Phosphorus-containing wastewater treatment agent and preparation method thereof

Abstract

The invention provides a phosphorus-containing wastewater treatment agent, which is prepared from the following components in parts by weight: 3 to 10 parts of sodium polyphosphate, 0.1 to 1 part of alkyl epoxy carboxylic acid, 5 to 10 parts of ethylenediamine tetraacetic acid, 3 to 10 parts of EDTMPS (Ethylene Diamine Tetraacetic Acid), 0.1 to 3 parts of polyacrylamide, 5 to 15 parts of ferroferric oxide, 10 to 30 parts of polyaluminum chloride, 10 to 30 parts of modified bentonite and 0.5 to 5 parts of aminated carbon nanotubes. The preparation method comprises the following steps: adding ferroferric oxide magnetic nanoparticles into a polyaluminum chloride solution to obtain a precipitate complexing agent; the preparation method comprises the following steps: dissolving chitosan in an acetic acid solution, and then adding sodium bentonite to obtain modified bentonite; adding water into the remaining materials, uniformly mixing, adding the aminated carbon nanotubes and the precipitation complexing agent in batches, adding the modified bentonite, and uniformly mixing to obtain a premix; and treating the premix to obtain the product. Suspended particles and phosphate in a water body can be efficiently and stably adsorbed, the floc sedimentation rate is increased, and the phosphorus removal efficiency is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment agents, and in particular to a phosphorus-containing wastewater treatment agent and a preparation method thereof. Background Art

[0002] As we all know, phosphorus is an essential element for life in nature and affects the primary productivity of aquatic ecosystems. Phosphorus is also a controlling factor for eutrophication of most water bodies, so it is particularly important to control the phosphorus concentration in sewage. Phosphorus usually exists in water bodies in the form of low-concentration phosphates. Currently, there are strict restrictions on the phosphorus concentration in discharged sewage around the world.

[0003] Phosphorus removal from industrial wastewater can not only reduce phosphorus emissions and avoid eutrophication of water bodies, but also realize the resource utilization of phosphorus. At present, the treatment of phosphorus-containing wastewater mainly includes biological, chemical and adsorption methods. The removal rate of biological phosphorus removal is not high, and the treatment system is relatively complex. Chemical phosphorus removal will produce a large amount of sludge, and the selection of chemical agents is difficult, which can easily cause secondary pollution. Adsorption is one of the effective methods for phosphorus removal. At present, the research focus is on the development of new adsorption materials and the modification of traditional adsorption materials. How to improve the treatment efficiency of wastewater by treatment agents and reduce the total phosphorus concentration in wastewater is particularly important. Summary of the invention

[0004] The object of the present invention is to provide a phosphorus-containing wastewater treatment agent and a preparation method thereof, which can efficiently and stably adsorb suspended particles and phosphates in water bodies, accelerate the floc sedimentation rate, and enhance the phosphorus removal efficiency.

[0005] The embodiments of the present invention are implemented by the following technical solutions:

[0006] A phosphorus-containing wastewater treatment agent comprises, by weight, 3-10 parts of sodium polyphosphate, 0.1-1 parts of alkyl epoxy carboxylic acid, 5-10 parts of ethylenediaminetetraacetic acid, 3-10 parts of EDTMPS, 0.1-3 parts of polyacrylamide, 5-15 parts of ferrosoferric oxide, 10-30 parts of polyaluminium chloride, 10-30 parts of modified bentonite and 0.5-5 parts of amino carbon nanotubes.

[0007] A method for preparing a phosphorus-containing wastewater treatment agent comprises the following steps:

[0008] S1. Adding ferroferric oxide magnetic nanoparticles to a polyaluminium chloride solution, and subjecting the solution to magnetic stirring and aging for a period of time to obtain a precipitated composite;

[0009] S2. The chitosan was dissolved in an acetic acid solution to obtain a chitosan solution; sodium bentonite was then added to the chitosan solution and stirred continuously for a period of time, then allowed to stand for a period of time, and dried to obtain chitosan-modified bentonite;

[0010] S3. After the remaining materials are fully mixed, water is added and mixed, and then part of the amino carbon nanotubes and part of the precipitated composite agent are added, and stirred continuously to fully disperse them, and then the remaining amino carbon nanotubes and precipitated composite agent are added several times, and after fully dispersed, the modified bentonite is added and mixed to obtain a premix;

[0011] S4. Keep the premix at a constant temperature for a period of time, then gradually increase the temperature and keep it for a period of time; take out the treated mixture, cool, grind and sieve it to obtain the product.

[0012] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0013] 1. The treatment agent of the present invention can utilize magnetism, chemical adsorption and electrostatic attraction to efficiently and stably adsorb suspended particles and phosphates in water, accelerate the floc sedimentation rate, and enhance the phosphorus removal efficiency.

[0014] 2. The treatment agent of the present invention utilizes the porous nature and hollow tubular structure of carbon nanotubes, so that the modified bentonite and the precipitation composite agent can be more efficiently filled in the internal voids and surface of the carbon nanotubes, and load more modified bentonite, thereby achieving a better purification effect on phosphorus-containing wastewater. In addition, the present invention amino-amino carbon nanotubes to enhance the dispersion effect of carbon nanotubes, avoid secondary agglomeration of carbon nanotubes, and achieve better dispersion in wastewater, so that the adsorption effect can be more efficiently exerted. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0016] The following is a detailed description of a phosphorus-containing wastewater treatment agent and a preparation method thereof provided in an embodiment of the present invention.

[0017] A phosphorus-containing wastewater treatment agent comprises, by weight: 3-10 parts of sodium polyphosphate, 0.1-1 parts of alkyl epoxy carboxylic acid, 5-10 parts of ethylenediaminetetraacetic acid, 3-10 parts of EDTMPS, 0.1-3 parts of polyacrylamide, 5-15 parts of ferrosoferric oxide, 10-30 parts of polyaluminium chloride, 10-30 parts of chitosan-modified bentonite and 0.5-5 parts of amino carbon nanotubes.

[0018] Further, it includes: 3-5 parts of sodium polyphosphate, 0.1-0.5 parts of alkyl epoxy carboxylic acid, 5-8 parts of ethylenediaminetetraacetic acid, 3-8 parts of EDTMPS, 0.1-1 parts of polyacrylamide, 10-15 parts of ferrosoferric oxide, 15-25 parts of polyaluminium chloride, 15-25 parts of chitosan modified bentonite, and 0.5-2 parts of amino carbon nanotubes.

[0019] Further, it includes: 4 parts of sodium polyphosphate, 0.3 parts of alkyl epoxy carboxylic acid, 6 parts of ethylenediaminetetraacetic acid, 5 parts of EDTMPS, 0.5 parts of polyacrylamide, 15 parts of ferrosoferric oxide, 20 parts of polyaluminium chloride, 20 parts of chitosan modified bentonite and 1 part of amino carbon nanotubes.

[0020] The invention adopts a coprecipitation method to prepare ferroferric oxide magnetic nanoparticles, which are added into a polyaluminium chloride solution and aged for 3-5 hours by magnetic stirring to obtain a magnetic-chemical precipitation composite agent; while the composite agent reacts chemically with phosphate, tiny suspended particles and small-diameter colloids in the water body can be adsorbed by aluminium phosphate flocs, and cationic hydroxyl complexes generated by hydrolysis of aluminium ions and negatively charged phosphates are enhanced in adsorption through an electrical neutralization reaction, thereby achieving the purpose of phosphorus removal; in addition, the magnetic nanoparticle ferroferric oxide forms a magnetic floc with magnetic powder as the core in a liquid phase to chemically adsorb and precipitate orthophosphate, and under the action of an external magnetic field, the floc sedimentation rate is accelerated, thereby enhancing the phosphorus removal efficiency.

[0021] Chitosan and bentonite are chemically bonded together, with larger interlayer spacing and specific surface area, which can achieve more efficient adsorption effect; and chitosan contains -OH and -NH 2 , under acidic conditions, -NH 2 Convert to -NH 3 + , can have electrostatic attraction with phosphorus; and the -OH and -NH 2 It also produces hydrogen bonds with phosphorus, which enhances the adsorption capacity of the modified bentonite for phosphorus.

[0022] The present invention utilizes the porous properties and hollow tubular structure of carbon nanotubes, so that modified bentonite and precipitation composite agents can be more efficiently filled in the internal voids and surfaces of carbon nanotubes, and more modified bentonite can be loaded, thereby achieving a better purification effect on phosphorus-containing wastewater. In addition, the present invention amino-anilines the carbon nanotubes, thereby improving the dispersion effect of the carbon nanotubes and avoiding secondary agglomeration of the carbon nanotubes, thereby achieving better dispersion in wastewater and more efficient adsorption effect.

[0023] Sodium polyphosphate, sodium alkyl epoxycarboxylate, ethylenediaminetetraacetic acid, EDTMPS, and polyacrylamide are used to sterilize and descale the wastewater, effectively removing suspended matter in the wastewater, reducing the chromaticity of the wastewater, and avoiding erosion of the equipment by the wastewater after dephosphorization treatment.

[0024] A method for preparing a phosphorus-containing wastewater treatment agent comprises the following steps:

[0025] S1. ferroferric oxide magnetic nanoparticles were prepared by coprecipitation method, added to polyaluminium chloride solution, and aged for 3-5 hours under magnetic stirring at 30-50°C to obtain a precipitated composite;

[0026] S2. Chitosan was dissolved in acetic acid solution to prepare a 1-5% (w / w) chitosan solution, and then a certain mass of sodium bentonite was added to the chitosan solution and stirred continuously for 3-5h, so that it was fully infiltrated and then allowed to stand for 24-48h, and dried at 70-90°C to obtain chitosan-modified bentonite;

[0027] S3. After the remaining materials are fully mixed, water is added and mixed, and then part of the amino carbon nanotubes and part of the precipitation composite are added, and stirred continuously to be fully dispersed, and then the remaining amino carbon nanotubes and magnetic-chemical precipitation composite are added several times, and after fully dispersed, the modified bentonite is added and mixed to obtain a premix; wherein the amino carbon nanotubes and the precipitation composite are each added at least twice, and each time an equal amount is added;

[0028] S4. The premix is ​​placed in a thermostat at 60°C to 70°C for 2 to 3 hours, then gradually heated to 80°C to 90°C at a heating rate of 1-5°C / min, and baked for 6 to 10 hours; the treated mixture is taken out, cooled, ground, and sieved to obtain the product.

[0029] Example 1

[0030] A phosphorus-containing wastewater treatment agent comprises, by weight: 4 parts of sodium polyphosphate, 0.3 parts of alkyl epoxy carboxylic acid, 6 parts of ethylenediaminetetraacetic acid, 5 parts of EDTMPS, 0.5 parts of polyacrylamide, 15 parts of ferrosoferric oxide, 20 parts of polyaluminium chloride, 20 parts of chitosan-modified bentonite and 1 part of amino-modified carbon nanotube.

[0031] A method for preparing a phosphorus-containing wastewater treatment agent comprises the following steps:

[0032] S1. ferroferric oxide magnetic nanoparticles were prepared by coprecipitation method, added to polyaluminium chloride solution, and aged for 4 hours under magnetic stirring at 40°C to obtain a precipitated composite;

[0033] S2. Chitosan was dissolved in 5% (v / v) acetic acid solution to prepare a 2% (w / w) chitosan solution, and then a certain mass of sodium bentonite was added to the chitosan solution and stirred continuously for 4 hours, so that it was fully infiltrated and then allowed to stand for 30 hours, and dried at 80°C to obtain chitosan-modified bentonite;

[0034] S3. After the remaining materials are fully mixed, water is added and mixed, and then part of the amino carbon nanotubes and part of the precipitated composite agent are added, and stirred continuously to fully disperse them, and then the remaining amino carbon nanotubes and precipitated composite agent are evenly added in 2 portions, and after fully dispersed, the modified bentonite is added and mixed to obtain a premix;

[0035] S4. The premix is ​​placed in a thermostat at 65°C for 2.5 hours, then gradually heated to 85°C and baked for 8 hours; the treated mixture is taken out, cooled, ground, and sieved to obtain the product.

[0036] Example 2

[0037] The difference between this embodiment and embodiment 1 is that: a phosphorus-containing wastewater treatment agent, calculated by weight, includes: 5 parts of sodium polyphosphate, 0.5 parts of alkyl epoxy carboxylic acid, 7 parts of ethylenediaminetetraacetic acid, 6 parts of EDTMPS, 1 part of polyacrylamide, 10 parts of ferrosoferric oxide, 15 parts of polyaluminum chloride, 15 parts of modified bentonite, and 0.5 parts of amino carbon nanotubes.

[0038] Example 3

[0039] The difference between this embodiment and embodiment 1 is that: a phosphorus-containing wastewater treatment agent, calculated by weight, includes: 8 parts of sodium polyphosphate, 0.6 parts of alkyl epoxy carboxylic acid, 8 parts of ethylenediaminetetraacetic acid, 9 parts of EDTMPS, 0.2 parts of polyacrylamide, 15 parts of ferrosoferric oxide, 25 parts of polyaluminum chloride, 25 parts of modified bentonite, and 4 parts of amino carbon nanotubes.

[0040] Example 4

[0041] The difference between this embodiment and embodiment 1 is that: a phosphorus-containing wastewater treatment agent, calculated by weight, includes: 7 parts of sodium polyphosphate, 0.8 parts of alkyl epoxy carboxylic acid, 6 parts of ethylenediaminetetraacetic acid, 8 parts of EDTMPS, 0.3 parts of polyacrylamide, 8 parts of ferrosoferric oxide, 18 parts of polyaluminum chloride, 20 parts of modified bentonite, and 1.5 parts of amino carbon nanotubes.

[0042] Example 5

[0043] The difference between this embodiment and embodiment 1 is that: a phosphorus-containing wastewater treatment agent, calculated by weight, includes: 9 parts of sodium polyphosphate, 0.9 parts of alkyl epoxy carboxylic acid, 9 parts of ethylenediaminetetraacetic acid, 7 parts of EDTMPS, 0.1 parts of polyacrylamide, 13 parts of ferrosoferric oxide, 22 parts of polyaluminum chloride, 22 parts of modified bentonite, and 0.5 parts of amino carbon nanotubes.

[0044] Example 6

[0045] The difference between this embodiment and embodiment 1 is that: a phosphorus-containing wastewater treatment agent, calculated by weight, includes: 3 parts of sodium polyphosphate, 0.1 parts of alkyl epoxy carboxylic acid, 6 parts of ethylenediaminetetraacetic acid, 3 parts of EDTMPS, 0.2 parts of polyacrylamide, 14 parts of ferrosoferric oxide, 18 parts of polyaluminum chloride, 16 parts of modified bentonite, and 0.5 parts of amino carbon nanotubes.

[0046] Comparative Example 1

[0047] The difference between this comparative example and Example 1 is that: a phosphorus-containing wastewater treatment agent does not include: modified bentonite and amino carbon nanotubes.

[0048] Comparative Example 2

[0049] The difference between this comparative example and Example 1 is that: a phosphorus-containing wastewater treatment agent does not include: ferrosoferric oxide and polyaluminium chloride.

[0050] Experimental Example 1

[0051] The treatment agents prepared in Examples 1-3 of the present invention and Comparative Examples 1-2 were subjected to performance tests.

[0052] Test method: This test takes the phosphorus-containing wastewater in the factory as the test object. The total phosphorus of the wastewater is 28.4 mg / L, COD is 4650 mg / L, BOD is 2545 mg / L, and ammonia nitrogen is 34.5 mg / L.

[0053] The wastewater was divided into five equal parts, and the treatment agents prepared in Examples 1-3 of the present invention and Comparative Examples 1-2 were added thereto respectively, with the concentration of the agent being 100 ppm (mass ratio). The supernatant of the wastewater treated with the treatment agent was then tested, and the results are shown in Table 1.

[0054] Table 1

[0055]

[0056]

[0057] It can be seen from the results in Table 1 that the treatment agent prepared in the embodiment of the present invention can effectively reduce the total phosphorus, COD, BOD and ammonia nitrogen values ​​in phosphorus-containing wastewater; while the treatment effect of the comparative example on phosphorus-containing wastewater is far inferior to that of the treatment agent in the embodiment of the present invention.

[0058] In summary, the fast-acting water treatment agent of the present invention has a significant treatment effect on total phosphorus in phosphorus-containing wastewater, and can effectively remove total COD, BOD and ammonia nitrogen in the wastewater. The dosage of the agent is small, and it can also effectively remove suspended matter in the wastewater and reduce the chromaticity of the wastewater. It is suitable for early pretreatment, terminal upgrading treatment and emergency treatment of high-concentration organic wastewater.

[0059] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A phosphorus-containing wastewater treatment agent, characterized in that: The invention comprises, by weight: 3-10 parts of sodium polyphosphate, 0.1-1 parts of alkyl epoxy carboxylic acid, 5-10 parts of ethylenediaminetetraacetic acid, 3-10 parts of EDTMPS, 0.1-3 parts of polyacrylamide, 5-15 parts of ferrosoferric oxide, 10-30 parts of polyaluminium chloride, 10-30 parts of modified bentonite and 0.5-5 parts of amino carbon nanotubes.

2. The phosphorus-containing wastewater treatment agent according to claim 1, characterized in that: Calculated by weight, the invention comprises: 3-5 parts of sodium polyphosphate, 0.1-0.5 parts of alkyl epoxy carboxylic acid, 5-8 parts of ethylenediaminetetraacetic acid, 3-8 parts of EDTMPS, 0.1-1 parts of polyacrylamide, 10-15 parts of ferrosoferric oxide, 15-25 parts of polyaluminium chloride, 15-25 parts of modified bentonite and 0.5-2 parts of amino carbon nanotubes.

3. The phosphorus-containing wastewater treatment agent according to claim 2, characterized in that: The invention comprises, by weight: 4 parts of sodium polyphosphate, 0.3 parts of alkyl epoxy carboxylic acid, 6 parts of ethylenediaminetetraacetic acid, 5 parts of EDTMPS, 0.5 parts of polyacrylamide, 15 parts of ferrosoferric oxide, 20 parts of polyaluminium chloride, 20 parts of modified bentonite and 1 part of amino carbon nanotube.

4. The phosphorus-containing wastewater treatment agent according to any one of claims 1 to 3, characterized in that: The modified bentonite is chitosan modified bentonite.

5. A method for preparing a phosphorus-containing wastewater treatment agent according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Adding ferroferric oxide magnetic nanoparticles to a polyaluminium chloride solution, and subjecting the solution to magnetic stirring and aging for a period of time to obtain a precipitated composite; S2. The chitosan was dissolved in an acetic acid solution to obtain a chitosan solution; sodium bentonite was then added to the chitosan solution and stirred continuously for a period of time, then allowed to stand for a period of time, and dried to obtain chitosan-modified bentonite; S3. After the remaining materials are fully mixed, water is added and mixed, and then part of the amino carbon nanotubes and part of the precipitated composite agent are added, and stirred continuously to fully disperse them, and then the remaining amino carbon nanotubes and precipitated composite agent are added several times, and after fully dispersed, the modified bentonite is added and mixed to obtain a premix; S4. Keep the premix at a constant temperature for a period of time, then gradually increase the temperature and keep it for a period of time; take out the treated mixture, cool, grind and sieve it to obtain the product.

6. The method for preparing a phosphorus-containing wastewater treatment agent according to claim 5, characterized in that: In S1, during aging, magnetic stirring is performed at 30-50°C for 3-5h.

7. The method for preparing a phosphorus-containing wastewater treatment agent according to claim 5, characterized in that: In S2, the mass concentration of the chitosan solution is 1-5%.

8. The method for preparing a phosphorus-containing wastewater treatment agent according to claim 5, characterized in that: In S3, the amino-modified carbon nanotubes and the precipitation composite agent are added at least twice, and the same amount is added each time.

9. The method for preparing a phosphorus-containing wastewater treatment agent according to claim 5, characterized in that: In S4, the premix is ​​kept in a thermostat at 60°C to 70°C for 2 to 3 hours; then the temperature is gradually raised to 80°C to 90°C and kept for 6 to 10 hours.

10. The method for preparing a phosphorus-containing wastewater treatment agent according to claim 5, characterized in that: In S4, the heating rate is 1-5°C / min.

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