A device and method for treating fluoroborate-containing wastewater

Abstract

The invention discloses a device for treating fluoroborate-containing wastewater, the device comprising a reaction chamber, a heating chamber and a water pump, the heating chamber being wrapped on the outer wall of the reaction chamber, the water inlet of the water pump being connected to the heating chamber through a water pipe, and the water outlet of the water pump being connected to the reaction chamber through a water pipe. The device of the invention can make full use of the heat generated in the reaction process of the raw materials to heat the fluoroborate wastewater, does not require an additional heat source, and has the advantages of small footprint and high energy utilization.

Description

Technical Field

[0001] The invention belongs to the field of wastewater treatment, and specifically relates to a device for treating wastewater containing fluoroborate, in particular for treating wastewater containing both fluoroborate and fluoride ions. Background Art

[0002] With the rapid development of fluorine-containing processing industries such as oil refining, electroplating and organic fluorine lubricant manufacturing, a series of fluorine pollution problems have been brought about. In addition, the petrochemical industry uses BF3 as a catalyst for production. Due to the BF4 contained in the discharged wastewater, - Will slowly hydrolyze and release a large amount of F - , which increases the difficulty of wastewater treatment. Due to the strong electronegativity of fluoride ions, it is very easy to combine with other elements. If excessive fluoride ions are absorbed by the human body, it will cause health problems. In order to control the concentration of fluoride ions in industrial wastewater, my country's "Comprehensive Wastewater Discharge Standard" (GB8978-1996) stipulates that F - The ion concentration is less than 10 mg / L. 4- Removal by potassium salt precipitation is the use of K + With BF 4- After the insoluble precipitate is generated, the supernatant is hydrolyzed and removed at medium to high temperature (75℃-95℃). - The calcium salt precipitation method is usually used to make F - With Ca 2+ CaF2 precipitation is generated, and F is removed through solid-liquid separation. - The purpose of BF 4- Hydrolysis uses industrial waste heat as a centralized heat source for heating, however this is not possible in some areas. Summary of the invention

[0003] The object of the present invention is to provide a device for treating fluoroborate-containing wastewater.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A device for treating fluoroborate-containing wastewater comprises a reaction chamber 10, a heating chamber 20 and a water pump 30, and is characterized in that: the heating chamber 20 is wrapped on the outer wall of the reaction chamber 10, the water inlet of the water pump 30 is connected to the heating chamber 20 through a water pipe, and the water outlet of the water pump 30 is connected to the inside of the reaction chamber 10 through a water pipe.

[0006] Preferably, the device is provided with a PLC control system, the reaction chamber is provided with a temperature sensor 13, and the temperature sensor 13 and the water pump 30 are respectively connected to the PLC control system. The PLC control system controls the opening of the water pump 30 according to the signal from the temperature sensor 13.

[0007] Preferably, the device is provided with a drainage pump 40, and a water inlet of the drainage pump 40 is connected to the reaction chamber 10 through a water pipe.

[0008] More preferably, a filter screen 41 is provided at the end of the water pipe connected to the water inlet of the drainage pump.

[0009] More preferably, a fluoroborate detection electrode 14 is provided in the reaction chamber.

[0010] More preferably, a liquid level meter 18 is provided on the side wall of the reaction chamber.

[0011] More preferably, the liquid level meter 18 , the fluoroborate detection electrode 14 and the drainage pump 40 are respectively connected to a PLC control system, which controls the opening or closing of the drainage pump 40 according to the signals from the fluoroboric acid detection electrode 14 and the liquid level meter 18 .

[0012] Preferably, a slag discharge port 17 is provided at the bottom of the reaction chamber.

[0013] Preferably, a gate valve is installed at the slag discharge port 17 .

[0014] More preferably, a fluoride ion detection electrode 15 is provided in the reaction chamber.

[0015] A method for treating fluoroborate-containing wastewater, comprising:

[0016] Adding fluoroborate-containing wastewater into the reaction chamber of the device, and adding a self-heating filler into the heating chamber of the device, wherein the self-heating filler mainly comprises calcium oxide, iron, carbon and electrolyte;

[0017] Water is added to the heating chamber to react with the self-heating filler to release heat;

[0018] When the temperature of the fluoroborate-containing wastewater in the reaction chamber reaches above 75° C., water from the heating chamber is pumped into the reaction chamber to mix with the fluoroborate-containing wastewater for reaction.

[0019] Preferably, the fluorine borate-containing wastewater also contains fluoride ions.

[0020] Preferably, before the water in the heating chamber is pumped into the reaction chamber, potassium salt or potassium salt and calcium salt are added to the fluoroborate-containing wastewater for precipitation treatment.

[0021] Preferably, the potassium salt is added first, followed by the calcium salt.

[0022] More preferably, the potassium salt is potassium chloride and the calcium salt is calcium chloride.

[0023] Preferably, the self-heating filler also contains aluminum.

[0024] More preferably, the self-heating filler further contains an adsorbent.

[0025] The adsorbent is diatomaceous earth. The exothermic reactants are adsorbed into the porous structures inside the diatomaceous earth and the coke powder by utilizing the adsorption effect of the diatomaceous earth and the coke powder, so that they are fully contacted and chemically reacted.

[0026] Preferably, the electrolyte is sodium chloride, and the electrolyte constitutes the salt bridge required for the aluminum-carbon primary battery reaction and the iron-carbon primary battery reaction.

[0027] Most preferably, the self-heating filler is composed of calcium oxide, aluminum, iron, carbon, electrolyte and adsorbent in a mass ratio of 4~5:1~1.2:2~2.6:1.2~1.5:1~2:0.5~1.

[0028] The principle of the present invention is as follows:

[0029] The calcium oxide in the self-heating filler reacts with water to generate calcium hydroxide and rapidly releases a large amount of heat. Iron forms an iron-carbon primary cell with carbon in the environment of the generated calcium hydroxide electrolyte solution, undergoes micro-electrolysis, and continues to release a large amount of heat. The released heat is transmitted into the room through the outer wall of the reaction chamber to heat the wastewater. When the wastewater is heated to a certain temperature, the supernatant containing calcium and iron ions in the heating chamber is pumped into the reaction chamber. Fluoroborate is rapidly hydrolyzed into FeF6 under the action of iron ions under high temperature conditions. 3- The calcium ions react with the fluoride ions in the wastewater to form insoluble CaF2 precipitates.

[0030] Preliminary precipitation treatment of the fluoroborate-containing wastewater with a water-soluble potassium salt can, on the one hand, precipitate part of the fluoroborate, and on the other hand, promote the condensation of calcium ions and fluoride ions around the potassium fluoroborate crystal nucleus to form CaF2 precipitation. Preferably, the mass ratio of K:BF4 - =6.5-9:1 adding water-soluble potassium salt, such as potassium chloride, after the pre-precipitation treatment, the removal rate of fluoroborate can reach 55-65%.

[0031] Formula 1

[0032] Formula 2

[0033] Formula 3

[0034] Formula 4

[0035] Iron-carbon micro-electrolysis reaction formula:

[0036] anode: Formula 5

[0037] cathode:

[0038] (Acidic conditions) Formula 6

[0039] (Alkaline conditions) Formula 7

[0040] Aluminum-carbon micro-electrolysis reaction formula:

[0041] anode: Formula 8

[0042] cathode:

[0043] (Acidic conditions) Formula 9

[0044] (Alkaline conditions) Formula 10

[0045] Fe 2+ Converted to Fe 3+ Reactions:

[0046] Formula 11

[0047] Compared with the prior art, the device of the present invention fully utilizes the heat generated in the raw material reaction process to heat the fluoroborate wastewater, does not require an additional heat source, and has the advantages of small footprint and high energy utilization. The device of the present invention is also applicable to waste liquid containing both fluoroborate and fluoride ions, which is beneficial to improving the waste liquid treatment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The present invention is a schematic diagram of a device for treating fluoroborate-containing wastewater.

[0049] Figure 2 This is a schematic diagram of the PLC control system structure.

[0050] Among them, 10. reaction chamber, 11. stirrer, 12. motor, 13. temperature sensor, 14. fluoroborate detection electrode, 15. fluoride ion detection electrode, 16. pH detection electrode, 17. slag discharge port, 18. liquid level meter, 20. heating chamber, 21. self-heating filler, 22. temperature sensor, 30. water pump, 40. drainage pump, 41. filter. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0052] Example 1

[0053] like Figure 1 As shown, the device for treating fluoroborate-containing wastewater of the present invention is an inner and outer double shell structure, wherein the inner shell constitutes the wall of the reaction chamber 10 , and the cavity between the inner shell and the outer shell constitutes the heating chamber 20 .

[0054] The inner shell, i.e. the wall of the reaction chamber, is made of thin-walled carbon steel with good thermal conductivity. To further improve the corrosion resistance of the wall, a corrosion-resistant and thermally conductive silicon carbide coating can be sprayed on the carbon steel surface. The outer shell is made of hard phenolic plastic with good thermal insulation performance and is wrapped with rock wool to reduce heat loss.

[0055] The cavity of the heating chamber 20 is used to fill the self-heating filler 21, and the self-heating filler reacts with tap water in the cavity to release heat.

[0056] The device is provided with a water pump 30, the water inlet of the water pump 30 is connected to the heating chamber 20 through a water pipe, and the water outlet is connected to the reaction chamber 10 through a water pipe. The water pump 30 is used to pump the supernatant in the heating chamber 20 into the reaction chamber 10, so that the supernatant containing calcium ions and iron ions reacts with the wastewater containing fluoroborate.

[0057] The reaction chamber 10 is provided with a temperature sensor 13 for monitoring the temperature of the wastewater in the reaction chamber.

[0058] The heating chamber 20 is provided with a temperature sensor 22 for monitoring the temperature of the supernatant in the heating chamber.

[0059] The device is also provided with a drainage pump 40, the water inlet of which is connected to the reaction chamber 10 through a water pipe, and is used to discharge the treated wastewater that meets the standards out of the reaction chamber 10. In order to prevent the waste residue in the reaction chamber from being sucked into the drainage pump 40, a filter screen 41 is provided at the end of the water pipe connected to the water inlet of the drainage pump 40.

[0060] The reaction chamber is provided with a fluoroborate detection electrode 14 for monitoring the fluoroborate concentration in the wastewater.

[0061] The reaction chamber is also provided with a fluoride ion detection electrode 15 and a pH detection electrode 16, which are used to monitor the fluoride ion concentration in the wastewater and the pH value of the wastewater respectively.

[0062] The bottom of the reaction chamber 10 is provided with a slag discharge port 17 penetrating the heating chamber 20 for discharging the generated waste slag. The slag discharge port 17 is installed with a gate valve.

[0063] A liquid level meter 18 is provided on the side wall of the reaction chamber for monitoring the water level of the wastewater in the reaction chamber.

[0064] The device is also equipped with a PLC (Programmable Logic Controller) control system. The temperature sensor (13, 22), fluoroborate detection electrode 14, fluoride ion detection electrode 15, pH detection electrode 16, liquid level meter 18, gate valve of slag discharge port 17, motor 12, water pump 30, and drainage pump 40 are respectively connected to the PLC control system. The structural schematic diagram of the PLC control system is shown in FIG. Figure 2 As shown, the PLC control system obtains data from the temperature sensor (13, 22), the fluoroborate detection electrode 14, the fluoride ion detection electrode 15, the pH detection electrode 16, and the liquid level meter 18 through the input module, and after the CPU runs the program set by the programming device, the gate valve of the slag discharge port 17, the motor 12, the water pump 30, and the drainage pump 40 are automatically started or closed through the output module.

[0065] Example 2

[0066] The method for treating wastewater containing fluoroborate and fluoride ions comprises the following steps:

[0067] Add the fluorine borate-containing wastewater into the reaction chamber 10 of the device described in Example 1, and add the self-heating filler 21 into the heating chamber 20 of the device, wherein the self-heating filler has a mass ratio of CaO:Al:Fe:coke powder:NaCl:diatomaceous earth=4-5:1-1.2:2-2.6:1.2-1.5:1-2:0.5-1;

[0068] Pretreatment: Turn on the stirrer 11 and add K:BF4 into the reaction chamber 10 according to the mass ratio - =6.5-9:1 ratio of potassium chloride, the total amount of potassium chloride added does not exceed 35g / 100ml, after the formation of potassium fluoroborate precipitation, add anhydrous calcium chloride in a molar ratio of Ca:F=1.5:2. In this step, BF4 - The removal rate can reach 55-65%, F - The removal rate can reach 85-90%. The specific dosage of potassium chloride and calcium chloride is determined according to the test results of fluoroborate and fluoride ion concentrations.

[0069] Then, tap water is added to the heating chamber 20. The tap water reacts with the self-heating filler 21 to release a large amount of heat, thereby heating the wastewater in the reaction chamber 10.

[0070] When the wastewater temperature in the reaction chamber 10 reaches above 75°C (preferably above 85°C), the water pump 30 is turned on to pump the supernatant in the heating chamber 20 into the reaction chamber 10 to mix with the wastewater for reaction;

[0071] When the concentration of fluoroborate and fluoride ions in the wastewater in the reaction chamber 10 reaches the discharge standard, the drainage pump 40 is turned on to discharge the wastewater that meets the standard. When the wastewater level drops to the lowest point, the drainage pump 40 is turned off, and the gate valve of the slag discharge port 17 is opened to discharge the waste slag.

[0072] The above description is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, without departing from the technical principle of the present invention, if the technical solutions recorded in the aforementioned embodiments are modified, or some of the technical features therein are replaced by equivalents, it should be regarded as within the scope of protection of the present invention.

Claims

1. A device for treating fluoroborate-containing wastewater, the device comprising a reaction chamber, a heating chamber and a water pump, characterized in that: The heating chamber is wrapped around the outer wall of the reaction chamber, the water inlet of the water pump is connected to the heating chamber through a water pipe, and the water outlet of the water pump is connected to the reaction chamber through a water pipe; A self-heating filler is added to the heating chamber of the device, the self-heating filler comprising calcium oxide, iron, carbon and electrolyte.

2. The device according to claim 1, characterized in that: The device is provided with a PLC control system, the reaction chamber is provided with a temperature sensor, and the temperature sensor and the water pump are respectively connected to the PLC control system.

3. The device according to claim 1 or 2, characterized in that: The device is provided with a drainage pump, and a water inlet of the drainage pump is connected to the reaction chamber through a water pipe.

4. The device according to claim 3, characterized in that: A filter screen is arranged at the end of the water pipe connected to the water inlet of the drainage pump.

5. The device according to claim 3, characterized in that: The reaction chamber is provided with a fluoroborate detection electrode.

6. The device according to claim 5, characterized in that: A liquid level gauge is provided on the side wall of the reaction chamber.

7. The device according to claim 6, characterized in that: The liquid level meter, fluoroborate detection electrode and drainage pump are respectively connected to the PLC control system.

8. The device according to claim 1, characterized in that: A slag discharge port is provided at the bottom of the reaction chamber.

9. The device according to claim 8, characterized in that: A gate valve is installed at the slag discharge port.

10. The device according to claim 1, characterized in that: A fluoride ion detection electrode is arranged in the reaction chamber.

11. A method for treating fluoroborate-containing wastewater, comprising: Adding fluoroborate-containing wastewater into the reaction chamber of the device of claim 1, and adding a self-heating filler into the heating chamber of the device, wherein the self-heating filler comprises calcium oxide, iron, carbon and electrolyte; Water is added to the heating chamber to react with the self-heating filler to release heat; When the temperature of the fluoroborate-containing wastewater in the reaction chamber reaches above 75° C., water from the heating chamber is pumped into the reaction chamber to mix with the fluoroborate-containing wastewater for reaction.

12. The method according to claim 11, characterized in that: The fluorine borate-containing wastewater also contains fluoride ions.

13. The method according to claim 11 or 12, characterized in that: Before the water in the heating chamber is pumped into the reaction chamber, potassium salt or potassium salt and calcium salt are added to the fluoroborate-containing wastewater for precipitation treatment.

14. The method according to claim 13, characterized in that: Add the potassium salt first, then the calcium salt.

15. The method according to claim 14, characterized in that: The potassium salt is potassium chloride, and the calcium salt is calcium chloride.

16. The method according to claim 11, characterized in that: Self-heating fillers also contain aluminum.

17. The method according to claim 16, characterized in that: The self-heating filler further contains an adsorbent.

18. The method according to claim 17, characterized in that: The electrolyte is sodium chloride, and the adsorbent is diatomaceous earth.

19. The method according to claim 17, characterized in that: The self-heating filler is composed of calcium oxide, aluminum, iron, carbon, electrolyte and adsorbent in a mass ratio of 4-5:1-1.2:2-2.6:1.2-1.5:1-2:0.5-1.

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