Fluorine removal agent for sewage and preparation method thereof

Abstract

The invention relates to the technical field of fluorine removal, and provides a fluorine removal agent for sewage and a preparation method of the fluorine removal agent. The fluorine removal agent for sewage is prepared from the following raw material components in parts by weight: 40 to 60 parts of polyaluminum ferric chloride, 5 to 10 parts of sodium carboxymethyl cellulose, 2 to 20 parts of ferric ammonium ethylenediaminetetraacetate, 5 to 20 parts of sodium lauryl phosphate, 5 to 15 parts of ethylenediaminetetraacetic acid, 1 to 10 parts of polyethylene glycol and 200 to 240 parts of water. By means of the technical scheme, the problem that in the prior art, the fluorine removal rate of a fluorine removal agent for sewage is low is solved.

Description

Technical Field

[0001] The invention relates to the technical field of fluorine removal, and in particular to a defluorination agent for sewage and a preparation method thereof. Background Art

[0002] With the rapid development of industry, the fluoride content in wastewater discharged by industries such as aluminum electrolysis, steel, phosphate fertilizer, glass, ceramics, and electronics is increasing. At the same time, in certain specific geological areas, groundwater may also naturally contain high concentrations of fluoride ions. If these fluoride-containing wastewaters are directly discharged without effective treatment, they will pose a serious threat to the ecological environment and human health.

[0003] Fluorine is one of the essential trace elements for the human body, but excessive intake can lead to diseases such as dental fluorosis and skeletal fluorosis, affecting the normal development and function of bones and teeth. In terms of the environment, high concentrations of fluoride ions will have a negative impact on the aquatic ecosystem, interfere with the normal physiological metabolism and reproduction of aquatic organisms, and destroy the ecological balance of the water body. Traditional fluoride removal methods include precipitation, adsorption, ion exchange, etc., but these methods often have some limitations. The precipitation method is not ideal for removing low-concentration fluoride ions and will produce a large amount of sludge; the adsorbent regeneration of the adsorption method is difficult and the cost is high; the ion exchange method has strict requirements on the influent water quality and is complicated to operate.

[0004] In summary, the existing defluoridation agents for sewage have a low defluoridation rate. Therefore, the development of efficient defluoridation agents for sewage has important practical significance. Summary of the invention

[0005] The invention provides a defluorinating agent for sewage and a preparation method thereof, which solves the problem of low defluorination rate of the defluorinating agent for sewage in the related art.

[0006] The technical solution of the present invention is as follows: The invention provides a defluoridating agent for sewage. The raw materials include the following components by weight: 40-60 parts of polyaluminium ferric chloride, 5-10 parts of sodium carboxymethyl cellulose, 2-20 parts of ammonium ferric ethylenediaminetetraacetate, 5-20 parts of sodium lauryl phosphate, 5-15 parts of ethylenediaminetetraacetic acid, 1-10 parts of polyethylene glycol and 200-240 parts of water.

[0007] As a further technical solution, the mass ratio of the ammonium ferric ethylenediaminetetraacetate to the sodium lauryl phosphate is 0.5~1.5:1.

[0008] The present invention further improves the fluorine removal rate of the defluorinating agent for sewage by adjusting the mass ratio of ammonium ferric ethylenediaminetetraacetate to sodium lauryl phosphate to 0.5-1.5:1.

[0009] As a further technical solution, the mass ratio of the ammonium ferric ethylenediaminetetraacetate to the sodium lauryl phosphate is 1:1.

[0010] The present invention further improves the fluorine removal rate of the defluorinating agent for sewage by adjusting the mass ratio of ammonium ferric ethylenediaminetetraacetate to sodium lauryl phosphate to 1:1.

[0011] As a further technical solution, the mass ratio of the ethylenediaminetetraacetic acid to the polyethylene glycol is 1-3:1.

[0012] The present invention further improves the fluorine removal rate of the sewage defluorinator by adjusting the mass ratio of ethylenediaminetetraacetic acid to polyethylene glycol to 1-3:1.

[0013] As a further technical solution, the mass ratio of the ethylenediaminetetraacetic acid to the polyethylene glycol is 2:1.

[0014] The present invention further improves the fluorine removal rate of the defluorinating agent for sewage by adjusting the mass ratio of ethylenediaminetetraacetic acid to polyethylene glycol to 2:1.

[0015] As a further technical solution, the basicity of the polyaluminium ferric chloride is 60% to 90%.

[0016] As a further technical solution, the polyethylene glycol includes one of PEG-800, PEG-1000 and PEG-1500.

[0017] As a further technical solution, the polyethylene glycol is PEG-1000.

[0018] The present invention also proposes a method for preparing a defluoridating agent for sewage, comprising the following steps: S1, dissolving polyaluminium ferric chloride in water, adding sodium carboxymethyl cellulose to obtain a first mixed solution; S2, mixing ammonium ferric ethylenediaminetetraacetate and sodium lauryl phosphate, adding the first mixed solution, dissolving, and obtaining a second mixed solution; S3. Add ethylenediaminetetraacetic acid and polyethylene glycol to the second mixed solution, mix well, and obtain a defluorinating agent.

[0019] As a further technical solution, the dissolving temperature in S2 is 35~55°C.

[0020] The working principle and beneficial effects of the present invention are: In the present invention, polyaluminium ferric chloride is used as an important raw material of the defluoridation agent, and the various high-valent polynuclear ions produced by its hydrolysis can react with fluoride ions to form a precipitate or be adsorbed on the surface of its hydrolysate, thereby effectively removing fluoride ions in sewage. At the same time, compared with a single aluminum salt or iron salt, polyaluminium ferric chloride has a wider pH adaptability and better coagulation effect when treating complex water quality, thereby improving the defluoridation rate. In the defluoridation process, sodium carboxymethyl cellulose can increase the viscosity of the solution, so that other defluoridation components are better dispersed in the sewage, ensuring that the defluoridation reaction is more uniform and fully carried out. At the same time, the carboxyl group in its molecular structure has certain adsorption properties, can interact weakly with fluoride ions, assist other main defluoridation components, and enhance the overall defluoridation effect. The synergistic compounding of ammonium ferric ethylenediaminetetraacetate and sodium lauryl phosphate improves the defluoridation effect of the defluoridation agent for sewage. Ethylenediaminetetraacetic acid has a strong chelating ability and can form stable chelates with a variety of metal ions. During the defluorination process, it can react with interfering metal ions (such as calcium, magnesium, iron, etc.) that may exist in sewage to prevent these metal ions from forming complexes with fluoride ions that are difficult to remove, thereby reducing interference with the defluorination process and enabling the defluoridation agent to act more effectively on fluoride ions. Polyethylene glycol has good water solubility and dispersibility, which can improve the solubility and dispersion of the various components of the defluoridation agent in sewage, ensure that the various components are in full contact with fluoride ions, and improve the reaction efficiency. Ethylenediaminetetraacetic acid and polyethylene glycol work synergistically to improve the defluorination rate of the defluoridation agent for sewage. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 are within the scope of protection of the present invention.

[0022] In the following embodiments and comparative examples, the basicity of polyaluminium ferric chloride is 90%, and the manufacturer is Zhengzhou Chuangshi Water Purification Materials Co., Ltd.; the viscosity of sodium carboxymethyl cellulose is 3100 mPa·s, the degree of substitution is 0.92, and the content is 99.7wt%; the content of ammonium ferric ethylenediaminetetraacetate is 98wt%, the content of sodium lauryl phosphate is 98wt%, the content of ethylenediaminetetraacetic acid is 98wt%, and the polyethylene glycol is PEG-1000.

[0023] Example 1 A defluoridating agent for sewage, the raw materials comprising the following components by weight: 60 parts of polyaluminium ferric chloride, 10 parts of sodium carboxymethyl cellulose, 2 parts of ammonium ferric ethylenediaminetetraacetate, 20 parts of sodium lauryl phosphate, 5 parts of ethylenediaminetetraacetic acid, 10 parts of polyethylene glycol, and 240 parts of water; The preparation method thereof comprises the following steps: S1, dissolving polyaluminium ferric chloride in water, adding sodium carboxymethyl cellulose to obtain a first mixed solution; S2, mixing ammonium ferric ethylenediaminetetraacetate and sodium lauryl phosphate, adding the first mixed solution, and dissolving at 55° C. to obtain a second mixed solution; S3. Add ethylenediaminetetraacetic acid and polyethylene glycol to the second mixed solution, mix well, and obtain a defluorinating agent.

[0024] Example 2 A defluoridating agent for sewage, the raw materials comprising the following components by weight: 40 parts of polyaluminium ferric chloride, 5 parts of sodium carboxymethyl cellulose, 20 parts of ammonium ferric ethylenediaminetetraacetate, 5 parts of sodium lauryl phosphate, 15 parts of ethylenediaminetetraacetic acid, 1 part of polyethylene glycol, and 200 parts of water; The preparation method thereof comprises the following steps: S1, dissolving polyaluminium ferric chloride in water, adding sodium carboxymethyl cellulose to obtain a first mixed solution; S2, mixing ammonium ferric ethylenediaminetetraacetate and sodium lauryl phosphate, adding the first mixed solution, and dissolving at 35° C. to obtain a second mixed solution; S3. Add ethylenediaminetetraacetic acid and polyethylene glycol to the second mixed solution, mix well, and obtain a defluorinating agent.

[0025] Example 3 A defluoridating agent for sewage, the raw materials comprising the following components by weight: 50 parts of polyaluminium ferric chloride, 8 parts of sodium carboxymethyl cellulose, 12 parts of ammonium ferric ethylenediaminetetraacetate, 6 parts of sodium lauryl phosphate, 10 parts of ethylenediaminetetraacetic acid, 2 parts of polyethylene glycol, and 220 parts of water; The preparation method thereof comprises the following steps: S1, dissolving polyaluminium ferric chloride in water, adding sodium carboxymethyl cellulose to obtain a first mixed solution; S2, mixing ammonium ferric ethylenediaminetetraacetate and sodium lauryl phosphate, adding the first mixed solution, and dissolving at 45° C. to obtain a second mixed solution; S3. Add ethylenediaminetetraacetic acid and polyethylene glycol to the second mixed solution, mix well, and obtain a defluorinating agent.

[0026] Example 4 The only difference between this embodiment and embodiment 3 is that the raw materials of this embodiment include the following components by weight: 50 parts of polyaluminum ferric chloride, 8 parts of sodium carboxymethyl cellulose, 4 parts of ammonium ferric ethylenediaminetetraacetate, 14 parts of sodium lauryl phosphate, 10 parts of ethylenediaminetetraacetic acid, 2 parts of polyethylene glycol, and 220 parts of water.

[0027] Example 5 The only difference between this embodiment and embodiment 3 is that the raw materials of this embodiment include the following components by weight: 50 parts of polyaluminum ferric chloride, 8 parts of sodium carboxymethyl cellulose, 6 parts of ammonium ferric ethylenediaminetetraacetate, 12 parts of sodium lauryl phosphate, 10 parts of ethylenediaminetetraacetic acid, 2 parts of polyethylene glycol, and 220 parts of water.

[0028] Example 6 The only difference between this embodiment and embodiment 3 is that the raw materials of this embodiment include the following components by weight: 50 parts of polyaluminum ferric chloride, 8 parts of sodium carboxymethyl cellulose, 9 parts of ammonium ferric ethylenediaminetetraacetate, 9 parts of sodium lauryl phosphate, 10 parts of ethylenediaminetetraacetic acid, 2 parts of polyethylene glycol, and 220 parts of water.

[0029] Example 7 The only difference between this embodiment and embodiment 3 is that the raw materials of this embodiment include the following components by weight: 50 parts of polyaluminum ferric chloride, 8 parts of sodium carboxymethyl cellulose, 10.8 parts of ammonium ferric ethylenediaminetetraacetate, 7.2 parts of sodium lauryl phosphate, 10 parts of ethylenediaminetetraacetic acid, 2 parts of polyethylene glycol, and 220 parts of water.

[0030] Example 8 The only difference between this embodiment and embodiment 6 is that the raw materials of this embodiment include the following components by weight: 50 parts of polyaluminum ferric chloride, 8 parts of sodium carboxymethyl cellulose, 9 parts of ammonium ferric ethylenediaminetetraacetate, 9 parts of sodium lauryl phosphate, 4 parts of ethylenediaminetetraacetic acid, 8 parts of polyethylene glycol, and 220 parts of water.

[0031] Example 9 The only difference between this embodiment and embodiment 6 is that the raw materials of this embodiment include the following components by weight: 50 parts of polyaluminum ferric chloride, 8 parts of sodium carboxymethyl cellulose, 9 parts of ammonium ferric ethylenediaminetetraacetate, 9 parts of sodium lauryl phosphate, 6 parts of ethylenediaminetetraacetic acid, 6 parts of polyethylene glycol, and 220 parts of water.

[0032] Example 10 The only difference between this embodiment and embodiment 6 is that the raw materials of this embodiment include the following components by weight: 50 parts of polyaluminum ferric chloride, 8 parts of sodium carboxymethyl cellulose, 9 parts of ammonium ferric ethylenediaminetetraacetate, 9 parts of sodium lauryl phosphate, 8 parts of ethylenediaminetetraacetic acid, 4 parts of polyethylene glycol, and 220 parts of water.

[0033] Embodiment 11 The only difference between this embodiment and embodiment 6 is that the raw materials of this embodiment include the following components by weight: 50 parts of polyaluminum ferric chloride, 8 parts of sodium carboxymethyl cellulose, 9 parts of ammonium ferric ethylenediaminetetraacetate, 9 parts of sodium lauryl phosphate, 9 parts of ethylenediaminetetraacetic acid, 3 parts of polyethylene glycol, and 220 parts of water.

[0034] Comparative Example 1 The only difference between this comparative example and Example 2 is that the raw materials of this comparative example include the following components by weight: 40 parts of polyaluminium ferric chloride, 5 parts of sodium carboxymethyl cellulose, 25 parts of ammonium ferric ethylenediaminetetraacetate, 15 parts of ethylenediaminetetraacetic acid, 1 part of polyethylene glycol, and 200 parts of water.

[0035] Comparative Example 2 The only difference between this comparative example and Example 2 is that the raw materials of this comparative example include the following components by weight: 40 parts of polyaluminium ferric chloride, 5 parts of sodium carboxymethyl cellulose, 25 parts of sodium lauryl phosphate, 15 parts of ethylenediaminetetraacetic acid, 1 part of polyethylene glycol, and 200 parts of water.

[0036] Comparative Example 3 The only difference between this comparative example and Example 2 is that the raw materials of this comparative example include the following components by weight: 40 parts of polyaluminium ferric chloride, 5 parts of sodium carboxymethyl cellulose, 15 parts of ethylenediaminetetraacetic acid, 1 part of polyethylene glycol, and 200 parts of water.

[0037] Comparative Example 4 The only difference between this comparative example and Example 2 is that the raw materials of this comparative example include the following components by weight: 40 parts of polyaluminum ferric chloride, 5 parts of sodium carboxymethyl cellulose, 20 parts of ammonium ferric ethylenediaminetetraacetate, 5 parts of sodium lauryl phosphate, 16 parts of ethylenediaminetetraacetic acid, and 200 parts of water.

[0038] Comparative Example 5 The only difference between this comparative example and Example 2 is that the raw materials of this comparative example include the following components by weight: 40 parts of polyaluminum ferric chloride, 5 parts of sodium carboxymethyl cellulose, 20 parts of ammonium ferric ethylenediaminetetraacetate, 5 parts of sodium lauryl phosphate, 16 parts of polyethylene glycol, and 200 parts of water.

[0039] Comparative Example 6 The only difference between this comparative example and Example 2 is that the raw materials of this comparative example include the following components by weight: 40 parts of polyaluminum ferric chloride, 5 parts of sodium carboxymethyl cellulose, 20 parts of ammonium ferric ethylenediaminetetraacetate, 5 parts of sodium lauryl phosphate, and 200 parts of water.

[0040] The defluoridating agents for sewage prepared in Examples 1 to 11 and Comparative Examples 1 to 6 were tested according to the following method: Take a batch of sewage with a fluorine content of 20.0 mg / L, take 10 L of each as a sample, add 15 mL of the defluorinating agent prepared in Examples 1 to 11 and Comparative Examples 1 to 6, respectively, stir at 50 rpm for 12 h at room temperature, detect the fluorine content, and calculate the defluorination rate. The specific test data are shown in Table 1.

[0041] The calculation method of fluorine removal rate is: A=(20.0-c1) / c1×100%; c1 is the fluorine content concentration measured after 12 hours.

[0042]

[0043] Comparing Example 2 with Comparative Examples 1 to 3, it is shown that the synergistic effect of ethylenediaminetetraacetic acid ammonium ferric and sodium lauryl phosphate in the present invention improves the fluorine removal rate of the defluoridation agent for sewage. Comparing Example 2 with Comparative Examples 4 to 6, it is shown that the synergistic effect of ethylenediaminetetraacetic acid and polyethylene glycol in the present invention improves the fluorine removal rate of the defluoridation agent for sewage.

[0044] Comparing Examples 5 to 7 with Examples 3 to 4, it is shown that when the mass ratio of ammonium ferric ethylenediaminetetraacetate to sodium lauryl phosphate is adjusted to 0.5 to 1.5:1 in the present invention, the fluorine removal rate of the defluoridation agent for sewage is further improved. Comparing Example 6 with Example 5 and Example 7, it is shown that when the mass ratio of ammonium ferric ethylenediaminetetraacetate to sodium lauryl phosphate is adjusted to 1:1 in the present invention, the fluorine removal rate of the defluoridation agent for sewage is best. Comparing Examples 9 to 11 with Examples 6 and 8, it is shown that when the mass ratio of ethylenediaminetetraacetic acid to polyethylene glycol is adjusted to 1 to 3:1 in the present invention, the fluorine removal rate of the defluoridation agent for sewage is further improved. Comparing Example 10 with Example 9 and Example 11, it is shown that when the mass ratio of ethylenediaminetetraacetic acid to polyethylene glycol is adjusted to 2:1 in the present invention, the fluorine removal rate of the defluoridation agent for sewage is best.

[0045] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A defluoridating agent for sewage, characterized in that: The raw materials include the following components by weight: 40-60 parts of polyaluminium ferric chloride, 5-10 parts of sodium carboxymethyl cellulose, 2-20 parts of ammonium ferric ethylenediaminetetraacetate, 5-20 parts of sodium lauryl phosphate, 5-15 parts of ethylenediaminetetraacetic acid, 1-10 parts of polyethylene glycol, and 200-240 parts of water.

2. A defluoridating agent for sewage according to claim 1, characterized in that: The mass ratio of the ammonium ferric ethylenediaminetetraacetate to the sodium lauryl phosphate is 0.5-1.5:

1.

3. A defluoridating agent for sewage according to claim 2, characterized in that: The mass ratio of the ammonium ferric ethylenediaminetetraacetate to the sodium lauryl phosphate is 1:

1.

4. A defluoridating agent for sewage according to claim 1, characterized in that: The mass ratio of the ethylenediaminetetraacetic acid to the polyethylene glycol is 1-3:

1.

5. A defluoridating agent for sewage according to claim 4, characterized in that: The mass ratio of the ethylenediaminetetraacetic acid to the polyethylene glycol is 2:

1.

6. A defluoridating agent for sewage according to claim 1, characterized in that: The basicity of the polyaluminium ferric chloride is 60% to 90%.

7. A defluoridating agent for sewage according to claim 1, characterized in that: The polyethylene glycol includes one of PEG-800, PEG-1000 and PEG-1500.

8. A defluoridating agent for sewage according to claim 7, characterized in that: The polyethylene glycol is PEG-1000.

9. The method for preparing a defluoridating agent for sewage according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, dissolving polyaluminium ferric chloride in water, adding sodium carboxymethyl cellulose to obtain a first mixed solution; S2, mixing ammonium ferric ethylenediaminetetraacetate and sodium lauryl phosphate, adding the first mixed solution, dissolving, and obtaining a second mixed solution; S3. Add ethylenediaminetetraacetic acid and polyethylene glycol to the second mixed solution, mix well, and obtain a defluorinating agent.

10. The method for preparing a defluoridating agent for sewage according to claim 9, characterized in that: The dissolving temperature in S2 is 35-55°C.

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