A device and method for treating wastewater containing thallium

Abstract

The present invention belongs to the technical field of wastewater treatment, and specifically discloses a thallium-containing wastewater treatment device, including a sedimentation tank and a reaction tank arranged above the sedimentation tank, wherein the reaction tank includes an electrocatalytic tank, a pH regulating tank, an electroflocculation tank, a magnetic medium inoculation tank and a stabilization tank connected in sequence; the pH regulating tank is provided with a drainage trough 1 connected to the electrocatalytic tank, and the outlet of the drainage trough 1 is connected to the electroflocculation tank through a vortex trough 1 and an arc-shaped water outlet trough 1 in sequence; the structures of the magnetic medium inoculation tank and the stabilization tank are the same as those of the pH regulating tank; pH probes are installed inside the pH regulating tank and the stabilization tank. A method for treating thallium-containing wastewater is also disclosed. The thallium-containing wastewater treatment device of the present invention occupies little space, has good removal effect, and has stable effluent; and no thallium removal agent, flocculant, etc. need to be added during operation, which greatly reduces the operating cost.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a device and method for treating thallium-containing wastewater. Background Art

[0002] Thallium (Tl) is a highly toxic heavy metal element with high water solubility, strong accumulation and biological toxicity. In natural water environments, thallium is extremely easy to migrate and spread. It can be enriched and amplified through the food chain, threatening the survival and reproduction of aquatic plants and animals and causing regional water ecological imbalance.

[0003] At present, the removal of thallium pollution is still mainly based on chemical precipitation. The basic principle of chemical precipitation is to remove thallium by adding thallium removal agents (including hydroxides, sulfides, etc.) to react with thallium ions in wastewater to generate insoluble precipitates. In order to improve the treatment effect of wastewater, the wastewater should be treated together with electrocatalytic cells, pH adjustment cells, etc. during the wastewater treatment process. However, the existing chemical precipitation method still has some shortcomings: First, electrocatalytic cells, pH adjustment cells, etc. occupy a large area and have high investment costs. Second, it is necessary to continuously add thallium removal agents during operation, and the dosage is large, and the price of thallium removal agents is expensive, resulting in high operating costs; in addition, the addition of a large amount of thallium removal agents will lead to unstable effluent water quality, and often require callback treatment, resulting in high operating costs. Third, due to the extremely strong toxicity of thallium, the concentration of thallium allowed to be discharged in wastewater is extremely low, so the stability of the treatment device is extremely high; and the chemical precipitation method is extremely sensitive to the pH value of wastewater, and the fluctuation of pH value often leads to excessive thallium in the effluent.

[0004] It can be seen that it is urgent to develop a low-cost, efficient and stable thallium removal device and method to meet the increasingly stringent environmental emission requirements. Summary of the invention

[0005] The problem to be solved by the present invention is to overcome the above technical defects and provide a device and method for treating thallium-containing wastewater.

[0006] The technical solution of the present invention is as follows:

[0007] The first invention object of the present invention is to provide a thallium-containing wastewater treatment device, comprising a sedimentation tank and a reaction tank arranged above the sedimentation tank, wherein the reaction tank comprises an electrocatalytic tank, a pH regulating tank, an electrocoagulation tank, a magnetic medium inoculation tank and a stabilization tank connected in sequence;

[0008] The pH adjustment tank is provided with a drainage groove 1 connected to the electrocatalytic tank, and the outlet of the drainage groove 1 is connected to the electric flocculation tank through a vortex groove 1 and an arc-shaped water outlet groove 1 in sequence;

[0009] The structures of the magnetic medium inoculation pool and the stabilization pool are the same as that of the pH adjustment pool; pH probes are installed inside the pH adjustment pool and the stabilization pool.

[0010] The present invention arranges the reaction tank in the upper layer of the sedimentation tank, which makes full use of the space, greatly saves the floor space and reduces the investment cost.

[0011] The present invention installs pH probes for detecting the pH value of wastewater in the pH adjustment tank and the stabilization tank, thereby accurately controlling the pH value of the wastewater in the tank, ensuring the stability of the reaction and the pH value of the effluent, and greatly reducing the probability of excessive thallium in the effluent due to pH value fluctuations; at the same time, the equipment can operate automatically, further improving the stability of the treatment device.

[0012] The structure of the magnetic medium inoculation pool and the stabilization pool of the present invention is the same as that of the pH adjustment pool, and the cross-section of the flow channel of the wastewater is an S-shaped structure, which prolongs the treatment time of the wastewater in the pool and promotes the precipitation of impurities. At the same time, the vortex tank makes the water flow form a vortex to achieve stirring and mixing, reducing the use of the mixer and further reducing the operating cost.

[0013] In a further embodiment, a basket filter and an electrocatalytic reaction device are provided inside the electrocatalytic cell, a reaction water inlet pipe is connected to the top of one side of the electrocatalytic cell, and the outlet of the reaction water inlet pipe is located inside the basket filter. Wastewater coming from the reaction water inlet pipe must first pass through the basket filter to filter out larger particles in the wastewater before entering the electrocatalytic reaction device for electrocatalytic oxidation.

[0014] In a further solution, the electrocatalytic cell is connected to the pH adjusting cell via a reaction water outlet, and the pH adjusting cell is connected to the electric flocculation cell via an adjustment water outlet; the reaction water inlet pipe and the reaction water outlet are located at opposite corners of the electrocatalytic cell, and the inner side walls of the other opposite corner are both arc-shaped walls; the electrocatalytic reaction device is located between the reaction water inlet pipe and the reaction water outlet; the reaction water outlet and the adjustment water outlet are located at opposite corners of the pH adjusting cell.

[0015] According to a further solution, the cross-section of the drainage groove 1 gradually decreases from the water inlet end to the vortex groove 1 and is in a trumpet shape; the cross-section of the vortex groove 1 is a circular structure, the arc-shaped water outlet groove 1 is located outside the vortex groove 1, and the groove wall of the arc-shaped water outlet groove 1 is an arc-shaped structure.

[0016] In a further embodiment, a pH probe is installed at the connection between the vortex groove 1 and the arc-shaped water outlet groove 1; the distance between the pH probe 1 and the center of the vortex groove 1 is greater than the radius of the vortex groove 1;

[0017] An acid dosing pipe and an alkali dosing pipe are arranged side by side inside the drainage trough 1.

[0018] A further solution is that the magnetic medium inoculation tank is provided with two connected drainage troughs, two vortex troughs, and two arc-shaped water outlet troughs in sequence, wherein the interior of the drainage trough is provided with a magnetic medium inoculation port and a magnetic medium sludge return port side by side, and the magnetic medium sludge return port is connected to the sedimentation tank through a sludge pump and introduces part of the sludge into the magnetic medium inoculation tank for recycling.

[0019] According to a further solution, the stabilization tank is provided with a drainage trough three, a vortex trough three, and an arc-shaped water outlet trough three which are connected in sequence, an acid dosing pipe two and an alkali dosing pipe two are arranged side by side inside the drainage trough three, and the arc-shaped water outlet trough three is provided with a water outlet channel connected to the sedimentation tank.

[0020] Preferably, the bottom end of the water outlet channel is connected to the bottom of the inner wall of the sedimentation tank through a water conduit.

[0021] In a further solution, the reaction tank divides the sedimentation tank horizontally into a sinking area and an open area, the open area is provided with an inclined plate filler, a plurality of overflow weirs interconnected are provided at the water surface above the inclined plate filler, and a drainage outlet is opened on the side wall of the open area.

[0022] In a further solution, a funnel-shaped sedimentation plate is provided at the bottom of the sedimentation tank, and the funnel-shaped sedimentation plate includes an inclined bottom plate and a bracket located at the bottom end of the inclined bottom plate for support; a sludge hopper for depositing sludge is opened at the center of the funnel-shaped sedimentation plate.

[0023] A further solution also includes a deflocculant and a magnetic medium separation device, the sludge hopper is connected to a sludge pump, the sludge pump is arranged outside the sedimentation tank, the outlet of the sludge pump is connected to the deflocculant, the outlet of the deflocculant is connected to the magnetic medium separation device to separate the magnetic medium from the sludge; the magnetic medium separation device is provided with a magnetic medium outlet and a sludge discharge port, the magnetic medium outlet is connected to the magnetic medium inoculation tank through a magnetic seed dosing pump; the sludge discharge port realizes the discharge of residual sludge.

[0024] The inclination angle of the inclined bottom plate is not less than 8°.

[0025] In a further solution, a sealed equipment warehouse is arranged inside the sedimentation tank side by side with the reaction tank, and the deflocculation device, magnetic medium separation device and magnetic seed dosing pump are all arranged in the equipment warehouse; a medicine box and a dosing pump are also arranged in the equipment warehouse.

[0026] A second object of the present invention is to provide a method for treating thallium-containing wastewater, which comprises the following steps:

[0027] S1. After filtering out larger particles from the thallium-containing wastewater, add the wastewater to an electrocatalytic reaction device, and utilize electrocatalytic oxidation to oxidize the monovalent thallium in the wastewater into trivalent thallium;

[0028] S2, adjusting the pH value of the wastewater treated in step S1 to 8-10, so that trivalent thallium in the wastewater is converted into thallium hydroxide;

[0029] S3, adding into the electric flocculation reaction device to carry out flocculation reaction;

[0030] S4. Add magnetic media to promote further flocculation of suspended matter in wastewater;

[0031] S5, adjust the pH value to 8.5-9;

[0032] S6. The conditioned wastewater is precipitated and the clear liquid is then discharged through the inclined plate filler.

[0033] In a further embodiment, the pH value is adjusted in steps S2 and S6 using an acidic regulator or an alkaline regulator, wherein the acidic regulator is one or more of sulfuric acid, hydrochloric acid, oxalic acid and citric acid;

[0034] The alkaline regulator is one or more of sodium hydroxide, calcium hydroxide and calcium oxide.

[0035] Part of the precipitated sludge is returned to step S4 as a magnetic medium for recycling, and the other part is deflocculated and then separated. The separated magnetic medium is recycled, and the sludge is directly discharged.

[0036] Compared with the existing technology, the present invention has the following beneficial effects:

[0037] 1. The present application arranges the reaction tank and the equipment bin in the upper layer of the sedimentation tank, that is, the sedimentation tank is divided into two parts in the longitudinal direction, and the upper part is used to place the reaction tank and the equipment bin, that is, to expand its longitudinal depth, make full use of the space, greatly save the floor space, and reduce the investment cost. At the same time, the reaction tank divides the sedimentation tank into a sinking area and an open area in the transverse direction, wherein the open area is provided with an inclined plate filler, an overflow weir and a drain port, which is convenient for the precipitation of suspended matter in the wastewater and the discharge of the treated wastewater.

[0038] 2. The present invention simultaneously utilizes the electro-flocculation process + magnetic medium to accelerate the settling speed of the suspended matter, further reducing the floor space of the sedimentation tank.

[0039] 3. The present invention sets the internal structures of the magnetic medium inoculation pool, the stabilization pool and the pH adjustment pool into drainage grooves, vortex grooves and arc-shaped water outlet grooves that are connected in sequence, that is, the cross-section of the flow channel of the wastewater is an S-shaped structure, which increases the treatment time of the wastewater in the pool and reduces the floor space of each pool, and also promotes the precipitation speed of impurities. At the same time, the vortex groove makes the water flow form a vortex to achieve stirring and mixing between the wastewater and the acidic or alkaline regulator, thereby eliminating the use of a stirrer in the treatment device and further reducing the operating cost.

[0040] 4. The channels for wastewater circulation inside the electrocatalytic cell, pH adjustment cell, electrocoagulation cell, magnetic medium inoculation cell and stabilization cell all have arc-shaped walls, which reduces dead corners and overcomes the problem of difficulty in cleaning caused by suspended matter in the wastewater being deposited at corners; therefore, the arrangement of the arc-shaped walls in the present invention can drain the wastewater while avoiding the problem of suspended matter deposition.

[0041] 5. The present invention adopts a two-stage pH adjustment tank + stabilization tank to adjust the pH value of the wastewater, and pH probes for detecting the pH value of the wastewater in the tank are installed inside the pH adjustment tank and the stabilization tank, thereby accurately controlling the pH value of the wastewater in the tank, ensuring the stability of the reaction and effluent pH value, and greatly reducing the probability of excessive thallium in the effluent due to pH value fluctuations; at the same time, the equipment can operate automatically, further improving the stability of the equipment.

[0042] 6. The thallium removal process of the present invention is simple. After the monovalent thallium in the wastewater is oxidized into trivalent thallium by an electrocatalytic process, the pH value is controlled to be alkaline to precipitate the thallium pollutants, and then the suspended matter is quickly precipitated and separated by electrocoagulation and magnetic medium coagulation, thereby achieving efficient and rapid separation of thallium pollutants.

[0043] 7. The treatment method of the present invention does not use thallium removal agents, which greatly reduces the cost of treatment agents. At the same time, the treatment method only uses acidic regulators and alkaline regulators to control the pH value of the wastewater; at the same time, the electrocoagulation process is used to replace the use of coagulants and flocculants, further reducing the cost of agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings:

[0045] Figure 1 is a top view of the processing device of the present application,

[0046] Figure 2 for Figure 1 The left view of

[0047] Figure 3 for Figure 2 Right view of

[0048] Figure 4 This is a top view of the reaction pool in this application.

[0049] Figure 5 Schematic diagram of the connection structure of the electrocatalytic cell and the pH adjustment cell in this application,

[0050] Figure 6 This is a schematic diagram of the connection structure of the electric flocculation tank, the magnetic medium inoculation tank and the stabilization tank in this application.

[0051] Figure 7It is a schematic diagram of the connection between the reaction tank and the sedimentation tank in this application,

[0052] Figure 8 This is a top view of the bottom of the sedimentation tank in this application.

[0053] Fig. 9 This is a flow chart of the processing method of Example 2 in this application.

[0054] Notes in the figure:

[0055] Reaction tank 1, electrocatalytic tank 11, reaction water inlet pipe 111, basket filter 112, electrocatalytic reaction device 113, first arc-shaped baffle 114, reaction water outlet 115;

[0056] pH regulating tank 12, drainage trough 121, vortex trough 122, arc-shaped water outlet trough 123, regulating water outlet 124, pH probe 125, acid dosing pipe 126, alkali dosing pipe 127;

[0057] An electric flocculation tank 13, an electric flocculation reaction device 131, a third arc-shaped baffle 132, and a flocculation water outlet 133;

[0058] Magnetic medium inoculation pool 14, drainage trough 2 141, vortex zone 2 142, arc-shaped water outlet trough 2 143, magnetic medium inoculation port 144, magnetic medium sludge return port 145;

[0059] Stabilization tank 15, drainage trough three 151, vortex zone three 152, arc-shaped water outlet trough three 153, water outlet channel 154, pH probe two 155, acid dosing pipe two 156, alkali dosing pipe two 157, water guide pipe 158;

[0060] Sedimentation tank 2, inclined bottom plate 21, sludge hopper 22, inclined plate filler 23, overflow weir 24, drain outlet 25, bracket 26;

[0061] Equipment warehouse 3, sludge pump 4. DETAILED DESCRIPTION

[0062] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. If the specific implementation steps or conditions are not specified in the embodiments, the operations or conditions of the conventional method steps described in the regulations or documents in this field can be carried out.

[0063] Embodiment 1:

[0064] See also Figure 1-8 As shown, this embodiment provides a thallium-containing wastewater treatment device, including a sedimentation tank 2 and a reaction tank 1 arranged above the sedimentation tank 2, wherein the reaction tank 1 includes an electrocatalytic tank 11, a pH adjustment tank 12, an electrocoagulation tank 13, a magnetic medium inoculation tank 14 and a stabilization tank 15 connected in sequence.

[0065] In this embodiment, the reaction tank is arranged in the upper layer of the sedimentation tank, which makes full use of the space, greatly saves the floor space and reduces the investment cost.

[0066] The reaction pool of this embodiment is composed of an electrocatalytic cell 11, a pH regulating cell 12, an electrocoagulation cell 13, a magnetic medium inoculation cell 14 and a stabilization cell 15 which are connected in sequence and arranged side by side (such as Figure 4 As shown in the figure, its total volume is small, accounting for only about half of the sedimentation tank surface; and the wastewater stays in each tank for a short time. In addition, the electrocoagulation process and magnetic media are used to accelerate the sedimentation rate of suspended matter in the wastewater, further reducing the area occupied by the sedimentation tank.

[0067] The pH adjustment tank 12 is provided with a drainage groove 121 connected to the electrocatalytic tank 11, and the outlet of the drainage groove 121 is connected to the electric flocculation tank 13 through a vortex groove 122 and an arc-shaped water outlet groove 123 in sequence;

[0068] The structures of the magnetic medium inoculation tank 14 and the stabilization tank 15 are the same as that of the pH adjustment tank 12; the pH adjustment tank 12 and the stabilization tank 15 are respectively installed with a pH probe 125 and a pH probe 2 155 for detecting the pH value of the wastewater in the tank.

[0069] The present invention installs pH probes for detecting the pH value of wastewater in the pH adjustment tank and the stabilization tank, thereby accurately controlling the pH value of the wastewater in the tank, ensuring the stability of the reaction and effluent pH value, and greatly reducing the probability of excessive thallium in the effluent due to pH value fluctuations; at the same time, the device can operate automatically, further improving the stability of the device.

[0070] The structure of the magnetic medium inoculation pool and the stabilization pool of the present invention is the same as that of the pH adjustment pool. The cross-section of the flow channel of the wastewater in the pool is an S-shaped structure, which increases the treatment time of the wastewater in the pool and reduces the floor space of each pool, while also promoting the precipitation speed of impurities. At the same time, the vortex tank makes the water flow form a vortex to achieve stirring and mixing, reducing the use of the mixer and further reducing the operating cost.

[0071] like Figure 1As shown, a basket filter 112 and an electrocatalytic reaction device 113 are provided inside the electrocatalytic cell 11, and a reaction water inlet pipe 111 is connected to the top of one side of the electrocatalytic cell 11, and the outlet of the reaction water inlet pipe 111 is located inside the basket filter 112. After the wastewater enters from the reaction water inlet pipe 111, it enters the basket filter 112 for filtration, and then flows through the gap between the positive and negative electrode plates of the electrocatalytic reaction device 113 for oxidation reaction, thereby oxidizing the monovalent thallium in the wastewater into trivalent thallium.

[0072] In another embodiment, Figure 5 As shown, a reaction water inlet pipe 111 is connected to the top of one side of the electrocatalytic cell 11, and the electrocatalytic cell 11 is connected to the pH regulating cell 12 through a reaction water outlet 115, and the pH regulating cell 12 is connected to the electrocoagulation cell 13 through an adjustment water outlet 124; the reaction water inlet pipe 111 and the reaction water outlet 115 are located at opposite corners of the electrocatalytic cell 11, and the inner side walls of the other opposite corners are both arc-shaped walls. Figure 5 As shown, the electrocatalytic cell 11 is a rectangular parallelepiped structure, and its four sides are connected by corners (generally right angles). In order to reduce dead corners and overcome the problem of suspended matter in wastewater being deposited at corners and difficult to clean, the first arc-shaped baffles 114 are installed on the inner sides of two adjacent corners of the water inlet in this embodiment to form a smooth arc-shaped wall, which can drain the wastewater while preventing the suspended matter therein from being deposited on it.

[0073] The electrocatalytic reaction device 113 is located between the reaction water inlet pipe 111 and the reaction water outlet 115 for electrocatalytic treatment of the incoming wastewater; similarly, in the pH adjustment tank 12, the reaction water outlet 115 and the adjustment water outlet 124 are located at opposite corners of the pH adjustment tank 12.

[0074] Similarly, the structure of the electrocoagulation cell 13 is the same as that of the electrocatalytic cell 11. Figure 6 As shown, the electro-flocculation tank 13 is provided with an electro-flocculation reaction device 131 inside, and the wastewater in the pH adjustment tank 12 enters the electro-flocculation tank 13 through the adjustment outlet 124, and then flocculates and precipitates in the wastewater through the gap between the positive and negative electrode plates of the electro-flocculation reaction device 131. Then the wastewater enters the magnetic medium inoculation tank 14 from the flocculation outlet 133 at the diagonal. Similarly, the third arc-shaped baffle 132 is installed on the inner side of the two adjacent corners of the water inlet to form a smooth arc-shaped wall, which can drain the wastewater while preventing the suspended matter therein from being deposited on it.

[0075] Electrocatalytic reaction devices and electroflocculation reaction devices are both conventional equipment in the field of environmental protection, especially in wastewater treatment, and can be directly purchased and used. The electrocatalytic reaction device uses the electric field to change the activation state of the reactants, thereby promoting the chemical reaction. In this embodiment, the monovalent thallium in the wastewater is oxidized into trivalent thallium under the action of electrocatalytic oxidation.

[0076] The electrocoagulation reaction device is a device that uses the principle of electrolysis to flocculate and precipitate pollutants in wastewater.

[0077] As above, the water inlet and outlet of the pH adjustment tank 12, the electric flocculation tank 13, the magnetic medium inoculation tank 14 and the stabilization tank 15 in this embodiment are all located at the relative corners of each tank, and the inner side wall of the other relative corner is an arc wall. That is, the flow direction of the wastewater in each tank is the diagonal direction, that is, the length of the flow channel is lengthened in a limited space.

[0078] Specific as Figure 5 As shown, the cross-section of the drainage groove 121 gradually decreases from the water inlet end to the vortex groove 122 and is in a trumpet shape; the cross-section of the vortex groove 122 is a circular structure, and a water outlet connected to the arc-shaped water outlet groove 123 is provided on the side wall at the connection with the arc-shaped water outlet groove 123; the arc-shaped water outlet groove 123 is located on the outside of the vortex groove 122, and the groove wall of the arc-shaped water outlet groove 123 is an arc-shaped structure.

[0079] In the embodiment, the pH adjustment tank 12 is a rectangular parallelepiped structure, and a curved plate is vertically installed inside it to guide the wastewater, that is, the flow channel through which the wastewater flows is a smooth curved wall, which can drain the wastewater while preventing the suspended matter therein from being deposited on the side walls at the corners. Figure 5 The drainage trough 121 is composed of two arc-shaped plates, one end of which is connected to the reaction water outlet 115 and the distance between the two is gradually reduced to form a trumpet shape, and the other end is connected to the vortex trough 122. Through the guidance of the drainage trough 121, the wastewater enters the circular vortex trough 122 to form a vortex and further mixes with the acidic or alkaline regulator in the wastewater more fully; then it falls into the arc-shaped water outlet trough 123, and finally enters the electric flocculation tank 13.

[0080] In another embodiment, the pH probe 125 in the pH adjustment tank 12 is installed at the connection between the vortex tank 122 and the arc-shaped water outlet tank 123, and the distance between the pH probe 125 and the center of the vortex tank 122 is greater than the radius of the vortex tank 122, that is, the installation position of the pH probe 125 is set at the outlet outside the circular area of ​​the vortex tank 1, and it detects the pH value of the wastewater after being fully mixed by the vortex tank 1, thereby improving the accuracy of the detection.

[0081] The drainage trough 121 is provided with an acid dosing pipe 126 and an alkali dosing pipe 127 side by side. Specifically, according to the pH value of the wastewater detected by the pH probe 125, the corresponding acidic or alkaline regulator is added through the acid dosing pipe 126 or the alkali dosing pipe 127, where it can be fully mixed with the wastewater generating the vortex, and the stirring equipment can be saved for stirring and mixing.

[0082] like Figure 6 As shown, the magnetic medium inoculation tank 14 is provided with a connected drainage trough 141, a vortex trough 142, and an arc-shaped water outlet trough 143 in sequence, wherein the interior of the drainage trough 141 is provided with a magnetic medium inoculation port 144 and a magnetic medium sludge return port 145 side by side, and the magnetic medium sludge return port 145 is connected to the sedimentation tank 2 through a sludge pump 4 and introduces part of the sludge into the magnetic medium inoculation tank 14 for recycling.

[0083] The drainage trough 2 141, vortex trough 2 142, and arc-shaped outlet trough 2 143 in the magnetic medium inoculation tank 14 have the same structure as the pH adjustment tank 12. The wastewater flowing out of the electroflocculation tank 13 is guided by the drainage trough 2 141, mixed with the magnetic medium (magnetic powder is selected in this embodiment) added in the magnetic medium inoculation port 144 and the sludge containing the magnetic medium added in the magnetic medium sludge return port 145, and then enters the vortex trough 2 142, and after further mixing through the generated vortex, flows into the pH stabilization tank 15 from the arc-shaped outlet trough 2 143.

[0084] In this embodiment, the stabilization tank 15 is used to further adjust the pH value of the wastewater, and the stabilization tank 15 is provided with a connected drainage tank 3 151, a vortex tank 3 152, and an arc-shaped water outlet tank 3 153 in sequence. The interior of the drainage tank 3 151 is provided with an acid dosing pipe 2 156 and an alkali dosing pipe 2 157 side by side, and the arc-shaped water outlet tank 3 153 is provided with a water outlet channel 154 connected to the sedimentation tank 2. A pH probe 2 155 is installed at the connection between the vortex tank 3 152 and the arc-shaped water outlet tank 3 153 to detect the pH value of the wastewater. According to the detected data, the corresponding acidic or alkaline regulator is added from the acid dosing pipe 2 156 or the alkali dosing pipe 2 157, and then mixed with the wastewater and enters the vortex tank 3 152 area to generate a vortex, thereby further mixing fully, and the stirring equipment can be saved for stirring and mixing. The pH value of the effluent is further controlled to improve the stability of the pH value of the effluent, thereby reducing the probability of excessive thallium in the effluent due to pH fluctuations; at the same time, the stability of the treatment device is further improved.

[0085] like Figure 7 As shown, the bottom end of the water outlet channel 154 is connected to the bottom of the inner wall of the sedimentation tank 2 through the water guide pipe 158. The wastewater flowing out of the magnetic medium inoculation tank 14 is guided into the vortex area 3 152 through the drainage groove 3 151, mixed with the added acidic or alkaline regulator here, and then flows into the water outlet channel 154 through the arc-shaped water outlet groove 3 153, and is discharged into the bottom of the sedimentation tank 2 through the water guide pipe 158.

[0086] like Figure 1-3 As shown, the reaction tank 1 divides the sedimentation tank 2 transversely into a sinking area and an open area. The open area is provided with an inclined plate filler 23, and a plurality of overflow weirs 24 interconnected with each other are provided at the water surface above the inclined plate filler 23. A drainage outlet 25 is opened on the side wall of the open area.

[0087] The inclined plate filler 23 in this embodiment is a commonly used filler in sewage treatment, and its material includes polypropylene (PP), polyvinyl chloride (PVC), and glass fiber reinforced plastic (FRP), which mainly plays a role in improving the clarification effect of the effluent. Specifically, the height of the inclined plate filler 23 is not less than half the height of the open area of ​​the sedimentation tank 2, and the distance between the top of the inclined plate filler and the water surface is less than 0.5m.

[0088] A funnel-shaped sedimentation plate is provided at the bottom of the sedimentation tank 2, and the funnel-shaped sedimentation plate includes an inclined bottom plate 21 and a bracket 26 located at the bottom end of the inclined bottom plate 21 for support. The funnel-shaped sedimentation plate has a circular bottom made of the inclined bottom plate 21. In order to better allow the suspended matter to settle and collect in the sludge hopper 22, the inclination angle of the inclined bottom plate 21 is not less than 8°; a sludge hopper 22 for depositing sludge is opened at the center of the funnel-shaped sedimentation plate.

[0089] The wastewater discharged from the outlet channel 154 of the pH stabilization tank 15 enters the sinking area of ​​the sedimentation tank 2, and falls on the inclined bottom plate 21 of the funnel-shaped sedimentation plate in the form of a tangent along its outer wall, forming a slow vortex in the concave funnel-shaped sedimentation plate and achieving sedimentation and separation of suspended matter under the action of gravity. The wastewater flows to the open area, and enters the overflow weir 24 after passing through the inclined plate filler 23, and finally gathers at the drain port 25 for discharge; the suspended matter therein will settle down and fall on the inclined bottom plate 21 with a slope, and gather into the sludge hopper 22 under the action of gravity.

[0090] In another embodiment, in order to further improve the recycling of raw materials, the processing device also includes a deflocculant device and a magnetic medium separation device, the sludge hopper 22 is connected to a sludge pump 4, wherein the sludge pump 4 is arranged outside the sedimentation tank 2, and the outlet of the sludge pump 4 is connected to the deflocculant device, and the outlet of the deflocculant device is connected to the magnetic medium separation device to separate the magnetic medium in the sludge; the magnetic medium separation device is provided with a magnetic medium outlet and a sludge discharge port, and the magnetic medium outlet is connected to the magnetic medium inoculation tank 14 through a magnetic seed dosing pump; the sludge discharge port safely discharges the remaining sludge.

[0091] In another embodiment, a sealed equipment compartment 3 (such as Figure 1 As shown in the figure, the deflocculation device, magnetic medium separation device and magnetic seed dosing pump are all arranged in the equipment warehouse 3; the equipment warehouse 3 is also provided with a medicine box and a dosing pump. The medicine box and the dosing pump are respectively connected to the acid dosing pipe 126 and the alkali dosing pipe 127 in the pH adjustment tank 12, and the acid dosing pipe 2 156 and the alkali dosing pipe 2 157 in the stabilization tank 15. The magnetic seed dosing pump is connected to the magnetic medium inoculation port 144 in the magnetic medium inoculation tank 14 for adding magnetic medium.

[0092] Similarly, the equipment bin is set on the upper layer of the sedimentation tank to make full use of the space, greatly save floor space and reduce investment costs.

[0093] It should be noted that the deflocculation device, magnetic medium separation device, magnetic seed dosing pump, etc. used in this embodiment are all conventional equipment in the art, and this application does not involve improvements to their structures or principles.

[0094] The steps of using the treatment device of this embodiment to treat thallium-containing wastewater are as follows:

[0095] The wastewater reaction water inlet pipe 111 enters the electrocatalytic cell 11, is first filtered through the basket filter 112 to remove the larger particles therein, and then enters the electrocatalytic reaction device 113, where the monovalent thallium in the wastewater is oxidized into trivalent thallium by electrocatalytic oxidation; and then is discharged into the pH adjustment tank 12 through the reaction outlet 115.

[0096] In the pH adjustment tank, the pH value of the wastewater is detected by the pH probe 125, and then the corresponding acidic regulator or alkaline regulator is added from the acid dosing pipe 126 or the alkali dosing pipe 127 according to the value. The specific amount of addition can be calculated according to the pH value of the added acidic regulator or alkaline regulator and the amount of wastewater, and the pH value detected in real time by the pH probe 125, so as to control the pH value of the wastewater between 8 and 10. Under alkaline conditions, the trivalent thallium in the wastewater is converted into thallium hydroxide (Tl(OH) 3 ) is precipitated and then discharged into the electrocoagulation tank 13.

[0097] In the electrocoagulation tank 13, the electrocoagulation reaction device 131 uses an electrocoagulation effect, and its positive electrode plate undergoes an oxidation reaction under the action of the current to release metal cations (Al3⁺, Fe2⁺ or Fe3⁺); and quickly combines with the hydroxide ions (OH⁻) in the wastewater to generate the corresponding metal hydroxide colloidal flocculant (Al(OH) 3 、Fe(OH) 2 or Fe(OH) 3 ). These flocculants have strong adsorption capacity and flocculation performance, so they can combine with suspended matter and magnetic media in wastewater to form larger flocs and precipitate, and the wastewater on the upper layer is discharged into the magnetic medium inoculation tank 14.

[0098] In the magnetic medium inoculation pool 14, magnetic medium is added to the wastewater through the magnetic medium inoculation port 144 to promote the coagulation of the wastewater and improve the coagulation and sedimentation effect. The wastewater is discharged into the stabilization pool 15 after passing through the drainage trough 141, the vortex zone 142 and the arc outlet trough 143.

[0099] In the stabilization tank 15, the pH value of the wastewater in the tank is again detected by the pH probe 155, and then the corresponding acidic regulator or alkaline regulator is added through the acid dosing pipe 156 or the alkali dosing pipe 157 to control the pH value of the wastewater between 8.5-9 and stabilize the pH value range of the wastewater to enhance the treatment effect, and then discharged into the bottom of the sedimentation tank 2 through the outlet channel 154 and the water pipe 158.

[0100] The wastewater entering the sedimentation tank 2 flows out from the overflow weir after passing through the inclined plate filler and is collected at the drain port 25 for discharge. The suspended matter in the wastewater will settle down and fall on the inclined bottom plate 21 with a slope, and will be collected in the sludge hopper 22 under the action of gravity. Since the sludge contains magnetic medium, part of the sludge will be returned through the sludge pump 4, that is, added to the magnetic medium inoculation tank 14 from the magnetic medium sludge return port 145 for recycling; the remaining sludge will be discharged into the deflocculation device through the sludge pump 4 for deflocculation, and then pumped into the magnetic medium separator for separation, and the obtained magnetic medium will be added to the magnetic medium inoculation tank 14 as a magnetic seed again, and the remaining sludge will be discharged.

[0101] Embodiment 2:

[0102] A method for treating thallium-containing wastewater comprises the following steps:

[0103] S1. After filtering out larger particles from the thallium-containing wastewater, add the wastewater to an electrocatalytic reaction device, and utilize electrocatalytic oxidation to oxidize the monovalent thallium in the wastewater into trivalent thallium;

[0104] S2, adjusting the pH value of the wastewater treated in step S1 to 8-10, so that trivalent thallium is converted into thallium hydroxide; this step is to precipitate the suspended matter in the wastewater;

[0105] S3, adding into the electric flocculation reaction device to carry out flocculation reaction, promoting the flocculation of suspended matter in the wastewater;

[0106] S4, adding magnetic powder to promote further flocculation of suspended matter in wastewater;

[0107] S5, adjust the pH value to 8.5-9;

[0108] S6. Settle the conditioned wastewater and then discharge the clear liquid through the inclined plate filler.

[0109] That is, under the action of gravity, the suspended matter after flocculation containing magnetic powder has a larger specific gravity and will settle down quickly. Some small suspended matter will not enter the outlet water due to the obstruction of the inclined plate filler.

[0110] Part of the sludge remaining at the bottom of the inclined plate filler is returned to step S4 as a magnetic medium for recycling, and the other part is deflocculated and then separated. The separated magnetic medium is recycled, and the sludge is directly discharged.

[0111] In steps S2 and S6, the pH value is adjusted using an acidic regulator or an alkaline regulator, wherein the acidic regulator is one or more of sulfuric acid, hydrochloric acid, oxalic acid and citric acid;

[0112] The alkaline regulator is one or more of sodium hydroxide, calcium hydroxide and calcium oxide.

[0113] In this embodiment, the acidic regulator is hydrochloric acid and the alkaline regulator is sodium hydroxide.

[0114] In this embodiment, the positive electrode plate of the electrocatalytic reaction device is a titanium-based coating electrode, and the negative electrode plate is a stainless steel electrode. The positive and negative electrode plates are installed alternately with an interval of 1.5-3.5 cm; the inter-cell voltage is controlled at 6-10V;

[0115] The positive electrode plate material of the electric flocculation reaction device is an iron-based or aluminum-based electrode, and the negative electrode plate material is a stainless steel electrode. The positive and negative electrode plates are installed alternately with an interval of 2.0-8.0 cm; the inter-cell voltage is controlled at 6-10V.

[0116] Embodiment 3:

[0117] The test results of thallium-containing wastewater from a certain enterprise are shown in the following table, where “influent” is used to represent the water volume, which is 50m 3 / d, pH value was 5.8, and thallium content was 75μg / L. The thallium content was detected by inductively coupled plasma mass spectrometry.

[0118] Then, the treatment device of Example 1 and the treatment method of Example 2 were used to treat the influent water, and the pH value of the effluent water was detected to be 8.8 and the thallium content was 4.8 μg / L. The specific results are shown in the following table:

[0119]

[0120] It is explained that the treatment device and treatment method of the present application can significantly reduce the thallium content, so that the effluent meets the thallium emission standard specified in the "Lead and Zinc Industrial Pollutant Emission Standard" (GB25466-2010); and the entire thallium removal operation cost is low and the efficiency is high.

[0121] The above shows and describes the basic principles, main features and characteristics of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of the present invention to be protected includes the attached claims and their equivalents.

Claims

1. A thallium-containing wastewater treatment device, comprising a sedimentation tank (2) and a reaction tank (1) arranged above the sedimentation tank (2), characterized in that: The reaction pool (1) comprises an electrocatalytic pool (11), a pH adjustment pool (12), an electrocoagulation pool (13), a magnetic medium inoculation pool (14) and a stabilization pool (15) which are connected in sequence; The pH regulating pool (12) is provided with a drainage groove 1 (121) connected to the electrocatalytic pool (11); the outlet of the drainage groove 1 (121) is connected to the electro-flocculation pool (13) via a vortex groove 1 (122) and an arc-shaped water outlet groove 1 (123) in sequence; the cross-section of the drainage groove 1 (121) gradually decreases in a trumpet shape from the water inlet end to the vortex groove 1 (122); the cross-section of the vortex groove 1 (122) is a circular structure; the arc-shaped water outlet groove 1 (123) is located outside the vortex groove 1 (122), and the groove wall of the arc-shaped water outlet groove 1 (123) is an arc-shaped structure; The structures of the magnetic medium inoculation pool (14) and the stabilization pool (15) are the same as the structure of the pH adjustment pool (12); pH probes are installed inside the pH adjustment pool (12) and the stabilization pool (15).

2. A thallium-containing wastewater treatment device according to claim 1, characterized in that: A basket filter (112) and an electrocatalytic reaction device (113) are provided inside the electrocatalytic cell (11), a reaction water inlet pipe (111) is connected to the top of one side of the electrocatalytic cell (11), and an outlet of the reaction water inlet pipe (111) is located inside the basket filter (112).

3. A thallium-containing wastewater treatment device according to claim 2, characterized in that: The electrocatalytic cell (11) and the pH regulating cell (12) are connected via a reaction water outlet (115), and the pH regulating cell (12) and the electroflocculation cell (13) are connected via a regulating water outlet (124); the reaction water inlet pipe (111) and the reaction water outlet (115) are located at opposite corners of the electrocatalytic cell (11), and the inner side walls of the other opposite corners are both arc-shaped walls; the electrocatalytic reaction device (113) is located between the reaction water inlet pipe (111) and the reaction water outlet (115); and the reaction water outlet (115) and the regulating water outlet (124) are located at opposite corners of the pH regulating cell (12).

4. A thallium-containing wastewater treatment device according to claim 1, characterized in that: A pH probe 1 (125) is installed at the connection between the vortex groove 1 (122) and the arc-shaped water outlet groove 1 (123), and the distance between the pH probe 1 (125) and the center of the vortex groove 1 (122) is greater than the radius of the vortex groove 1 (122); An acid dosing tube (126) and an alkali dosing tube (127) are arranged side by side inside the drainage trough 1 (121).

5. A thallium-containing wastewater treatment device according to claim 1, characterized in that: The magnetic medium inoculation tank (14) is provided with a second drainage trough (141), a second vortex trough (142), and a second arc-shaped water outlet trough (143) which are connected in sequence, wherein the interior of the second drainage trough (141) is provided with a magnetic medium inoculation port (144) and a magnetic medium sludge return port (145) side by side, and the magnetic medium sludge return port (145) is connected to the sedimentation tank (2) via a sludge pump (4) and guides part of the sludge into the magnetic medium inoculation tank (14) for recycling.

6. A thallium-containing wastewater treatment device according to claim 1, characterized in that: The stabilization tank (15) is provided with a drainage trough (151), a vortex trough (152), and an arc-shaped water outlet trough (153) which are connected in sequence. An acid dosing pipe (156) and an alkali dosing pipe (157) are arranged side by side inside the drainage trough (151). The arc-shaped water outlet trough (153) is provided with a water outlet channel (154) which is connected to the sedimentation tank (2).

7. A thallium-containing wastewater treatment device according to claim 6, characterized in that: The bottom end of the water outlet channel (154) is connected to the bottom of the inner wall of the sedimentation tank (2) through a water guide pipe (158).

8. A thallium-containing wastewater treatment device according to claim 1, characterized in that: The reaction tank (1) divides the sedimentation tank (2) transversely into a sinking area and an open area, the open area is provided with an inclined plate filler (23), a plurality of overflow weirs (24) interconnected are provided at the water surface above the inclined plate filler (23), and a drainage outlet (25) is provided on the side wall of the open area.

9. A thallium-containing wastewater treatment device according to claim 1, characterized in that: A funnel-shaped sedimentation plate is provided at the bottom of the sedimentation tank (2), and the funnel-shaped sedimentation plate comprises an inclined bottom plate (21) and a bracket (26) located at the bottom end of the inclined bottom plate (21) for supporting the bottom end; a sludge hopper (22) for depositing sludge is provided at the center of the funnel-shaped sedimentation plate.

10. A thallium-containing wastewater treatment device according to claim 9, characterized in that: It also includes a deflocculating device and a magnetic medium separation device, wherein the sludge hopper (22) is connected to a sludge pump (4), the outlet of the sludge pump (4) is connected to the deflocculating device, and the outlet of the deflocculating device is connected to the magnetic medium separation device to separate the magnetic medium from the sludge; the magnetic medium separation device is provided with a magnetic medium outlet and a sludge discharge port, and the magnetic medium outlet is connected to a magnetic medium inoculation tank (14) via a magnetic seed dosing pump; The inclination angle of the inclined bottom plate (21) is not less than 8°.

11. A thallium-containing wastewater treatment device according to claim 10, characterized in that: A sealed equipment bin (3) is arranged inside the sedimentation tank (2) and side by side with the reaction tank (1); the deflocculation device, the magnetic medium separation device, and the magnetic seed dosing pump are all arranged in the equipment bin (3); a medicine box and a dosing pump are also arranged in the equipment bin (3).

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