CN115784358B - Floating auxiliary agent for water recovery system and preparation method and application thereof - Google Patents
Floating auxiliary agent for water recovery system and preparation method and application thereof Download PDFInfo
- Publication number
- CN115784358B CN115784358B CN202211497715.3A CN202211497715A CN115784358B CN 115784358 B CN115784358 B CN 115784358B CN 202211497715 A CN202211497715 A CN 202211497715A CN 115784358 B CN115784358 B CN 115784358B
- Authority
- CN
- China
- Prior art keywords
- floating
- water
- auxiliary agent
- functional monomer
- modified polyacrylamide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Separation Of Suspended Particles By Flocculating Agents (AREA)
Abstract
The invention discloses an upward floating auxiliary agent for a water recovery system, and a preparation method and application thereof, and relates to the technical field of water treatment. The floating auxiliary agent comprises the following components: a modified polyacrylamide-based polymer comprising at least one ethylenically unsaturated monomer, and a functional monomer; the above-mentioned ethylenically unsaturated monomers include acrylamide compounds; the functional monomer is obtained by connecting acryloyl chloride and barley malt alkali through chemical bonds and then carrying out quaternization reaction with N- (3-chloropropyl) methane sulfonamide. The floating auxiliary agent provided by the invention has more excellent flocculation capacity, can be well combined with fine solid floccules in water, and accelerates the combination of the floccules and bubbles in water, thereby accelerating the floating speed of floccule particles and improving the solid-liquid separation effect.
Description
Technical Field
The invention belongs to the technical field of water treatment, and particularly relates to an upward floating auxiliary agent for a water recovery system, and a preparation method and application thereof.
Background
The dissolved air flotation DAF is a high-efficiency solid-liquid separation technology, is matched with processes such as coagulation, filtration and the like to achieve the aim of improving water quality, and is widely applied to the field of water treatment. The technology increases the solubility of air in water by pressurizing the air, and highly dispersed micro bubbles are formed after decompression and release, so that the micro bubbles are adhered to the floccules, thereby realizing the forced floating of the floccules. The operation process of the air floatation technology can be basically divided into four parts: firstly, adding a coagulant and a coagulant aid into water to be treated to promote the destabilization of colloidal particles suspended in the water to form flocs with a certain size; secondly, introducing a large number of micron-sized bubbles into the air floatation tank through an air dissolving system; then a large number of micro bubbles collide with the flocs, are adsorbed and wrapped to form air-borne flocs with stable structure and density smaller than water; and finally, floating the air-borne flocs to form a floating slag layer, and realizing solid-liquid separation through a slag removal system.
The air floatation process is put into use in a sewage treatment method for many years, but more researchers focus on the aspects of air floatation theory exploration, air floatation reactor improvement, water purification effect improvement and the like, and because of the limitation of technical equipment, more microscopic exploration on air floatation reaction is not available. In recent years, with the further understanding of the air floatation technology, scientific researchers put forward more theories and technologies to perfect the air floatation process, and microscopic exploration of air floatation reaction is an indispensable item, so that research on air-borne flocs in the air floatation reaction is imperative.
Disclosure of Invention
The invention aims to provide an upward floating auxiliary agent for a water recovery system, a preparation method and application thereof, wherein the upward floating auxiliary agent has more excellent flocculation capacity, can be well combined with fine solid floccules in water, and accelerates the combination of the floccules and bubbles in water, thereby accelerating the upward floating speed of floccule particles and improving the solid-liquid separation effect.
The technical scheme adopted by the invention for achieving the purpose is as follows:
an ascent aid comprising: a modified polyacrylamide-based polymer comprising at least one ethylenically unsaturated monomer, and a functional monomer; the above-mentioned ethylenically unsaturated monomers include acrylamide compounds; the functional monomer is obtained by connecting acryloyl chloride and barley malt alkali through chemical bonds and then carrying out quaternization reaction with N- (3-chloropropyl) methane sulfonamide. The invention adopts the barley malt alkali and N- (3-chloropropyl) methane sulfonamide to prepare the functional monomer through chemical bond and acrylamide chloride, and the functional monomer and the acrylamide monomer are subjected to free radical polymerization reaction to obtain the modified polyacrylamide polymer, so that the modified polyacrylamide polymer has better flocculation capability, and the modified polyacrylamide polymer is compounded with other components for use, so that the prepared floating auxiliary has stronger flocculation effect; the method is applied to water treatment in a dissolved air flotation process, the formed floccule is more excellent in characteristic, the particle size is increased, the structure is more loose, the combination with bubbles is better, and the removal effect of the air flotation process is better; and the flocculation effect of the floating auxiliary agent and fine solids in water can be enhanced, the obtained floc has better characteristics, the time for floating is obviously reduced, and the water treatment efficiency is effectively improved. The reason for this may be that the polymer prepared from the functional monomer and the acrylamide monomer is introduced with various functional groups in the polymer chain structure, so that the electrostatic repulsion between chain links is enhanced, the polymer chain structure becomes more stretched, the bridging effect is more beneficial, the flocculation sedimentation effect of the polymer is further effectively improved, and the polymer can be better applied to the water treatment process.
The molecular weight of the modified polyacrylamide polymer was 3×10 7 ~5×10 7 。
The polyacrylamide compound includes acrylamide.
It should be noted that the floating auxiliary agent also comprises polyaluminum chloride.
More preferably, modified polyaluminum chloride is used instead of polyaluminum chloride.
The modified polyaluminum chloride is modified polyaluminum chloride containing acryloyloxyethyl dimethyl benzyl ammonium chloride and N, N' -methylenebisacrylamide. According to the invention, the aluminum polychloride is chemically modified by adopting the acryloyloxyethyl dimethylbenzyl ammonium chloride and the N, N' -methylene bisacrylamide through an in-situ polymerization method, so that the flocculation performance of the modified aluminum polychloride can be effectively enhanced, and the modified aluminum polychloride is compounded with a modified polyacrylamide compound for use, so that the obtained floating auxiliary agent has more excellent flocculation capability; the method can be applied to water treatment in a dissolved air floatation process, so that the particle size of the formed floccules is further increased, and the floccules are better combined with bubbles; and the flocculation effect of the floating auxiliary agent and fine solids in water can be further enhanced, the time required by floating is effectively reduced, and the water treatment efficiency is remarkably improved. The reason for this may be that the organic and inorganic components in the modified polyaluminium chloride structure prepared by the method are bonded in a covalent bond form, the property is stable, the formed product structure may be better and loose, the granularity is increased, the adsorption and bridging effects are more easily exerted, and the flocculation performance is more excellent.
The invention also discloses a preparation method of the modified polyaluminum chloride, which comprises the following steps: the preparation method comprises the step of carrying out chemical modification on polyaluminium chloride by adopting an in-situ polymerization method by adopting acryloyloxyethyl dimethyl benzyl ammonium chloride and N, N' -methylene bisacrylamide.
Specifically, the preparation method of the modified polyaluminum chloride comprises the following steps:
taking an aqueous solution of polyaluminum chloride with the concentration of 20-30wt%, adding N, N' -methylene bisacrylamide, filling nitrogen for 20-40 min, slowly dropwise adding an ammonium persulfate solution with the concentration of 8-12wt%, carrying out oscillation reaction for 1-3 h, adding acryloyloxyethyl dimethyl benzyl ammonium chloride, and continuing to react for 2-4 h; and then ethanol precipitation and acetone washing are carried out, and the modified polyaluminum chloride is obtained after constant-temperature drying at 50-55 ℃.
The mass ratio of the N, N' -methylene bisacrylamide to the polyaluminum chloride is 0.14-0.19: 1, a step of; the molar ratio of the acryloyloxyethyl dimethyl benzyl ammonium chloride to the N, N' -methylenebisacrylamide is 1:1 to 1.4.
The addition amount of ammonium persulfate is 0.8 to 1.2wt% of N, N' -methylenebisacrylamide.
The mass ratio of the modified polyacrylamide polymer to the polyaluminum chloride is 1:0.5 to 0.8.
The preparation method of the functional monomer comprises the following steps:
taking barley malt alkali to react with acryloyl chloride to prepare an intermediate product A;
and (3) preparing the intermediate product A and N- (3-chloropropyl) methane sulfonamide into a functional monomer through quaternization.
Further specifically, the preparation method of the functional monomer comprises the following steps:
adding diethyl ether into barley malt alkali, slowly dropwise adding acryloyl chloride under the condition of condensing reflux, heating to 40-45 ℃ in a water bath, reacting for 4-6 hours, distilling and purifying filtrate at 50 ℃ to remove solvent, adding a proper amount of water for extraction, taking upper liquid, adding anhydrous calcium chloride for water absorption, filtering, and distilling under reduced pressure to remove water to obtain an intermediate product A;
and (3) adding diethyl ether into the intermediate product A, N- (3-chloropropyl) methane sulfonamide, heating to 30-40 ℃ in a water bath, reacting for 10-15 h, cooling, crystallizing, filtering under reduced pressure, washing with diethyl ether for 3-5 times, and drying in vacuum to obtain the functional monomer.
The solid-liquid ratio of the barley malt alkali to the diethyl ether is 0.5-1.5 g:1mL; the molar ratio of the acryloyl chloride to the barley malt alkali is 1: 1.8-2.
The solid-to-liquid ratio of the intermediate product A to the diethyl ether is 0.2-0.5 g:1mL; intermediate A, N- (3-chloropropyl) methanesulfonamide in a molar ratio of 1:1.4 to 1.7.
The invention also discloses a preparation method of the modified polyacrylamide polymer, which comprises the following steps: and (3) mixing the acrylamide compound with a functional monomer, and carrying out free radical polymerization under the condition of an initiator to prepare the modified polyacrylamide polymer.
Further, the preparation method of the modified polyacrylamide polymer specifically comprises the following steps:
taking acrylamide and functional monomers, adding deionized water, and adjusting the pH value of the system to be neutral by using sodium hydroxide solution; and then introducing nitrogen, placing in a constant-temperature water bath, heating to 60-65 ℃, then dropwise adding an initiator, reacting for 2-4 hours, adding 10% hydroquinone solution, finishing the reaction, purifying with acetone and absolute ethyl alcohol, washing for several times, drying to constant weight at 60-65 ℃, and crushing to obtain the modified polyacrylamide polymer.
The molar ratio of acrylamide to functional monomer was 1: 2-4; the solid-to-liquid ratio of acrylamide to deionized water was 1g: 90-110 mL.
The initiator includes K 2 S 2 O 8 The method comprises the steps of carrying out a first treatment on the surface of the The addition amount of the initiator is 0.5-1wt% of the total amount of the polymerization monomers.
The invention also aims to disclose the application of the modified polyacrylamide polymer in preparing a floating auxiliary agent.
The invention also discloses application of the floating auxiliary agent in the field of water treatment.
The addition amount of the floating auxiliary agent is 0.5-5 mg/L.
Compared with the prior art, the invention has the following beneficial effects:
the invention adopts the barley malt alkali and N- (3-chloropropyl) methane sulfonamide to prepare the functional monomer through chemical bond and acrylamide chloride, and the functional monomer and the acrylamide monomer are subjected to free radical polymerization reaction to obtain the modified polyacrylamide polymer, so that the modified polyacrylamide polymer has better flocculation capability, and the modified polyacrylamide polymer is compounded with other components for use, so that the prepared floating auxiliary has stronger flocculation effect; the water treatment is carried out by applying the water treatment agent to a dissolved air floatation process, so that the particle size of the formed floccule is increased, and the structure is looser; can enhance flocculation of floating auxiliary agent and fine solids in water, obviously reduce the time required by floating, and effectively improve the water treatment efficiency. Meanwhile, the invention adopts the acryloyloxyethyl dimethyl benzyl ammonium chloride and the N, N' -methylene bisacrylamide to carry out chemical modification on the polyaluminium chloride by an in-situ polymerization method, so that the flocculation performance of the modified polyaluminium chloride can be effectively enhanced, and the modified polyaluminium chloride is compounded with a modified polyacrylamide compound for use, and the obtained floating auxiliary agent shows more excellent flocculation capability; further increases the particle size of the formed flocs, better combines with bubbles, effectively reduces the time required by floating, and further improves the water treatment efficiency.
Therefore, the invention provides the floating auxiliary agent for the water recovery system, and the preparation method and application thereof, wherein the floating auxiliary agent has more excellent flocculation capacity, can be well combined with fine solid floccules in water, and accelerates the combination of the floccules and bubbles in water, thereby accelerating the floating speed of floccule particles and improving the solid-liquid separation effect.
Drawings
FIG. 1 shows the results of an infrared spectrum test of intermediate A, a functional monomer in example 1 of the present invention;
FIG. 2 shows the results of an infrared spectrum test of the modified polyacrylamide polymer in example 1 of the present invention;
FIG. 3 shows the results of an infrared spectrum test of the modified polyaluminum chloride of example 5 of the present invention.
Detailed Description
The technical scheme of the invention is further described in detail below with reference to the specific embodiments:
example 1:
the floating auxiliary agent comprises a modified polyacrylamide polymer and polyaluminium chloride, wherein the mass ratio of the modified polyacrylamide polymer to the polyaluminium chloride is 1:0.64.
preparation of the modified polyacrylamide polymer:
taking acrylamide and functional monomer (the molar ratio of the acrylamide to the functional monomer is 1:3.2), adding deionized water, wherein the solid-liquid ratio of the acrylamide to the deionized water is as follows1g:100mL; and adjusting the pH value of the system to be neutral by using sodium hydroxide solution; then nitrogen is introduced, the mixture is placed in a constant temperature water bath to be heated to 60 ℃, and then an initiator K is added dropwise 2 S 2 O 8 (the addition amount is 0.78wt% of the total amount of the polymerization monomers), adding 10% hydroquinone solution after 3 hours of reaction, finishing the reaction, purifying with acetone and absolute ethyl alcohol, washing for several times, drying to constant weight at 60 ℃, and crushing to obtain the modified polyacrylamide polymer with the molecular mass of 4.35 multiplied by 10 7 。
The preparation of the functional monomer comprises the following steps:
adding diethyl ether (solid-liquid ratio is 0.8g:1 mL) into barley malt alkali, slowly dropwise adding acryloyl chloride (molar ratio to barley malt alkali is 1:2) under the condition of condensing and refluxing, heating to 45 ℃ in a water bath, reacting for 5 hours, distilling and purifying filtrate at 50 ℃ to remove solvent, adding a proper amount of water for extraction, taking upper liquid, adding anhydrous calcium chloride for absorbing water, filtering, and distilling under reduced pressure to remove water to obtain an intermediate product A;
intermediate A, N- (3-chloropropyl) methane sulfonamide (the molar ratio of the intermediate A, N to the ether is 1:1.55) is taken, diethyl ether is added, and the solid-to-liquid ratio of intermediate A to diethyl ether is 0.3g:1mL, heating to 35 ℃ in water bath, reacting for 12h, cooling, crystallizing, filtering under reduced pressure, washing with diethyl ether for 5 times, and vacuum drying to obtain the functional monomer.
Example 2:
the preparation of the functional monomer described above was the same as in example 1.
The modified polyacrylamide polymer was prepared as described above, which differs from example 1 in that:
the molar ratio of the acrylamide to the functional monomer is 1:4, a step of; the initiator was added in an amount of 1wt% based on the total amount of the polymerized monomers.
The floating auxiliary agent comprises a modified polyacrylamide polymer and polyaluminium chloride, wherein the mass ratio of the modified polyacrylamide polymer to the polyaluminium chloride is 1:0.5.
example 3:
the preparation of the functional monomer described above was the same as in example 1.
The modified polyacrylamide polymer was prepared as described above, which differs from example 1 in that:
the molar ratio of the acrylamide to the functional monomer is 1:2; the initiator was added in an amount of 0.6wt% based on the total amount of the polymerized monomers.
The floating auxiliary agent comprises a modified polyacrylamide polymer and polyaluminium chloride, wherein the mass ratio of the modified polyacrylamide polymer to the polyaluminium chloride is 1:0.8.
example 4:
the preparation of the functional monomer described above was the same as in example 1.
The modified polyacrylamide polymer was prepared as described above, which differs from example 1 in that:
the molar ratio of the acrylamide to the functional monomer is 1:2.5; the initiator was added in an amount of 0.9wt% based on the total amount of the polymerized monomers.
The floating auxiliary agent comprises a modified polyacrylamide polymer and polyaluminium chloride, wherein the mass ratio of the modified polyacrylamide polymer to the polyaluminium chloride is 1:0.6.
example 5:
the preparation of the functional monomer described above was the same as in example 1.
The modified polyacrylamide polymer was prepared in the same manner as in example 1.
The floating aid differs from example 1 in that: and adopting modified polyaluminium chloride to replace polyaluminium chloride.
Preparation of the modified polyaluminium chloride:
adding N, N '-methylene bisacrylamide (the mass ratio of the N, N' -methylene bisacrylamide to the polyaluminum chloride is 0.17:1) into a 25wt% concentration polyaluminum chloride aqueous solution, filling nitrogen for 30min, slowly dropwise adding a 10wt% concentration ammonium persulfate (the addition amount of the ammonium persulfate is 1.05wt% of the N, N '-methylene bisacrylamide) solution, oscillating for 2h, adding acryloyloxyethyl dimethyl benzyl ammonium chloride (the molar ratio of the acrylamide to the N, N' -methylene bisacrylamide is 1:1.25), and continuing to react for 3h; and then ethanol precipitation and acetone washing are carried out, and the modified polyaluminium chloride is obtained after constant-temperature drying at 50 ℃.
Example 6:
the modified polyacrylamide polymer was produced as described above, which differs from example 5 in that:
an equimolar amount of acrylamide was used instead of the functional monomer.
The floating aid differs from example 5 in that: the modified polyacrylamide polymer was prepared in this example.
The preparation of the modified polyaluminum chloride described above was the same as in example 5.
Example 7:
the modified polyacrylamide polymer was prepared in the same manner as in example 6.
The floating aid differs from example 6 in that: modified polyaluminium chloride was prepared in this example.
The preparation of the modified polyaluminium chloride described above differs from example 6 in that: an equimolar amount of N, N' -methylenebisacrylamide was used instead of acryloyloxyethyl dimethyl benzyl ammonium chloride.
Comparative example 1:
the modified polyacrylamide polymer was prepared as described above, which differs from example 1 in that:
an equimolar amount of acrylamide was used instead of the functional monomer.
The floating aid differs from example 1 in that: the modified polyacrylamide polymer was prepared in this example.
Test example 1:
infrared sign
The test is carried out by adopting a potassium bromide tabletting method and utilizing a Fourier transform infrared spectrometer, wherein the instrument model is MB154S of Bomen company in Canada, and the wavelength range is 4000-500 cm -1 。
The above test was performed on the intermediate product a and the functional monomer prepared in example 1, and the results are shown in fig. 1. From the analysis in the figure, 3100cm in the IR spectrum of intermediate A -1 ~2900cm -1 Characteristic absorption peaks of methyl and methylene appear in the range; 1720cm -1 Characteristic absorption peak of c=o in ester group appears nearby, 1625cm -1 Characteristic absorption peak of C=C appears nearby, 1500cm -1 ~1400cm -1 Characteristic absorption peaks of benzene rings appear in the range, indicating successful preparation of intermediate a in example 1. In the infrared spectrum of the functional monomer prepared, 1350cm -1 、1170cm -1 New appearance of SO 2 Is a characteristic absorption peak of (2) indicating successful preparation of the functional monomer of example 1.
The above test was conducted on the modified polyacrylamide polymer prepared in example 1, and the results are shown in FIG. 2. As can be seen from the analysis of the figure, 1654cm of the modified polyacrylamide polymer was obtained in the infrared spectrum -1 The absorption band of the primary amide appears nearby; 1806cm -1 Characteristic absorption peak of C=O in ester group appears nearby, 1335cm -1 、1143cm -1 Near SO 2 Is 965cm -1 Characteristic absorption peaks of the quaternary ammonium salt appear nearby, indicating successful preparation of the modified polyacrylamide polymer in example 1.
The above test was performed on the modified polyaluminum chloride prepared in example 5, and the results are shown in fig. 3. As can be seen from the analysis in the figure, 1718cm of the modified polyacrylamide polymer was obtained in the infrared spectrum -1 Characteristic absorption peak of c=o in ester group appears nearby, 1625cm -1 Near is the angular variation vibration of crystal water-OH in the sample structure; 1680cm -1 、1535cm -1 Characteristic absorption peak of amide group appears nearby, 1500cm -1 ~1400cm -1 Characteristic absorption peak of benzene ring appears in the range of 1143cm -1 Characteristic absorption peaks of C-N bonds appear nearby, indicating successful preparation of the modified polyaluminum chloride of example 5.
Determination of molecular weight
The test was performed using the viscosity method. Determination of polymer intrinsic viscosity: a solution with a certain concentration is prepared according to a specified condition, the flowing time t of the solvent and the solution is respectively measured by an air-bearing liquid column type Ubbelohde viscometer at 30 ℃, and then the intrinsic viscosity (mL/g) is calculated according to the measured t value, and the method is specifically carried out according to a method specified in GB 17514. The final calculation formula is as follows:
η r =t/t 0
in the method, in the process of the invention,η r represents the relative viscosity; t represents the flow-through time of the sample solution, s; t is t 0 Represents the flow-through time, s, of a 1mol sodium chloride solution.
η sp =η r -1
In the method, in the process of the invention,η sp representing specific viscosity increaseDegree.
In [ of ]η]Representing the intrinsic viscosity.
Calculation of results after determination of polymer, solvent and temperature, the value of intrinsic viscosity is determined only by the relative molecular mass of the sample, and the relationship is shown as follows:
[η]=KM a
the formula is a Mark-Houwink equation, wherein K, a is related to temperature, polymer type and solvent property, and is generally between 0.5 and 1.0.
Test example 2:
flocculation capacity determination
The kaolin suspension with the concentration of 1wt% is prepared as simulated waste liquid through experiments, the mixture is uniformly mixed and kept stand for 10min, then 50mL of the mixture is taken and added into a 50mL measuring cylinder with a plug, a test sample with the concentration of 2mg/L is added, the measuring cylinder is uniformly turned and mixed for 5 times, then the mixture is kept stand for 40min, and the supernatant at the position 10mm away from the liquid level is taken, and the light transmittance (taking distilled water as a reference and marked as 100%) is measured by a spectrophotometer.
The floating auxiliary agents prepared in comparative example 1 and examples 1 to 7 were subjected to the above test, and the results are shown in table 1:
TABLE 1 flocculation ability test results
| Sample of | Transmittance (%) |
| Example 1 | 87.5 |
| Example 2 | 86.3 |
| Example 3 | 87.9 |
| Example 4 | 87.0 |
| Example 5 | 94.2 |
| Example 6 | 83.7 |
| Example 7 | 79.8 |
| Comparative example 1 | 76.4 |
From the data analysis in table 1, the light transmittance is obviously higher than that of comparative example 1 after the floating auxiliary agent prepared in example 1 is adopted, and the effects of examples 2-4 are equivalent to those of example 1, which shows that the functional monomer prepared by using barley malt alkali and N- (3-chloropropyl) methane sulfonamide is compounded with other components to prepare the modified polyacrylamide polymer, and then the modified polyacrylamide polymer is matched with polyaluminium chloride, so that the obtained floating auxiliary agent has better flocculation capability. The effect of example 5 is obviously better than that of example 1, the effect of example 6 is better than that of example 7 and comparative example 1, and the effect of example 7 is better than that of comparative example 1, which shows that the flocculation capability of the floating auxiliary agent can be further enhanced by adopting N, N' -methylenebisacrylamide and acryloyloxyethyl dimethyl benzyl ammonium chloride to chemically modify polyaluminum chloride, and the light transmittance of the treated wastewater is obviously increased.
Test example 3:
application of floating auxiliary agent in water treatment system
Construction of dissolved air floatation microscopic observation system
The experimental system mainly comprises a dissolved air floatation system and a fiber observation system. The dissolved air flotation process consists of a water inlet system, a medicine adding system, a dissolved air system and a countercurrent dissolved air flotation separation column; the microscopic observation system is a system structure consisting of a whole microscope, a computer and an observation container.
The dissolved air flotation separation column is a countercurrent organic glass column with the height of 40cm and the inner diameter of 20cm, the effective volume of the column is 12.5L, and the upper part of the column is open. After being mixed and stirred uniformly, experimental water is pumped into a pipeline system by a water pump, an upward floating auxiliary agent is added after the pump, the experimental water enters from the bottom of the dissolved air flotation column after being fully mixed in the pipeline, meanwhile, return water enters into the bottom of the dissolved air flotation column through the pressurization of the dissolved air pump, a large amount of microbubbles are generated after the pressure is released, and after the raw water is combined with the raw water for coagulation, the tiny flocs are generated to form air-borne flocs in the column body, and the air-borne flocs rise to the top for solid-liquid separation. In the process of ascending the air-borne flocs, a part of air-borne flocs mixed solution enters an observation container through an air-dissolving air-floating column. In the test process, the dosing pump is a hydraulic diaphragm metering pump, and the volume is 0.9L/h; the dissolved air pressure is 0.4MPa; the addition amount of the floating auxiliary agent is 1mg/L. The turbidity of the test water sample is (45+/-0.5) NTU.
Index testing
(1) Bubble and airborne floc particle size
In the air-float reaction, compared with the bubbles with large size, when the contact area reacts, smaller bubbles enter the flocs more easily and are wrapped, and the rising speed of the bubbles is calculated according to the Stokes formula. The size of the captured air bubbles and air-borne flocs were measured, counted and analyzed using NIS-Elements D3.2 software.
(2) Two-dimensional fractal dimension
The fractal dimension can truly and accurately represent the character characteristics of the flocs. The smaller the numerical value is, the more open and loose the structure of the flocs is, the larger the porosity is, and the compactness is poor; otherwise, the more compact the floc structure. In experimental tests, a straight line is obtained by obtaining a lnA-lnL logarithmic graph of the projection area A of the flocs on the maximum outer diameter L according to the following formula:
LnA=D 2 lnL+lnα
the slope of the straight line is the two-dimensional fractal dimension D of the floc under the coagulation condition 2 。
(3) Turbidity removal rate
Turbidity is an important physical indicator for sewage and can characterize the concentration of opaque floating impurities and colloids in water. The experiment was performed using a HI93703-1 turbidimeter.
The floating auxiliary agents prepared in comparative example 1 and examples 1 to 7 were subjected to the above test, and the results are shown in table 2:
table 2 index test results
| Sample of | Average particle diameter (mm) | D 2 | Turbidity removal (%) |
| Example 1 | 0.64 | 1.1041 | 88.60 |
| Example 2 | 0.63 | 1.0987 | 88.94 |
| Example 3 | 0.65 | 1.1003 | 88.32 |
| Example 4 | 0.64 | 1.1035 | 87.99 |
| Example 5 | 0.71 | 0.9946 | 92.45 |
| Example 6 | 0.63 | 1.1247 | 85.01 |
| Example 7 | 0.60 | 1.1869 | 82.87 |
| Comparative example 1 | 0.58 | 1.2364 | 80.43 |
From the data analysis in Table 2, it is known that after the floating auxiliary agent prepared in example 1 is added for treatment, the average particle size of the flocs is obviously higher than that of comparative example 1, and the effects of examples 2-4 are equivalent to those of example 1, which shows that the functional monomer prepared by using barley malt alkali and N- (3-chloropropyl) methane sulfonamide is compounded with other components for use to prepare modified polyacrylamide polymer, and then the modified polyacrylamide polymer is compatible with polyaluminium chloride, so that the obtained floating auxiliary agent has better flocculation effect, and the particle size of the formed flocs is further increased. The effect of example 5 is obviously better than that of example 1, the effect of example 6 is better than that of example 7 and comparative example 1, and the effect of example 7 is better than that of comparative example 1, which shows that the chemical modification of polyaluminum chloride by using N, N' -methylenebisacrylamide and acryloyloxyethyl dimethyl benzyl ammonium chloride can further enhance flocculation of floating auxiliary agent and fine solids in water, and the particle size distribution of the obtained flocs is further improved.
Meanwhile, D after the floating auxiliary agent prepared in example 1 is added 2 The values of (2) and (4) are obviously lower than those of comparative example 1, the turbidity removal rate is obviously higher than that of comparative example 1, the effect of examples 2-4 is equivalent to that of example 1, and the effect of the functional monomer prepared from barley malt alkali and N- (3-chloropropyl) methane sulfonamide is shown to be better, and the functional monomer is compounded with other components to prepare the modified polyacrylamide polymer, and then the modified polyacrylamide polymer is compatible with polyaluminium chloride, so that the obtained floating auxiliary has better flocculation capacity, the formed flocculation structure is looser, the combination of bubbles and the flocculation is better, and the removal effect through air floatation is better. The effect of example 5 is obviously better than that of example 1, the effect of example 6 is better than that of example 7 and comparative example 1, and the effect of example 7 is better than that of comparative example 1, which shows that the chemical modification of polyaluminum chloride by adopting N, N' -methylenebisacrylamide and acryloyloxyethyl dimethyl benzyl ammonium chloride can further enhance the flocculation effect of the floating auxiliary agent and fine solids in water, and the obtained floccule has better characteristics and better solid-liquid separation effect.
(4) Time required for complete floating of flocs
The test results are shown in table 3:
TABLE 3 floc floating time test results
| Sample of | Time required for floating (min) |
| Example 1 | 35 |
| Example 2 | 35 |
| Example 3 | 34 |
| Example 4 | 36 |
| Example 5 | 20 |
| Example 6 | 44 |
| Example 7 | 56 |
| Comparative example 1 | 74 |
From the data analysis in Table 3, it is known that after the floating auxiliary agent prepared in example 1 is added and treated, the time required for forming the flocs to float completely is lower than that of comparative example 1, and the effects of examples 2-4 are equivalent to those of example 1, which shows that the functional monomer prepared by using barley malt alkali and N- (3-chloropropyl) methane sulfonamide is compounded with other components to prepare the modified polyacrylamide polymer, and then the modified polyacrylamide polymer is matched with polyaluminium chloride, so that the obtained floating auxiliary agent has better flocculation capability, the formed flocs can be combined with bubbles better, the time required by floating is obviously reduced, and the water treatment efficiency is increased. The effect of example 5 is obviously better than that of example 1, the effect of example 6 is better than that of example 7 and comparative example 1, and the effect of example 7 is better than that of comparative example 1, which shows that the chemical modification of polyaluminum chloride by adopting N, N' -methylenebisacrylamide and acryloyloxyethyl dimethyl benzyl ammonium chloride can further enhance flocculation of floating auxiliary agent and fine solids in water, and the obtained floccule has better characteristics and higher water treatment efficiency.
The conventional technology in the above embodiments is known to those skilled in the art, and thus is not described in detail herein.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (7)
1. An ascent aid comprising: a modified polyacrylamide-based polymer comprising at least one ethylenically unsaturated monomer, and a functional monomer; the ethylenically unsaturated monomers include acrylamide compounds; the functional monomer is obtained by connecting acryloyl chloride and barley malt alkali through chemical bonds and then carrying out quaternization reaction with N- (3-chloropropyl) methane sulfonamide;
the preparation method of the functional monomer comprises the following steps:
adding diethyl ether into barley malt alkali, slowly dropwise adding acryloyl chloride under the condition of condensing reflux, heating to 40-45 ℃ in a water bath, reacting for 4-6 hours, distilling and purifying filtrate at 50 ℃ to remove solvent, adding a proper amount of water for extraction, taking upper liquid, adding anhydrous calcium chloride for water absorption, filtering, and distilling under reduced pressure to remove water to obtain an intermediate product A;
taking an intermediate product A, N- (3-chloropropyl) methane sulfonamide, adding diethyl ether, heating to 30-40 ℃ in a water bath, reacting for 10-15 h, cooling, crystallizing, filtering under reduced pressure, washing with diethyl ether for 3-5 times, and vacuum drying to obtain a functional monomer;
the preparation method of the modified polyacrylamide polymer comprises the following steps: mixing an acrylamide compound with a functional monomer, and carrying out free radical polymerization reaction under the condition of an initiator to prepare a modified polyacrylamide polymer;
the floating auxiliary agent also comprises polyaluminum chloride.
2. The floating aid according to claim 1, wherein: the molecular weight of the modified polyacrylamide polymer is 3 multiplied by 10 7 ~5×10 7 。
3. The floating aid according to claim 1, wherein: the acrylamide compound comprises acrylamide.
4. The floating aid according to claim 1, wherein: the mass ratio of the modified polyacrylamide polymer to the polyaluminum chloride is 1:0.5 to 0.8.
5. The use of the modified polyacrylamide polymer as defined in claim 1 for preparing a floating assistant.
6. The use of the floating aid of claim 1 in the field of water treatment.
7. The use according to claim 6, characterized in that: the adding amount of the floating auxiliary agent is 0.5-5 mg/L.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211497715.3A CN115784358B (en) | 2022-11-28 | 2022-11-28 | Floating auxiliary agent for water recovery system and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211497715.3A CN115784358B (en) | 2022-11-28 | 2022-11-28 | Floating auxiliary agent for water recovery system and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115784358A CN115784358A (en) | 2023-03-14 |
| CN115784358B true CN115784358B (en) | 2023-07-11 |
Family
ID=85441942
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211497715.3A Active CN115784358B (en) | 2022-11-28 | 2022-11-28 | Floating auxiliary agent for water recovery system and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115784358B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2746102A1 (en) * | 1976-10-26 | 1978-04-27 | American Cyanamid Co | METHOD OF PURIFICATION OF RAW WATER |
| DE4436317A1 (en) * | 1994-10-11 | 1996-04-18 | Nalco Chemical Co | Prodn. of paper with improved screen draining and retention |
| CN103319653A (en) * | 2013-06-08 | 2013-09-25 | 山东水衡化工有限责任公司 | Preparation method of hydrophobic modified cation polyacrylamide flocculating agent |
-
2022
- 2022-11-28 CN CN202211497715.3A patent/CN115784358B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2746102A1 (en) * | 1976-10-26 | 1978-04-27 | American Cyanamid Co | METHOD OF PURIFICATION OF RAW WATER |
| DE4436317A1 (en) * | 1994-10-11 | 1996-04-18 | Nalco Chemical Co | Prodn. of paper with improved screen draining and retention |
| CN103319653A (en) * | 2013-06-08 | 2013-09-25 | 山东水衡化工有限责任公司 | Preparation method of hydrophobic modified cation polyacrylamide flocculating agent |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115784358A (en) | 2023-03-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ma et al. | Synthesis of cationic polyacrylamide by low-pressure UV initiation for turbidity water flocculation | |
| Lu et al. | UV-initiated synthesis of a novel chitosan-based flocculant with high flocculation efficiency for algal removal | |
| Zheng et al. | UV-initiated polymerization of hydrophobically associating cationic flocculants: Synthesis, characterization, and dewatering properties | |
| US3147218A (en) | Separating mineral fines with cationic polyacrylamides | |
| JPWO2016190388A1 (en) | Wastewater treatment method | |
| JPS63218718A (en) | Vinylamine copolymer, flocculant containing same and production thereof | |
| CN106311164A (en) | Amidoxime group-containing chitosan modified adsorbent and preparation method thereof | |
| EP0419654A1 (en) | Water-soluble cationic polymer | |
| CN108264610A (en) | A kind of chitosan flocculant and its preparation method and application | |
| CN112897667A (en) | Ammonium salt sewage treatment flocculant | |
| Chen et al. | Fabricating a hydrophobic modified flocculant through UVC irradiation initiation for metalworking wastewater treatment | |
| CN112175152A (en) | Hydrogel and preparation method and application thereof | |
| CN115784358B (en) | Floating auxiliary agent for water recovery system and preparation method and application thereof | |
| Liu et al. | Synthesis of a cationic polyacrylamide by a photocatalytic surface-initiated method and evaluation of its flocculation and dewatering performance: Nano-TiO 2 as a photo initiator | |
| Du et al. | Insight into the purification of algael water by a novel flocculant with enhanced branched nanochitosan structure | |
| CN108329432B (en) | Modified cyclodextrin and preparation method and application thereof | |
| CN112645423A (en) | Lignin-based polymer flocculant and preparation method thereof | |
| CN113996272B (en) | Molecularly imprinted polymer and preparation method and application thereof | |
| Senkal et al. | Removal of dyes from water by poly (vinyl pyrrolidone) hydrogel | |
| CN110040831B (en) | Preparation method of sodium alginate-polymethacryloxyethyl trimethyl ammonium chloride organic flocculant | |
| CN109553170B (en) | Inorganic-organic composite polymer dephosphorization flocculant and preparation method thereof | |
| US3707465A (en) | Clarification of aqueous suspensions with oxyaminated polyacrylamide flocculating agents | |
| CN105820278B (en) | One kind polymerization bisacrylamide base cationic compound and preparation method thereof | |
| Wang et al. | Removal effect and mechanism of amphiphilic chitosan modified microbubbles on microcystis aeruginosa | |
| Suna et al. | An alternative strategy for enhanced algae removal by cationic chitosan-based flocculants |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |