A process and device for separating and recovering chromium and lead ions in wastewater

Abstract

The present invention relates to the field of wastewater treatment technology, and more particularly to a process and apparatus for separating and recovering chromium and lead ions from wastewater. The apparatus comprises a flotation sedimentation tank equipped with an inlet pipe and a drain pipe, a feeding mechanism, and a dispersion mechanism. The flotation sedimentation tank is used to receive the wastewater to be treated. The feeding mechanism is disposed within the flotation sedimentation tank and is used to inject a reactant, a collector, and aeration gas into the flotation sedimentation tank. The dispersion mechanism is connected to the feeding mechanism and is used to disperse the reactant, collector, and aeration gas within the flotation sedimentation tank so that they come into full contact with the wastewater. The process comprises: introducing a reactant into the wastewater to cause the chromium ions and lead ions to react, respectively, to produce a chromium precipitate and a lead precipitate; introducing a collector into the wastewater to cause the lead precipitate to combine with the collector to impart hydrophobicity; aerating the wastewater to cause the lead precipitate to form froth; and separating and recovering the froth from the chromium precipitate. The present invention can achieve simultaneous separation and recovery of chromium and lead ions from wastewater, achieving high separation and recovery rates.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and more specifically, to a process and device for separating and recovering chromium and lead ions in wastewater. Background Art

[0002] Due to constraints such as technical conditions, management mechanisms, and economic benefits, my country's mineral resource development still faces severe ecological and environmental challenges. The high proportion of low-grade ore and relatively backward beneficiation and smelting technology result in large quantities of tailings and waste residues during ore processing. These wastes not only occupy farmland resources, but the heavy metals they contain continue to migrate and spread into the surrounding environment through surface runoff and groundwater infiltration, posing long-term risks to human health through the soil-water-animal and plant chain. Therefore, the remediation of heavy metal contamination in soil and the treatment and resource utilization of heavy metal-containing wastewater around mines are receiving increasing attention and are becoming increasingly important.

[0003] After years of sampling and experimental research, it was found that my country's lead ore resources are generally accompanied by chromium, such as chrome lead ore. Therefore, the wastewater generated during the mining process (or the leaching water of the surrounding soil) generally contains high concentrations of lead ions (Pb 2+ ) and chromium ions (Cr 3+ ), these two heavy metal ions are both highly biologically toxic and can be enriched in the human body through the food chain, causing serious health problems such as damage to the nervous system and organ dysfunction. Therefore, mine wastewater containing these two heavy metal ions, leachate from the surrounding soil, and even the surrounding soil containing these two heavy metals need to be treated accordingly to reduce heavy metal pollution. In the process of removing heavy metal pollution in soil, the soil is often acidified to convert the heavy metals in the soil into heavy metal ions and enter the liquid, producing liquids containing high concentrations of lead ions (Pb 2+ ) and chromium ions (Cr 3+ ) of wastewater.

[0004] The current commonly used industrial treatment processes for heavy metal-containing wastewater are: the first method is to perform chemical precipitation one by one according to the physicochemical properties of different heavy metals, then perform solid-liquid separation, and finally perform reduction to recover the heavy metal element or available compound. The second method is to mix the wastewater with an alkaline solution to obtain a hydroxide precipitate mixed with multiple metals, perform solid-liquid separation, and obtain a hydroxide of a certain heavy metal through multiple separations, and then perform reduction to recover the heavy metal element or available compound. Among them, the first method requires setting up multiple process flows and reactors according to the characteristics of different heavy metals, which is complex and costly. The second method is more difficult to separate the hydroxides of different heavy metals from the hydroxide precipitate mixed with multiple metals, and the purity of the separated heavy metals is low, and the actual utilization rate is not high, which affects the large-scale industrial promotion. The above-mentioned wastewater treatment process also has the problems of complex process, high cost and low separation recovery rate when treating wastewater containing high concentrations of lead ions and chromium ions. Summary of the Invention

[0005] In order to overcome the problems of complex separation and recovery process of chromium and lead ions in wastewater, high cost and low separation recovery rate in the above-mentioned prior art, the first aspect of the present invention provides a separation and recovery process of chromium and lead ions in wastewater.

[0006] A second aspect of the present invention provides a device for separating and recovering chromium and lead ions in wastewater.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a process for separating and recovering chromium and lead ions in wastewater, comprising the following steps:

[0008] S1: introducing a reactant into the wastewater containing chromium ions and lead ions to react with the chromium ions and lead ions to produce chromium precipitate and lead precipitate respectively;

[0009] S2: Adding a collector into the wastewater to make the lead precipitate combine with the collector to obtain hydrophobicity;

[0010] S3: adding aeration to the wastewater to form froth from the hydrophobic lead precipitate obtained in step S2;

[0011] S4: Separate and recover the scum and chromium precipitate in the wastewater.

[0012] In the technical solution of the present invention, the inventors, based on the precipitation characteristics of heavy metal ions in wastewater and accumulated experimental experience, have creatively proposed a new process for separating and recovering chromium and lead ions from wastewater. This solution simultaneously separates and recovers chromium and lead ions from wastewater by reacting lead ions to form a precipitate, which is then collected as froth, while chromium ions are separated by precipitation and sinking. This process is simple, low-cost, and achieves a high separation and recovery rate.

[0013] Preferably, the reactant is hydrogen sulfide, and the collector is dibutylammonium dithiophosphate.

[0014] In this scheme, hydrogen sulfide is used as a reactant to react with chromium ions to form chromium sulfide precipitates and with lead ions to form lead sulfide precipitates. Dibutylammonium dithiophosphate is used as a collector to combine with lead sulfide to produce black foamy froth that floats to the liquid surface. Chromium sulfide is not affected by the collector and sinks to the bottom for separation and recovery.

[0015] The present invention provides a device for separating and recovering chromium and lead ions in wastewater. The device comprises: a flotation sedimentation tank provided with a water inlet pipe and a drain pipe, the flotation sedimentation tank being used to accommodate wastewater to be treated; a feeding mechanism, the feeding mechanism being arranged in the flotation sedimentation tank and being used to respectively inject a reactant, a collector and an aeration gas into the flotation sedimentation tank; and a dispersing mechanism, the dispersing mechanism being connected to the feeding mechanism and being used to disperse the reactant, the collector and the aeration gas in the flotation sedimentation tank so as to fully contact the wastewater.

[0016] In this solution, the device is used to implement the above-mentioned process of separating and recovering chromium and lead ions in wastewater. The flotation sedimentation tank serves as the reaction vessel, and the feeding mechanism introduces reactants, collectors and aeration gas respectively according to the process sequence. The dispersion mechanism can promote the contact reaction of each reagent and improve the precipitation rate and separation rate.

[0017] Furthermore, the feeding mechanism includes an air inlet pipe, a collector liquid inlet pipe and an inner tube, the inner tube has a first inner inlet, a second inner inlet and an inner outlet, the air inlet pipe is connected to the first inner inlet, the collector liquid inlet pipe is connected to the second inner inlet, and the first inner inlet is located above the second inner inlet.

[0018] In this solution, an external reactant supply pipeline and aeration pipeline are connected through an air inlet pipe to supply reactants or aeration gas to the flotation sedimentation tank as needed, and an external collector supply pipeline is connected through a collector liquid inlet pipe to supply collector to the flotation sedimentation tank; since the first internal inlet is arranged above the second internal inlet, that is, the reactant inlet is located above the collector inlet, it can prevent the introduced collector from entering the air inlet pipe and contaminating and corroding the air inlet pipe.

[0019] Furthermore, the dispersion mechanism includes an outer tube and a plurality of blades. The outer tube is rotatably arranged in the flotation sedimentation tank. The blades are distributed along the circumference of the outer tube and are fixedly connected to the outer tube.

[0020] In this solution, the wastewater in the flotation sedimentation tank is stirred by rotating blades to mix with the reactants, collectors and aeration gas respectively, thereby promoting the reaction and improving the sedimentation rate and separation rate.

[0021] Furthermore, the dispersion mechanism also includes a diverter, the external tube has an external inlet and an external outlet, the external inlet is connected to the internal outlet, the external tube is rotatably connected to the lower end of the internal tube, the diverter is connected to the external outlet, the paddle is a hollow structure and has multiple outflow holes, and each paddle is respectively connected to the diverter.

[0022] In this solution, the inner tube is connected to the outer tube, which is then connected to each blade via a diverter. Reactants, collectors, and aeration gas enter the outer tube from the inner tube and then flow out of the outflow holes of each blade via the diverter. Under the action of centrifugal force, vortex flow of the wastewater in the flotation sedimentation tank can be achieved, while the reactants and collectors are evenly distributed in the wastewater containing chromium and lead ions. Under the action of the vortex flow of the mixed liquid, the reaction time of the reactants and collectors in the wastewater can be extended, the precipitation rate and collection rate of chromium and lead ions in the wastewater can be increased, and the reaction efficiency can be comprehensively improved.

[0023] Furthermore, it also includes a scraping mechanism, which includes a rotating ring and multiple scraping components. The rotating ring is rotatably connected to the upper end of the external tube. Each of the scraping components is distributed along the circumference of the rotating ring and is hinged to the rotating ring. The scraping component is connected to a float, and the scraping component can deflect around the hinge between the horizontal direction and the vertical direction.

[0024] In this solution, a scraping mechanism is used to rotate and scrape off the foam on the liquid surface of the flotation sedimentation tank to facilitate separation and collection. Since the scraping assembly is hinged on the rotating ring, when the device is in a non-working state, no wastewater is injected into the flotation sedimentation tank, and the scraping assembly is in a vertical state. On the one hand, it is convenient for staff to enter the flotation sedimentation tank for maintenance. On the other hand, it can also reduce the shear stress generated by the scraping mechanism's own gravity when it is horizontal, thereby extending the service life of the scraping frame. Since the scraping assembly is connected to a float, when the device is in a working state, wastewater is injected into the flotation tank, and the scraping mechanism gradually floats from the lower end of the vertical state to the horizontal state around the hinge, thereby realizing the normal function of scraping off foam.

[0025] Furthermore, the scraping assembly includes a scraping frame, a slide member, a positioning member and a lifting movable column, one end of the positioning member is fixedly connected to the rotating ring, the other end of the positioning member is rotatably connected to one end of the lifting movable column, the upper end of the slide member is fixedly connected to the rotating ring, one end of the scraping frame is movably connected to the slide member, and the middle part of the scraping frame is rotatably connected to the other end of the lifting movable column.

[0026] In this solution, the foam scraper frame is used to directly contact and scrape off the foam. By setting the sliding groove parts, positioning parts and lifting movable columns, on the one hand, it can limit the foam scraper frame so that the foam scraper frame can be deflected within the corresponding range. On the other hand, it can also improve the structural strength of the foam scraper assembly, making it more stable and reliable during the process of rotating to scrape off the foam.

[0027] Furthermore, a collecting trough is provided on the top of the side wall of the flotation sedimentation tank, the bottom of the collecting trough is arc-shaped, and the bottom of the collecting trough is connected to a collecting pipe.

[0028] In this solution, a collection trough is provided to ensure that lead sulfide foam is not easily splashed, so that it is easy to collect. The arc-shaped bottom of the collection trough makes it easier to discharge the collected lead sulfide foam from the collection pipe, while also reducing the amount of wall adhesion and improving the collection rate.

[0029] Furthermore, a crossbeam is fixedly connected to the top of the flotation sedimentation tank, and a driving device is fixedly connected to the crossbeam. The driving device is respectively connected to the external pipe and the rotating ring in a transmission manner, and the external pipe and the rotating ring rotate in opposite directions.

[0030] In this solution, the crossbeam can be used to install a driving device, which drives the external pipe and the rotating ring to rotate in opposite directions, thereby improving the collection efficiency of lead sulfide foam. The vortex also cleans the pool wall and funnel-shaped pool bottom, extending the service life of the equipment and improving economic benefits.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention provides a novel process for separating and recovering chromium and lead ions in wastewater, based on the precipitation characteristics of heavy metal ions in wastewater and accumulated experimental experience. The process involves reacting lead ions to generate a precipitate, which is then collected as froth, while allowing chromium ions to form a precipitate and sink for separation, thereby achieving simultaneous separation and recovery of chromium and lead ions in wastewater. The process is simple and low in cost.

[0033] 2. The device for separating and recovering chromium and lead ions in wastewater of the present invention is used to realize the above-mentioned process for separating and recovering chromium and lead ions in wastewater. The flotation sedimentation tank is used as a reaction vessel. The feeding mechanism introduces reactants, collecting agents and aeration gas respectively according to the process sequence. The dispersion mechanism can promote the contact reaction of each reagent and improve the precipitation rate and separation rate.

[0034] 3. The device for separating and recovering chromium and lead ions in wastewater of the present invention can realize vortex flow of wastewater in the flotation sedimentation tank through a dispersion mechanism, so that the reactants and collectors are evenly distributed in the wastewater containing chromium and lead ions. Under the action of the vortex flow of the mixed liquid, the reaction time of the reactants and collectors in the wastewater can be extended, the precipitation rate and collection rate of chromium and lead ions in the wastewater can be increased, and the reaction efficiency can be comprehensively improved.

[0035] 4. The device for separating and recovering chromium and lead ions in wastewater of the present invention scrapes off the foam on the liquid surface of the flotation sedimentation tank through a scraping mechanism to facilitate separation and collection. The scraping assembly can change between a vertical state and a horizontal state along with the liquid surface in the flotation sedimentation tank, making it easier for staff to enter the flotation sedimentation tank for maintenance. It can also reduce the shear stress of the scraping mechanism when it is horizontal, thereby extending the service life of the scraping frame.

[0036] 5. The device for separating and recovering chromium and lead ions in wastewater of the present invention realizes, through a transmission mechanism, that the scraping mechanism and the vortex flow of the wastewater in the flotation sedimentation tank are in opposite directions, thereby improving the collection efficiency of lead sulfide foam. At the same time, the vortex flow of the wastewater in the tank also concentrates the sinking chromium sulfide precipitates at the precipitation collection port and flows into the drain pipe, thereby improving the collection efficiency of the chromium sulfide precipitates. The vortex flow also cleans the tank walls and the funnel-shaped tank bottom, thereby extending the service life of the equipment and improving economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the overall structure of the chromium and lead ion separation and recovery device for wastewater in a non-working state according to the present invention;

[0038] Figure 2 yes Figure 1 Schematic diagram of the structure without the upper part of the flotation sedimentation tank.

[0039] Figure 3 This is an enlarged cross-sectional view of the collection tank and collection pipe of the flotation sedimentation tank;

[0040] Figure 4 This is a schematic diagram of the overall structure of the device for separating and recovering chromium and lead ions in wastewater in the present invention in a working state;

[0041] Figure 5 yes Figure 4 A magnified view of the monitoring component;

[0042] Figure 6 This is a schematic diagram of part of the structure of the chromium and lead ion separation and recovery device in wastewater in a non-working state;

[0043] Figure 7 yes Figure 6 Schematic diagram of part of the structure after removing the crossbeam and the components above it;

[0044] Figure 8 yes Figure 7 An enlarged view of the scraping mechanism;

[0045] Figure 9 This is an enlarged cross-section of the float;

[0046] Figure 10 yes Figure 8 Schematic diagram of the structure after removing the transmission structure;

[0047] Figure 11 yes Figure 10 Structural diagram from another perspective;

[0048] Figure 12 It is a schematic diagram of the structure of a decentralized organization;

[0049] Figure 13 This is an enlarged cross-section of the blade;

[0050] Figure 14 This is a schematic diagram of the overall structure of the chromium and lead ion separation and recovery device for wastewater according to the present invention in a working state from another angle;

[0051] Figure 15 yes Figure 14 An enlarged view of the scraping mechanism;

[0052] Figure 16 yes Figure 15 Structural diagram from another perspective;

[0053] Figure 17 yes Figure 14 A magnified view of the float;

[0054] Figure 18 It is an enlarged top view of the scraping mechanism.

[0055] In the accompanying drawings: 1. Flotation sedimentation tank; 11. Collection tank; 12. Collection pipe; 13. Crossbeam; 14. Water inlet pipe; 15. Sedimentation collection port; 16. Drain pipe; 2. Feed mechanism; 21. Air inlet pipe; 22. Collector liquid inlet pipe; 23. Internal pipe; 231. First internal inlet; 232. Second internal inlet; 233. Internal outlet; 24. Double-tube stabilizing plug; 3. Dispersion mechanism; 31. External pipe; 311. External inlet; 312. External outlet; 32. Paddle; 321. Outflow hole; 33. Diverter; 34. Connecting shaft Bearing; 341. Fixed column; 4. Scraping mechanism; 41. Rotating ring; 411. Support column; 42. Scraping assembly; 421. Scraping frame; 422. Slide member; 423. Positioning member; 424. Lifting column; 425. Roller; 43. Float; 5. Driving device; 51. Output shaft; 52. Diagonal support rod; 6. Transmission structure; 61. First driving gear; 62. First driven gear; 63. Second driving gear; 64. Second driven gear; 7. Monitoring assembly; 71. Monitoring tube; 72. Monitoring tank; 73. Monitoring retaining bolt. DETAILED DESCRIPTION

[0056] The drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate the embodiments, some components in the drawings may be omitted, enlarged, or reduced in size, and do not represent actual product dimensions. Those skilled in the art will understand that some well-known structures and their descriptions may be omitted from the drawings. The positional relationships depicted in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0057] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "long", "short", etc. indicating the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0058] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0059] Example 1

[0060] This embodiment discloses a process for separating and recovering chromium and lead ions in wastewater, comprising the following steps:

[0061] S1: introducing a reactant into the wastewater containing chromium ions and lead ions to react with the chromium ions and lead ions to produce chromium precipitate and lead precipitate respectively;

[0062] S2: Adding a collector into the wastewater to make the lead precipitate combine with the collector to obtain hydrophobicity;

[0063] S3: adding aeration to the wastewater to form froth from the hydrophobic lead precipitate obtained in step S2;

[0064] S4: Separate and recover the scum and chromium precipitate in the wastewater.

[0065] In this example, based on the precipitation characteristics of heavy metal ions in wastewater and accumulated experimental experience, a novel process for separating and recovering chromium and lead ions in wastewater is creatively proposed. This solution simultaneously separates and recovers chromium and lead ions from wastewater by reacting lead ions to form a precipitate, which is then collected as froth, while chromium ions are separated by precipitation and sinking. This process is simple and low-cost.

[0066] This example uses wastewater containing trivalent chromium ions and divalent lead ions as an example, with hydrogen sulfide as the reactant. When hydrogen sulfide gas dissolves in water, it reacts with trivalent chromium ions to form chromium sulfide precipitates, and with divalent lead ions to form lead sulfide precipitates. After the precipitates form, a collector for lead sulfide is added to the wastewater. The collector is butylammonium black powder, namely dibutylammonium dithiophosphate (C4H9)2PSSNH4. This makes the lead sulfide surface hydrophobic. Aeration of the wastewater causes the lead sulfide precipitate to form a black, foamy substance that floats to the surface. The chromium sulfide precipitate is largely unaffected by the collector, and due to its relatively large molecular weight (200.18), it settles downward. The process of this example allows for the separation of chromium and lead ions in wastewater for easy recovery, facilitating the subsequent resource utilization of heavy metals and improving economic efficiency.

[0067] Example 2

[0068] like Figures 1 to 18 As shown, this embodiment provides a device for separating and recovering chromium and lead ions in wastewater, which is used to implement the process for separating and recovering chromium and lead ions in wastewater in Example 1. Figure 1 and Figure 2 The device of this embodiment includes a flotation sedimentation tank 1 provided with an inlet pipe 14 and a drain pipe 16, a feeding mechanism 2 and a dispersion mechanism 3. The flotation sedimentation tank 1 is used to accommodate wastewater to be treated. The feeding mechanism 2 is arranged in the flotation sedimentation tank 1 and is used to inject a reactant, a collector and aeration gas into the flotation sedimentation tank 1 respectively. The dispersion mechanism 3 is connected to the feeding mechanism 2 and is used to disperse the reactant, the collector and the aeration gas in the flotation sedimentation tank 1 so that they are fully in contact with the wastewater.

[0069] In this embodiment, a flotation sedimentation tank 1 serves as a reaction vessel capable of accommodating wastewater and performing reactions. The bottom of the flotation sedimentation tank 1 is funnel-shaped and slopes downward. A sedimentation collection port 15 is provided at the bottom center of the flotation sedimentation tank 1. A drain pipe 16 is connected to the sedimentation collection port 15. A valve is provided on the drain pipe 16. After the reaction is completed, the wastewater is drained through the drain pipe 16 and filtered to obtain a chromium precipitate, which is then readily accessible for subsequent resource recovery processes. The feeding mechanism 2 is used to introduce reactants, collectors, and aeration gas in accordance with the process sequence of Example 1. The dispersion mechanism 3 can promote the contact reaction of each reagent, thereby improving the precipitation rate and separation rate.

[0070] The chromium and lead ion separation and recovery device for wastewater in this embodiment can realize the simultaneous precipitation, separation and collection of trivalent chromium ions and divalent lead ions in heavy metal wastewater, and has a high precipitation rate and separation rate.

[0071] refer to Figure 1 、 Figure 6 and Figure 7 The feeding mechanism 2 includes an air inlet pipe 21, a collector liquid inlet pipe 22 and an internal pipe 23. The internal pipe 23 has a first internal inlet 231, a second internal inlet 232 and an internal outlet 233. The air inlet pipe 21 is connected to the first internal inlet 231, the collector liquid inlet pipe 22 is connected to the second internal inlet 232, and the first internal inlet 231 is located above the second internal inlet 232.

[0072] In this embodiment, the air inlet pipe 21 is connected to an external reactant supply pipeline and aeration pipeline to supply reactants or aeration gas to the flotation sedimentation tank 1 as needed. The collector inlet pipe 22 is connected to an external collector supply pipeline to supply collector to the flotation sedimentation tank 1. Because the first internal inlet 231 is located above the second internal inlet 232, that is, the reactant inlet is located above the collector inlet, the introduced collector is prevented from entering the air inlet pipe 21 and contaminating and corroding the air inlet pipe 21.

[0073] Specifically, refer to Figure 1 A crossbeam 13 is fixedly connected to the top of the flotation sedimentation tank 1, and the feeding mechanism 2 is fixedly connected to the crossbeam 13. A double-tube stabilizing plug 24 is fixedly connected to the crossbeam 13. The double-tube stabilizing plug 24 has two vertical openings, through which the air inlet pipe 21 and the collector inlet pipe 22 are respectively fixedly connected. The double-tube stabilizing plug 24 not only secures the air inlet pipe 21 and the collector inlet pipe 22 to the crossbeam 13, but also allows them to be vertically aligned, reducing the horizontal space occupied on the crossbeam 13.

[0074] In this embodiment, the internal outlet 233 of the internal pipe 23 is directly or indirectly connected to the bottom of the flotation sedimentation tank 1, so that the reactants, collectors, and aeration gas can be injected into the flotation sedimentation tank 1 from the bottom to promote sufficient reaction with the wastewater. Valves are provided on both the air inlet pipe 21 and the collector inlet pipe 22 for opening and closing the pipes. The air inlet pipe 21 can be connected to an external reactant supply pipe and aeration pipe, respectively, to connect and supply reactants or aeration gas according to process requirements.

[0075] refer to Figure 2 The dispersion mechanism 3 includes an external pipe 31 and a plurality of paddles 32. The external pipe 31 is rotatably disposed in the flotation sedimentation tank 1. The paddles 32 are distributed circumferentially along the external pipe 31 and are fixedly connected to the external pipe 31. The rotation of the paddles 32 stirs the wastewater in the flotation sedimentation tank 1 and mixes it with the reactant, collector, and aeration gas, thereby promoting the reaction and improving the sedimentation rate and separation rate.

[0076] In some embodiments, the lower end of the inner tube 23 is connected to the upper end of the outer tube 31 and extends to the bottom of the flotation sedimentation tank 1, capable of transporting reactants, collectors, and aeration gas to the bottom of the flotation sedimentation tank 1. The outer tube 31 and the inner tube 23 are rotatably connected via a bearing. The outer tube 31 can rotate about a vertical axis under the action of the external drive device 5, driving the blades 32 to rotate and stir the wastewater, generating a vortex to promote the reaction.

[0077] It is understood that since the density of hydrogen sulfide gas (relative molecular mass 34.08) is greater than that of air (relative molecular mass approximately 29), when hydrogen sulfide gas is introduced, it will flow downward into the outer tube 31 at the inner tube 23 and will not escape from the connection between the inner tube 23 and the outer tube 31. In other embodiments, a movable sealing structure may be added at the connection between the inner tube 23 and the outer tube 31 to prevent gas leakage.

[0078] In this embodiment, reference Figure 12 、 Figure 13 as well as Figure 7 The dispersion mechanism 3 also includes a diverter 33. The external tube 31 has an external inlet 311 and an external outlet 312. The external inlet 311 is connected to the internal outlet 233. The external tube 31 is rotatably connected to the lower end of the internal tube 23. The diverter 33 is connected to the external outlet 312. The paddle 32 is a hollow structure and has multiple outflow holes 321. Each paddle 32 is respectively connected to the diverter 33.

[0079] In this embodiment, an external inlet 311 is provided at the upper end of the external tube 31, and an external outlet 312 is provided at the lower end of the external tube 31. The lower end of the internal tube 23 is connected to the upper end of the external tube 31, and the lower end of the external tube 31 is connected to each paddle 32 via a diverter 33. Reactants, collectors, and aeration gas enter the external tube 31 from the internal tube 23, then flow out of the outflow holes 321 of each paddle 32 through the diverter 33. Under the action of centrifugal force, a swirling flow of the wastewater within the flotation sedimentation tank 1 is achieved. Simultaneously, the reactants and collectors are evenly distributed throughout the wastewater containing chromium and lead ions. The swirling flow of the mixed solution prolongs the reaction time of the reactants and collectors in the wastewater, increasing the precipitation rate and collection rate of chromium and lead ions in the wastewater, and comprehensively improving reaction efficiency.

[0080] refer to Figure 12 as well as Figure 7 The diverter 33 is roughly cubic in shape, with a hollow structure inside. The front side of the diverter 33 is hidden in the figure. The top of the diverter 33 is connected to the lower end of the external tube 31, and the diverter 33 is connected with paddles 32 on all sides. The external tube 31, the diverter 33 and the paddles 32 are connected in sequence, so that the reactants, collectors and aeration gas can enter the interior of the paddles 32 and flow out from the external flow holes 321. The external flow holes 321 are evenly distributed at the bottom of the paddles 32. As the paddles 32 rotate, the reactants, collectors and aeration gas are evenly dispersed into the flotation sedimentation tank 1, fully contacting with the wastewater, and can achieve a higher sedimentation rate and separation rate.

[0081] refer to Figure 1 and Figure 3 A collection trough 11 is provided at the top of the sidewall of the flotation sedimentation tank 1. The bottom of the collection trough 11 is curved. A collection pipe 12 is connected to the bottom of the collection trough 11 and is equipped with a valve. In this embodiment, the provision of the collection trough 11 prevents the lead sulfide foam from splashing, facilitating its collection. The curved bottom of the collection trough 11 facilitates the discharge of the collected lead sulfide foam from the collection pipe 12, while also reducing the amount of foam adhering to the wall and improving the collection rate.

[0082] Specifically, the collection trough 11 is shaped like a "U" with its opening upward. The side of the collection trough 11 facing the interior of the flotation sedimentation tank 1 is the inner side, and the opposite side is the outer side. The upper end of the outer sidewall of the collection trough 11 is curved and tilted upward and inward, and is higher than the wall of the flotation sedimentation tank 1. This can prevent lead sulfide foam from splashing out, thereby ensuring the collection amount.

[0083] refer to Figure 1 as well as Figures 6 to 8A drive device 5 is fixedly connected to the crossbeam 13 at the top of the flotation sedimentation tank 1. The drive device 5 is in driving connection with the outer tube 31. The inner tube 23 is rotationally connected to the outer tube 31 via a bearing and is fixedly connected to the crossbeam 13. The drive device 5 can be a drive motor, which is fixedly connected above the crossbeam 13 via a diagonal brace 52. The upper end of the outer tube 31 is rotationally connected to the crossbeam 13 via a connecting bearing 34. The inner ring of the connecting bearing 34 is fixedly connected to the outer tube 31, and the outer ring of the connecting bearing 34 is fixedly connected to the crossbeam 13 via a fixing column 341.

[0084] In this solution, the crossbeam 13 is used to fix the driving device 5 and the inner tube 23. The driving device 5 drives the outer tube 31 to rotate, stirring the wastewater to produce a vortex. The vortex can promote the reaction and also clean the pool wall and the funnel-shaped pool bottom, thereby extending the service life of the equipment and improving economic benefits.

[0085] refer to Figures 6 to 8 The drive device 5 is connected to the external tube 31 via a transmission structure 6. The transmission structure 6 includes at least a first driving gear 61 and a first driven gear 62. The first driving gear 61 is coaxially fixedly connected to the output shaft 51 of the drive device 5. The first driven gear 62 is coaxially fixedly connected to the external tube 31. The first driving gear 61 meshes with the first driven gear 62, driving the external tube 31 to rotate through the first driving gear 61 and the first driven gear 62.

[0086] refer to Figure 4 and Figure 5 The water inlet pipe 14 is connected to the left side of the flotation sedimentation tank 1, and a water inlet valve is provided on the water inlet pipe 14. A monitoring assembly 7 is provided on the lower right side of the flotation sedimentation tank 1. The monitoring assembly 7 includes a monitoring pipe 71, a monitoring tank 72 and a monitoring retaining plug 73. One end of the monitoring pipe 71 is connected to the flotation sedimentation tank 1, and the other end of the monitoring pipe 71 is connected to the monitoring tank 72. One end of the monitoring retaining plug 73 is fixedly connected to the outer wall of the flotation sedimentation tank 1. The monitoring tank 72 is fixedly connected to the monitoring retaining plug 73, and a valve is provided on the monitoring pipe 71. The detection pool can take samples for experiments to measure the ion concentration in the wastewater. If it is reduced to a certain ion concentration, the water can be drained, filtered and separated, and enter the subsequent resource treatment process to ensure the precipitation rate of chromium and lead ions.

[0087] Example 3

[0088] like Figures 1 to 18 As shown, this embodiment is similar to embodiment 2, except that Figure 4 and Figure 6The chromium and lead ion separation and recovery device for wastewater of this embodiment also includes a scraping mechanism 4, which includes a rotating ring 41 and a plurality of scraping assemblies 42. The rotating ring 41 is rotatably connected to the upper end of the outer tube 31. Each scraping assembly 42 is distributed along the circumference of the rotating ring 41 and is hinged to the rotating ring 41. The scraping assembly 42 is connected to a float 43, and the scraping assembly 42 can deflect around the hinge between the horizontal direction and the vertical direction. The rotating ring 41 is rotatably connected to the outer tube 31 through a bearing. The float 43 is connected to the position of the scraping assembly 42 away from the rotating ring 41, which can be the middle or the end. The additional buoyancy provided by the float 43 is greater than the self-weight of the scraping assembly 42, so the scraping assembly 42 can be deflected and floated by the float 43.

[0089] In this embodiment, a scraping mechanism 4 is used to scrape off the foam on the liquid surface of the flotation sedimentation tank 1 so as to facilitate separation and collection. Since the scraping assembly 42 is hinged on the rotating ring 41 and can deflect around the hinge between the horizontal direction and the vertical direction, Figure 1 and Figure 6 When the device is in the non-working state, no wastewater is injected into the flotation sedimentation tank 1, and the scraper assembly 42 is in a vertical state. On the one hand, it is convenient for the staff to enter the flotation sedimentation tank 1 for maintenance. On the other hand, it can also reduce the shear stress generated by the gravity of the scraper mechanism 4 when it is horizontal, thereby extending the service life of the scraper frame 421. Since the scraper assembly 42 is connected to the float 43, when wastewater is injected into the flotation tank, Figure 4 When the device is in working state, the scraping mechanism 4 gradually floats up from the lower end of the vertical state to the horizontal state around the hinge, realizing the normal function of scraping off the foam.

[0090] refer to Figures 6 to 18 The scraping assembly 42 includes a scraping frame 421, a sliding groove member 422, a positioning member 423 and a lifting movable column 424. One end of the positioning member 423 is fixedly connected to the rotating ring 41, and the other end of the positioning member 423 is rotatably connected to one end of the lifting movable column 424. The upper end of the sliding groove member 422 is fixedly connected to the rotating ring 41, one end of the scraping frame 421 is movably connected to the sliding groove member 422, and the middle part of the scraping frame 421 is rotatably connected to the other end of the lifting movable column 424.

[0091] In this embodiment, the foam scraping frame 421 is used to directly contact and scrape off the foam. By setting the sliding groove part 422, the positioning part 423 and the lifting movable column 424, on the one hand, it can limit the foam scraping frame 421 so that the foam scraping frame 421 can be deflected within the corresponding range. On the other hand, it can also improve the structural strength of the foam scraping assembly 42, making it more stable and reliable during the process of rotating to scrape off the foam.

[0092] More specifically, refer to Figures 6 to 8 as well as Figure 11 、 Figure 15 and Figure 18 The positioning member 423 is slotted on one side away from the rotating ring 41, and a horizontally arranged shaft is fixedly connected in the slot. The upper end of the lifting movable column 424 is provided with a shaft sleeve and is connected to the shaft through a bearing for rotation. The middle part of the scraper frame 421 is also fixedly connected to a horizontally arranged shaft. The lower end of the lifting movable column 424 is provided with a shaft sleeve and is connected to the shaft through a bearing for rotation. The upper end of the slide member 422 is fixedly connected to the rotating ring 41, and the slide member 422 extends in the vertical direction. The upper end of the scraper plate is connected to a roller 425 through a shaft and a bearing, and is rollingly connected in the slide member 422 through the roller 425. Reference Figure 15 When the foam scraping frame 421 is horizontally arranged and in working state, a triangular structure is formed between the sliding groove member 422, the lifting movable column 424 and the foam scraping frame 421, which has high stability during the working process.

[0093] refer to Figure 1 as well as Figures 6 to 8 The driving device 5 is respectively connected to the outer tube 31 and the rotating ring 41 in a transmission manner, and the rotation directions of the outer tube 31 and the rotating ring 41 are opposite.

[0094] In this solution, the crossbeam 13 is used to fix the drive device 5, which drives the external pipe 31 and the rotating ring 41 to rotate in opposite directions, thereby improving the collection efficiency of lead sulfide foam. The vortex also plays a role in cleaning the pool wall and funnel-shaped pool bottom, extending the service life of the equipment and improving economic benefits.

[0095] refer to Figures 6 to 8The drive device 5 is connected to the external tube 31 and the rotating ring 41 via a transmission structure 6. The transmission structure 6 includes a first driving gear 61, a first driven gear 62, a second driving gear 63, and a second driven gear 64. The first driving gear 61 and the second driving gear 63 are both coaxially fixedly connected to the output shaft 51 of the drive device 5. The first driven gear 62 is coaxially fixedly connected to the external tube 31. The first driving gear 61 meshes with the first driven gear 62, and the external tube 31 is driven to rotate by the first driving gear 61 and the first driven gear 62. The second driven gear 64 is coaxially fixedly connected to the rotating ring 41 via the support column 411. The second driving gear 63 meshes with the second driven gear 64, and the rotating ring 41 is driven to rotate by the second driving gear 63 and the second driven gear 64. Since the first driving gear 61 and the first driven gear 62 are both external gears and transmission is achieved through external engagement, the first driving gear 61 and the first driven gear 62 rotate in opposite directions. The second driving gear 63 is an outer gear, and the second driven gear 64 is an inner gear. The second driving gear 63 and the second driven gear 64 are interlocked and meshed. Therefore, the second driving gear 63 and the second driven gear 64 rotate in the same direction. Since the first driving gear 61 and the second driving gear 63 are coaxially fixed and rotate in the same direction, the first driven gear 62 and the second driven gear 64 rotate in opposite directions. Therefore, the rotation direction of the outer tube 31 is opposite to the rotation direction of the rotating ring 41.

[0096] In this embodiment, the first driving gear 61, the first driven gear 62, the second driving gear 63, and the second driven gear 64 have different radii. By setting different gear radius ratios, the outer tube 31 and the rotating ring 41 have different rotational speeds. For example, when the first driving gear 61 and the second driving gear 63 rotate once, the outer tube 31 rotates once, while the rotating ring 41 rotates 0.12 times. Therefore, the rotation speed of the outer tube 31 is 8.3 times that of the rotating ring 41, and the rotation speed of the paddle 32 is 8.3 times that of the scraping mechanism 4. The direction of the swirling flow of the liquid in the pool is the same as the rotation direction of the paddle 32. While maintaining the stirring effect of the paddle 32, the scraping mechanism 4 rotates in the opposite direction to the paddle 32, which improves the collection efficiency of the lead sulfide foam.

[0097] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A device for separating and recovering chromium and lead ions in wastewater, characterized by: include: A flotation sedimentation tank (1) provided with a water inlet pipe (14) and a drain pipe (16), wherein the flotation sedimentation tank (1) is used to accommodate wastewater to be treated; A feeding mechanism (2), the feeding mechanism (2) being arranged in the flotation sedimentation tank (1) and being used to respectively inject a reactant, a collector and an aeration gas into the flotation sedimentation tank (1); a dispersion mechanism (3), the dispersion mechanism (3) being connected to the feeding mechanism (2) and being used for dispersing the reactant, the collector and the aeration gas in the flotation sedimentation tank (1) so as to fully contact the wastewater; The feeding mechanism (2) comprises an air inlet pipe (21), a collecting agent liquid inlet pipe (22) and an inner tube (23); the inner tube (23) has a first inner inlet (231), a second inner inlet (232) and an inner outlet (233); the air inlet pipe (21) is connected to the first inner inlet (231); the collecting agent liquid inlet pipe (22) is connected to the second inner inlet (232); the first inner inlet (231) is located above the second inner inlet (232); The dispersion mechanism (3) comprises an external pipe (31) and a plurality of blades (32), wherein the external pipe (31) is rotatably disposed in the flotation sedimentation tank (1), and each of the blades (32) is distributed along the circumference of the external pipe (31) and is fixedly connected to the external pipe (31); The dispersion mechanism (3) further comprises a flow divider (33); the external communication tube (31) comprises an external communication inlet (311) and an external communication outlet (312); the external communication inlet (311) is in communication with the internal communication outlet (233); the external communication tube (31) is rotatably connected to the lower end of the internal communication tube (23); the flow divider (33) is in communication with the external communication outlet (312); the paddle (32) is a hollow structure and is provided with a plurality of outflow holes (321); and each paddle (32) is in communication with the flow divider (33). The invention also comprises a foam scraping mechanism (4), the foam scraping mechanism (4) comprising a rotating ring (41) and a plurality of foam scraping assemblies (42), the rotating ring (41) being rotatably connected to the upper end of the external communication tube (31), the foam scraping assemblies (42) being distributed along the circumference of the rotating ring (41) and being hinged to the rotating ring (41), the foam scraping assemblies (42) being connected to floats (43), and the foam scraping assemblies (42) being capable of deflecting around the hinge between the horizontal direction and the vertical direction.

2. The device for separating and recovering chromium and lead ions in wastewater according to claim 1, characterized in that: The foam scraping assembly (42) includes a foam scraping frame (421), a slide member (422), a positioning member (423) and a lifting movable column (424), one end of the positioning member (423) is fixedly connected to the rotating ring (41), the other end of the positioning member (423) is rotatably connected to one end of the lifting movable column (424), the upper end of the slide member (422) is fixedly connected to the rotating ring (41), one end of the foam scraping frame (421) is movably connected to the slide member (422), and the middle part of the foam scraping frame (421) is rotatably connected to the other end of the lifting movable column (424).

3. The device for separating and recovering chromium and lead ions in wastewater according to claim 1, characterized in that: A collecting trough (11) is provided on the top of the side wall of the flotation sedimentation tank (1), the bottom of the collecting trough (11) is arc-shaped, and the bottom of the collecting trough (11) is connected to a collecting pipe (12).

4. The device for separating and recovering chromium and lead ions in wastewater according to claim 1, characterized in that: A crossbeam (13) is fixedly connected to the top of the flotation sedimentation tank (1), and a driving device (5) is fixedly connected to the crossbeam (13). The driving device (5) is respectively connected to the external pipe (31) and the rotating ring (41) in a transmission manner. The external pipe (31) and the rotating ring (41) rotate in opposite directions.

5. A process for separating and recovering chromium and lead ions in wastewater, characterized by: The device used comprises: a flotation sedimentation tank (1) provided with a water inlet pipe (14) and a drain pipe (16), wherein the flotation sedimentation tank (1) is used to accommodate wastewater to be treated; A feeding mechanism (2), the feeding mechanism (2) being arranged in the flotation sedimentation tank (1) and being used to respectively inject a reactant, a collector and an aeration gas into the flotation sedimentation tank (1); a dispersion mechanism (3), the dispersion mechanism (3) being connected to the feeding mechanism (2) and being used for dispersing the reactant, the collector and the aeration gas in the flotation sedimentation tank (1) so as to fully contact the wastewater; The feeding mechanism (2) comprises an air inlet pipe (21), a collecting agent liquid inlet pipe (22) and an inner tube (23); the inner tube (23) has a first inner inlet (231), a second inner inlet (232) and an inner outlet (233); the air inlet pipe (21) is connected to the first inner inlet (231); the collecting agent liquid inlet pipe (22) is connected to the second inner inlet (232); the first inner inlet (231) is located above the second inner inlet (232); The dispersion mechanism (3) comprises an external pipe (31) and a plurality of blades (32), wherein the external pipe (31) is rotatably disposed in the flotation sedimentation tank (1), and each of the blades (32) is distributed along the circumference of the external pipe (31) and is fixedly connected to the external pipe (31); The dispersion mechanism (3) further comprises a flow divider (33); the external communication tube (31) comprises an external communication inlet (311) and an external communication outlet (312); the external communication inlet (311) is in communication with the internal communication outlet (233); the external communication tube (31) is rotatably connected to the lower end of the internal communication tube (23); the flow divider (33) is in communication with the external communication outlet (312); the paddle (32) is a hollow structure and is provided with a plurality of outflow holes (321); and each paddle (32) is in communication with the flow divider (33). The device further comprises a foam scraping mechanism (4), the foam scraping mechanism (4) comprising a rotating ring (41) and a plurality of foam scraping assemblies (42), the rotating ring (41) being rotatably connected to the upper end of the external communication tube (31), the foam scraping assemblies (42) being distributed along the circumference of the rotating ring (41) and being hinged to the rotating ring (41), the foam scraping assemblies (42) being connected to floats (43), and the foam scraping assemblies (42) being capable of deflecting around the hinge between a horizontal direction and a vertical direction; The process comprises the following steps: S1: introducing a reactant into the wastewater containing chromium ions and lead ions to react with the chromium ions and lead ions to produce chromium precipitate and lead precipitate respectively; S2: Adding a collector into the wastewater to make the lead precipitate combine with the collector to obtain hydrophobicity; S3: adding aeration to the wastewater to form froth from the hydrophobic lead precipitate obtained in step S2; S4: Separate and recover the scum and chromium precipitate in the wastewater.

6. The process for separating and recovering chromium and lead ions in wastewater according to claim 5, characterized in that: The reactant is hydrogen sulfide, and the collector is dibutyl ammonium dithiophosphate.

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