System and method for synergistically treating phosphorus-fluorine wastewater by using calcium oxide-iron composite agent

Abstract

The invention belongs to the field of water treatment, and particularly relates to a system and a method for synergistically treating phosphorus-fluorine wastewater by using a calcium oxide-iron composite reagent. The system provided by the invention comprises a calcium oxide emulsion preparation and dosing device, an iron medicament preparation and dosing device and a phosphorus-fluorine wastewater flow control and treatment device. The system provided by the invention can simultaneously realize accurate metering and cooperative addition of a calcium oxide emulsion (liquid-phase medicament) and an iron medicament (solid-phase medicament), and greatly improves the treatment efficiency of phosphorus-fluorine wastewater.

Description

Technical Field

[0001] The present invention belongs to the field of water treatment, and in particular relates to a system and method for collaboratively treating phosphorus and fluorine wastewater using a calcium oxide-iron composite agent. Background Art

[0002] Phosphorus and fluorine wastewater from industrial production poses a serious threat to water resources and the environment. Among the various treatment processes for phosphorus and fluorine wastewater, chemical precipitation is the most widely used. This method involves adding an oxidizing agent to the wastewater, causing it to react with soluble salts in the wastewater to form water-insoluble substances, which are ultimately removed as precipitates.

[0003] Currently, researchers have developed a variety of chemical precipitation-based processes for treating phosphorus and fluorine wastewater. However, most existing processes use a single agent form, limiting further improvements in phosphorus and fluorine wastewater treatment efficiency. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a system and method for the coordinated treatment of phosphorus and fluorine wastewater with a calcium oxide-iron composite agent. The present invention can simultaneously achieve the precise metering and coordinated addition of calcium oxide emulsion (liquid phase agent) and iron agent (solid phase agent), greatly improving the treatment efficiency of phosphorus and fluorine wastewater.

[0005] The present invention provides a system for collaboratively treating phosphorus and fluorine wastewater using a calcium oxide-iron composite agent, comprising: a calcium oxide emulsion preparation and dosing device, an iron agent preparation and dosing device, and a phosphorus and fluorine wastewater flow control and treatment device;

[0006] The calcium oxide emulsion preparation and dosing device is used to prepare calcium oxide emulsion and feed the prepared calcium oxide emulsion into the pipeline mixer of the phosphorus and fluorine wastewater flow control and treatment device;

[0007] The iron agent preparation and dosing device is used to prepare the iron agent and feed the prepared iron agent into the pipeline mixer of the phosphorus and fluorine wastewater flow control and treatment device;

[0008] The phosphorus and fluorine wastewater flow control and treatment device includes: a wastewater flow control valve, a wastewater flow meter, a wastewater pipeline, a pipeline mixer and a reaction tank; wherein the water outlet of the wastewater flow control valve is connected to the water inlet of the wastewater flow meter, the water outlet of the wastewater flow meter is connected to the water inlet of the wastewater pipeline, the water outlet of the wastewater pipeline is connected to the water inlet of the pipeline mixer, and the outlet of the pipeline mixer is connected to the inlet of the reaction tank.

[0009] Preferably, the calcium oxide emulsion preparation and dosing device includes: a first clean water pipe, a calcium oxide emulsion agitator, a calcium oxide emulsion preparation tank, a calcium oxide emulsion discharge valve, a variable frequency flexible pump, an electromagnetic flowmeter and a calcium oxide emulsion hydraulic pipeline; wherein, the water outlet of the first clean water pipe faces the calcium oxide emulsion preparation tank, the stirring head of the calcium oxide emulsion agitator penetrates into the calcium oxide emulsion preparation tank, the feed port of the calcium oxide emulsion discharge valve is connected to the discharge port of the calcium oxide emulsion preparation tank, the feed port of the variable frequency flexible pump is connected to the discharge port of the calcium oxide emulsion discharge valve, the discharge port of the variable frequency flexible pump is connected to the feed port of the electromagnetic flowmeter, and the discharge port of the electromagnetic flowmeter is connected to the feed port of the calcium oxide emulsion hydraulic pipeline;

[0010] The discharge port of the calcium oxide emulsion hydraulic pipeline is connected to the calcium oxide emulsion feed port of the pipeline mixer.

[0011] Preferably, the iron agent preparation and dosing device includes: an iron agent agitator, an iron agent preparation tank, an iron agent flow meter, an iron agent hydraulic pipeline, an iron agent discharge valve, a three-way pipe, a slurry pump, an iron agent flow control valve, a second clean water pipe, a reflux valve and a reflux pipe; wherein the stirring head of the iron agent agitator is deep into the iron agent preparation tank, the discharge port of the iron agent preparation tank is connected to the feed port of the iron agent discharge valve, the discharge port of the iron agent discharge valve is connected to the three-way pipe, and the other end of the three-way pipe is connected to the feed port of the iron agent discharge valve. The two ends are respectively connected to the water outlet of the second clean water pipe and the feed port of the slurry pump, the discharge port of the slurry pump is respectively connected to the feed port of the iron agent flow control valve and the feed port of the reflux valve, the discharge port of the iron agent flow control valve is connected to the feed port of the iron agent flow meter, the discharge port of the iron agent flow meter is connected to the feed port of the iron agent hydraulic pipeline, the discharge port of the reflux valve is connected to the feed port of the reflux pipeline, and the discharge port of the reflux pipeline faces the inside of the iron agent preparation tank;

[0012] The discharge port of the iron agent hydraulic pipeline is connected to the iron agent feed port of the pipeline mixer.

[0013] The present invention provides a method for treating phosphorus and fluorine wastewater by using a calcium oxide-iron composite agent. The method comprises the following steps:

[0014] preparing calcium oxide emulsion by the calcium oxide emulsion preparation and dosing device, and feeding the prepared calcium oxide emulsion into the calcium oxide emulsion feed port of the pipeline mixer;

[0015] preparing an iron agent by the iron agent preparation and dosing device, and feeding the prepared iron agent into the iron agent feed port of the pipeline mixer;

[0016] The phosphorus and fluorine wastewater flows through the wastewater flow control valve, the wastewater flow meter and the wastewater pipeline, and then enters the pipeline mixer;

[0017] The calcium oxide emulsion, iron reagent and phosphorus-fluorine wastewater converge and mix in the pipeline mixer, and then enter the reaction tank to react to obtain treated wastewater.

[0018] Preferably, the ingredients of the calcium oxide emulsion include calcium oxide, magnesium oxide, a dispersant and a retarding fluid.

[0019] Preferably, the dispersant comprises methyl formate, ethylene glycol and ethyl acetate, and the mass ratio of methyl formate, ethylene glycol and ethyl acetate is (20-30):(15-25):(5-15).

[0020] Preferably, the components of the retarding liquid include starch, citric acid and water, and the usage ratio of the starch, citric acid and water is (2-28) g: (0.5-16) g: (50-500) mL.

[0021] Preferably, the mass ratio of the calcium oxide and the magnesium oxide is (50-65):(20-35); the mass ratio of the total mass of the calcium oxide and the magnesium oxide to the dispersant is (10-35):(3-20); and the ratio of the total mass of the calcium oxide, magnesium oxide and the dispersant to the volume of the retarding liquid is (5-37) g:(100-1650) mL.

[0022] Preferably, the iron agent comprises iron powder, a dispersant and water.

[0023] Preferably, the particle size of the iron powder is 100-200 mesh.

[0024] Preferably, the dispersant is one or more of carboxymethyl cellulose, methylpentanol and fatty acid polyethylene glycol ester.

[0025] Preferably, the usage ratio of the iron powder, dispersant and water is (3-100) g: (10-25) g: (100-900) mL.

[0026] Compared with the prior art, the present invention provides a system and method for the coordinated treatment of phosphorus and fluorine wastewater with a calcium oxide-iron composite agent. The system provided by the present invention includes: a calcium oxide emulsion preparation and dosing device, an iron agent preparation and dosing device, and a phosphorus and fluorine wastewater flow control and treatment device. The system provided by the present invention can simultaneously achieve the precise metering and coordinated addition of calcium oxide emulsion (liquid phase agent) and iron agent (solid phase agent), greatly improving the treatment efficiency of phosphorus and fluorine wastewater. More specifically, the system of the present invention has at least the following advantages:

[0027] (1) The present invention designs a device for the simultaneous preparation and addition of calcium oxide emulsion and iron reagent. The calcium oxide emulsion can remove phosphorus and fluorine in wastewater through chemical precipitation, while the iron reagent can improve the treatment effect through physical and chemical processes such as adsorption, precipitation and co-precipitation. The synergistic effect of the two can significantly improve the treatment efficiency of phosphorus and fluorine wastewater.

[0028] (2) The calcium oxide emulsion preparation and dosing device uses a combination of a variable frequency flexible pump and an electromagnetic flowmeter to ensure accurate control of the calcium oxide emulsion dosing flow rate.

[0029] (3) The iron agent preparation and dosing device monitors the iron agent dosing flow in real time through a flow meter and a control valve to ensure the accurate dosage of the agent; and through the design of a clean water pipe and a return pipe, it effectively avoids the problems of iron agent deposition and pipe blockage, further ensuring the stable operation of the device and the uniform addition of the agent.

[0030] (4) The calcium oxide emulsion and the iron reagent are simultaneously mixed into the phosphorus and fluorine wastewater through a pipeline mixer to ensure sufficient contact and mixing between the wastewater and the reagent, thereby promoting the efficient removal of phosphorus and fluorine. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0032] Figure 1 This is a schematic structural diagram of a system for collaboratively treating phosphorus and fluorine wastewater using a calcium oxide-iron composite reagent provided by an embodiment of the present invention;

[0033] Figure 2 This is a schematic structural diagram of a calcium oxide emulsion preparation and dosing device provided in an embodiment of the present invention;

[0034] Figure 3 Schematic diagram of the structure of the iron agent preparation and dosing device provided in an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of the structure of the phosphorus and fluorine wastewater flow control device provided by an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of the structure of a pipeline mixer provided by an embodiment of the present invention.

[0037] Explanation of the accompanying symbols: 1 is a calcium oxide emulsion preparation and dosing device, 2 is an iron agent preparation and dosing device, 3 is a phosphorus and fluorine wastewater flow control and treatment device, 101 is a first clean water pipe, 102 is a calcium oxide emulsion stirrer, 103 is a calcium oxide emulsion preparation tank, 104 is a calcium oxide emulsion discharge valve, 105 is a variable frequency flexible pump, 106 is an electromagnetic flowmeter, 107 is a calcium oxide emulsion hydraulic pipeline, 201 is an iron agent stirrer, 20 2 is an iron reagent preparation tank, 203 is an iron reagent flow meter, 204 is an iron reagent hydraulic pipeline, 205 is an iron reagent discharge valve, 206 is a three-way pipe, 207 is a slurry pump, 208 is an iron reagent flow control valve, 209 is a second clean water pipe, 210 is a reflux valve, 211 is a reflux pipeline, 301 is a wastewater flow control valve, 302 is a wastewater flow meter, 303 is a wastewater pipeline, 304 is a pipeline mixer, and 305 is a reaction tank. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] The present invention provides a system for treating phosphorus and fluorine wastewater by using a calcium oxide-iron composite agent. Figure 1 As shown, it includes: a calcium oxide emulsion preparation and dosing device 1, an iron agent preparation and dosing device 2 and a phosphorus and fluorine wastewater flow control and treatment device 3;

[0040] The calcium oxide emulsion preparation and dosing device 1 is used to prepare calcium oxide emulsion and send the prepared calcium oxide emulsion into the pipeline mixer 304 of the phosphorus and fluorine wastewater flow control and treatment device 3. Its structure is as follows: Figure 2 As shown, it includes: a first clean water pipe 101, a calcium oxide emulsion stirrer 102, a calcium oxide emulsion preparation tank 103, a calcium oxide emulsion discharge valve 104, a variable frequency flexible pump 105, an electromagnetic flowmeter 106 and a calcium oxide emulsion hydraulic pipeline 107; wherein, the water outlet of the first clean water pipe 101 is directed toward the calcium oxide emulsion preparation tank 103, the stirring head of the calcium oxide emulsion stirrer 102 penetrates into the calcium oxide emulsion preparation tank 103, the feed port of the calcium oxide emulsion discharge valve 104 is connected to the discharge port of the calcium oxide emulsion preparation tank 103, the feed port of the variable frequency flexible pump 105 is connected to the discharge port of the calcium oxide emulsion discharge valve 104, the discharge port of the variable frequency flexible pump 105 is connected to the feed port of the electromagnetic flowmeter 106, and the discharge port of the electromagnetic flowmeter 106 is connected to the feed port of the calcium oxide emulsion hydraulic pipeline 107;

[0041] The iron agent preparation and dosing device 2 is used to prepare the iron agent and send the prepared iron agent into the pipeline mixer 304 of the phosphorus and fluorine wastewater flow control and treatment device 3. Its structure is as follows: Figure 3 As shown, it includes: an iron agent stirrer 201, an iron agent preparation tank 202, an iron agent flow meter 203, an iron agent hydraulic pipeline 204, an iron agent discharge valve 205, a three-way pipe 206, a slurry pump 207, an iron agent flow control valve 208, a second clean water pipe 209, a return valve 210 and a return pipe 211; wherein, the stirring head of the iron agent stirrer 201 is deep into the iron agent preparation tank 202, the discharge port of the iron agent preparation tank 202 is connected to the feed port of the iron agent discharge valve 205, the discharge port of the iron agent discharge valve 205 is connected to the three-way pipe 206, and the three-way The other two ends of the pipe 206 are respectively connected to the water outlet of the second clean water pipe 209 and the feed port of the slurry pump 207, the discharge port of the slurry pump 207 is respectively connected to the feed port of the iron agent flow control valve 208 and the feed port of the return valve 210, the discharge port of the iron agent flow control valve 208 is connected to the feed port of the iron agent flow meter 203, the discharge port of the iron agent flow meter 203 is connected to the feed port of the iron agent hydraulic pipeline 204, the discharge port of the return valve 210 is connected to the feed port of the return pipe 211, and the discharge port of the return pipe 211 faces the inside of the iron agent preparation tank 202;

[0042] The structure of the phosphorus and fluorine wastewater flow control and treatment device 3 is as follows: Figure 4 As shown, it includes: a wastewater flow control valve 301, a wastewater flow meter 302, a wastewater pipeline 303, a pipeline mixer 304 and a reaction tank 305; wherein, the water outlet of the wastewater flow control valve 301 is connected to the water inlet of the wastewater flow meter 302, the water outlet of the wastewater flow meter 302 is connected to the water inlet of the wastewater pipeline 303, the water outlet of the wastewater pipeline 303 is connected to the water inlet of the pipeline mixer 304, and the outlet of the pipeline mixer 304 is connected to the inlet of the reaction tank 305;

[0043] The discharge port of the calcium oxide emulsion hydraulic pipeline 107 in the calcium oxide emulsion preparation and dosing device 1 is connected to the calcium oxide emulsion feed port of the pipeline mixer 304 in the phosphorus and fluorine wastewater flow control and treatment device 3;

[0044] The discharge port of the iron agent hydraulic pipeline 204 in the iron agent preparation and dosing device 2 is connected to the iron agent feed port of the pipeline mixer 304 in the phosphorus and fluorine wastewater flow control and treatment device 3.

[0045] In the system provided by the present invention, for the calcium oxide emulsion preparation and dosing device 1, in the initial preparation stage, a set volume of process water is injected into the calcium oxide emulsion preparation tank 103 through the first clean water pipe 101; then the operator quantitatively adds various raw materials for preparing calcium oxide emulsion into the calcium oxide emulsion preparation tank 103 according to the component formula of the calcium oxide emulsion, and starts the calcium oxide emulsion agitator 102. The calcium oxide emulsion agitator 102 is preferably fixedly installed on the top of the calcium oxide emulsion preparation tank 103, adopts a vertical installation structure, and achieves sufficient homogenization of the solid and liquid phases through axial flow blades to ensure the formation of a stable suspended emulsion system. When the phosphorus and fluorine wastewater treatment system is started, the calcium oxide emulsion discharge valve 104 and the variable frequency flexible pump 105 are opened in turn, and the prepared emulsion is pressurized and transported to the pipeline mixer 304. In this process, an electromagnetic flowmeter 106 is used to implement real-time flow monitoring of the flow of the calcium oxide emulsion, and the flow of the calcium oxide emulsion is controlled by adjusting the pump speed of the variable frequency flexible pump 105. To ensure the measurement accuracy of the electromagnetic flowmeter 106, a different-path layout scheme for the calcium oxide emulsion hydraulic pipeline 107 is preferably designed. By setting a vertical height difference to form gravity flow compensation, the medium is ensured to remain full when flowing through the measurement section, effectively eliminating the gas-liquid two-phase flow phenomenon that is prone to occur in traditional horizontal pipelines, and the flow measurement error can be controlled within ±1.5%. In the present invention, the vertical height difference is preferably 1-2 meters, and more preferably 1.5 meters.

[0046] In the system provided by the present invention, for the iron agent preparation and dosing device 2, in the initial preparation stage, first, a set volume of process water is injected into the iron agent preparation tank 202; then, the operator quantitatively adds various raw materials for preparing the iron agent into the iron agent preparation tank 202 according to the component formula of the iron agent; then the iron agent agitator 201 is activated to ensure that the raw materials and water are fully mixed. When the phosphorus and fluorine wastewater treatment system is started, the iron agent discharge valve 205 is opened, the slurry pump 207 is started, and the prepared iron agent is pressurized and transported to the pipeline mixer 304. In order to reduce the construction cost of the iron agent preparation and dosing device 2, a reflux device is set in the iron agent delivery pipeline to control the dosage of the agent, the reflux valve 210 is used to control the opening or closing of the agent reflux, the iron agent flow control valve 208 is used to adjust the flow of the agent, and the iron agent flow meter 203 is used to measure the dosage flow of the iron agent in real time. In order to avoid the deposition of iron powder in the iron agent and prevent the pipeline from being blocked, a second clean water pipe 209 is provided. The pipe is connected to the iron agent delivery pipeline through a tee pipe 206, which can be flushed in front of the slurry pump to prevent iron powder from accumulating in the pipeline. Since the iron agent flow rate is small, it may cause the agent to fail to fill the pipeline, thereby affecting the accurate measurement of the flow meter. Therefore, an iron agent hydraulic pipeline 204 is provided behind the iron agent flow meter 203 to form a hydraulic pressure difference to ensure that the iron agent fills the pipeline, thereby improving the measurement accuracy of the iron agent flow meter 203. In addition, the iron agent delivery pipeline preferably adopts PVC steel wire pipe to ensure that the pipeline has excellent resistance to high negative pressure and corrosion resistance; and the PVC steel wire pipe has a large bending radius when bending, which can effectively avoid the problem of iron powder deposition or blockage at the bend of the pipeline caused by a small curvature radius.

[0047] In the system provided by the present invention, for the phosphorus-fluorine wastewater flow control and treatment device 3, when the phosphorus-fluorine wastewater treatment system is started, the wastewater flow control valve 301 is first opened, and the wastewater flow is measured by the wastewater flow meter 302; then, the calcium oxide emulsion and the iron agent are transported to the pipeline mixer 304 to ensure that the wastewater and the agent are fully mixed; the mixed wastewater and the agent are discharged into the reaction tank 305. In the present invention, the reaction tank 305 preferably has a larger cross-sectional area, which can slow down the flow rate of the wastewater, prolong the residence time of the wastewater in the reaction tank 305, and improve the wastewater treatment effect. In the present invention, after the phosphorus-fluorine wastewater treatment is completed, it is preferred to flush the sediment in the reaction tank with a large amount of clean water to clean the device and ensure its continued effective operation.

[0048] In the system provided by the present invention, the structure of the pipeline mixer 304 is preferably as follows: Figure 5As shown, it is preferably welded with several angled baffles to promote thorough mixing of wastewater and reagent. The number of baffles is preferably 3 to 8, more preferably 5, and the angle of the baffles is preferably 30 to 60 degrees, more preferably 45 degrees. This design can effectively increase the contact area between the reagent and wastewater by guiding the flow direction and enhancing the turbulence of the fluid, ensuring uniform mixing of the reagent and wastewater, and improving wastewater treatment efficiency.

[0049] The present invention also provides a method for treating phosphorus and fluorine wastewater by using a calcium oxide-iron composite agent. The method comprises the following steps:

[0050] Calcium oxide emulsion is prepared by the calcium oxide emulsion preparation and dosing device 1, and the prepared calcium oxide emulsion is fed into the calcium oxide emulsion feed port of the pipeline mixer 304;

[0051] The iron agent is prepared by the iron agent preparation and dosing device 2, and the prepared iron agent is fed into the iron agent feed port of the pipeline mixer 304;

[0052] After the phosphorus and fluorine wastewater flows through the wastewater flow control valve 301, the wastewater flow meter 302 and the wastewater pipeline 303, it enters the pipeline mixer 304;

[0053] The calcium oxide emulsion, iron reagent and phosphorus-fluorine wastewater converge and mix in the pipeline mixer 304, and then enter the reaction tank 305 to react to obtain treated wastewater.

[0054] In the method provided by the present invention, the components of the calcium oxide emulsion preferably include calcium oxide, magnesium oxide, a dispersant and a retarding fluid. wherein the calcium oxide and magnesium oxide are preferably ball-milled; the components of the dispersant preferably include methyl formate, ethylene glycol and ethyl acetate, and the mass ratio of the methyl formate, ethylene glycol and ethyl acetate is preferably (20-30):(15-25):(5-15); the components of the retarding solution preferably include starch, citric acid and water, and the amount ratio of the starch, citric acid and water is preferably (2-28) g:(0.5-16) g:(50-500) mL; the mass ratio of the calcium oxide and magnesium oxide is preferably (50-65):(20-35); the mass ratio of the total mass of the calcium oxide and magnesium oxide to the dispersant is preferably (10-35):(3-20); and the ratio of the total mass of the calcium oxide, magnesium oxide and dispersant to the volume of the retarding solution is preferably (5-37) g:(100-1650) mL.

[0055] In the method provided by the present invention, the components of the iron agent preferably include iron powder, a dispersant, and water. The iron powder preferably has a particle size of 100-200 mesh, more preferably 150 mesh; the dispersant is preferably one or more of carboxymethyl cellulose, methylpentyl alcohol, and fatty acid polyethylene glycol ester; and the ratio of the iron powder, dispersant, and water is preferably (3-100) g: (10-25) g: (100-900) mL.

[0056] The system and method provided by the present invention can simultaneously achieve precise metering and coordinated addition of calcium oxide emulsion (liquid phase agent) and iron agent (solid phase agent), greatly improving the treatment efficiency of phosphorus and fluorine wastewater. More specifically, the technical solution of the present invention has at least the following advantages:

[0057] (1) The present invention designs a device for the simultaneous preparation and addition of calcium oxide emulsion and iron reagent. The calcium oxide emulsion can remove phosphorus and fluorine in wastewater through chemical precipitation, while the iron reagent can improve the treatment effect through physical and chemical processes such as adsorption, precipitation and co-precipitation. The synergistic effect of the two can significantly improve the treatment efficiency of phosphorus and fluorine wastewater.

[0058] (2) The calcium oxide emulsion preparation and dosing device uses a combination of a variable frequency flexible pump and an electromagnetic flowmeter to ensure accurate control of the calcium oxide emulsion dosing flow rate.

[0059] (3) The iron agent preparation and dosing device monitors the iron agent dosing flow in real time through a flow meter and a control valve to ensure the accurate dosage of the agent; and through the design of a clean water pipe and a return pipe, it effectively avoids the problems of iron agent deposition and pipe blockage, further ensuring the stable operation of the device and the uniform addition of the agent.

[0060] (4) The calcium oxide emulsion and the iron reagent are simultaneously mixed into the phosphorus and fluorine wastewater through a pipeline mixer to ensure sufficient contact and mixing between the wastewater and the reagent, thereby promoting the efficient removal of phosphorus and fluorine.

[0061] For the purpose of greater clarity, the present invention is described in detail with reference to the following examples.

[0062] Example 1

[0063] A system for treating phosphorus and fluorine wastewater by using calcium oxide-iron compound reagents in a coordinated manner, such as Figure 1 As shown, it includes: a calcium oxide emulsion preparation and dosing device 1, an iron agent preparation and dosing device 2 and a phosphorus and fluorine wastewater flow control and treatment device 3;

[0064] The structure of the calcium oxide emulsion preparation and dosing device 1 is as follows: Figure 2As shown, it includes: a first clean water pipe 101, a calcium oxide emulsion stirrer 102, a calcium oxide emulsion preparation tank 103, a calcium oxide emulsion discharge valve 104, a variable frequency flexible pump 105, an electromagnetic flowmeter 106 and a calcium oxide emulsion hydraulic pipeline 107;

[0065] The structure of the iron agent preparation and dosing device 2 is as follows Figure 3 As shown, it includes: an iron agent agitator 201, an iron agent preparation tank 202, an iron agent flow meter 203, an iron agent hydraulic pipeline 204, an iron agent discharge valve 205, a tee pipe 206, a slurry pump 207, an iron agent flow control valve 208, a second clean water pipe 209, a reflux valve 210 and a reflux pipeline 211;

[0066] The structure of the phosphorus and fluorine wastewater flow control and treatment device 3 is as follows: Figure 4 As shown, it includes: a wastewater flow control valve 301, a wastewater flow meter 302, a wastewater pipeline 303, a pipeline mixer 304 and a reaction tank 305. The structure of the pipeline mixer 304 is preferably as follows Figure 5 As shown, there are five partitions welded inside with an inclination angle of 45°;

[0067] The positions and connection relationships of the various components in the system have been introduced in the previous article and will not be repeated here.

[0068] Example 2

[0069] A method for treating phosphorus and fluorine wastewater using a calcium oxide-iron composite agent, using the system described in Example 1 to treat phosphorus and fluorine wastewater, includes the following steps:

[0070] Calcium oxide emulsion is prepared by the calcium oxide emulsion preparation and dosing device 1, and the prepared calcium oxide emulsion is fed into the calcium oxide emulsion feed port of the pipeline mixer 304;

[0071] The iron agent is prepared by the iron agent preparation and dosing device 2, and the prepared iron agent is fed into the iron agent feed port of the pipeline mixer 304;

[0072] After the phosphorus and fluorine wastewater flows through the wastewater flow control valve 301, the wastewater flow meter 302 and the wastewater pipeline 303, it enters the pipeline mixer 304;

[0073] The calcium oxide emulsion, iron reagent and phosphorus-fluorine wastewater converge and mix in the pipeline mixer 304, and then enter the reaction tank 305 to react to obtain treated wastewater.

[0074] In this embodiment, the calcium oxide emulsion used includes calcium oxide, magnesium oxide, a dispersant, and a retarding liquid. The calcium oxide and magnesium oxide are ball-milled (using 5 mm diameter agate beads, a rotation speed of 240 rpm, and a ball milling time of 1 hour), and the mass ratio of calcium oxide to magnesium oxide is 65:35. The dispersant is a mixture of methyl formate, ethylene glycol, and ethyl acetate, and the mass ratio of methyl formate, ethylene glycol, and ethyl acetate is 25:20:15. The retarding liquid is a mixture of starch, citric acid, and water, and the amount ratio of starch, citric acid, and water is 28 g:16 g:500 mL. The mass ratio of the total mass of calcium oxide and magnesium oxide to the dispersant is 10:6. The ratio of the total mass of calcium oxide, magnesium oxide, and dispersant to the volume of the retarding liquid is 37 g:1650 mL.

[0075] In this embodiment, the components of the iron agent used include iron powder, dispersant and water; wherein, the iron powder particle size is 150 mesh, the dispersant is carboxymethyl cellulose, and the amount ratio of iron powder, dispersant and water is 100g:25g:900mL.

[0076] In this embodiment, the raw water index of phosphorus-fluorine wastewater is phosphorus concentration 275mg / L, fluorine concentration 58mg / L; the water flow rate in the pipeline mixer 304 is 100m 3 / h, the dosing flow rate of calcium oxide emulsion is 1.6m 3 / h, the dosing flow rate of iron agent is 2.8m 3 / h; the residence time of the wastewater in the reaction tank 305 is 60s; the effluent index of the reaction tank 305 is phosphorus concentration ≤5mg / L, fluorine concentration ≤10mg / L.

[0077] Example 3

[0078] A method for treating phosphorus and fluorine wastewater by using a calcium oxide-iron composite agent is provided. The phosphorus and fluorine wastewater is treated using the system described in Example 1. The treatment process is the same as that in Example 2 and will not be described in detail.

[0079] In this embodiment, the calcium oxide emulsion used includes calcium oxide, magnesium oxide, a dispersant, and a retarding liquid. The calcium oxide and magnesium oxide are ball-milled (using 5 mm diameter agate beads, the rotation speed is set to 240 rpm, and the ball milling time is 2.5 hours), and the mass ratio of calcium oxide to magnesium oxide is 50:20. The dispersant is a mixture of methyl formate, ethylene glycol, and ethyl acetate, and the mass ratio of methyl formate, ethylene glycol, and ethyl acetate is 20:15:5. The retarding liquid is a mixture of starch, citric acid, and water, and the amount ratio of starch, citric acid, and water is 2 g:0.5 g:50 mL. The mass ratio of the total mass of calcium oxide and magnesium oxide to the dispersant is 35:20. The ratio of the total mass of calcium oxide, magnesium oxide, and dispersant to the volume of the retarding liquid is 5 g:100 mL.

[0080] In this embodiment, the components of the iron agent used include iron powder, dispersant and water; wherein, the iron powder particle size is 150 mesh, the dispersant is carboxymethyl cellulose, and the amount ratio of iron powder, dispersant and water is 3g:10g:100mL.

[0081] In this embodiment, the raw water index of phosphorus-fluorine wastewater is phosphorus concentration 239 mg / L, fluorine concentration 76 mg / L; the water flow rate in the pipeline mixer 304 is 8m 3 / h, the dosing flow rate of calcium oxide emulsion is 0.18m 3 / h, the dosing flow rate of iron agent is 0.2m 3 / h; the residence time of the wastewater in the reaction tank 305 is 60s; the effluent index of the reaction tank 305 is phosphorus concentration ≤5mg / L, fluorine concentration ≤10mg / L.

[0082] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A system for synergistically treating phosphorus and fluorine wastewater using a calcium oxide-iron composite agent, characterized in that: include: Calcium oxide emulsion preparation and dosing equipment, iron agent preparation and dosing equipment, and phosphorus and fluorine wastewater flow control and treatment equipment; The calcium oxide emulsion preparation and dosing device is used to prepare calcium oxide emulsion and feed the prepared calcium oxide emulsion into the pipeline mixer of the phosphorus and fluorine wastewater flow control and treatment device; The iron agent preparation and dosing device is used to prepare the iron agent and feed the prepared iron agent into the pipeline mixer of the phosphorus and fluorine wastewater flow control and treatment device; The phosphorus and fluorine wastewater flow control and treatment device includes: a wastewater flow control valve, a wastewater flow meter, a wastewater pipeline, a pipeline mixer and a reaction tank; wherein the water outlet of the wastewater flow control valve is connected to the water inlet of the wastewater flow meter, the water outlet of the wastewater flow meter is connected to the water inlet of the wastewater pipeline, the water outlet of the wastewater pipeline is connected to the water inlet of the pipeline mixer, and the outlet of the pipeline mixer is connected to the inlet of the reaction tank.

2. The system according to claim 1, wherein: The calcium oxide emulsion preparation and dosing device includes: a first clean water pipe, a calcium oxide emulsion stirrer, a calcium oxide emulsion preparation tank, a calcium oxide emulsion discharge valve, a variable frequency flexible pump, an electromagnetic flowmeter and a calcium oxide emulsion hydraulic pipeline; wherein, the water outlet of the first clean water pipe faces the calcium oxide emulsion preparation tank, the stirring head of the calcium oxide emulsion stirrer penetrates into the calcium oxide emulsion preparation tank, the feed port of the calcium oxide emulsion discharge valve is connected to the discharge port of the calcium oxide emulsion preparation tank, the feed port of the variable frequency flexible pump is connected to the discharge port of the calcium oxide emulsion discharge valve, the discharge port of the variable frequency flexible pump is connected to the feed port of the electromagnetic flowmeter, and the discharge port of the electromagnetic flowmeter is connected to the feed port of the calcium oxide emulsion hydraulic pipeline; The discharge port of the calcium oxide emulsion hydraulic pipeline is connected to the calcium oxide emulsion feed port of the pipeline mixer.

3. The system according to claim 1, wherein: The iron agent preparation and dosing device includes: an iron agent stirrer, an iron agent preparation tank, an iron agent flow meter, an iron agent hydraulic pipeline, an iron agent discharge valve, a three-way pipe, a slurry pump, an iron agent flow control valve, a second clean water pipe, a reflux valve and a reflux pipe; wherein, the stirring head of the iron agent stirrer is deep into the iron agent preparation tank, the discharge port of the iron agent preparation tank is connected to the feed port of the iron agent discharge valve, the discharge port of the iron agent discharge valve is connected to the three-way pipe, and the other two ends of the three-way pipe are connected to the three-way pipe. They are respectively connected to the water outlet of the second clean water pipe and the feed port of the slurry pump, the discharge port of the slurry pump is respectively connected to the feed port of the iron agent flow control valve and the feed port of the reflux valve, the discharge port of the iron agent flow control valve is connected to the feed port of the iron agent flow meter, the discharge port of the iron agent flow meter is connected to the feed port of the iron agent hydraulic pipeline, the discharge port of the reflux valve is connected to the feed port of the reflux pipeline, and the discharge port of the reflux pipeline faces the inside of the iron agent preparation tank; The discharge port of the iron agent hydraulic pipeline is connected to the iron agent feed port of the pipeline mixer.

4. A method for treating phosphorus and fluorine wastewater by using a calcium oxide-iron composite agent, characterized in that: The method of treating phosphorus and fluorine wastewater by using the system according to any one of claims 1 to 3 comprises the following steps: preparing calcium oxide emulsion by the calcium oxide emulsion preparation and dosing device, and feeding the prepared calcium oxide emulsion into the calcium oxide emulsion feed port of the pipeline mixer; preparing an iron agent by the iron agent preparation and dosing device, and feeding the prepared iron agent into the iron agent feed port of the pipeline mixer; The phosphorus and fluorine wastewater flows through the wastewater flow control valve, the wastewater flow meter and the wastewater pipeline, and then enters the pipeline mixer; The calcium oxide emulsion, iron reagent and phosphorus-fluorine wastewater converge and mix in the pipeline mixer, and then enter the reaction tank to react to obtain treated wastewater.

5. The method according to claim 4, characterized in that The components of the calcium oxide emulsion include calcium oxide, magnesium oxide, a dispersant and a retarding liquid.

6. The method according to claim 5, characterized in that The dispersant comprises methyl formate, ethylene glycol and ethyl acetate, and the mass ratio of the methyl formate, ethylene glycol and ethyl acetate is (20-30):(15-25):(5-15); The components of the retarding liquid include starch, citric acid and water, and the usage ratio of the starch, citric acid and water is (2-28) g: (0.5-16) g: (50-500) mL.

7. The method according to claim 5, characterized in that The mass ratio of the calcium oxide to the magnesium oxide is (50-65):(20-35); the mass ratio of the total mass of the calcium oxide and the magnesium oxide to the dispersant is (10-35):(3-20); and the ratio of the total mass of the calcium oxide, magnesium oxide and the dispersant to the volume of the retarding liquid is (5-37) g:(100-1650) mL.

8. The method according to claim 4, characterized in that The components of the iron medicine include iron powder, dispersant and water.

9. The method according to claim 8, characterized in that The particle size of the iron powder is 100-200 mesh; The dispersant is one or more of carboxymethyl cellulose, methyl amyl alcohol and fatty acid polyethylene glycol ester.

10. The method according to claim 8, characterized in that The usage ratio of the iron powder, the dispersant and the water is (3-100) g: (10-25) g: (100-900) mL.

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