wastewater, comprising the following specific steps:

[0048] Wastewater continuously enters the tower through the inlet. Under aeration in the aeration unit, COD is removed. The micro-nano bubbles have a diameter of 10 nm, the temperature is 80℃, and the residence time is 30 min. Acidic gases rise to the deacidification unit, while the water flows downwards to the outlet for discharge. Water vapor containing acidic gases is separated by five trays spaced 50 cm apart. After treatment, the acidic gases are defoamed by a foam destroyer and then discharged through the outlet. After treatment using this method, the COD in the wastewater is reduced by 50%, and the acidic gas removal rate is 90%.

[0049] Example 2

[0050] The basic content of this embodiment is the same as that of Embodiment 1, except that: this embodiment provides a method for the synergistic treatment of sulfites and acidic gases in wastewater. The specific steps include: wastewater continuously enters the tower body through the inlet, and COD is removed from the wastewater under aeration in the aeration unit. The micro-nano bubbles have a diameter of 100 nm, the temperature is 90℃, and the residence time is 40 min. The acidic gases rise to the deacidification unit, while the water flows downward to the outlet for discharge. Water vapor containing acidic gases is separated by six trays spaced 60 cm apart. After treatment, the acidic gases are defoamed by a foam destroyer and then discharged through the outlet. After treatment using this embodiment, the COD in the wastewater is reduced by 60%, and the acidic gas removal rate is 92%.

[0051] Example 3

[0052] The basic content of this embodiment is the same as that of Embodiment 1, except that: this embodiment provides a method for the synergistic treatment of sulfites and acidic gases in wastewater. The specific steps include: wastewater continuously enters the tower body through the inlet, and COD is removed from the wastewater under aeration in the aeration unit. The micro-nano bubbles have a diameter of 1000 nm, the temperature is 100℃, and the residence time is 60 min. The acidic gases rise to the deacidification unit, while the water flows downward to the outlet for discharge. Water vapor containing acidic gases is separated by 10 trays with a spacing of 100 cm. After treatment, the acidic gases are defoamed by a foam destroyer and then discharged through the outlet. After treatment using this embodiment, the COD in the wastewater is reduced by 65%, and the acidic gas removal rate is 93%.

[0053] Example 4

[0054] The basic content of this embodiment is the same as that of Embodiment 1, except that: this embodiment provides a method for the synergistic treatment of sulfites and acidic gases in wastewater. The specific steps include: wastewater continuously enters the tower body through the inlet, and COD is removed from the wastewater under aeration in the aeration unit. The micro-nano bubbles have a diameter of 10 μm, the temperature is 140℃, and the residence time is 90 min. The acidic gases rise to the deacidification unit, while the water flows downward to the outlet for discharge. Water vapor containing acidic gases is separated by 15 trays spaced 150 cm apart. After treatment, the acidic gases are defoamed by a foam destroyer and then discharged through the outlet. After treatment using this embodiment, the COD in the wastewater is reduced by 75%, and the acidic gas removal rate is 95%.

[0055] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the data used is only one embodiment of the present invention. The actual combination of data is not limited to this. Therefore, if those skilled in the art are inspired by this description and, without departing from the spirit of the present invention, devise similar embodiments and examples of the technical solution without creative design, all such embodiments and examples should fall within the protection scope of the present invention.

Claims

1. An apparatus for the synergistic treatment of sulfites and acidic gases in wastewater, characterized in that: The tower body (100) includes an inlet (101) at the top and an outlet (102) at the bottom. The tower body (100) is equipped with an aeration unit and a deacidification unit for simultaneously performing air micro-nano bubble aeration and heating deacidification treatment. The aeration unit includes an air inlet (210), an aeration main pipe (220), and an aeration branch pipe (230). The air inlet (210) is located between the water inlet (101) and the water outlet (102). The aeration main pipe (220) is connected to the air inlet (210), and the aeration branch pipe (230) is connected to the aeration main pipe (220). It is used to aerate the wastewater with air micro-nano bubbles. The deacidification unit includes heating pipes (310), trays (320), packing layer (330), and air outlet (340), used for heating and deacidifying wastewater. The heating pipes (310) are located at the bottom of the tower body (100), the trays (320) are staggered in the upper tower body (100), and the trays (320) are located above the aeration unit. The packing layer (330) is located at the top of the tower body (100), and the air outlet (340) is located at the top of the aeration unit. 0) Set at the top of the tower body (100), the packing layer (330) is connected to the air outlet (340); one end of the tray (320) is fixed to the inner wall of the tower body (100), and the other end of the tray (320) does not contact the inner wall of the tower body (100). A baffle (350) is set at the end of the tray (320) that does not contact the inner wall of the tower body (100), and a foam destroyer (360) is set on the air outlet (340).

2. The apparatus for co-treating sulfites and acidic gases in wastewater according to claim 1, characterized in that: The number of trays (320) is 5 to 15, and the spacing between the trays (320) is 50 to 150 cm.

3. The apparatus for co-treating sulfites and acidic gases in wastewater according to claim 1, characterized in that: The height of the packing layer (330) is 20~100cm, and the packing structure is one or more of the following: rectangular, circular, and triangular.

4. An apparatus for co-treating sulfites and acidic gases in wastewater according to any one of claims 1-3, characterized in that: The top of the tower body (100) is provided with a cleaning water inlet (103) for cleaning the inside of the tower body.

5. The apparatus for synergistic treatment of sulfites and acidic gases in wastewater according to claim 4, characterized in that: A temperature gauge (370) and a pressure gauge (380) are installed on the top of the tower body (100).

6. A method for synergistic treatment of sulfites and acidic gases in wastewater, characterized in that: The method includes using the device according to any one of claims 1-5 to simultaneously perform air micro-nano bubble aeration and heating deacidification treatment on wastewater. The specific steps are as follows: wastewater enters the tower body (100) from the inlet (101), flows through the tray (320) to the aeration unit, the air inlet (210) is opened to perform air micro-nano bubble aeration on the wastewater, and at the same time the heating return water inlet is opened to heat the wastewater through the heating pipe (310). The deacidification unit is used to remove acid, and sulfites and acidic gases in the wastewater are removed together. The acidic gases are discharged from the air outlet (340) at the top of the tower body (100), and the treated wastewater is discharged from the outlet (102).

7. A method for synergistic treatment of sulfites and acidic gases in wastewater according to claim 6, characterized in that: The treatment time for wastewater to undergo simultaneous air micro-nano bubble aeration and heating deacidification is 30~90 min.

8. A method for synergistic treatment of sulfites and acidic gases in wastewater according to claim 6, characterized in that: The diameter of the air micro-nano bubble aeration is 10 nm to 10 μm, and the heating temperature is 80℃ to 140℃.

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