A process for treating industrial wastewater containing thallium

Abstract

The application discloses an industrial thallium-containing wastewater treatment process, comprising the following steps: adding thallium-containing wastewater into a sedimentation tank, adjusting the pH of the wastewater to be alkaline by adding alkali, and removing trivalent thallium ions by precipitation; adjusting the pH of supernatant obtained by removing trivalent thallium ions to be neutral; then adding a magnetic coagulation sedimentation tank, adding magnetic adsorption material, PAC and PAM, and performing flocculation and sedimentation after the addition is completed, and then filtering; wherein the magnetic adsorption material is a mixture of Fe3O4 and Co3O4, and the mass ratio of Fe3O4 to Co3O4 is 3-10:1. The application provides an industrial thallium-containing wastewater treatment process based on a magnetic coagulation sedimentation tank, through optimization and control of the process, short-process and high-efficiency thallium removal is realized, Fe3O4 and Co3O4 are used as the magnetic adsorption material in a mass ratio of 3-10:1 to efficiently adsorb monovalent thallium, and the thallium content can be reduced to below 50 mu g / L.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a process for treating industrial thallium-containing wastewater. Background Technology

[0002] Thallium (Tl) is a highly toxic and scarce metal, even more toxic to mammals than well-known harmful heavy metals such as mercury (Hg), lead (Pb), and cadmium (Cd). In natural aquatic environments, thallium concentrations are extremely low, with average concentrations in rivers, lakes, and groundwater ranging from 0.006–0.715 μg / L, 0.001–0.036 μg / L, and 0.001–0.25 μg / L, respectively. However, in waters affected by human activities, thallium concentrations are significantly elevated. Industries discharging thallium-containing wastewater include lead-zinc, steel, tin-antimony, sulfuric acid, and phosphate fertilizer companies, primarily due to their use of thallium-containing raw materials and auxiliary materials in production. To minimize the health risks of thallium intake, the U.S. Environmental Protection Agency (EPA) has set maximum permissible thallium concentrations in drinking water and wastewater at 2 μg / L and 140 μg / L, respectively, while China has a stricter standard of 0.1 μg / L for drinking water. About 16 types of thallium and its compounds, including thallium malonate, thallium iodide, and thallium formate, are listed in the Catalogue of Hazardous Chemicals.

[0003] Thallium exists primarily as trivalent oxides in seawater, locally highly oxidizing freshwater, and soil. It is generally found in soil, readily soluble in water under acidic conditions. Monovalent thallium is more stable in its dissolved state, while trivalent thallium can precipitate from water as oxides or hydroxides. Since both forms of thallium are highly toxic, with trivalent thallium being more toxic, thallium pollution control is of great importance in industrial activities. Traditional treatment technologies are limited by low treatment depth, poor selectivity, and interference from impurity ions, making them ineffective in treating thallium-containing wastewater.

[0004] Currently, the main processes for treating thallium-containing wastewater include chemical precipitation, adsorption, ion exchange, membrane methods, and biological methods. Adsorption of Tl using various chemical and biological materials (including MnO), polyacrylamide, TiO2, ferrous sulfates, carbon nanotubes, sawdust, and microalgae has been proven effective in removing Tl. Oxidation combined with precipitation using lime or caustic alkali has also been shown to successfully remove Tl. Ion exchange is an effective method for removing Tl and other metals (including uranium, chromium, and platinum). Solvent extraction of Tl(III) using certain organic extractants in an HCl medium is a good method for enriching and recovering Tl. Other methods for Tl purification include ultrafiltration, reverse osmosis, and electrodialysis, but these are difficult to promote and apply in actual industrial production due to high material and maintenance costs.

[0005] Chinese patent application CN115652114A discloses a resource recovery process for thallium in a thallium-containing solution, comprising the following steps: adsorbing thallium from the thallium-containing solution using a thiol resin; washing the thallium-adsorbing resin; eluting the thallium from the resin; subjecting the eluted solution to precipitation, impurity removal, and reduction treatment; and cleaning and melting the sponge thallium to obtain metallic thallium ingots. This process utilizes thiol resin as the thallium adsorption resin, enabling highly selective adsorption of thallium in the solution. + and Tl 3 + This process thoroughly separates thallium from the solution and avoids introducing other impurities, thus facilitating the production of a high-concentration, high-purity thallium-containing eluent. Furthermore, through a single impurity removal and reduction process, the thallium-containing eluent can be converted into metallic thallium products with a purity of over 99.99%. This method boasts advantages such as simple process, convenient operation, low processing cost, and high returns. It can recover thallium from different solutions, facilitating the resource utilization of thallium, and has good use value and application prospects.

[0006] Chinese patent application CN220245805U discloses a system for deep thallium removal from industrial wastewater, comprising: a first reaction tank configured to adjust the pH of the industrial wastewater to 2.5-4; a primary oxidation unit configured to add hydrogen peroxide to the first reaction tank for primary oxidation treatment of thallium in the industrial wastewater; an ion exchange unit configured to pass the primary oxidized industrial wastewater through an ion exchange resin reaction column to obtain purified water; a secondary oxidation unit configured to add a secondary oxidant to the purified water for secondary oxidation treatment of residual thallium in the purified water; a second reaction tank configured to adjust the pH of the secondary oxidized wastewater to 10-12 and add a flocculant to the wastewater to aid coagulation; and a flocculation tank configured to perform solid-liquid separation to remove residual thallium from the wastewater in the second reaction tank.

[0007] Existing industrial thallium-containing wastewater treatment typically requires multi-stage oxidation and precipitation, or biochemical reactions, electrochemical adsorption, and ion exchange. The trivalent thallium formed by oxidation is more toxic, increasing treatment risks, and requires more equipment, resulting in complex processes and limited treatment capacity. A simple and efficient process is needed to treat thallium in industrial wastewater. Traditional thallium removal processes require complex and expensive thallium removal reagents, which are also subject to high losses and low recovery rates. Highly efficient, inexpensive, and readily available thallium removal reagents can significantly reduce the cost of thallium removal treatment.

[0008] Chinese patent application CN117902770A discloses a highly efficient and rapid magnetic coagulation treatment system and method for treating thallium-containing wastewater. The system includes: an oxidation treatment unit that uses magnetic materials and sodium persulfate to oxidize the thallium-containing wastewater; a magnetic coagulation unit that uses chemical coagulants to perform magnetic coagulation treatment on the thallium-containing wastewater; a microwave digestion unit that uses a microwave digester to digest the magnetically coagulated material; and a magnetic separation unit that recovers the magnetic materials from the coagulated material. This system effectively addresses thallium pollution and also possesses the ability to degrade organic pollutants. It not only has the advantages of high thallium removal rate and high stability, but also promotes the removal of dissolved substances, resulting in denser flocs and less chemical sludge. Furthermore, it boasts high magnetic seed recovery rate, low residual metal ions, and low energy consumption. However, it still requires oxidation treatment, fails to achieve graded treatment of thallium, requires the addition of large amounts of oxidizing agents, and the preparation method of the magnetic nanomaterials used is complex, limiting its application. Summary of the Invention

[0009] The technical problem to be solved by this invention is how to remove thallium from industrial thallium-containing wastewater in a simple and efficient manner.

[0010] The present invention solves the above-mentioned technical problems through the following technical means:

[0011] An industrial thallium-containing wastewater treatment process includes the following steps:

[0012] (1) Add thallium-containing wastewater to a sedimentation tank, add alkali to adjust the pH of the wastewater to alkaline, and precipitate to remove trivalent thallium ions;

[0013] (2) The pH of the supernatant obtained after removing trivalent thallium ions is adjusted to neutral; then it is added to a magnetic coagulation sedimentation tank, and magnetic adsorption material, PAC and PAM are added. After the addition is completed, flocculation and sedimentation are carried out and filtered; wherein, the magnetic adsorption material is a mixture of Fe3O4 and Co3O4, and the mass ratio of Fe3O4 to Co3O4 is 3-10:1.

[0014] Preferably, in (1), the base is sodium hydroxide.

[0015] Preferably, in (1), alkali is added to adjust the pH of the wastewater to 12.

[0016] Preferably, in (1), the rate of addition of thallium-containing wastewater is 3t / h.

[0017] Preferably, in (2), sulfuric acid is added to adjust the pH to neutral.

[0018] Preferably, in (2), the mass ratio of Fe3O4 to Co3O4 is 4.2:1.

[0019] Preferably, in (2), the amount of magnetic adsorption material added is 30 g / L.

[0020] Preferably, in (2), the PAC and PAM are added as a 5% PAC solution and a 0.2% PAM solution, respectively, with the addition amount of the 5% PAC solution being 0.5 L / h and the addition amount of the 0.2% PAM solution being 0.2 L / h.

[0021] Preferably, in (2), the residence time for sedimentation reaction during flocculation and sedimentation is 0.5h.

[0022] Preferably, in (2), a quartz sand filter and an activated carbon filter are used for filtration.

[0023] The advantages of this invention are:

[0024] This invention provides an industrial thallium-containing wastewater treatment process based on a magnetic coagulation sedimentation tank. Through process optimization and control, a short-process, staged, and efficient thallium removal is achieved. A magnetic adsorption material (FC-1) of Fe3O4 and Co3O4 in a mass ratio of 3 to 10:1 is used to efficiently adsorb monovalent thallium.

[0025] This invention applies magnetic coagulation technology to the treatment of industrial thallium-containing wastewater. The addition of magnetic adsorption materials enhances the flocculation effect, and the magnetic flocs formed by combining the special effects of flocculants can settle more quickly. The wastewater after magnetic coagulation sedimentation enters a quartz sand and activated carbon filter. The filter removes residual suspended solids and magnetic adsorption materials from the supernatant. The quartz sand and activated carbon filters automatically perform forward and reverse washing operations. The filtered effluent can reduce the thallium content to below 50 μg / L, and in a preferred embodiment, to below 5 μg / L, meeting discharge standards.

[0026] This invention is applicable to the treatment of thallium-containing wastewater in various industrial enterprises, such as lead-zinc, steel, tin-antimony, sulfuric acid, and phosphate fertilizer industries.

[0027] This invention's process eliminates the traditional oxidation process by classifying trivalent and monovalent thallium, effectively reducing the treatment risks associated with oxidation to trivalent thallium. This makes the process safer, simpler, and more efficient. The main equipment in this invention is an inclined tube sedimentation tank and a magnetic coagulation sedimentation tank. These devices are highly mature, have high processing capacity, and can stably and efficiently treat thallium-containing wastewater. Due to the simplified process and mature equipment, the effect is more stable. No oxidizing agents are required, and the agents used are efficient, inexpensive, and readily available. The flocculant and magnetic adsorption material with Fe3O4 as the main component greatly contribute to reducing the cost of thallium removal. The amount of agents used is reduced, and there is no secondary pollution. The magnetic adsorption material in the magnetic coagulation sedimentation tank can be recycled, significantly reducing agent costs. Through an intelligent operation and maintenance control platform, the equipment has a small footprint, high maturity, and strong stability. The system also has a high degree of automation and intelligence, resulting in low maintenance costs. This allows for low-cost, stable, and efficient treatment of industrial thallium-containing wastewater, with a more intelligent control system. Attached Figure Description

[0028] Figure 1 This is a flowchart of the industrial thallium-containing wastewater treatment process in Embodiment 1 of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0031] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0032] In the following examples and comparative examples, the precipitation tank used to remove trivalent thallium ions was an inclined tube precipitation tank.

[0033] Comparative Example 1

[0034] An industrial thallium-containing wastewater treatment process includes the following steps: Wastewater (thallium content 10 mg / L) from a thallium-containing wastewater equalization tank is pumped into a sedimentation tank at a flow rate of 3 t / h. Sodium hydroxide is added to control the pH at 12, and the wastewater undergoes sedimentation to remove trivalent thallium ions. The supernatant from the sedimentation tank is then transferred to an intermediate water tank where sulfuric acid is added to adjust the pH to neutral. The wastewater is then pumped into a magnetic coagulation sedimentation tank, where Fe3O4 magnetic adsorbent material (30 g / L), a 5% PAC solution (0.5 L / h), and a 0.2% PAM solution (0.2 L / h) are added sequentially. Each of the three reagent addition tanks is equipped with a stirring motor and stirring rod. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank, with a sedimentation reaction time of 0.5 h. The supernatant from the magnetic coagulation sedimentation tank sequentially enters a quartz sand filter and an activated carbon filter, and the filtered water reduces the thallium content to 62 μg / L.

[0035] The entire system uses PLCs and an intelligent operation and maintenance platform to ensure the automated and intelligent operation of the processing system.

[0036] Example 1

[0037] Reference Figure 1 An industrial thallium-containing wastewater treatment process includes the following steps: Wastewater (thallium content 10 mg / L) from a thallium-containing wastewater equalization tank is pumped into a sedimentation tank at a flow rate of 3 t / h. Sodium hydroxide is added to control the pH at 12, and the wastewater undergoes sedimentation to remove trivalent thallium ions. The supernatant from the sedimentation tank is then transferred to an intermediate water tank where sulfuric acid is added to adjust the pH to neutral. The wastewater is then pumped into a magnetic coagulation sedimentation tank, where magnetic adsorption material composed of Fe3O4 and Co3O4 in a mass ratio of 10:1 (dosage 30 g / L), a 5% PAC solution (dosage 0.5 L / h), and a 0.2% PAM solution (dosage 0.2 L / h) are added sequentially. Each of the three reagent addition tanks is equipped with a stirring motor and stirring rod. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank, with a sedimentation reaction time of 0.5 h. The supernatant from the magnetic coagulation sedimentation tank sequentially enters a quartz sand filter and an activated carbon filter. The filtered water reduces the thallium content to 39 μg / L, and the sludge undergoes sludge treatment.

[0038] The entire system uses PLCs and an intelligent operation and maintenance platform to ensure the automated and intelligent operation of the processing system.

[0039] Example 2

[0040] An industrial thallium-containing wastewater treatment process includes the following steps: Wastewater (thallium content 10 mg / L) from a thallium-containing wastewater equalization tank is pumped into a sedimentation tank at a flow rate of 3 t / h. Sodium hydroxide is added to control the pH at 12, and the wastewater undergoes sedimentation to remove trivalent thallium ions. The supernatant from the sedimentation tank is then transferred to an intermediate water tank where sulfuric acid is added to adjust the pH to neutral. The wastewater is then pumped into a magnetic coagulation sedimentation tank, where magnetic adsorption material composed of Fe3O4 and Co3O4 in a mass ratio of 8:1 (dosage 30 g / L), a 5% PAC solution (dosage 0.5 L / h), and a 0.2% PAM solution (dosage 0.2 L / h) are added sequentially. Each of the three reagent addition tanks is equipped with a stirring motor and stirring rod. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank, with a sedimentation reaction time of 0.5 h. The supernatant from the magnetic coagulation sedimentation tank enters a quartz sand filter and an activated carbon filter in sequence. The filtered water reduces the thallium content to 35 μg / L.

[0041] The entire system uses PLCs and an intelligent operation and maintenance platform to ensure the automated and intelligent operation of the processing system.

[0042] Example 3

[0043] An industrial thallium-containing wastewater treatment process includes the following steps: Wastewater (thallium content 10 mg / L) from a thallium-containing wastewater equalization tank is pumped into a sedimentation tank at a flow rate of 3 t / h. Sodium hydroxide is added to control the pH at 12, and the wastewater undergoes sedimentation to remove trivalent thallium ions. The supernatant from the sedimentation tank is then transferred to an intermediate water tank where sulfuric acid is added to adjust the pH to neutral. The wastewater is then pumped into a magnetic coagulation sedimentation tank, where magnetic adsorption material composed of Fe3O4 and Co3O4 in a mass ratio of 5:1 (dosage 30 g / L), a 5% PAC solution (dosage 0.5 L / h), and a 0.2% PAM solution (dosage 0.2 L / h) are added sequentially. Each of the three reagent addition tanks is equipped with a stirring motor and stirring rod. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank, with a sedimentation reaction time of 0.5 h. The supernatant from the magnetic coagulation sedimentation tank sequentially enters a quartz sand filter and an activated carbon filter, and the filtered water reduces the thallium content to 5 μg / L.

[0044] The entire system uses PLCs and an intelligent operation and maintenance platform to ensure the automated and intelligent operation of the processing system.

[0045] Example 4

[0046] An industrial thallium-containing wastewater treatment process includes the following steps: Wastewater (thallium content 10 mg / L) from a thallium-containing wastewater equalization tank is pumped into a sedimentation tank at a flow rate of 3 t / h. Sodium hydroxide is added to control the pH at 12, and the wastewater undergoes sedimentation to remove trivalent thallium ions. The supernatant from the sedimentation tank is then transferred to an intermediate water tank where sulfuric acid is added to adjust the pH to neutral. The wastewater is then pumped into a magnetic coagulation sedimentation tank, where magnetic adsorption material composed of Fe3O4 and Co3O4 in a mass ratio of 4.2:1 (dosage 30 g / L), a 5% PAC solution (dosage 0.5 L / h), and a 0.2% PAM solution (dosage 0.2 L / h) are added sequentially. Each of the three reagent addition tanks is equipped with a stirring motor and stirring rod. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank, with a sedimentation reaction time of 0.5 h. The supernatant from the magnetic coagulation sedimentation tank enters a quartz sand filter and an activated carbon filter in sequence, and the filtered water reduces the thallium content to 3 μg / L.

[0047] The entire system uses PLCs and an intelligent operation and maintenance platform to ensure the automated and intelligent operation of the processing system.

[0048] Example 5

[0049] An industrial thallium-containing wastewater treatment process includes the following steps: Wastewater (thallium content 10 mg / L) from a thallium-containing wastewater equalization tank is pumped into a sedimentation tank at a flow rate of 3 t / h. Sodium hydroxide is added to control the pH at 12, and the wastewater undergoes sedimentation to remove trivalent thallium ions. The supernatant from the sedimentation tank is then transferred to an intermediate water tank where sulfuric acid is added to adjust the pH to neutral. The wastewater is then pumped into a magnetic coagulation sedimentation tank, where a magnetic adsorption material composed of Fe3O4 and Co3O4 in a mass ratio of 3:1 (30 g / L), a 5% PAC solution (0.5 L / h), and a 0.2% PAM solution (0.2 L / h) are added sequentially. Each of the three reagent addition tanks is equipped with a stirring motor and stirring rod. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank, with a sedimentation reaction time of 0.5 h. The supernatant from the magnetic coagulation sedimentation tank enters a quartz sand filter and an activated carbon filter in sequence, and the filtered water reduces the thallium content to 50 μg / L.

[0050] The entire system uses PLCs and an intelligent operation and maintenance platform to ensure the automated and intelligent operation of the processing system.

[0051] Comparative Example 2

[0052] The only difference from Example 5 is that the mass ratio of Fe3O4 to Co3O4 is 1:1. Specifically, the following steps are included: Wastewater from the thallium-containing wastewater conditioning tank (thallium content 10 mg / L) is pumped into the sedimentation tank at a flow rate of 3 t / h. Sodium hydroxide is added to control the pH at 12, and the wastewater undergoes sedimentation to remove trivalent thallium ions. The supernatant from the sedimentation tank is then added to an intermediate water tank with sulfuric acid to restore the pH to neutral. Next, the wastewater is pumped into a magnetic coagulation sedimentation tank, where magnetic adsorption material composed of Fe3O4 and Co3O4 in a 1:1 mass ratio (30 g / L), a 5% PAC solution (0.5 L / h), and a 0.2% PAM solution (0.2 L / h) are added sequentially. Each of the three reagent addition tanks is equipped with a stirring motor and stirring rod. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank, with a sedimentation reaction time of 0.5 h. The supernatant from the magnetic coagulation sedimentation tank sequentially enters a quartz sand filter and an activated carbon filter, and the filtered water reduces the thallium content to 862 μg / L.

[0053] The entire system uses PLCs and an intelligent operation and maintenance platform to ensure the automated and intelligent operation of the processing system.

[0054] Comparative Example 3

[0055] An industrial thallium-containing wastewater treatment process includes the following steps: Wastewater (thallium content 10 mg / L) from a thallium-containing wastewater equalization tank is pumped into a sedimentation tank at a flow rate of 3 t / h. Sodium hydroxide is added to control the pH at 12, and the wastewater undergoes sedimentation to remove trivalent thallium ions. The supernatant from the sedimentation tank is then transferred to an intermediate water tank where sulfuric acid is added to adjust the pH to neutral. The wastewater is then pumped into a magnetic coagulation sedimentation tank, where a magnetic adsorption material composed of Fe3O4 and Co3O4 in a mass ratio of 1:2 (30 g / L), a 5% PAC solution (0.5 L / h), and a 0.2% PAM solution (0.2 L / h) are added sequentially. Each of the three reagent addition tanks is equipped with a stirring motor and stirring rod. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank, with a sedimentation reaction time of 0.5 h. The supernatant from the magnetic coagulation sedimentation tank enters a quartz sand filter and an activated carbon filter in sequence, and the filtered water reduces the thallium content to 5 mg / L.

[0056] The entire system uses PLCs and an intelligent operation and maintenance platform to ensure the automated and intelligent operation of the processing system.

[0057] In this invention, the wastewater from the thallium-containing wastewater equalization tank is pumped into the inclined tube sedimentation tank for initial pH adjustment. Sodium hydroxide is added to adjust the pH to 12, resulting in primary sedimentation. The main function of primary sedimentation is to precipitate Tl(OH)3 formed under alkaline conditions, thus removing trivalent thallium from the wastewater. The supernatant from the inclined tube sedimentation tank enters an intermediate water tank to adjust the pH to neutral, and then enters the magnetic coagulation sedimentation tank. Magnetic adsorbent material, polyaluminum chloride (PAC), and polyacrylamide (PAM) are then added sequentially. After the reagents are added, the wastewater undergoes flocculation and sedimentation in the magnetic coagulation sedimentation tank. FC-1 magnetic adsorbent material has a high adsorption rate for monovalent thallium and can effectively remove monovalent thallium from the wastewater after primary sedimentation. The magnetic coagulation process includes sludge return and magnetic drum equipment. After sedimentation, a portion of the magnetic adsorbent material and flocs is returned to the reaction tank for recycling, saving coagulant usage and increasing the sludge concentration in the reaction tank. The remaining portion is separated from the sludge by the magnetic drum; the sludge then enters the sludge treatment unit, while the magnetic adsorbent material returns to the reaction tank for recycling, thus reducing the loss rate of the magnetic adsorbent material. After entering the sludge tank, the sludge from the magnetic coagulation sedimentation tank is further processed by a plate and frame filter press.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An industrial thallium-containing wastewater treatment process, characterized by: The method comprises the following steps: (1) adding thallium-containing wastewater into a sedimentation tank, adjusting the pH of the wastewater to be alkaline by adding alkali, and removing trivalent thallium ions by precipitation; (2) adjusting the pH of supernatant obtained by removing trivalent thallium ions to be neutral, then adding a magnetic coagulation and sedimentation tank, adding magnetic adsorption material, PAC and PAM, carrying out flocculation and sedimentation after the addition is completed, and filtering; wherein the magnetic adsorption material is a mixture of Fe3O4 and Co3O4, and the mass ratio of Fe3O4 to Co3O4 is 3-10:

1.

2. The industrial thallium-containing wastewater treatment process of claim 1, wherein: In (1), the alkali is sodium hydroxide.

3. The industrial thallium-containing wastewater treatment process of claim 1, wherein: In (1), the pH of the wastewater is adjusted to 12 by adding alkali.

4. The industrial thallium-containing wastewater treatment process of claim 1, wherein: In (1), the adding speed of thallium-containing wastewater is 3t / h.

5. The industrial thallium-containing wastewater treatment process of claim 1, wherein: In (2), sulfuric acid is added to adjust the pH to be neutral.

6. The industrial thallium-containing wastewater treatment process of claim 1, wherein: In (2), the mass ratio of Fe3O4 to Co3O4 is 4.2:

1.

7. The industrial thallium-containing wastewater treatment process of claim 1, wherein: In (2), the adding amount of the magnetic adsorption material is 30g / L.

8. The industrial thallium-containing wastewater treatment process of claim 1, wherein: In (2), the PAC and PAM are added in the form of a 5% PAC solution and a 0.2% PAM solution respectively, the adding amount of the 5% PAC solution is 0.5L / h, and the adding amount of the 0.2% PAM solution is 0.2L / h.

9. The industrial thallium-containing wastewater treatment process of claim 1, wherein: In (2), the residence time of the sedimentation reaction in the flocculation and sedimentation process is 0.5h.

10. The industrial wastewater treatment process according to any one of claims 1 to 9, characterized in that: In (2), quartz sand filter and activated carbon filter are used for filtering.

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