A method for quickly testing the quality of defluorination agents

Abstract

The present invention relates to the technical field of wastewater defluorination, and specifically to a method for quickly testing the quality of a defluorination agent, comprising the following steps: S1. placing a fluorine-containing wastewater sample in a beaker to determine the fluorine content in the wastewater; S2. determining the corresponding defluorination agent dosage according to the fluorine content in the wastewater; S3. adding a defluorination agent into the beaker, stirring to produce flocs; S4. adding an inorganic base into the beaker to adjust the pH of the wastewater system to 7; S5. adding a flocculant into the beaker to stir, the flocs produce mud and precipitate, and the supernatant is separated; S6. determining the fluorine content in the supernatant; S7. judging the quality of the defluorination agent according to the following indicators: the amount of mud produced in step S5 and the fluorine content in step S6. The method for quickly testing the quality of the defluorination agent provided by the present invention does not require complex equipment and harsh reaction conditions during the detection reaction process, is simple and easy to operate, takes a short time, is easy to control, and is easy to apply.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater defluorination, and in particular to a method for quickly testing the quality of a defluorination agent. Background Art

[0002] Liquid defluoridation agent is a kind of agent specially developed for high-difficulty fluoride-containing wastewater, focusing on the defluoridation agent treatment stage; its mechanism is to use the strong polar electron cloud hybrid orbit of the effective component to form a strong chemical bond of multi-dentate ligand with the fluorine element in the wastewater to achieve the effect of removing fluorine. The fluoride formed is more stable than the general complex and can effectively separate fluoride from the wastewater. It is suitable for the treatment of excessive fluoride in wastewater in various industries; the reaction speed is fast, only 10-15 minutes, and the removal rate can reach more than 98%; it is easy to operate.

[0003] At present, the amount of fluorine-containing industrial wastewater is large, the distribution is wide, and the composition of fluorine-containing wastewater is complex. With the continuous development of defluorination technology, according to the different characteristics of fluorine-containing wastewater generated in various industries, the types of defluorination agents that match fluorine-containing wastewater are increasing. High-quality agents have high purity, low impurity content, low defluorination agent dosage, and low sludge volume. Low-quality defluorination agents have complex ingredients and extremely poor efficacy. The use of low-quality agents will cause the fluoride in the effluent of the defluorination device to exceed the standard, increase the cost of defluorination, and cannot effectively control the cost of using the company's agents. If you need to accurately determine the quality of the defluorination agent, you need to send the agent sample to a professional company for inspection. The test items include content detection, index detection, component analysis, etc. The inspection cycle is basically 7 to 15 working days, which is long, complicated, and time-effective. It cannot be applied to industrial enterprises with continuous production, which in turn affects the defluorination stability of the agent in the entire defluorination device and affects the unit consumption of the agent. Therefore, in order to fundamentally solve the problem of fluorine removal costs, it is necessary to conduct rapid inspections on defluorine removal agent samples, stabilize the quality of defluorine removal agents, and ensure low-consumption and stable operation of defluorine removal equipment. Summary of the invention

[0004] In view of the problems of the prior art defluorination agent inspection method having multiple processes and poor time efficiency, the present invention provides a method for quickly inspecting the quality of defluorination agents. The method is simple and easy to operate, and is easy to control, which greatly shortens the inspection time.

[0005] The present invention provides a method for quickly testing the quality of a defluorination agent, comprising the following steps:

[0006] S1. Place the fluoride-containing wastewater sample in a beaker and measure the fluoride content in the wastewater;

[0007] S2. Determine the dosage of the corresponding defluorination agent according to the fluorine content in the wastewater;

[0008] S3. Add defluorination agent into the beaker and stir to produce flocs;

[0009] S4. Add inorganic alkali into the beaker to adjust the pH of the wastewater system to 7;

[0010] S5. Add flocculant into the beaker and stir, the floccules will precipitate and sink, and the supernatant will be separated;

[0011] S6. Determine the fluorine content in the supernatant;

[0012] S7. Determine the quality of the defluorination agent based on the following indicators: the amount of sludge produced in step S5 and the fluorine content in step S6.

[0013] Furthermore, the method for determining the fluorine content in step S1 and step S6 is to determine the fluorine ion content in the system using a fluorine electrode method.

[0014] Furthermore, in step S2, the dosage of the defluoridation agent is determined according to the fluoride content of the wastewater and the standard fluoride value of the defluoridation agent.

[0015] Furthermore, in step S3, the stirring time is 8 to 12 minutes.

[0016] Furthermore, in step S4, the quality of the defluorination agent is preliminarily judged by the diameter of the flocs. The judgment method is that if the flocs are in a clumping shape and the floc diameter is ≥0.5 cm, the defluorination agent is of high quality; when the floc diameter is <0.5 cm, the defluorination agent is of medium quality; if the flocs are in the form of dispersed particles, the defluorination agent is of low quality.

[0017] Furthermore, in step S4, the inorganic base is sodium hydroxide or potassium hydroxide.

[0018] Furthermore, in step S5, the flocculant is anionic polyacrylamide, and the concentration of anionic polyacrylamide is 1‰.

[0019] Furthermore, in step S7, if the sludge production in step S5 is less than 5 ppm and the fluorine content in step S6 is less than 3 mg / L, the defluorination agent is of high quality; if the sludge production in step S5 is greater than 20 ppm and / or the fluorine content in step S6 is greater than 4 mg / L, the defluorination agent is of low quality; otherwise, the defluorination agent is of medium quality.

[0020] The beneficial effect of the present invention is that the method for quickly testing the quality of the defluorination agent provided by the present invention does not require complicated equipment and harsh reaction conditions for the detection reaction process, is simple and easy to operate, takes a short time, is easy to control, and is easy to apply. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. 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 creative work should fall within the scope of protection of the present invention.

[0022] Example 1

[0023] A method for quickly testing the quality of a defluorination agent comprises the following steps:

[0024] (1) Take a raw water sample and determine the fluoride ion content in the system using the fluoride electrode method;

[0025] (2) Take 200 mL of raw water sample and place it in a beaker. Add defluorination agent according to the fluoride ion content of the wastewater and the reference dosage provided by a certain manufacturer. Mix and stir with a glass rod for 2 minutes. Observe the flocs and record them.

[0026] (3) Add sodium hydroxide to the beaker and adjust the pH to 7. Observe the flocs and record them. If the flocs are clumping, it can be preliminarily judged that the defluorination agent is of medium or high quality.

[0027] (4) After mixing and stirring evenly, add 2.5 mL of 1‰ anionic PAM agent, stir for 1 min, and then let stand;

[0028] (5) After standing and settling for 2 minutes, the supernatant was taken for analysis of the fluoride ion content after treatment, and the remaining mixed solution was filtered and baked with filter paper to obtain the sludge production.

[0029] In order to make the test operation more accurate, the above operations were performed in 4 groups. The specific test parameters are shown in Table 1.

[0030] Table 1 Test parameters for each group in Example 1

[0031]

[0032]

[0033] It can be seen from Table 1 that although the average fluoride ion index after treatment with the defluoridation agent is less than 3 mg / L, the average sludge production of the defluoridation agent is between 5 and 20 ppm, so it can be judged that the defluoridation agent is of medium quality.

[0034] Example 2

[0035] A method for quickly testing the quality of a defluorination agent comprises the following steps:

[0036] (1) Take a raw water sample and determine the fluoride ion content in the system using the fluoride electrode method;

[0037] (2) Take 200 mL of raw water sample and place it in a beaker. Add defluorination agent according to the fluoride ion content of the wastewater and the reference dosage provided by a certain manufacturer. Mix and stir with a glass rod for 2 minutes. Observe the flocs and record them.

[0038] (3) Add sodium hydroxide to the beaker and adjust the pH to 7. Observe the flocs and record them. If the flocs are dispersed particles, it can be preliminarily judged that the defluorination agent is of low quality.

[0039] (4) After the mixture is stirred evenly, 2 mL of 1‰ anionic PAM reagent is added, and the mixture is stirred for 1 min and then allowed to stand;

[0040] (5) After standing and settling for 2 minutes, the supernatant was taken for analysis of the fluoride ion content after treatment, and the remaining mixed solution was filtered and baked with filter paper to obtain the sludge production.

[0041] In order to make the test operation more accurate, the above operations were performed in 4 groups. The specific test parameters are shown in Table 2.

[0042] Table 2 Test parameters for each group in Example 2

[0043]

[0044]

[0045] It can be seen from Table 2 that although the average sludge production of the defluoridation agent is less than 5ppm, the average fluoride ion index after treatment with the defluoridation agent is greater than 4mg / L, so it can be judged that the defluoridation agent is of low quality.

[0046] Example 3

[0047] A method for quickly testing the quality of a defluorination agent comprises the following steps:

[0048] (1) Take a raw water sample and determine the fluoride ion content in the system using the fluoride electrode method;

[0049] (2) Take 200 mL of raw water sample and place it in a beaker. Add defluorination agent according to the fluoride ion content of the wastewater and the reference dosage provided by a certain manufacturer. Mix and stir with a glass rod for 2 minutes. Observe the flocs and record them.

[0050] (3) Add sodium hydroxide to the beaker and adjust the pH to 7. Observe and record the flocs. The flocs are in a clumping shape with a diameter of 0.8 cm. It can be preliminarily judged that the defluorination agent is of high quality.

[0051] (4) After mixing and stirring evenly, add 5 mL of 1‰ anionic PAM agent, stir for 1 min, and then let stand;

[0052] (5) After standing and settling for 2 minutes, the supernatant was taken for analysis of the fluoride ion content after treatment, and the remaining mixed solution was filtered and baked with filter paper to obtain the sludge production.

[0053] In order to make the test operation more accurate, the above operations were performed in 4 groups. The specific test parameters are shown in Table 3.

[0054] Table 3 Test parameters for each group in Example 3

[0055]

[0056] It can be seen from Table 3 that the average sludge production of the defluorination agent is less than 5ppm, and the average fluoride ion index after treatment with the defluorination agent is less than 3mg / L, which means that the defluorination agent is of high quality.

[0057] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily conceive of changes or substitutions within the technical scope disclosed by the present invention, and such changes or substitutions shall be within the scope of protection of the present invention.

Claims

1. A method for quickly testing the quality of a defluorination agent, characterized in that: The steps include: S1. Place the fluoride-containing wastewater sample in a beaker and measure the fluoride content in the wastewater; S2. Determine the dosage of the corresponding defluorination agent according to the fluorine content in the wastewater; S3. Add defluorination agent into the beaker and stir to produce flocs; S4. Add inorganic alkali into the beaker to adjust the pH of the wastewater system to 7, observe the flocs and record them; S5. Add flocculant into the beaker and stir, the floccules will precipitate and sink, and the supernatant will be separated; S6. Determine the fluorine content in the supernatant; S7. Determine the quality of the defluorination agent based on the following indicators: the amount of sludge produced in step S5 and the fluorine content in step S6; In step S4, the quality of the defluorination agent is preliminarily judged by the diameter of the flocs. The judgment method is that if the flocs are in a clumping shape and the floc diameter is ≥0.5 cm, the defluorination agent is of high quality; if the floc diameter is <0.5 cm, the defluorination agent is of medium quality; if the flocs are in a dispersed particle shape, the defluorination agent is of low quality; In step S7, if the sludge production in step S5 is less than 5ppm and the fluorine content in step S6 is less than 3mg / L, the defluorination agent is of high quality; if the sludge production in step S5 is greater than 20ppm and / or the fluorine content in step S6 is greater than 4mg / L, the defluorination agent is of low quality; otherwise, the defluorination agent is of medium quality.

2. The method for quickly testing the quality of a defluorination agent as claimed in claim 1, characterized in that: The method for determining the fluorine content in step S1 and step S6 is to determine the fluorine ion content in the system using a fluorine electrode method.

3. The method for quickly testing the quality of a defluorination agent as claimed in claim 1, characterized in that: In step S2, the dosage of the defluoridation agent is determined according to the fluoride content of the wastewater and the standard fluoride value of the defluoridation agent.

4. The method for quickly testing the quality of a defluorination agent according to claim 1, wherein: In step S3, the stirring time is 8 to 12 minutes.

5. The method for rapidly testing the quality of a defluorination agent as claimed in claim 1, characterized in that: In step S4, the inorganic base is sodium hydroxide or potassium hydroxide.

6. The method for quickly testing the quality of a defluorination agent according to claim 1, wherein: In step S5, the flocculant is anionic polyacrylamide, and the concentration of anionic polyacrylamide is 1‰.

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