Device for removing carbonate in wastewater

Abstract

The utility model discloses a device for removing carbonate radicals from wastewater, which has the advantages that the operation energy consumption is reduced, the carbon dioxide in the treated water is reduced to 0.5 mg / L, and the effect is better. The acid adding reaction storage tank comprises a tank body, a stirrer, an acid flow inlet, a waste water inlet and a waste water flow outlet, and a stirring shaft of the stirrer is arranged in an inner cavity of the tank body for stirring operation; an inlet of the wastewater circulation pipeline is integrated with a lifting pump, and the wastewater circulation pipeline is provided with a water inlet flow meter and a plurality of security filters in the wastewater circulation direction; and each group of decarbonization membrane contactors comprises a contactor body, a wastewater inlet, a wastewater outlet, a purge gas inlet and a purge gas outlet.

Description

Technical Field

[0001] This utility model relates to the technical field of wastewater treatment, specifically to a device for removing carbonate ions from wastewater. Background Technology

[0002] Current methods for treating lithium carbonate wastewater involve first adding acid to lower the pH value, converting carbonate ions in the water into carbon dioxide, and then treating it with a decarbonation tower. However, when using a decarbonation tower, the pH must be adjusted to below 4 when adding acid, resulting in a large amount of acid consumption. Furthermore, the gas-to-water ratio of the decarbonation tower needs to reach 40:1, requiring a large fan power and high operating energy consumption. After decarbonation treatment, the carbon dioxide content in the water can only be reduced to about 5 mg / L. Utility Model Content

[0003] To address the aforementioned problems, this invention provides a device for removing carbonate ions from wastewater, which reduces operating energy consumption and lowers the carbon dioxide concentration in the treated water to 0.5 mg / L, resulting in better performance.

[0004] An apparatus for removing carbonate ions from wastewater, characterized in that it comprises:

[0005] An acid reaction storage tank includes a tank body, a stirrer, an acid inlet, a wastewater inlet, and a wastewater outlet. The stirring shaft of the stirrer is built into the inner cavity of the tank body to perform stirring operations.

[0006] The wastewater flow pipeline has an integrated booster pump at its inlet, and the wastewater flow pipeline is equipped with an inlet flow meter and several security filters along the wastewater flow direction.

[0007] At least one set of decarbonization membrane contactors, each set of decarbonization membrane contactors includes a contactor body, a wastewater inlet, a wastewater outlet, a purge gas inlet, and a purge gas outlet;

[0008] The wastewater outlet is connected to the inlet of the booster pump via an outlet pipe. The outlet of the wastewater flow pipe is connected to the wastewater inlet of the first decarbonization membrane contactor. All the decarbonization membrane contactors are connected in series to form a wastewater inlet and a wastewater outlet corresponding to the wastewater channel. The wastewater outlet of the last decarbonization membrane contactor is connected to the treated wastewater outlet pipe. The purge air inlet pipe is connected in parallel to each of the purge air inlets, and each of the purge air outlets is connected in parallel to the inlet of the purge air outlet pipe.

[0009] Its further features are:

[0010] The top cover of the tank is also equipped with a pH meter, and the detection end of the pH meter is located in the inner cavity of the tank, which allows the tank to accurately control the pH value of the wastewater after acid is added.

[0011] An acid metering pump is integrated into the acid inlet to ensure accurate and reliable metering of acid addition.

[0012] The number of decarbonation membrane contactors is two sets, and the two sets of decarbonation membrane contactors are arranged vertically in parallel. The wastewater inlet of the decarbonation membrane contactor is located at the bottom and the wastewater outlet is located at the top. The two sets of decarbonation membrane contactors are the first decarbonation membrane contactor and the second decarbonation membrane contactor. The top wastewater outlet of the first decarbonation membrane contactor is connected to the bottom wastewater inlet of the second decarbonation membrane contactor through a bent connecting pipe to form a series mechanism.

[0013] The main pipe of the purge air intake pipeline is equipped with a pressure transmitter and an air flow meter to ensure that the purge air is delivered into each decarbonization membrane contactor according to the set pressure and total amount.

[0014] The treated wastewater outflow pipeline is also connected to an online dissolved carbon dioxide detector to ensure reliable monitoring of the water.

[0015] The wastewater flow pipeline includes a first lifting section, a first horizontal section, a second descending section, and a second horizontal section. A lifting pump is installed at the bottom inlet of the first lifting section, and an inlet flow meter is integrated on the first lifting section. Several security filters are installed on the second descending section, and the outlet of the second horizontal section is connected to the wastewater inlet of the first decarbonization membrane contactor through a vertical connecting pipe.

[0016] The working principle of the membrane contactor after adopting the above technical solution is as follows: Figure 2The gas transport membrane material used is a selectively permeable material. The membrane contactor contains numerous hollow fibers with tiny pores on their walls, allowing only gas molecules to pass through. Gas can permeate bidirectionally, while liquids cannot. Gas-liquid contact is established on both sides of the material, and the gas flow from the liquid is carried into the liquid, thus reducing the gas content in the liquid. During operation, carbonate-containing wastewater is transported to the wastewater inlet of the tank and then enters the tank. Sulfuric acid is added to the tank through the acid inlet to adjust the pH value of the wastewater. A stirrer ensures thorough mixing and reaction between the wastewater and the sulfuric acid solution, controlling the pH of the wastewater after acid addition to around 4.5. The acidified wastewater is then pumped through a booster pump. The wastewater is pressurized to 0.15 MPa and then filtered through a security filter to remove impurities, reducing the turbidity to less than 0.1 NTU. It then enters the decarbonation membrane contactor, where compressed air enters the purge air intake pipe. By controlling the purge air flow rate, the air-to-water ratio must be greater than 3:1. The decarbonation membrane contactor removes dissolved carbon dioxide from the wastewater. The removed carbon dioxide and purge air are discharged together through the purge air outlet pipe. At this point, the dissolved carbon dioxide content in the wastewater is less than 0.5 mg / L, and the pH value of the wastewater rises to approximately 6.3, allowing it to proceed directly to the next treatment step without the need for alkali addition for readjustment. This reduces operating energy consumption, and the treated water has a carbon dioxide content reduced to 0.5 mg / L, resulting in better performance. Attached Figure Description

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

[0018] Figure 2 This is a schematic diagram of the decarburization membrane contactor used in this utility model;

[0019] The names corresponding to the serial numbers in the diagram are as follows:

[0020] 1. Contactor body; 2. Wastewater inlet; 3. Wastewater outlet; 4. Purge gas inlet; 5. Purge gas outlet; 6. Bent connecting pipe.

[0021] Acid reaction storage tank 10, tank body 11, agitator 12, acid inlet 13, wastewater inlet 14, wastewater outlet 15, outlet pipeline 16, pH meter 17, acid metering pump 18, wastewater flow pipeline 20, first lifting section 201, first horizontal section 202, second descending section 203, second horizontal section 204, lifting pump 21, inlet flow meter 22, security filter 23, vertical connecting pipe 24, first decarbonization membrane contactor 30, second decarbonization membrane contactor 40, treated wastewater outlet pipeline 50, purging air inlet pipeline 60, pressure transmitter 61, air flow meter 62, purging air outlet pipeline 70, dissolved carbon dioxide online detector in water 80, control box 90. Detailed Implementation

[0022] An apparatus for removing carbonate ions from wastewater, see Figure 1 It includes an acid reaction storage tank 10, a wastewater flow pipeline 20, and two sets of decarbonization membrane contactors;

[0023] The acid reaction storage tank 10 includes a tank body 11, a stirrer 12, an acid inlet 13, a wastewater inlet 14, and a wastewater outlet 15. The stirring shaft of the stirrer 12 is built into the inner cavity of the tank body 11 to perform stirring operations.

[0024] The wastewater flow pipe 20 has an integrated booster pump 21 at its inlet, and the wastewater flow pipe 20 is equipped with an inlet flow meter 22 and several security filters 23 along the wastewater flow direction.

[0025] The two sets of decarbonization membrane contactors are specifically a first decarbonization membrane contactor 30 and a second decarbonization membrane contactor 40. Each set of decarbonization membrane contactors includes a contactor body 1, a wastewater inlet 2, a wastewater outlet 3, a purge gas inlet 4, and a purge gas outlet 5. The two sets of decarbonization membrane contactors are arranged vertically in parallel, with the wastewater inlet of the decarbonization membrane contactor located at the bottom and the wastewater outlet located at the top. The wastewater outlet 3 at the top of the first decarbonization membrane contactor 30 is connected to the wastewater inlet 2 at the bottom of the second decarbonization membrane contactor 40 through a bent connecting pipe 6, forming a series mechanism.

[0026] Wastewater outlet 15 is connected to the inlet of booster pump 21 via outlet pipe 16. The outlet of wastewater flow pipe 20 is connected to the wastewater inlet 2 of the first decarbonization membrane contactor 30. The wastewater outlet 3 of the second decarbonization membrane contactor 40 is connected to the treated wastewater outlet pipe 50. The purge air inlet pipe 60 is connected in parallel to each purge air inlet 4. Each purge air outlet 5 is connected in parallel to the inlet of purge air outlet pipe 70.

[0027] In practice, a pH meter 17 is also installed on the top cover of the tank 11. The detection end of the pH meter 17 is located in the inner cavity of the tank, which allows the tank to accurately control the pH value of the wastewater after acid is added.

[0028] An acid metering pump 18 is integrated on the acid inlet 13 to ensure accurate and reliable metering of acid addition.

[0029] In practice, a pressure transmitter 61 and an air flow meter 62 are installed on the main pipe of the 60-way purge air intake pipe to ensure that the purge air is delivered into each decarbonization membrane contactor according to the set pressure and total amount.

[0030] In practice, the treated wastewater outflow pipe 50 is also connected to the detection end of the online dissolved carbon dioxide detector 80. The display end of the online dissolved carbon dioxide detector 80 is located below the control box 90 to ensure reliable monitoring of the water.

[0031] The wastewater flow pipeline 20 includes a first lifting section 201, a first horizontal section 202, a second descending section 203, and a second horizontal section 204. A lifting pump 21 is installed at the bottom inlet of the first lifting section 201. An inlet flow meter 22 is integrated on the first lifting section 201. Several security filters 23 are installed on the second descending section 203. The outlet of the second horizontal section 204 is connected to the wastewater inlet 2 of the first decarbonization membrane contactor 30 through a vertical connecting pipe 24.

[0032] Its working principle is as follows; the working principle of the membrane contactor can be found here. Figure 2 The gas transport membrane material used is a selectively permeable material. The membrane contactor contains a large number of hollow fibers with tiny pores on the fiber walls. Only gas molecules can pass through the micropores, allowing gas to permeate bidirectionally while liquids cannot. Gas-liquid contact is established on both sides of the material. The gas flow carries the gas in the liquid into the liquid, thereby reducing the gas content in the liquid. During operation, carbonate-containing wastewater is transported to the wastewater inlet of the tank and then enters the tank. Sulfuric acid is added to the tank through the acid metering pump at the acid inlet to adjust the pH value of the wastewater. The agitator is used to stir the wastewater and sulfuric acid solution to ensure thorough mixing and reaction, controlling the pH of the wastewater after acid addition to around 4.5. The acidified wastewater is then pressurized by a booster pump to 0. The water is initially treated at 15 MPa, then filtered through a security filter to remove impurities, reducing the turbidity to less than 0.1 NTU. It then enters the decarbonation membrane contactor, where compressed air enters the purge air intake pipe. The air intake pressure must be less than 0.1 MPa via a pressure transmitter, and the purge air flow rate is controlled by an air flow meter to ensure a gas-to-water ratio greater than 3:1. The decarbonation membrane contactor removes dissolved carbon dioxide from the wastewater. The removed carbon dioxide and purge air are discharged together through the purge air outlet pipe. At this point, the dissolved carbon dioxide content in the wastewater is less than 0.5 mg / L, and the pH value rises to approximately 6.3, allowing for direct further treatment without the need for alkali addition for readjustment. This reduces operating energy consumption and achieves better results by lowering the carbon dioxide content in the treated water to 0.5 mg / L.

[0033] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0034] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An apparatus for removing carbonate ions from wastewater, characterized in that, It includes: An acid reaction storage tank includes a tank body, a stirrer, an acid inlet, a wastewater inlet, and a wastewater outlet. The stirring shaft of the stirrer is built into the inner cavity of the tank body to perform stirring operations. The wastewater flow pipeline has an integrated booster pump at its inlet, and the wastewater flow pipeline is equipped with an inlet flow meter and several security filters along the wastewater flow direction. At least one set of decarbonization membrane contactors, each set of decarbonization membrane contactors includes a contactor body, a wastewater inlet, a wastewater outlet, a purge gas inlet, and a purge gas outlet; The wastewater outlet is connected to the inlet of the booster pump via an outlet pipe. The outlet of the wastewater flow pipe is connected to the wastewater inlet of the first decarbonization membrane contactor. All the decarbonization membrane contactors are connected in series to form a wastewater inlet and a wastewater outlet corresponding to the wastewater channel. The wastewater outlet of the last decarbonization membrane contactor is connected to the treated wastewater outlet pipe. The purge air inlet pipe is connected in parallel to each of the purge air inlets, and each of the purge air outlets is connected in parallel to the inlet of the purge air outlet pipe.

2. The apparatus for removing carbonate ions from wastewater according to claim 1, characterized in that: A pH meter is also installed on the top cover of the tank, and the detection end of the pH meter is located inside the tank.

3. The apparatus for removing carbonate ions from wastewater according to claim 2, characterized in that: An acid metering pump is integrated into the acid inlet.

4. The apparatus for removing carbonate ions from wastewater according to claim 1, characterized in that: The decarbonization membrane contactor consists of two sets, arranged vertically in parallel. The wastewater inlet of the decarbonization membrane contactor is located at the bottom, and the wastewater outlet is located at the top. The two sets of decarbonization membrane contactors are the first decarbonization membrane contactor and the second decarbonization membrane contactor, respectively. The top wastewater outlet of the first decarbonization membrane contactor is connected to the bottom wastewater inlet of the second decarbonization membrane contactor through a bent connecting pipe, forming a series mechanism.

5. The apparatus for removing carbonate ions from wastewater according to claim 1, characterized in that: A pressure transmitter and an air flow meter are installed on the main pipe of the purge air intake pipeline.

6. The apparatus for removing carbonate ions from wastewater according to claim 1, characterized in that: The treated wastewater outflow pipeline is also connected to an online dissolved carbon dioxide detector.

7. The apparatus for removing carbonate ions from wastewater according to claim 4, characterized in that: The wastewater flow pipeline includes a first lifting section, a first horizontal section, a second descending section, and a second horizontal section. A lifting pump is installed at the bottom inlet of the first lifting section, and an inlet flow meter is integrated on the first lifting section. Several security filters are installed on the second descending section, and the outlet of the second horizontal section is connected to the wastewater inlet of the first decarbonization membrane contactor through a vertical connecting pipe.

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