Method and device for preparing polyaluminium sulfate flocculant using aluminium-containing acidic wastewater

Abstract

The invention relates to the technical field of wastewater treatment, and specifically discloses a method and device for preparing a polyaluminum sulfate flocculant by using aluminum-containing acidic wastewater, wherein the aluminum-containing acidic wastewater is distilled at room temperature and pressure in a distillation device to remove low-boiling organic matter in the wastewater, the concentrated aluminum-containing acidic wastewater is placed in a temperature-controllable reactor with stirring, a preset amount of alkalizer is weighed and a preset amount of water is added to dissolve and stir to form an alkalizer solution, the alkalizer solution is added dropwise to the reactor, and a constant temperature stirring is maintained to perform a polymerization reaction, after the reaction is completed, the temperature during the reaction is maintained, stirring is stopped to perform maturation, and after the maturation is completed, the polyaluminum sulfate flocculant is filtered to obtain the polyaluminum sulfate flocculant. In the invention, after the wastewater is treated by the method, the obtained polyaluminum sulfate flocculant has a good flocculation treatment effect on some industrial wastewaters, realizes the maximization of benefits, and has certain commercial value.

Description

Technical Field

[0001] The invention relates to a method for preparing a polyaluminium sulfate flocculant, in particular to a method for preparing a polyaluminium sulfate flocculant by using aluminium-containing acidic wastewater, and belongs to the technical field of wastewater treatment. Background Art

[0002] Some electroplating manufacturers in the prior art will produce acidic wastewater containing a large amount of aluminum ions during the electroplating process. If this wastewater is treated and discharged, it will cost a certain amount of money. Since it contains a large amount of aluminum ions, sulfate ions, and phosphate ions, phosphoric acid can be recovered by extraction to obtain a waste liquid containing a large amount of aluminum sulfate. This waste liquid is then reacted again to synthesize a polyaluminum sulfate flocculant. Polyaluminum sulfate is a type of polyaluminum. Like other inorganic polymer coagulants, it can not only remove turbidity, decolorize, and deodorize, but also has a high removal rate for microorganisms, bacteria, and algae in wastewater, which can realize the utilization of wastewater resources, turn waste into treasure, and maximize economic benefits.

[0003] However, in the process of using wastewater to prepare polyaluminum sulfate flocculant, the wastewater will be subjected to a large impact when entering the mixing barrel, which will cause foam on the surface of the wastewater. Moreover, these foams will become more and more as the wastewater is stirred by the stirring mechanism. If they are not treated in time, the foam has a certain viscosity, which greatly reduces the oxygenation efficiency in the mixing barrel, resulting in insufficient reaction between the aluminum sulfate in the wastewater and the alkalizer, thereby reducing the preparation efficiency of the polyaluminum sulfate flocculant. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to provide a method for preparing polyaluminum sulfate flocculant using aluminum-containing acidic wastewater.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing a polyaluminium sulfate flocculant using aluminium-containing acidic wastewater, the method comprising the following steps:

[0007] Step 1: Distillation and concentration: The aluminum-containing acidic wastewater is distilled in a distillation device at room temperature and pressure, and the distillation is stopped when the COD is concentrated to a preset concentration, so as to remove low-boiling point organic matter in the wastewater;

[0008] Step 2: Alkalization reaction: placing the aluminum-containing acidic wastewater concentrated in the above step 1 in a temperature-controllable reactor with stirring, weighing a preset amount of alkalizer, adding a preset amount of water, dissolving and stirring to form an alkalizer solution, adding the alkalizer solution dropwise into the reactor, maintaining constant temperature and stirring to carry out polymerization reaction;

[0009] Step 3: Constant temperature aging: After the polymerization reaction in step 2 is completed, the reaction temperature is maintained, stirring is stopped, and aging is performed. After aging is completed, the polyaluminum sulfate flocculant can be obtained by filtering.

[0010] Optionally, in the distillation concentration stage, the COD concentration range is 500-800 mg / L.

[0011] Optionally, in the alkalization reaction stage, the alkalizing agent can be any one of NaOH, Ca(OH)2, and NaHCO3, and the molar ratio of the alkalizing agent to aluminum sulfate is 2 to 4.

[0012] Optionally, in the alkalization reaction stage, the polymerization reaction temperature is 60-80° C., the stirring speed of the polymerization reaction is 80-120 r / min, the polymerization reaction time is 60-80 min, and the reactor used in the polymerization reaction is a stirring barrel with controllable temperature.

[0013] Optionally, in the constant temperature aging stage, the aging time is 2 to 4 hours.

[0014] Optionally, a device for preparing polyaluminum sulfate flocculant using aluminum-containing acidic wastewater is applied to the above-mentioned preparation method, and the device comprises a stirring barrel and a base, wherein the stirring barrel is installed on the top of the base, a top plate is installed on the top of the stirring barrel, and a storage barrel is installed on the top thereof, a first stirring mechanism and a second stirring mechanism are respectively provided in the stirring barrel and the interior of the storage barrel is also provided with a defoaming mechanism for processing foam, and the defoaming mechanism includes a mounting plate arranged inside the stirring barrel, and two drainage outlets are symmetrically arranged at the bottom of the mounting plate.

[0015] Optionally, the second stirring mechanism includes a motor installed on the top of the storage barrel, the output end of the motor extends to the interior of the storage barrel and is connected to a rotating shaft, a plurality of second stirring blades are installed on the outer wall of the rotating shaft, a feed hopper is installed on the top of the storage barrel near the motor, two through holes are symmetrically provided at the bottom of the storage barrel, two sealing blocks are installed on the inner bottom surface of the storage barrel near the two through holes, a first electric telescopic rod is installed inside the second stirring blade at the bottom, and the extended end of the first electric telescopic rod can respectively abut against the two sealing blocks when in an extended state.

[0016] Optionally, the first stirring mechanism includes a second electric telescopic rod, which is arranged inside the stirring barrel, and the bottom end of the rotating shaft passes through the storage barrel and the top plate and is connected to the top end of the second electric telescopic rod. The bottom of the stirring barrel is connected to a filter screen through multiple third electric telescopic rods, and a first stirring blade is rotatably installed at the center position of the top of the filter screen. The bottom of the stirring barrel is also provided with a sealing cover for sealing the filter screen. A slot is provided at the top of the first stirring blade, and a plug block matching the slot is installed at the protruding end of the second electric telescopic rod.

[0017] Optionally, the mounting plate is slidably matched with the outer wall of the second electric telescopic rod, and two blocks are installed on the outer wall of the second electric telescopic rod. A through groove matching the two blocks is opened inside the mounting plate, and telescopic plates are hinged at both opposite ends of the mounting plate, and the two telescopic plates are semicircular telescopic plates when they are in the extended and expanded state. Two sealing plates are installed on one side of one of the telescopic plates close to the mounting plate, and the two sealing plates can respectively block the two drainage outlets.

[0018] Optionally, two slide grooves are symmetrically opened on the top of the mounting plate near the drain outlet, and electric sliders are installed at both ends of the two slide grooves, movable plates are installed on the tops of the two electric sliders, pull ropes are connected to the tops of the two movable plates, and the ends of the two pull ropes away from the two movable plates are connected to an external winding mechanism.

[0019] The beneficial effects of the present invention are:

[0020] 1. In the invention, after the wastewater is treated by the method, the obtained polyaluminum sulfate flocculant has a good flocculation treatment effect on some industrial wastewaters, and the synthesis cost is much lower than directly treating the wastewater to meet the discharge standards. It truly turns the wastewater into treasure and maximizes the benefits, which has certain commercial value.

[0021] 2. In the present invention, while the alkalizer solution in the storage barrel drips downward through the through hole into the stirring barrel to mix with the wastewater, the telescopic plates at both ends of the mounting plate and the mounting plate body can enclose a collecting chamber to temporarily store part of the alkalizer solution in the collecting chamber. When foam is generated on the surface of the wastewater, the two telescopic plates can be controlled to rotate a certain angle away from each other, so that the alkalizer solution in the collecting chamber can be driven by the rotating shaft to drive the second electric telescopic rod to rotate at a high speed in the stirring barrel, and be thrown out from the drain port at the bottom of the mounting plate to the surface of the wastewater, so that the foam on the water surface is broken, thereby effectively reducing the amount of foam, and will not affect the mixing of the wastewater and the alkalizer solution, thereby improving the preparation efficiency of the polyaluminum sulfate flocculant.

[0022] 3. In the present invention, while the wastewater in the mixing barrel is being stirred and mixed with the alkalizing agent solution, a small amount of water-insoluble scum or other debris will exist on the water surface. The motor can drive the rotating shaft and the second electric telescopic rod to rotate a certain angle, so that the external winding mechanism can control the mounting plate through the upper block and engage with the lower block through the pull rope. At this time, the mounting plate is just located on the water surface, and then the two telescopic plates are driven downwardly away from each other by the external driving mechanism. At this time, one of the telescopic plates with a sealing plate on the outer wall rotates with the other telescopic plate on the water surface, and the water-insoluble scum and other debris on the water surface can be salvaged and collected, so as to avoid the quality of the polyaluminum sulfate flocculant being affected by excessive scum or other debris in the future.

[0023] 4. In the present invention, after the preparation of the polyaluminum sulfate flocculant in the stirring barrel is completed, the polyaluminum sulfate flocculant will be precipitated at the bottom of the stirring barrel, and the excess waste water can be discharged. The two telescopic plates are controlled to rotate downward by an external driving mechanism, so that the two telescopic plates are in an unfolded state. Then, the two telescopic plates are driven downward by the external driving mechanism to move to the position of the extended end of the second electric telescopic rod. The extended end of the second electric telescopic rod can be extended downward to push the mounting plate and the telescopic plates in the unfolded state at both ends to move downward, thereby squeezing the polyaluminum sulfate flocculant at the bottom of the stirring barrel, thereby accelerating the filtration efficiency and avoiding the problem that the long filtration time affects the preparation efficiency of the polyaluminum sulfate flocculant. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the overall structure of a device for preparing polyaluminium sulfate flocculant by using aluminium-containing acidic wastewater proposed by the present invention;

[0026] Figure 2 for Figure 1 Structural cross-sectional view of the mixing tank and storage tank;

[0027] Figure 3 It is a structural cross-sectional view of the storage barrel and one of the second stirring blades in the present invention;

[0028] Figure 4 It is a structural cross-sectional view of the mixing barrel in the present invention;

[0029] Figure 5 It is a structural schematic diagram of the bottom of the mounting plate in the present invention;

[0030] Figure 6 A schematic diagram of the structure of one of the telescopic plates in the present invention in an unfolded state;

[0031] Figure 7 It is a structural schematic diagram of the defoaming mechanism in the present invention.

[0032] In the figure: 1. mixing barrel; 2. base; 3. sealing cover; 4. top plate; 5. storage barrel; 6. feed hopper; 7. motor; 8. rotating shaft; 9. second electric telescopic rod; 10. first mixing blade; 11. mounting plate; 12. second mixing blade; 13. filter screen; 15. first electric telescopic rod; 16. sealing block; 17. through hole; 18. pull rope; 19. third electric telescopic rod; 20. plug-in block; 21. slot; 22. drain outlet; 23. block; 24. through groove; 25. telescopic plate; 26. sealing plate; 27. slide groove; 28. moving plate; 29. ​​electric slider. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. 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.

[0034] Reference Figure 1-Figure 7 A method for preparing a polyaluminium sulfate flocculant using aluminium-containing acidic wastewater, the method comprising the following steps:

[0035] Step 1: Distillation and concentration: The aluminum-containing acidic wastewater is distilled in a distillation device at room temperature and pressure, and the distillation is stopped when the COD is concentrated to a preset concentration, which is used to remove low-boiling point organic matter in the wastewater, such as dimethylamine, dichloromethane, methanol, etc.;

[0036] Step 2: Alkalization reaction: placing the aluminum-containing acidic wastewater concentrated in the above step 1 in a temperature-controllable reactor with stirring, weighing a preset amount of alkalizer, adding a preset amount of water, dissolving and stirring to form an alkalizer solution, adding the alkalizer solution dropwise into the reactor, maintaining constant temperature and stirring to carry out polymerization reaction;

[0037] Step 3: Constant temperature aging: After the polymerization reaction in step 2 is completed, the reaction temperature is maintained, stirring is stopped, and aging is performed. After aging is completed, the polyaluminum sulfate flocculant can be obtained by filtering.

[0038] As a technical optimization solution of the present invention, in the distillation concentration stage, the concentration range of COD concentration is 500-800 mg / L.

[0039] As a technical optimization scheme of the present invention, in the alkalization reaction stage, the alkalizing agent can be any one of NaOH, Ca(OH)2, and NaHCO3, and the molar ratio of the alkalizing agent to aluminum sulfate is 2 to 4.

[0040] As a technical optimization scheme of the present invention, in the alkalization reaction stage, the polymerization reaction temperature is 60-80°C, the stirring speed of the polymerization reaction is 80-120r / min, the polymerization reaction time is 60-80min, and the reactor used in the polymerization reaction is a stirring barrel 1 with controllable temperature.

[0041] As a technical optimization solution of the present invention, in the constant temperature aging stage, the aging time is 2 to 4 hours.

[0042] As a technical optimization scheme of the present invention, a device for preparing polyaluminum sulfate flocculant by using aluminum-containing acidic wastewater, the device comprises a stirring barrel 1 and a base 2, the stirring barrel 1 is installed on the top of the base 2, a top plate 4 is installed on the top of the stirring barrel 1, and a storage barrel 5 is installed on the top thereof, a first stirring mechanism and a second stirring mechanism are respectively provided in the stirring barrel 1 and the storage barrel 5, a defoaming mechanism for treating foam is also provided inside the stirring barrel 1, and the defoaming mechanism comprises a mounting plate 11 arranged inside the stirring barrel 1, and two drainage ports 22 are symmetrically provided at the bottom of the mounting plate 11.

[0043] As a technical optimization scheme of the present invention, the second stirring mechanism includes a motor 7 installed on the top of the storage barrel 5, the output end of the motor 7 extends to the inside of the storage barrel 5 and is connected to the rotating shaft 8, the outer wall of the rotating shaft 8 is installed with a plurality of second stirring blades 12, and the top of the storage barrel 5 is installed with a hopper 6 near the motor 7. Before adding the alkalizer to the wastewater in the stirring barrel 1, it can be placed in the storage barrel 5 through the hopper 6, and a proper amount of water is added to the storage barrel 5, and the motor 7 is started to drive the rotating shaft 8 and the plurality of second stirring blades 12 on the outer wall to rotate synchronously, and the alkalizer and water inside the storage barrel 5 are fully stirred to form an alkalizer solution, which is convenient for adding it to the inside of the stirring barrel 1 later. The bottom of the storage barrel 5 is symmetrically provided with two through holes 17, and two sealing blocks 16 are installed near the inner bottom surface of the storage barrel 5 near the two through holes 17. The first electric telescopic rod 15 is installed inside the second stirring blade 12 at the bottom, and the extended end of the first electric telescopic rod 15 can be respectively abutted with the two sealing blocks 16 when it is in an extended state. After the alkalizing agent solution in the storage barrel 5 is stirred, the extended end of the first electric telescopic rod 15 in the second stirring blade 12 at the bottom can be controlled to extend downward. While the motor 7 drives the second stirring blade 12 to rotate, the extended first electric telescopic rod 15 will continuously abut against the two sealing blocks 16 installed at the bottom of the storage barrel 5. When the first electric telescopic rod 15 abuts against the sealing blocks 16, the first electric telescopic rod 15 will push the sealing blocks 16 to rotate a certain angle, so that the through hole 17 is exposed, and the solution in the storage barrel 5 can drip downward into the interior of the stirring barrel 1 through the through hole 17, so as to facilitate the mixing reaction of aluminum sulfate and the alkalizing agent in the wastewater.

[0044] As a technical optimization scheme of the present invention, the first stirring mechanism includes a second electric telescopic rod 9, which is arranged inside the stirring barrel 1, and the bottom end of the rotating shaft 8 passes through the storage barrel 5 and the top plate 4 and is connected to the top of the second electric telescopic rod 9. The bottom of the stirring barrel 1 is connected to a filter screen 13 through multiple third electric telescopic rods 19, and a first stirring blade 10 is rotatably installed at the center position of the top of the filter screen 13. The bottom of the stirring barrel 1 is also provided with a sealing cover 3 for sealing the filter screen 13. A slot 21 is opened at the top of the first stirring blade 10, and a plug block 20 adapted to the slot 21 is installed at the protruding end of the second electric telescopic rod 9. Since the second electric telescopic rod 9 is connected to the bottom end of the rotating shaft 8, the motor 7 can drive the rotating shaft 8 to rotate and simultaneously drive the second electric telescopic rod 9 to rotate in the mixing barrel 1. When the extended end of the second electric telescopic rod 9 is in an extended state, the plug block 20 installed at the extended end can be inserted into the slot 21 at the top of the first stirring blade 10, and then can synchronously drive the first stirring blade 10 to rotate inside the mixing barrel 1, so that the wastewater can be fully mixed with the alkalizing agent solution, which is beneficial to the reaction between the aluminum sulfate in the wastewater and the alkalizing agent.

[0045] As a technical optimization solution of the present invention, the mounting plate 11 is slidably matched with the outer wall of the second electric telescopic rod 9, and two blocks 23 are installed on the outer wall of the second electric telescopic rod 9. A through groove 24 adapted to the two blocks 23 is opened inside the mounting plate 11. As a technical optimization solution of the present invention, telescopic plates 25 are hinged at both opposite ends of the mounting plate 11, and the two telescopic plates 25 are semicircular telescopic plates 25 when they are in an extended and unfolded state. Two sealing plates 26 are installed on one side of the telescopic plates 25 close to the mounting plate 11, and the two sealing plates 26 can respectively block the two drain outlets 22.

[0046] As a technical optimization solution of the present invention, two slide grooves 27 are symmetrically opened on the top of the mounting plate 11 near the drain outlet 22, and electric sliders 29 are installed at both ends of the two slide grooves 27, and movable plates 28 are installed on the tops of the two electric sliders 29. Pull ropes 18 are connected to the tops of the two movable plates 28, and the ends of the two pull ropes 18 away from the two movable plates 28 are connected to an external winding mechanism. When the storage barrel 5 discharges the alkalizing agent solution into the mixing barrel 1 through the through hole 17, the telescopic plate 25 with a sealing plate 26 installed on one of the outer walls is controlled by an external driving mechanism to rotate downward 90 degrees to a horizontal state. At this time, the sealing plate 26 does not block the drain port 22 of the mounting plate 11, so that the solution dripping from the through hole 17 can freely pass through the drain port 22 to contact and mix with the wastewater. When foam appears on the surface of the wastewater in the mixing barrel 1, the pull rope 18 can be controlled to extend by an external winding mechanism, so that the mounting plate 11 can move downward on the outer wall of the second electric telescopic rod 9 to the top of the stopper 23 located above, and the rectangular groove opened at the bottom of the mounting plate 11 can be plugged into the top of the stopper 23, and then one of the telescopic plates 25 can be controlled to reset by an external driving mechanism, so that the sealing plate 26 on its outer wall can block the drain port 22. At this time, the solution dripping from the through hole 17 will fall on the two telescopic plates 25 and the sealing plate 2 6 is collected in the collecting chamber surrounded by the second electric telescopic rod 9. When the solution collected in the collecting chamber is sufficient, one of the telescopic plates 25 can be controlled to rotate downward slightly again, so that the solution accumulated on the top of the sealing plate 26 can slowly flow to the top of the mounting plate 11 along the filter screen at the connection position between the sealing plate 26 and the telescopic plate 25, and slowly drip downward from the drain port 22. Since the mounting plate 11 is plugged into the block 23 on the outer wall of the second electric telescopic rod 9 through the rectangular groove at the bottom at this time, when the rotating shaft 8 drives the second electric telescopic rod 9 to rotate, it can also synchronously drive the mounting plate 11 to rotate inside the mixing barrel 1, so that the solution that originally dripped slowly downward from the drain port 22 is affected by the high-speed rotating second electric telescopic rod 9, and can be splashed onto the surface of the wastewater at a high speed, breaking the foam on the water surface, thereby achieving the effect of defoaming, and avoiding the influence of a large amount of foam on the preparation efficiency of the polyaluminum sulfate flocculant.While the wastewater in the mixing barrel 1 is being stirred and mixed with the alkalizing agent solution, there will be a small amount of insoluble scum or other debris on the water surface. The external winding mechanism can drive the mounting plate 11 to move upward for a distance through the pull rope 18, so that the rectangular groove at the bottom of the mounting plate 11 falls off from the block 23. Then, the motor 7 drives the rotating shaft 8 and the second electric telescopic rod 9 to rotate 90 degrees, so that the position of the block 23 can coincide with the position of the through groove 24 inside the mounting plate 11. Then, the external winding mechanism can control the mounting plate 11 to move upward by extending the pull rope 18. After passing through the two upper blocks 23, the motor 7 controls the rotating shaft 8 and the second electric telescopic rod 9 to reset. The external winding mechanism continues to control the extension of the pull rope 18 to drive the mounting plate 11 to move downward and contact the two stoppers 23 below, so that the rectangular groove at the bottom of the mounting plate 11 can be plugged into the two stoppers 23 below. At this time, the mounting plate 11 is just located on the water surface. Then, the two telescopic plates 25 are driven by the external driving mechanism to rotate downward 90 degrees in the direction away from each other. Then, the two telescopic plates 25 are located on the water surface. Since the mounting plate 11 is plugged into the two stoppers 23 below at this time, the motor 7 can drive the mounting plate 11 and the two telescopic plates 25 to rotate on the water surface through the rotating shaft 8 and the second electric telescopic rod 9. The telescopic plate 25 in a flat state can collect the water-insoluble scum and other debris on the water surface, so as to avoid the subsequent problem of affecting the quality of the polyaluminum sulfate flocculant due to excessive scum or other debris; and most of the collected scum or other debris will be concentrated on the top of the mounting plate 11. After the scum or other debris on the water surface is collected, the two telescopic plates 25 can be driven to rotate and reset by an external driving mechanism. At this time, the sealing plate 26 can squeeze the scum or other debris on the top of the mounting plate 11 while rotating toward the mounting plate 11, and squeeze the wastewater adsorbed inside and discharge it into the mixing barrel 1 through the drain port 22 on the top of the mounting plate 11, so as to avoid a small amount of wastewater from being discharged along with the scum or other debris. The adsorption of the two telescopic plates 25, the mounting plate 11 and the sealing plate 26 is wasted; and when the two telescopic plates 25, the mounting plate 11 and the sealing plate 26 cooperate to collect the scum or other debris, the two electric sliders 29 can be moved in the chute 27 in the direction of approaching each other, until the two electric sliders 29 move to the end where the two chute 27 are close to each other, and then the mobile plate 28 on the top of one of the electric sliders 29 is controlled to rotate by an external driving mechanism, so that one of the mobile plates 28 can fill the gap between the two sealing plates 26 after rotation, thereby avoiding the problem that a large amount of scum or other debris is exposed from the gap between the two sealing plates 26 during the collection of scum or other debris, thereby reducing the collection efficiency;Moreover, when the two electric sliders 29 drive the moving plate 28 on the top thereof to move to a position close to each other, the resetting of the sealing plate 26 will not be affected. After the sealing plate 26 is reset to squeeze and drain the scum or other debris on the top of the mounting plate 11, the telescopic plate 25 with the sealing plate 26 is controlled by an external driving mechanism to rotate downward 90 degrees again in a direction away from the mounting plate 11, and then the two electric sliders 29 are controlled to move in the chute 27 in a direction away from each other, so that the scum or other debris squeezed by the sealing plate 26 on the mounting plate 11 can be pushed to both ends of the mounting plate 11, thereby facilitating the subsequent staff to clean up the scum or other debris and improving the practicality of the device. ;

[0047] In the present invention, when the user uses the device, the waste water is poured into the mixing barrel 1 through the opening at the top of the mixing barrel 1, and then the alkalizer is placed in the storage barrel 5 through the feed hopper 6, and a proper amount of water is added to the storage barrel 5, and the motor 7 is started to drive the second stirring mechanism to fully stir the alkalizer and water in the storage barrel 5 to form an alkalizer solution; after the alkalizer solution in the storage barrel 5 is stirred, the extended end of the first electric telescopic rod 15 can be controlled to extend downward, and while the motor 7 drives the second stirring blade 12 to rotate, the first electric telescopic rod 15 in the extended state is controlled to extend downward. The telescopic rod 15 will push the sealing block 16 to rotate a certain angle, so that the solution in the storage barrel 5 can drip downward into the interior of the mixing barrel 1 through the through hole 17; because the second electric telescopic rod 9 is connected to the bottom end of the rotating shaft 8, the motor 7 can synchronously drive the second electric telescopic rod 9 to rotate in the mixing barrel 1, and then synchronously drive the first stirring blade 10 to rotate in the mixing barrel 1, so that the wastewater can be fully mixed with the alkalizing agent solution, which is beneficial to the reaction of aluminum sulfate in the wastewater with the alkalizing agent and facilitates the mixing reaction of aluminum sulfate and the alkalizing agent in the wastewater.

[0048] When foam appears on the surface of the wastewater in the mixing barrel 1, one of the telescopic plates 25 is controlled to reset through an external driving mechanism so that the sealing plate 26 on its outer wall can block the drain port 22. At this time, the solution dripping from the through hole 17 will fall into the collecting chamber surrounded by the two telescopic plates 25 and the sealing plate 26 for collection. When the solution collected in the collecting chamber is sufficient, one of the telescopic plates 25 can be controlled to rotate downward again, so that the solution accumulated on the top of the sealing plate 26 can slowly drip downward from the drain port 22. Since the mounting plate 11 is plugged into the block 23 on the outer wall of the second electric telescopic rod 9 through the rectangular groove at the bottom at this time, when the rotating shaft 8 drives the second electric telescopic rod 9 to rotate, it can also synchronously drive the mounting plate 11 to rotate inside the mixing barrel 1. The solution can splash onto the surface of the wastewater at high speed to break the foam on the water surface, thereby achieving the effect of defoaming and avoiding the influence of a large amount of foam on the preparation efficiency of the polyaluminum sulfate flocculant.

[0049] While the wastewater in the mixing barrel 1 is being stirred and mixed with the alkalizing agent solution, a small amount of water-insoluble scum or other debris may exist on the water surface. The mounting plate 11 may be controlled to be plugged into the two blocks 23 below by an external winding mechanism, and then the two telescopic plates 25 may be driven by an external driving mechanism to rotate downward 90 degrees in a direction away from each other. Since the mounting plate 11 is plugged into the two blocks 23 below at this time, the motor 7 may drive the mounting plate 11 and the two telescopic plates 25 to rotate on the water surface, and the water-insoluble scum and other debris on the water surface may be collected, thereby avoiding the subsequent problem of affecting the quality of the polyaluminum sulfate flocculant due to excessive scum or other debris.

[0050] After the scum or other debris on the water surface is collected, the two telescopic plates 25 can be driven to rotate and reset by an external driving mechanism. At this time, the sealing plate 26 can squeeze the scum or other debris to avoid a small amount of waste water being wasted due to the adsorption of the scum or other debris; and when the two telescopic plates 25, the mounting plate 11 and the sealing plate 26 cooperate to collect the scum or other debris, the two electric sliders 29 can be moved in the chute 27 in a direction close to each other, and then the telescopic plate 25 with the sealing plate 26 can be controlled by the external driving mechanism to rotate downward 90 degrees in a direction away from the mounting plate 11 again, and then the two electric sliders 29 can be controlled to move in the chute 27 in a direction away from each other, so that the scum or other debris can be pushed to the two ends of the mounting plate 11, so as to facilitate the subsequent staff to clean up the scum or other debris.

[0051] After the polyaluminum sulfate flocculant in the mixing barrel 1 is prepared, the polyaluminum sulfate flocculant will be precipitated at the bottom of the mixing barrel 1. After the excess waste water can be discharged from the drain pipe of the mixing barrel 1, the sealing cover 3 at the bottom of the mixing barrel 1 is removed, and the two telescopic plates 25 are controlled to rotate downward by an external driving mechanism, so that the two telescopic plates 25 can automatically be unfolded after rotating downward to more than 90 degrees. Then, the pull rope 18 can be controlled to extend by an external winding mechanism, and then the mounting plate 11 is driven to move downward to a position close to the extended end of the second electric telescopic rod 9. The extended end of the second electric telescopic rod 9 is controlled to retract, so that the plug block 20 at the extended end and the top of the first mixing blade 10 are aligned. The slots 21 are disengaged until the plug block 20 at the protruding end passes through the through slot 24 inside the mounting plate 11 during the upward movement. The motor 7 drives the second electric telescopic rod 9 to rotate 90 degrees, so that the plug block 20 and the through slot 24 are misaligned. When the protruding end of the second electric telescopic rod 9 extends downward, it can push the mounting plate 11 and the two telescopic plates 25 at both ends of the mounting plate 11 to move downward together, squeeze the polyaluminum sulfate flocculant at the bottom of the mixing barrel 1, and speed up the filtration efficiency. After squeezing the polyaluminum sulfate flocculant, the filter screen 13 is driven downward by starting multiple third electric telescopic rods 19, so that the polyaluminum sulfate flocculant at the top of the filter screen 13 is discharged conveniently.

[0052] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0053] Embodiment 1:

[0054] The COD of a chemical wastewater is about 100 mg / L, with high turbidity. The water is turbid and milky white. A certain brand of PAC and the homemade polyaluminum sulfate flocculant prepared by this method were added to the chemical wastewater to compare the treatment effects.

[0055] Experiment 1: Take 100ml of chemical wastewater, add 1‰ of a certain brand of PAC, adjust the pH to 8-9, add 1ppm of anionic PAM, stir at 80r / min for 15min, let it settle for 15min after stirring, observe the water body and flocs, and measure COD;

[0056] Experiment 2: Take 100ml of chemical wastewater, add 1‰ homemade polyaluminum sulfate flocculant, adjust the pH to 8-9, add 1ppm anion PAM, stir at 80r / min for 15min, let it stand and settle for 15min after stirring, observe the water body and floccules, and measure COD.

[0057] The comparison of the results of the two experiments is shown in the following table:

[0058] COD(mg / L) Turbidity Floc situation Experiment 1 88 High removal rate, clear water The flocs are compact and the amount of flocs is small Experiment 2 102 High removal rate, clear water The flocs are tight and the amount of flocs is moderate

[0059] Through the above experimental comparison, it can be seen that the homemade PAS has the same effect as the commercial product in removing SS, and the flocs it produces are compact, easy to precipitate and handle, and the amount of flocs is slightly larger; it has basically no removal effect on COD. The reason is that the homemade PAS itself contains a certain amount of COD, and COD is introduced during the addition process. Although it may have a removal effect on COD during the flocculation process, the addition and removal offset each other, showing that COD remains unchanged.

[0060] The above experiments prove that homemade PAS has a good flocculation and sedimentation effect on chemical wastewater and can replace commercial PAC.

[0061] Embodiment 2:

[0062] The water of a certain electroplating wastewater is turbid and red, and the COD is about 1000mg / L. A certain brand of PAC and the homemade polyaluminum sulfate flocculant prepared by this method were added to the electroplating wastewater to compare the treatment effects.

[0063] Experiment 1: Take 100ml of electroplating wastewater, add 1‰ of a certain brand of PAC, adjust the pH to 8-9, add 1ppm of anionic PAM, stir at 80r / min for 15min, let it settle for 15min after stirring, observe the water body and flocs, and measure COD;

[0064] Experiment 2: Take 100ml of electroplating comprehensive wastewater, add 1‰ homemade polyaluminum sulfate flocculant, adjust the pH to 8-9, add 1ppm anion PAM, stir at 80r / min for 15min, let it stand and settle for 15min after stirring, observe the water body and floccules, and measure COD.

[0065] The comparison of the results of the two experiments is shown in the following table:

[0066] COD(mg / L) Turbidity Floc situation Experiment 1 850 High removal rate, clear water The flocs are compact and the amount of flocs is small Experiment 2 1020 Low removal rate, turbid water Loose flocs, small amount

[0067] For electroplating wastewater, the treatment effect of homemade PAS is average, with basically no flocculation effect. The possible reason is that certain metal ions in the electroplating wastewater make PAS ineffective and unable to show flocculation effect.

[0068] Embodiment 3:

[0069] The water of a certain saponification wastewater is turbid and white, and the COD is about 600 mg / L. A certain brand of PAC and the homemade polyaluminum sulfate flocculant prepared by this method were added to the saponification wastewater to compare the treatment effects.

[0070] Experiment 1: Take 100ml of saponified wastewater, add 1‰ of a certain brand of PAC, adjust the pH to 8-9, add 1ppm of anionic PAM, stir at 80r / min for 15min, let it settle for 15min after stirring, observe the water body and flocs, and measure COD;

[0071] Experiment 2: Take 100 ml of saponified wastewater, add 1‰ homemade polyaluminum sulfate flocculant, adjust the pH to 8-9, add 1ppm anion PAM, stir at 80r / min for 15min, let it stand and settle for 15min after stirring, observe the water body and floccules, and measure COD.

[0072] The comparison of the results of the two experiments is shown in the following table:

[0073] COD(mg / L) Turbidity Floc situation Experiment 1 545 High removal rate, clear water The flocs are compact and the amount of flocs is small Experiment 2 552 High removal rate, clear water The flocs are compact and the amount of flocs is small

[0074] For saponification wastewater, the homemade PAS has an excellent treatment effect, achieving the same treatment effect as commercial PAC in terms of turbidity removal, flocculent state and COD removal.

[0075] The homemade PAS from aluminum-containing acidic wastewater has different flocculation performances when treating different wastewaters, indicating that it does not have very strong universality and needs to be targeted at specific wastewaters to exert its maximum treatment capacity. However, the existence of applicable wastewater also proves its feasibility of replacing commercial flocculants. In addition, its low cost advantage has great practical significance and economic value.

[0076] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A device for preparing polyaluminium sulfate flocculant using aluminium-containing acidic wastewater, comprising a stirring barrel (1) and a base (2), characterized in that: The mixing barrel (1) is mounted on the top of the base (2); a top plate (4) is mounted on the top of the mixing barrel (1); a storage barrel (5) is mounted on the top of the mixing barrel (1); a first mixing mechanism and a second mixing mechanism are respectively arranged in the mixing barrel (1) and the storage barrel (5); a defoaming mechanism for processing foam is also arranged inside the mixing barrel (1); the defoaming mechanism comprises a mounting plate (11) arranged inside the mixing barrel (1); two drainage ports (22) are symmetrically arranged at the bottom of the mounting plate (11); The second stirring mechanism comprises a motor (7) mounted on the top of the storage barrel (5); the output end of the motor (7) extends to the inside of the storage barrel (5) and is connected to a rotating shaft (8); a plurality of second stirring blades (12) are mounted on the outer wall of the rotating shaft (8); a feed hopper (6) is mounted on the top of the storage barrel (5) near the motor (7); two through holes (17) are symmetrically provided on the bottom of the storage barrel (5); two sealing blocks (16) are mounted on the inner bottom surface of the storage barrel (5) near the two through holes (17); a first electric telescopic rod (15) is mounted inside the second stirring blade (12) at the bottom end; and the extended end of the first electric telescopic rod (15) can respectively abut against the two sealing blocks (16) when in an extended state; The first stirring mechanism comprises a second electric telescopic rod (9), the second electric telescopic rod (9) is arranged inside the stirring barrel (1), the bottom end of the rotating shaft (8) passes through the storage barrel (5) and the top plate (4) and is connected to the top end of the second electric telescopic rod (9), the bottom of the stirring barrel (1) is connected to a filter screen (13) through a plurality of third electric telescopic rods (19), a first stirring blade (10) is rotatably mounted at the center of the top of the filter screen (13), the bottom of the stirring barrel (1) is also provided with a sealing cover (3) for sealing the filter screen (13), a slot (21) is provided at the top of the first stirring blade (10), and an insert (20) adapted to the slot (21) is installed at the protruding end of the second electric telescopic rod (9); The mounting plate (11) is slidably matched with the outer wall of the second electric telescopic rod (9), the outer wall of the second electric telescopic rod (9) is installed with two stoppers (23), the interior of the mounting plate (11) is provided with a through groove (24) adapted to the two stoppers (23), the mounting plate (11) is hinged with telescopic plates (25) at opposite ends, and the two telescopic plates (25) are both semicircular telescopic plates (25) when in an extended and unfolded state, one of the telescopic plates (25) is installed with two sealing plates (26) on a side close to the mounting plate (11), and the two sealing plates (26) can respectively block the two drainage ports (22); Two slide grooves (27) are symmetrically provided on the top of the mounting plate (11) near the drain outlet (22), and electric sliders (29) are installed at both ends of the two slide grooves (27), and movable plates (28) are installed on the tops of the two electric sliders (29), and the tops of the two movable plates (28) are connected to pull ropes (18), and the ends of the two pull ropes (18) away from the two movable plates (28) are connected to an external winding mechanism; The steps for preparing polyaluminium sulfate flocculant are as follows: Step 1: Distillation and concentration: The aluminum-containing acidic wastewater is distilled in a distillation device at room temperature and pressure, and the distillation is stopped when the COD is concentrated to a preset concentration, so as to remove low-boiling point organic matter in the wastewater; Step 2: Alkalization reaction: placing the aluminum-containing acidic wastewater concentrated in the above step 1 in a temperature-controllable reactor with stirring, weighing a preset amount of alkalizer, adding a preset amount of water, dissolving and stirring to form an alkalizer solution, adding the alkalizer solution dropwise into the reactor, maintaining constant temperature and stirring to carry out polymerization reaction; Step 3: Constant temperature aging: After the polymerization reaction in step 2 is completed, the reaction temperature is maintained, stirring is stopped, and aging is performed. After aging is completed, the polyaluminum sulfate flocculant can be obtained by filtering.

2. The device for preparing polyaluminium sulfate flocculant by using aluminium-containing acidic wastewater according to claim 1, characterized in that: In the distillation concentration stage, the COD concentration range is 500-800 mg / L.

3. The device for preparing polyaluminium sulfate flocculant by using aluminium-containing acidic wastewater according to claim 1, characterized in that: In the alkalization reaction stage, the alkalizing agent is any one of NaOH, Ca(OH)2, and NaHCO3, and the molar ratio of the alkalizing agent to aluminum sulfate is 2-4.

4. The device for preparing polyaluminium sulfate flocculant by using aluminium-containing acidic wastewater according to claim 3, characterized in that: In the alkalization reaction stage, the polymerization temperature is 60-80°C, the stirring speed is 80-120r / min, the polymerization time is 60-80min, and the reactor used in the polymerization is a temperature-controllable stirring barrel (1).

5. The device for preparing polyaluminium sulfate flocculant by using aluminium-containing acidic wastewater according to claim 1, characterized in that: During the constant temperature aging stage, the aging time is 2 to 4 hours.

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