An apparatus and method for treating acid-containing wastewater

Abstract

The application relates to a treatment device and method of acid-containing wastewater, and relates to the field of wastewater treatment. The treatment device comprises a reaction tower, the inner cavity of the reaction tower comprises an upper cavity and a lower cavity in communication, a vertical resin separation piece is arranged in the lower cavity to divide the lower cavity into a cathode chamber and an anode chamber, the lower end surface of a partition plate is connected with the resin separation piece, a cathode rod is arranged in the cathode chamber, and an anode rod is arranged in the anode chamber; carbon particles and a semi-permeable membrane isolation screen are arranged in the cathode chamber and the anode chamber; the semi-permeable membrane isolation screen in the cathode chamber is located between the cathode rod and the resin separation piece, and the carbon particles and the cathode rod are located on the same side of the semi-permeable membrane isolation screen; the semi-permeable membrane isolation screen in the anode chamber is located between the anode rod and the resin separation piece, and the carbon particles and the anode rod are located on the same side of the semi-permeable membrane isolation screen. The treatment device can purify the acid-containing wastewater, remove metal ions in the wastewater, and recycle the acid washing water solution.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, specifically to an apparatus and method for treating acidic wastewater. Background Technology

[0002] The purification and treatment of industrial wastewater plays an increasingly important role in environmental pollution control and is of great significance for protecting the environment and maintaining ecological balance.

[0003] When acid washing of quartz sand is used, the resulting wastewater generally contains acid and metal ions, such as Fe. 3+ Ca 2+ Mg 2+ Na + H + For wastewater containing substances such as Cl-, existing technologies typically employ neutralization, physicochemical flocculation sedimentation, and filtration processes. This not only consumes a large amount of alkaline solution but also makes it extremely difficult to completely remove metal ions from the wastewater, resulting in low purification efficiency and high overall treatment costs, which has become a bottleneck for enterprise development. Summary of the Invention

[0004] The present invention aims to provide an apparatus and method for treating acidic wastewater, so as to efficiently purify metal ions in acidic wastewater.

[0005] To solve the above technical problems, this invention draws on the principles of bionics and adopts the following specific solution: an acid wastewater treatment device, including a reaction tower, with an inlet at the top and an outlet at the bottom. The inner cavity of the reaction tower includes an upper chamber and a lower chamber that are connected to each other. A vertical partition plate is provided in the upper chamber to divide the upper chamber into a first chamber and a second chamber. Exhaust ports are provided on the side walls of both the first chamber and the second chamber.

[0006] A vertical resin separator is provided in the lower chamber to divide the lower chamber into a cathode chamber and an anode chamber. The lower end face of the partition plate is connected to the resin separator. A cathode rod is provided in the cathode chamber and an anode rod is provided in the anode chamber.

[0007] Both the cathode chamber and the anode chamber are equipped with carbon particles and a semi-permeable membrane isolation screens. The semi-permeable membrane isolation screen in the cathode chamber is located between the cathode rod and the resin separator, and the carbon particles and the cathode rod are located on the same side of the semi-permeable membrane isolation screen. The semi-permeable membrane isolation screen in the anode chamber is located between the anode rod and the resin separator, and the carbon particles and the anode rod are located on the same side of the semi-permeable membrane isolation screen.

[0008] As a further optimization of the above technical solution, the semi-permeable membrane isolation screen includes a semi-permeable membrane and a multi-layer flow guide disposed on the semi-permeable membrane. The multi-layer flow guide is distributed in parallel and inclined upward.

[0009] As a further optimization of the above technical solution, the included angle between the flow guide and the semi-permeable membrane is 30-60°.

[0010] As a further optimization of the above technical solution, multi-layer flow guides are arranged opposite to each other on both sides of the semi-permeable membrane.

[0011] As a further optimization of the above technical solution, the semi-permeable membrane isolation screens in the cathode chamber and anode chamber are both configured to be multiple layers at intervals.

[0012] As a further optimization of the above technical solution, the resin separator includes a plurality of stacked resin spheres.

[0013] As a further optimization of the above technical solution, the resin separator is located directly below the inlet of the reaction tower.

[0014] As a further optimization of the above technical solution, both the anode rod and the cathode rod are multiple.

[0015] A method for treating acidic wastewater involves feeding the acidic wastewater into a reaction tower. After entering the lower chamber, anions move towards the anode rod, with some being electrolyzed into gas and discharged from the reaction tower; others are electrolyzed into gas and dissolved in the acidic wastewater within the reaction tower. Cations move towards the cathode rod, with divalent or higher metal cations being electrolyzed into elemental metals at the cathode rod, thus completing the treatment of the acidic wastewater.

[0016] As a further optimization of the above technical solution, the anion includes chloride ions, which are electrolyzed into chlorine gas at the anode rod.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] This invention removes metal ions from acidic wastewater by electrolyzing different ions in the acidic wastewater using cathode and anode rods installed in the reaction tower, thereby forming them into gas or elemental metals. Part of the gas is discharged outside the reaction tower, while part dissolves inside the tower to form acid, which can be used for acid washing of quartz sand. The elemental metals formed can be directly recycled.

[0019] By placing carbon particles in the cathode and anode chambers, the carbon particles can adsorb ions in acidic wastewater, thereby removing ions from the wastewater. On the other hand, the carbon particles are in contact with the cathode or anode rods. After the cathode or anode rods are energized, the corresponding carbon particles can also be energized as electrodes to participate in the electrolysis process, increasing the contact area with ions and thus improving the electrolysis effect. When electrolyzing ions adsorbed on the carbon particles, the adsorption properties of the carbon particles themselves and the opposite attraction of the charge on the ions after the carbon particles are energized further improve the efficiency of ion electrolysis, ionization, and adsorption.

[0020] A biomimetic semi-permeable membrane isolation screen is installed in the cathode and anode chambers. The semi-permeable membrane isolation screen can prevent carbon particles in the cathode and anode chambers from moving towards the resin separation component in the middle. It can also allow different ions to flow to different electrode chambers. For example, cations can only flow to the cathode chamber through the semi-permeable membrane of the cathode chamber, and anions can only flow to the anode chamber through the semi-permeable membrane of the anode chamber. In addition, the flow guide on the semi-permeable membrane isolation screen is inclined upward, which facilitates the upward flow of the gas generated by electrolysis, thereby quickly expelling it from the reaction tower. It also restricts the flow of gas generated in different electrode chambers to each other, making the gas discharged from different exhaust ports in the reaction tower relatively pure. Attached Figure Description

[0021] Figure 1 This is a cross-sectional schematic diagram of an acidic wastewater treatment device;

[0022] Figure 2 This is a side sectional view of an acidic wastewater treatment device;

[0023] Figure 3 This is a top-view cross-sectional schematic diagram of an acidic wastewater treatment device.

[0024] Figure 4 This is a schematic diagram of the structure of a semi-permeable membrane isolation screen;

[0025] Figure 5 This is a schematic diagram of the external structure of an acidic wastewater treatment device.

[0026] Reference numerals: 1. Liquid inlet, 2. First exhaust port, 3. Upper chamber, 301. First chamber, 302. Second chamber, 4. Process port, 5. Lower chamber, 501. Anode chamber, 502. Cathode chamber, 6. Carbon particles, 7. Anode rod, 8. Semi-permeable membrane isolation screen, 801. Semi-permeable membrane, 802. Flow guide, 9. Resin separator, 10. Anode connection port, 11. Liquid outlet, 12. Cathode rod, 13. Cathode connection port, 14. Divider plate, 15. Second exhaust port. Detailed Implementation

[0027] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention, such as the connection method between the cathode rod, the anode rod and the external power line, and the method of adding and replacing carbon particles through the process port, should be understood as prior art known or should be known by those skilled in the art.

[0028] This invention discloses an acid wastewater treatment device for purifying acid wastewater generated during the acid washing of quartz sand. Since the raw material used in acidic operations is acid, the main task in treating this type of acid wastewater is to remove metal ions from the wastewater. The liquid after removing metal ions can be reused as an acid washing solution, thus achieving recycling.

[0029] like Figure 1 , 5 As shown, the processing device of the present invention includes a vertical reaction tower, with an inlet 1 at the top and an outlet 11 at the bottom.

[0030] The reaction tower includes a sealed upper head, a middle cylinder, and a lower head. The cylinder is cylindrical, and the upper head, lower head, and cylinder can also be integrally formed. The liquid inlet 1 is located at the center of the upper head, and the liquid outlet 11 is located at the center of the lower head. The internal cavity of the reaction tower includes an upper chamber 3 and a lower chamber 5 that are connected. The upper chamber 3 is the inner cavity of the upper head, and the lower chamber 5 is the inner cavity of the middle cylinder and the lower head. The lower chamber 5 is the main reaction chamber of the reaction tower. The upper chamber 3 is used to supply acidic waste liquid to flow into the lower chamber 5 and to discharge the gas generated after the reaction in the lower chamber 5.

[0031] The upper chamber 3 is provided with a vertical partition plate 14 to divide the upper chamber 3 into a first chamber 301 and a second chamber 302. Exhaust ports are provided on the side walls of both the first chamber 301 and the second chamber 302.

[0032] Combination Figure 2 , 3 As shown, a vertical resin separator 9 is provided in the lower chamber 5 to divide the lower chamber 5 into an anode chamber 501 and a cathode chamber 502. The lower end face of the partition plate 14 is connected to the resin separator 9. A cathode rod 12 is provided in the cathode chamber 502, and an anode rod 7 is provided in the anode chamber 501. The cathode rod 12 and the anode rod 7 are respectively connected to an external power source through lines. A cathode connection port 13 and an anode connection port 10 are respectively provided on the side wall of the reaction tower.

[0033] Both the cathode chamber 502 and the anode chamber 501 are equipped with carbon particles 6 and a semi-permeable membrane partition 8. The semi-permeable membrane partition 8 in the cathode chamber 502 is located between the cathode rod 12 and the resin separator 9, with the carbon particles 6 and the cathode rod 12 on the same side of the partition 8. Similarly, the semi-permeable membrane partition 8 in the anode chamber 501 is located between the anode rod 7 and the resin separator 9, with the carbon particles 6 and the anode rod 7 on the same side of the partition 8. The semi-permeable membrane partitions 8 in the cathode chamber 502 and the anode chamber 501, along with the sidewall of the reaction tower, together enclose a space for holding the resin spheres. The resin spheres are stacked to form a vertical resin separator 9.

[0034] The resin separator 9 is located between the cathode rod 12 and the anode rod 7 to prevent short circuits from occurring inside the reaction tower after the cathode rod 12 and the anode rod 7 are powered on. Resin spheres are also provided between the two adjacent semi-permeable membrane isolation screens 8 to further improve insulation and prevent short circuits from occurring inside the reaction tower.

[0035] After the cathode rod 12 and the anode rod 7 are energized, an electric field is formed inside the reaction tower, and cations such as Fe in the acidic waste liquid are energized. 3+ Ca 2+ Mg 2+ Na + Moving towards the cathode rod 12, divalent and higher-valent cations are electrolyzed into metallic elements. Monovalent sodium ions have a weaker impact on water quality and can remain in the liquid environment, subsequently being discharged with the purified liquid. H+ at the cathode... + It can also be electrolyzed into hydrogen gas at higher voltages, and anions such as Cl in acidic waste liquids can also be converted into hydrogen gas. - NO3 - The isotropic anode rod 7 moves and is electrolyzed at the anode rod 7 into gases such as chlorine or nitrogen oxides.

[0036] In this embodiment, as Figure 1 As shown, the partition plate 14 is located to the right of the liquid inlet 1 to form a first chamber 301 on the left and a second chamber 302 on the right. The liquid inlet 1 of the reaction tower is connected to the first chamber 301. The exhaust port on the side wall of the first chamber 301 is the first exhaust port 2, which is used to discharge gases such as chlorine generated by electrolysis in the anode chamber 501. The exhaust port on the side wall of the second chamber 302 is the second exhaust port 15, which is used to discharge gases generated by electrolysis in the cathode chamber 502, mainly hydrogen.

[0037] When the chlorine gas produced by electrolysis is discharged through the first exhaust port 2, it will flow through the first chamber 301. Therefore, the chlorine gas that is not discharged in time can come into contact with the pickling waste liquid in the first chamber 301 and dissolve in the acid-containing waste liquid. The chlorine gas discharged from the first exhaust port 2 enters the subsequent acid system to form pickling liquid for recycling. The hydrogen gas produced by electrolysis is discharged through the second exhaust port 15. The second exhaust port 15 is connected to a night lamp. The hydrogen gas produced by electrolysis can be used as fuel for the night lamp. The structure and setting of the night lamp are existing technologies and will not be described in detail here.

[0038] By placing carbon particles 6, which are activated carbon, in the cathode chamber 502 and anode chamber 501, and having the activated carbon in contact with the electrode rods (including the cathode rod 12 and the anode rod 7), a large volume electric field is formed in the reaction tower as the electrode rods are energized, thereby electrolyzing the corresponding ions. The presence of carbon particles 6 increases the specific surface area of ​​the electrodes, improving the efficiency of electrolysis of metal ions and acid radical ions in the waste liquid. At the same time, the activated carbon can also adsorb ions, reducing the discharge of unadsorbed ions from the drain port, further improving the treatment efficiency of acidic wastewater. The electric field can constrain ions, reducing their kinetic energy and making them easier for the carbon particles to adsorb. In short, the interaction between the electric field and the activated carbon jointly improves the purification efficiency of metal ions in water-containing wastewater. The structural features and semi-permeable membrane electrical features of this invention are biomimetic to marine biological discharge and self-protection. By establishing a strong electric field in the adsorption material region (i.e., the lower chamber 5), the adsorption material’s ion absorption efficiency is improved without damaging the adsorption material itself. (For example, moray eels can release strong electricity to stun invasive organisms but will not stun themselves.)

[0039] The semi-permeable membrane barrier 8 prevents carbon particles 6 from moving towards the resin separator 9 in the middle, and also prevents the resin spheres of the resin separator 9 from moving towards the cathode chamber 502 or the anode chamber 501. The semi-permeable membrane structure of the semi-permeable membrane barrier 8 allows different ions to flow to different electrode chambers. For example, cations can only flow to the cathode chamber through the semi-permeable membrane barrier 8 in the cathode chamber, and anions can only flow to the anode chamber through the semi-permeable membrane barrier 8 in the anode chamber.

[0040] To improve the efficiency of gas discharge from electrolysis, such as Figure 4As shown, the semi-permeable membrane isolation screens 8 in the cathode chamber 502 and the anode chamber 501 are both biomimetic feather-shaped partition structures, including a semi-permeable membrane 801 and multi-layer flow guides 802 fixedly mounted on the semi-permeable membrane 801. The semi-permeable membrane 801 is a commercially available product. The flow guides 802 mounted on the semi-permeable membrane 801 are inclined upwards, and the angle between the flow guides 802 and the semi-permeable membrane 801 is 30-60°. In this embodiment, the angle between the flow guides 802 and the semi-permeable membrane 801 is 45°. The flow guides 802 can guide the gas flow generated by the electrolysis of the electrode rod, facilitating the gas flow to flow upwards in the reaction tower and improving the efficiency of the gas flow exiting the reaction tower. The flow guides 802 are made of acid- and corrosion-resistant materials, such as resin. The flow guides can be set in sheet or strip shape, and the flow guides are connected to the semi-permeable membrane by adhesive bonding. Each semipermeable membrane 801 has a flow guide 802 on both sides. The flow guides 802 on both sides of the semipermeable membrane 801 are arranged opposite each other. The flow guides 802 on both sides of the semipermeable membrane 801 are formed into a V-shaped cross section. The connection between the flow guide 802 and the semipermeable membrane isolation screen 8 is located at the lowest point of the flow guide 802 plate. After the electrode rod electrolyzes the corresponding ions to generate gas, the gas escapes upward to the first chamber 301 or the second chamber 302 at the top of the reaction tower, so as to minimize the flow of gas generated by the electrode rod electrolysis to the opposite chamber.

[0041] The semi-permeable membrane isolation screen 8 facilitates the flow of gas generated during electrolysis to the top of the reaction tower, preventing gas from flowing into the opposite reaction chamber and causing a chaotic composition of the exhaust gas. Taking the anode chamber 501 as an example, in this embodiment, the semi-permeable membrane isolation screen 8 of the anode chamber 501 has two layers. During the upward escape of the gas generated in the anode chamber 501, some gas will flow towards the opposite cathode chamber 502. When it comes into contact with the flow guide 802 of the semi-permeable membrane isolation screen 8, it moves upward under the action of the flow guide 802, reducing the tendency of the gas to flow towards the cathode chamber 502. Even if some gas flow passes through one layer of the semi-permeable membrane isolation screen 8 and flows between the two layers of semi-permeable membrane isolation screen 8, the flow guide 802 on the inner side of the semi-permeable membrane isolation screen 8 will prevent the gas from flowing into the cathode chamber 502. The guiding effect of component 2 still allows the airflow to tend to flow upwards. Through the obstruction and guidance of the two semi-permeable membrane isolation screens 8, on the one hand, the guiding effect of the flow guide component 802 causes the gas generated in the anode chamber 501 to flow to the top of the reaction tower; on the other hand, during the horizontal flow of the gas, due to the obstruction of the flow guide component 802 and the semi-permeable membrane isolation screen 8, the residence time of the gas in the cathode chamber 502 is prolonged, allowing soluble gases such as chlorine produced by electrolysis to dissolve in the solution in the reaction tower, and then flow out from the drain port as purified liquid. Similarly, when the voltage in the cathode chamber 502 is high, there is also a possibility of electrolysis producing hydrogen. The semi-permeable membrane isolation screen 8 facilitates the upward flow of hydrogen and its discharge outside the reaction tower.

[0042] In other embodiments of the present invention, the semi-permeable membrane isolation screen 8 may also be a commercially available semi-permeable membrane.

[0043] The side wall of the reaction tower is also equipped with a process port 4 for adding or replacing carbon particles 6, resin particles, etc., which is existing technology.

[0044] This invention also discloses a method for treating acidic wastewater, comprising the following steps: Acidic wastewater is fed into a reaction tower through inlet 1; the wastewater falls through upper chamber 3 onto resin separator 9 in lower chamber 5, and then diffuses into cathode chamber 502 and anode chamber 501; in the acidic wastewater in lower chamber 5, anions move towards anode rod 7, where Cl- ions are electrolyzed into chlorine gas; some chlorine gas rises and is discharged from the reaction tower through exhaust port; chlorine gas not discharged in time dissolves in the acidic wastewater within the reaction tower; simultaneously, cations move towards cathode rod 12, where divalent and higher-valent metal cations are electrolyzed into elemental metals, thus completing the treatment of the acidic wastewater; the treated acidic wastewater is discharged from the reaction tower through outlet 11. Through the treatment device and method of this invention, acidic wastewater in the pickling process can be efficiently removed, with a removal rate of divalent and higher-valent metal ions reaching 95%.

[0045] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An acid-containing wastewater treatment device, comprising a reaction tower, the top of the reaction tower is provided with a liquid inlet (1), and the bottom of the reaction tower is provided with a liquid outlet (11), characterized in that, The reaction tower inner cavity comprises an upper cavity (3) and a lower cavity (5) in communication, The upper cavity (3) is provided with a vertical partition plate (14) to divide the upper cavity (3) into a first cavity (301) and a second cavity (302), and the side walls of the first cavity (301) and the second cavity (302) are both provided with exhaust ports; The lower cavity (5) is provided with a vertical resin separation piece (9) to divide the lower cavity (5) into a cathode chamber (502) and an anode chamber (501), the lower end surface of the partition plate (14) is connected with the resin separation piece (9), the cathode chamber (502) is provided with a cathode rod (12), and the anode chamber (501) is provided with an anode rod (7); The cathode chamber (502) and the anode chamber (501) are both provided with carbon particles (6) and semi-permeable membrane isolation screens (8), the semi-permeable membrane isolation screen (8) in the cathode chamber (502) is located between the cathode rod (12) and the resin separation piece (9), and the carbon particles (6) and the cathode rod (12) are located on the same side of the semi-permeable membrane isolation screen (8), the semi-permeable membrane isolation screen (8) in the anode chamber (501) is located between the anode rod (7) and the resin separation piece (9), and the carbon particles (6) and the anode rod (7) are located on the same side of the semi-permeable membrane isolation screen (8); The semi-permeable membrane isolation screen (8) comprises a semi-permeable membrane (801) and a plurality of flow guide pieces (802) arranged on the semi-permeable membrane (801), and the plurality of flow guide pieces (802) are parallelly distributed and arranged obliquely upwards; The included angle between the flow guide piece (802) and the semi-permeable membrane (801) is 30-60°; The plurality of flow guide pieces (802) are oppositely arranged on both sides of the semi-permeable membrane (801); The semi-permeable membrane isolation screens (8) in the cathode chamber (502) and the anode chamber (501) are both arranged as a plurality of layers, and resin spheres are filled between adjacent two layers of semi-permeable membrane isolation screens (8); The semi-permeable membrane isolation screens (8) in the cathode chamber (502) and the anode chamber (501) are both in a bionic feather-like separation structure.

2. The apparatus for treating acid-containing wastewater according to claim 1, wherein The resin separation piece (9) comprises a plurality of resin spheres stacked.

3. The apparatus for treating acid-containing wastewater according to claim 1, wherein The resin separation piece (9) is located directly below the liquid inlet (1) of the reaction tower.

4. The apparatus for treating acid-containing wastewater according to claim 1, wherein The anode rod (7) and the cathode rod (12) are both a plurality of rods.

5. A method for treating acid-containing wastewater based on the treatment apparatus according to any one of claims 1 to 4, characterized by, The acid-containing wastewater is introduced into the reaction tower, after the acid-containing wastewater enters the lower cavity (5), anions move to the anode rod (7), a part of which is electrolyzed into gas and discharged out of the reaction tower; a part of which is electrolyzed into gas and dissolved in the acid-containing wastewater in the reaction tower; cations move to the cathode rod (12), and metal cations with valence of two or more are electrolyzed into metal elements at the cathode rod (12) to complete the treatment of the acid-containing wastewater.

6. The method of treating acid-containing wastewater of claim 5, wherein, The anions include chloride ions, and the chloride ions are electrolyzed into chlorine gas at the anode rod (7).

Images