CN114988561A - Method for coating and modifying surface of chemical sludge-based filler - Google Patents
Method for coating and modifying surface of chemical sludge-based filler Download PDFInfo
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- CN114988561A CN114988561A CN202210754033.XA CN202210754033A CN114988561A CN 114988561 A CN114988561 A CN 114988561A CN 202210754033 A CN202210754033 A CN 202210754033A CN 114988561 A CN114988561 A CN 114988561A
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- water
- filler
- sludge
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/02—Aerobic processes
- C02F3/10—Packings; Fillings; Grids
- C02F3/105—Characterized by the chemical composition
- C02F3/107—Inorganic materials, e.g. sand, silicates
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Abstract
The invention provides a method for surface coating modification of a chemical sludge-based filler, and relates to the technical field of preparation of sludge-based fillers. The method for coating and modifying the surface of the chemical sludge-based filler comprises the following steps: s1, firstly, extracting a sludge sample A of the area A; and S2, fully crushing and grinding the obtained sludge sample A by using a crusher at the rotating speed of 50-60 revolutions per minute, and sieving by using a stainless steel sieve to obtain sample powder A. By modifying the surface charge of the filler, the modified filter material forms a porous structure, and the specific surface area is increased, so that the modified filler has better dirt interception performance. The modified filler can be used for modifying old water treatment equipment, and the water-containing raw material balls can be dried in a constant-temperature air-blast drying oven at 100 ℃ for 1-1.5 hours to save cost to a great extent, so that the water is sufficiently reduced, and the water-containing raw material balls are prevented from cracking due to too high water content during high-temperature calcination.
Description
Technical Field
The invention relates to the technical field of preparation of sludge-based fillers, in particular to a method for coating and modifying the surface of a chemical sludge-based filler.
Background
At present, urban sewage treatment still mostly adopts aerobic biological treatment processes such as an activated sludge process and the like, however, the process generates a large amount of Sewage Sludge (SS) while realizing water purification, researches show that about 40% of pollutants enter the sludge in the sewage treatment process, the annual output of the sludge (with the water content of 80%) in China in 2025 is estimated to break through 9000 ten thousand tons, and SS organic components mainly comprise bacterial components including nucleic acid, protein, polysaccharide, humus, lipids, rotten products and undigested organic substances.
The chemical sludge-based filler is a resource product prepared by utilizing chemical excess sludge, the chemical excess sludge which is difficult to treat is changed into valuable from waste into usable resources, the chemical sludge-based filler has the characteristic of light weight and porosity, but the isoelectric point of the filler used in a water treatment structure is low, the attachment of organic matters and microorganisms is not facilitated, and the key for improving the performance of the filler is to improve the isoelectric point of the surface of the chemical sludge-based filler.
At present, the surface coating modification of the commercially available ceramsite is researched more, but the research on the performance improvement of the chemical sludge-based filler is rarely reported, and the chemical sludge-based filler has the advantages of light weight, porosity, high strength, large specific surface and the like compared with the commercially available ceramsite, and is beneficial to the surface coating modification of the filler and the improvement of the performance of the filler. Meanwhile, the chemical sludge-based filler has a low isoelectric point, generally has negative charges in water, is not beneficial to microbial adsorption, and is easy to crack during high-temperature calcination in the later period after the water content of the filler is over.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects of the prior art, the invention provides a method for coating and modifying the surface of a chemical sludge-based filler, which solves the problems that the existing chemical sludge-based filler has lower isoelectric points, generally has negative charges in water, is not beneficial to microorganism adsorption, and is easy to crack during high-temperature calcination in the later period after the water content of the filler is over.
(II) technical scheme
In order to achieve the purpose, the invention is realized by the following technical scheme: a method for coating and modifying the surface of a chemical sludge-based filler comprises the following steps:
s1, firstly, extracting a sludge sample A of the area A;
s2, sufficiently crushing and grinding the obtained sludge sample A at a rotating speed of 50-60 revolutions per minute by using a crusher, and screening by using a stainless steel screen to obtain sample powder A;
s3, mixing the sample powder A and deionized water, filling the mixture into a vacuum stirring kettle, mixing and stirring at the rotating speed of 120-125 revolutions per minute, and then placing the mixture into a vacuum filter for vacuum filtration to obtain filler mother liquor;
s4, taking the monopotassium phosphate filler and the filler mother liquor, completely dissolving the monopotassium phosphate filler and the filler mother liquor in pure water, continuously adding the pure water to dilute until the content of the pure water is 40-50%, and uniformly shaking for later use to obtain a standard stock solution;
s5, fully and uniformly mixing the weighed sludge, iron powder, clay and standard stock solution;
s6, adding ultrapure water into the three uniformly mixed raw materials until the raw materials have a good forming effect, and then preparing water-containing raw material balls with the diameter of 1-1.2 m by using a die;
s7, transferring the dried water-containing raw material spheres into a muffle furnace, firstly heating the muffle furnace to 320-350 ℃ from room temperature at the rate of 5-10 ℃ and keeping for 10-15 minutes, then heating to 500-510 ℃ at the temperature of 20-25 ℃, keeping the water-containing raw material spheres in the muffle furnace for a period of time, then cooling to 170-180 ℃ at the same rate, and then naturally cooling to 50-70 ℃, thus finishing modification.
Preferably, in the step S1, the sludge sample a is dehydrated and dried after anaerobic digestion before extraction.
Preferably, in the step S2, the sieved sample powder a is packaged with a valve bag and placed in a drying chamber, and is kept in a moisture-proof state.
Preferably, in the step S2, the stainless steel sieve is 50 to 80 mesh.
Preferably, in the step S3, the mixing and adding ratio of the sample powder a to the deionized water is: sample powder a: deionized water 5: 20.
preferably, in the step S4, the ratio of the monopotassium phosphate filler to the filler mother liquor is: potassium dihydrogen phosphate filler: the mother liquid of the filler is 2: 1.
Preferably, after the water-containing raw material balls are obtained in the step S6, the water-containing raw material balls are dried in a constant temperature forced air drying oven at 100-105 ℃ for 1-1.5 hours, so as to sufficiently reduce the water content and avoid cracking of the water-containing raw material balls due to too high water content during high temperature calcination.
Preferably, in the step S7, the muffle furnace chamber is pumped to a vacuum state of 0.05 to 0.2 mpa by a vacuum pump.
(III) advantageous effects
The invention provides a method for coating and modifying the surface of a chemical sludge-based filler. The method has the following beneficial effects:
1. the invention transfers the dried water-containing raw material ball into a muffle furnace, uses a vacuum pump to pump the hearth pressure of the muffle furnace to 0.2 MPa vacuum state in advance, firstly raises the temperature of the muffle furnace from room temperature to 350 ℃ at the speed of 10 ℃ and keeps the temperature for 15 minutes, then heating to 510 ℃ at 25 ℃, keeping the water-containing raw material ball in a muffle furnace for a period of time, cooling to 180 ℃ at the same speed, then naturally cooling to 70 ℃ to complete modification, and the isoelectric point can be improved by modification to ensure that the isoelectric point is positively charged in water, the surface charge modification is carried out on the filler, the modified filter material forms a porous structure, the specific surface area is increased, therefore, the modified filler has better dirt interception performance, can improve the filtering efficiency of the ceramic filler to the wastewater, is easy to regenerate the filler and is convenient for recycling. The modified filler can be used for the reconstruction of old water treatment equipment, not only can improve the water quality of effluent, but also can save the cost to a great extent.
2. According to the invention, ultrapure water is added into three raw materials which are uniformly mixed until the raw materials have a good forming effect, then the raw material balls containing water with the diameter of 1 meter are prepared by using a mould, after the raw material balls containing water are obtained, the raw material balls containing water are put into a constant-temperature forced air drying oven with the temperature of 100 ℃ for drying for 1-1.5 hours, so that the water content is fully reduced, and the raw material balls containing water are prevented from cracking due to too high water content during high-temperature calcination.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The first embodiment is as follows:
the embodiment of the invention provides a method for coating and modifying the surface of a chemical sludge-based filler, which comprises the following steps:
s1, firstly, extracting a sludge sample A of the area A, and dehydrating and drying the sludge sample A after anaerobic digestion before extraction;
s2, using a pulverizer to obtain a sludge sample A with 50 meshes in 50 meshes to obtain sample powder A, packaging the screened sample powder A by using a self-sealing bag, placing the self-sealing bag in a drying chamber, and standing in a moisture-proof manner;
s3, mixing the sample powder A and deionized water and filling the mixture into a vacuum stirring kettle, wherein the mixing and adding proportion of the sample powder A and the deionized water is as follows: sample powder a: deionized water 5: 20, mixing and stirring at the rotating speed of 120 revolutions per minute, and then placing the mixture in a vacuum filter for vacuum filtration to obtain filler mother liquor;
s4, taking the monopotassium phosphate filler and the filler mother liquor and dissolving the monopotassium phosphate filler and the filler mother liquor completely in pure water, wherein the proportion of the monopotassium phosphate filler to the filler mother liquor is as follows: potassium dihydrogen phosphate filler: adding pure water continuously to dilute the filler mother liquor to the pure water content of 40%, and shaking up for later use to obtain a standard stock solution;
s5, fully and uniformly mixing the weighed sludge, iron powder, clay and standard stock solution;
s6, adding ultrapure water into the three uniformly mixed raw materials until the raw materials have a good forming effect, then preparing water-containing raw material balls with the diameter of 1 meter by using a mould, and after the water-containing raw material balls are obtained, putting the water-containing raw material balls into a constant-temperature air-blast drying box at 100 ℃ for drying for 1-1.5 hours, so as to fully reduce the water content and avoid cracking of the water-containing raw material balls due to too high water content during high-temperature calcination;
s7, transferring the dried water-containing raw material spheres into a muffle furnace, pumping the pressure of the hearth of the muffle furnace to a 0.05 MPa vacuum state in advance by using a vacuum pump, firstly raising the temperature of the muffle furnace to 320 ℃ at a speed of 5 ℃ and keeping the temperature for 10 minutes, then heating the temperature to 500 ℃ at 20 ℃, keeping the water-containing raw material spheres in the muffle furnace for a period of time, then cooling the temperature to 170 ℃ at the same speed, then naturally cooling the temperature to 50 ℃ to complete modification, wherein the isoelectric point of the water-containing raw material spheres can be improved by modification to enable the water-containing raw material spheres to have positive charges in water, the filler is subjected to surface charge modification, and the modified filter material forms a porous structure and is increased in specific surface area, so that the modified filler has better dirt interception performance, the filtering efficiency of the ceramic filler on waste water can be improved, the regeneration of the filler is easy, and the filler is convenient to recycle. The modified filler can be used for the reconstruction of old water treatment equipment, not only can improve the water quality of effluent, but also can save the cost to a great extent.
Example two:
the embodiment of the invention provides a method for coating and modifying the surface of a chemical sludge-based filler, which comprises the following steps:
s1, firstly, extracting a sludge sample A of the area A, and dehydrating and drying the sludge sample A after anaerobic digestion before extraction;
s2, sufficiently crushing and grinding the obtained sludge sample A at the rotating speed of 50 revolutions per minute by using a crusher, screening by using a stainless steel sieve, packaging the screened sample powder A by using a self-sealing bag, placing the self-sealing bag in a drying chamber, and standing in a moisture-proof manner;
s3, mixing the sample powder A and deionized water and filling the mixture into a vacuum stirring kettle, wherein the mixing and adding proportion of the sample powder A and the deionized water is as follows: sample powder a: deionized water 5: 20, mixing and stirring at the rotating speed of 120 revolutions per minute, and then placing the mixture in a vacuum filter for vacuum filtration to obtain filler mother liquor;
s4, taking the monopotassium phosphate filler and the filler mother liquor and dissolving the monopotassium phosphate filler and the filler mother liquor completely in pure water, wherein the proportion of the monopotassium phosphate filler to the filler mother liquor is as follows: potassium dihydrogen phosphate filler: adding pure water continuously to dilute the filler mother liquor to the pure water content of 40%, and shaking up for later use to obtain a standard stock solution;
s5, fully and uniformly mixing the weighed sludge, iron powder, clay and standard stock solution;
s6, adding ultrapure water into the three raw materials which are uniformly mixed until the raw materials have a good forming effect, then preparing the raw material balls containing water with the diameter of 1.2 m by using a mould to obtain raw material balls containing water, and then putting the raw material balls containing water into a constant-temperature blast drying oven with the temperature of 105 ℃ for drying for 1.5 hours to fully reduce the water content and avoid the raw material balls containing water from cracking due to too high water content during high-temperature calcination;
s7, transferring the dried water-containing raw material spheres into a muffle furnace, pumping the pressure of the hearth of the muffle furnace to a 0.2 MPa vacuum state in advance by using a vacuum pump, firstly raising the temperature of the muffle furnace to 350 ℃ at a speed of 10 ℃ and keeping the temperature for 15 minutes, then heating the muffle furnace to 510 ℃ at 25 ℃, keeping the water-containing raw material spheres in the muffle furnace for a period of time, then cooling the water-containing raw material spheres to 180 ℃ at the same speed, then naturally cooling the temperature to 70 ℃ to complete modification, wherein the isoelectric points of the water-containing raw material spheres can be improved by modification to enable the water-containing raw material spheres to be positively charged in water, surface charge modification is carried out on the filler, and the modified filter material forms a porous structure and is increased in specific surface area, so that the modified filler has better dirt interception performance, the filtering efficiency of the ceramic filler on waste water can be improved, the regeneration of the filler is easy to recycle and convenient to recycle. The modified filler can be used for the reconstruction of old water treatment equipment, not only can improve the water quality of effluent, but also can save the cost to a great extent.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (8)
1. A method for coating and modifying the surface of a chemical sludge-based filler is characterized by comprising the following steps: the method comprises the following steps:
s1, firstly, extracting a sludge sample A of the area A;
s2, sufficiently crushing and grinding the obtained sludge sample A by using a crusher at the rotating speed of 50-60 revolutions per minute, and sieving by using a stainless steel sieve to obtain sample powder A;
s3, mixing the sample powder A and deionized water, filling the mixture into a vacuum stirring kettle, mixing and stirring at the rotating speed of 120-125 revolutions per minute, and then placing the mixture into a vacuum filter for vacuum filtration to obtain filler mother liquor;
s4, taking monopotassium phosphate filler and filler mother liquor, completely dissolving the monopotassium phosphate filler and the filler mother liquor in pure water, continuously adding the pure water to dilute until the content of the pure water is 40-50%, and uniformly shaking for later use to obtain a standard stock solution;
s5, fully and uniformly mixing the weighed sludge, iron powder, clay and standard stock solution;
s6, adding ultrapure water into the three uniformly mixed raw materials until the raw materials have a good forming effect, and then preparing water-containing raw material balls with the diameter of 1-1.2 m by using a die;
s7, transferring the dried water-containing raw material spheres into a muffle furnace, firstly heating the muffle furnace from room temperature to 320-350 ℃ at the rate of 5-10 ℃ and keeping for 10-15 minutes, then heating to 500-510 ℃ at 20-25 ℃, keeping the water-containing raw material spheres in the muffle furnace for a period of time, then cooling to 170-180 ℃ at the same rate, and then naturally cooling to 50-70 ℃ to finish modification.
2. The method for coating and modifying the surface of the chemical sludge-based filler according to claim 1, wherein the method comprises the following steps: in the step S1, the sludge sample A is dehydrated and dried after anaerobic digestion before being extracted.
3. The method for coating and modifying the surface of the chemical sludge-based filler according to claim 1, wherein the method comprises the following steps: in the step S2, the sieved sample powder a is packaged in a self-sealing bag and placed in a drying chamber, and allowed to stand in a moisture-proof manner.
4. The method for coating and modifying the surface of the chemical sludge-based filler according to claim 1, wherein the method comprises the following steps: in the step S2, the stainless steel sieve adopts a 50-80 mesh specification.
5. The method for coating and modifying the surface of the chemical sludge-based filler according to claim 1, wherein the method comprises the following steps: in the step S3, the mixing and adding ratio of the sample powder a to the deionized water is: sample powder a: deionized water 5: 20.
6. the method for coating and modifying the surface of the chemical sludge-based filler according to claim 1, wherein the method comprises the following steps: in the step S4, the ratio of the monopotassium phosphate filler to the filler mother liquor is: potassium dihydrogen phosphate filler: the mother liquid of the filler is 2: 1.
7. The method for coating and modifying the surface of the chemical sludge-based filler according to claim 1, wherein the method comprises the following steps: and S6, after the water-containing raw material balls are obtained, drying the water-containing raw material balls in a constant-temperature blast drying oven at 100-105 ℃ for 1-1.5 hours to fully reduce the water content and avoid cracking of the water-containing raw material balls due to too high water content during high-temperature calcination.
8. The method for coating and modifying the surface of the chemical sludge-based filler according to claim 1, wherein the method comprises the following steps: and in the step S7, the pressure of the muffle furnace chamber is pumped to a vacuum state of 0.05-0.2 MPa in advance by using a vacuum pump.
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| CN202210754033.XA CN114988561A (en) | 2022-06-30 | 2022-06-30 | Method for coating and modifying surface of chemical sludge-based filler |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1048399A (en) * | 1989-06-06 | 1991-01-09 | 普拉斯-斯托弗公司 | The aqeous suspension of the mineral of high density and/or filler and/or pigment |
| CN102285787A (en) * | 2011-06-03 | 2011-12-21 | 南京工业大学 | Method for preparing hadite from chemical sludge |
| CN103274670A (en) * | 2013-06-09 | 2013-09-04 | 南京工业大学 | Method for preparing light porous low-toxicity chemical sludge-based filler |
| CN104973739A (en) * | 2015-06-18 | 2015-10-14 | 南京工业大学 | Surface-coated modification method for chemical sludge-based filler |
| CN105541372A (en) * | 2015-12-25 | 2016-05-04 | 浙江绿治污泥处理技术有限公司 | Preparation method of ceramisite filter material for water treatment |
| CN106565209A (en) * | 2016-10-24 | 2017-04-19 | 南京工业大学 | Preparation method of modified multisource wasted mud ceramsite |
-
2022
- 2022-06-30 CN CN202210754033.XA patent/CN114988561A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1048399A (en) * | 1989-06-06 | 1991-01-09 | 普拉斯-斯托弗公司 | The aqeous suspension of the mineral of high density and/or filler and/or pigment |
| CN102285787A (en) * | 2011-06-03 | 2011-12-21 | 南京工业大学 | Method for preparing hadite from chemical sludge |
| CN103274670A (en) * | 2013-06-09 | 2013-09-04 | 南京工业大学 | Method for preparing light porous low-toxicity chemical sludge-based filler |
| CN104973739A (en) * | 2015-06-18 | 2015-10-14 | 南京工业大学 | Surface-coated modification method for chemical sludge-based filler |
| CN105541372A (en) * | 2015-12-25 | 2016-05-04 | 浙江绿治污泥处理技术有限公司 | Preparation method of ceramisite filter material for water treatment |
| CN106565209A (en) * | 2016-10-24 | 2017-04-19 | 南京工业大学 | Preparation method of modified multisource wasted mud ceramsite |
Non-Patent Citations (1)
| Title |
|---|
| 赵晓琳;朱晓丽;郁建元;: "利用污泥生产生态水泥的研究", 中国资源综合利用, no. 07 * |
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