CN115784358A - 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
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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: a modified polyacrylamide-based polymer comprising at least one ethylenically unsaturated monomer, and a functional monomer; the above ethylenically unsaturated monomer includes an acrylamide-based compound; the functional monomer is obtained by connecting acryloyl chloride and barley malt alkali through a chemical bond 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 the water, so that the floating speed of floccule particles is accelerated, and the solid-liquid separation effect is improved.
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
Dissolved air floatation DAF is a high-efficiency solid-liquid separation technology, achieves the aim of improving water quality by matching with processes such as coagulation, filtration and the like, and is widely applied to the field of water treatment. The technology increases the solubility of air in water by pressurizing the air, forms highly dispersed micro-bubbles after decompression and release, and leads the micro-bubbles to be adhered to flocs, thereby realizing the forced floating of the flocs, and simultaneously, the density of the bubbles is far less than that of water, the buoyancy is very large, thus promoting the flocs to quickly float, thereby realizing the solid-liquid separation. The air flotation technology operation process can be basically divided into four parts: firstly, adding a coagulant and a coagulant aid into water to be treated to promote destabilization of colloidal particles suspended in the water to form flocs of a certain size; secondly, introducing a large amount 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 wrap to form air-carried flocs with stable structures and density smaller than that of water; and finally floating the air-borne flocs to form a scum layer, and realizing solid-liquid separation through a deslagging system.
The air flotation process is used in a sewage treatment method for many years, but more researchers focus on the aspects of air flotation theory exploration, air flotation reactor improvement, water purification effect improvement and the like, and due to the limitation of technical equipment, more micro-exploration on the air flotation reaction is not carried out. In recent years, with the further understanding of the air flotation technology, scientific researchers put forward more theories and technologies to perfect the air flotation process, and the microscopic exploration of the air flotation reaction is an indispensable one, so that the research on the air-borne flocs in the air flotation reaction is imperative.
Disclosure of Invention
The invention aims to provide an upward floating auxiliary agent for a water recovery system, and a preparation method and application thereof.
The technical scheme adopted by the invention for realizing 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 ethylenically unsaturated monomer includes an acrylamide-based compound; the functional monomer is obtained by connecting acryloyl chloride and barley malt alkali through a chemical bond and then carrying out quaternization reaction with N- (3-chloropropyl) methane sulfonamide. According to the invention, the functional monomer is prepared by connecting the barley malt alkali and N- (3-chloropropyl) methane sulfonamide with acryloyl chloride through chemical bonds, and the functional monomer and the acrylamide monomer are subjected to free radical polymerization reaction to obtain a modified polyacrylamide polymer, so that the modified polyacrylamide polymer has better flocculation capacity, and can be used in combination with other components, and the prepared floating auxiliary agent has stronger flocculation effect; when the flocculant is applied to a dissolved air floatation process for water treatment, the formed floc has more excellent characteristics, increased particle size, looser structure and better combination with bubbles, so that the removal effect of the floatation 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 required by floating on the floc is obviously reduced, and the water treatment efficiency is effectively improved. The reason may be that the polymer prepared by the functional monomer and the acrylamide monomer is introduced with various functional groups in a macromolecular chain structure, so that the electrostatic repulsion between chain links is enhanced, the polymer chain structure is more extended, the bridging effect is more facilitated, the flocculation and sedimentation effects of the polymer are effectively improved, and the polymer can be better applied to a water treatment process.
The molecular weight of the modified polyacrylamide polymer is 3X 10 7 ~5×10 7 。
The polyacrylamide-based compound includes acrylamide.
The floating aid further includes polyaluminum chloride.
More preferably, modified polyaluminium chloride is used instead of polyaluminium chloride.
The modified polyaluminum chloride is prepared by modifying polyaluminum chloride with acryloyloxyethyldimethylbenzylammonium chloride and N, N' -methylenebisacrylamide. According to the invention, the polyaluminum chloride is chemically modified by adopting the acryloyloxyethyl dimethyl benzyl ammonium chloride and the N, N' -methylene bisacrylamide through an in-situ polymerization method, the flocculation performance of the modified polyaluminum chloride can be effectively enhanced, and the modified polyaluminum chloride is compounded with a modified polyacrylamide compound for use, so that the obtained floating auxiliary agent shows more excellent flocculation capability; the method can be applied to water treatment in a dissolved air floatation process, further increases the particle size of formed flocs, and is better combined with bubbles; and the flocculation 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 is probably that organic and inorganic components in the modified polyaluminium chloride structure prepared by the invention are bonded in a covalent bond form, the property is stable, and the formed product structure is likely to be better loose, the granularity is increased, the adsorption and bridging effect is 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 polyaluminum chloride is prepared by chemically modifying polyaluminum chloride by adopting acryloyloxyethyl dimethyl benzyl ammonium chloride and N, N' -methylene bisacrylamide through an in-situ polymerization method.
Specifically, the preparation method of the modified polyaluminum chloride comprises the following steps:
adding N, N' -methylene bisacrylamide into a polyaluminum chloride aqueous solution with the concentration of 20-30wt%, filling nitrogen for 20-40min, slowly dropwise adding an ammonium persulfate solution with the concentration of 8-12wt%, carrying out oscillation reaction for 1-3h, adding acryloyloxyethyl dimethyl benzyl ammonium chloride, and continuing to react for 2-4h; then precipitating with ethanol, washing with acetone, and drying at constant temperature of 50-55 ℃ to obtain the modified polyaluminum chloride.
The mass ratio of the N, N' -methylenebisacrylamide to the polyaluminum chloride is 0.14 to 0.19:1; the mol ratio of the acryloyloxyethyl dimethyl benzyl ammonium chloride to the N, N' -methylene bisacrylamide is 1:1 to 1.4.
The amount of ammonium persulfate to be added is 0.8 to 1.2wt% based on the amount 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:
reacting barley malt alkali with acryloyl chloride to prepare an intermediate product A;
and (3) carrying out quaternization reaction on the intermediate product A and N- (3-chloropropyl) methanesulfonamide to prepare the functional monomer.
More 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 condensation reflux, heating in a water bath to 40-45 ℃, reacting for 4-6 h, distilling and purifying the filtrate at 50 ℃ to remove the solvent, adding a proper amount of water for extraction, taking the upper layer liquid, adding anhydrous calcium chloride for absorbing water, filtering, and distilling under reduced pressure to remove water to obtain an intermediate product A;
adding diethyl ether into the intermediate product A and the N- (3-chloropropyl) methanesulfonamide, heating in a water bath to 30-40 ℃, reacting for 10-15h, 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-to-liquid ratio of the barley malt alkali to the ether is 0.5 to 1.5g:1mL; the molar ratio of acryloyl chloride to hordenine is 1:1.8 to 2.
The solid-to-liquid ratio of the intermediate product A to diethyl ether is 0.2 to 0.5g:1mL; the mol ratio of the intermediate product A to the N- (3-chloropropyl) methanesulfonamide is 1:1.4 to 1.7.
The invention also discloses a preparation method of the modified polyacrylamide polymer, which comprises the following steps: taking an acrylamide compound and a functional monomer for compounding, and carrying out free radical polymerization reaction 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:
adding deionized water into acrylamide and functional monomers, and adjusting the pH of the system to be neutral by using a sodium hydroxide solution; and then introducing nitrogen, heating the mixture to 60 to 65 ℃ in a constant-temperature water bath, then dropwise adding an initiator, reacting for 2 to 4 hours, adding a 10% hydroquinone solution, finishing the reaction, purifying the mixture by using acetone and absolute ethyl alcohol, washing the mixture for several times, drying the mixture to constant weight at the temperature of 60 to 65 ℃, and crushing the mixture to obtain the modified polyacrylamide polymer.
The molar ratio of acrylamide to functional monomer is 1:2 to 4; the solid-liquid ratio of acrylamide to deionized water is 1g:90 to 110mL.
In the specification, the following are introducedThe hair agent comprises K 2 S 2 O 8 (ii) a The addition amount of the initiator is 0.5 to 1wt% of the total amount of the polymerization monomers.
The invention also discloses the application of the modified polyacrylamide polymer in preparing a floating assistant.
The invention also discloses an application of the floating auxiliary agent in the field of water treatment.
The addition amount of the floating auxiliary agent is 0.5 to 5mg/L.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, the functional monomer is prepared by connecting the barley malt alkali and N- (3-chloropropyl) methane sulfonamide with acryloyl chloride through chemical bonds, and the functional monomer and the acrylamide monomer are subjected to free radical polymerization reaction to obtain a modified polyacrylamide polymer, so that the modified polyacrylamide polymer has better flocculation capacity, and can be used in combination with other components, and the prepared floating auxiliary agent has stronger flocculation effect; the flocculant is applied to a dissolved air floatation process for water treatment, the particle size of formed flocs is increased, and the structure is looser; can enhance the flocculation of the floating auxiliary agent and fine solids in water, obviously reduce the time required for floating, and effectively improve the water treatment efficiency. Meanwhile, the method adopts the acryloyloxyethyl dimethyl benzyl ammonium chloride and the N, N' -methylene bisacrylamide to carry out chemical modification on the polyaluminum chloride through an in-situ polymerization method, can effectively enhance the flocculation performance of the modified polyaluminum chloride, and is compounded with the modified polyacrylamide compound for use, so that the obtained floating auxiliary agent shows more excellent flocculation capacity; the particle size of the formed flocs is further increased, the flocs are better combined with bubbles, the time required by floating is effectively reduced, and the water treatment efficiency is further improved.
Therefore, the floating assistant for the water recovery system, and the preparation method and the application thereof are provided by the invention, the floating assistant has more excellent flocculation capacity, can be well combined with fine solid floccules in water, and is capable of accelerating the combination of the floccules and bubbles in the water, so that the floating speed of floccule particles is accelerated, and the solid-liquid separation effect is improved.
Drawings
FIG. 1 shows the IR spectrum test results of the intermediate product A and the functional monomer in example 1 of the present invention;
FIG. 2 shows the IR spectrum test results of the modified polyacrylamide polymer of example 1 according to the present invention;
FIG. 3 shows the results of IR spectroscopy on modified polyaluminum chloride of example 5 of the present invention.
Detailed Description
The technical solution of the present invention is further described in detail with reference to the following embodiments:
example 1:
the floating auxiliary agent comprises a modified polyacrylamide polymer and polyaluminium chloride, and the mass ratio of the modified polyacrylamide polymer to the polyaluminium chloride is 1:0.64.
preparation of the above-described modified polyacrylamide-based polymer:
taking acrylamide and a functional monomer (the molar ratio of the acrylamide to the functional monomer is 1: 100mL; adjusting the pH value of the system to be neutral by using a sodium hydroxide solution; then introducing nitrogen, placing the mixture in a constant-temperature water bath, heating the mixture to 60 ℃, and then dropwise adding an initiator K 2 S 2 O 8 (the addition amount is 0.78wt% of the total amount of the polymerization monomers), reacting for 3h, adding 10% hydroquinone solution, finishing the reaction, purifying with acetone and absolute ethyl alcohol, washing for several times, drying at 60 ℃ to constant weight, and crushing to obtain the modified polyacrylamide polymer with the molecular weight of 4.35 multiplied by 10 7 。
Preparation of the functional monomer:
adding barley malt alkali into diethyl ether (the solid-liquid ratio is 0.8g: 1mL), slowly dropwise adding acryloyl chloride (the molar ratio of the acryloyl chloride to the barley malt alkali is 1;
taking the intermediate product A and N- (3-chloropropyl) methanesulfonamide (the molar ratio of the intermediate product A to the N- (3-chloropropyl) methanesulfonamide is 1.55), adding diethyl ether, wherein the solid-liquid ratio of the intermediate product A to the diethyl ether is 0.3g:1mL, heating to 35 ℃ in a water bath, reacting for 12h, cooling, crystallizing, filtering under reduced pressure, washing with diethyl ether for 5 times, and drying in vacuum to obtain the functional monomer.
Example 2:
the above functional monomers were prepared as in example 1.
The preparation of the above-mentioned modified polyacrylamide-based polymer is different from that of example 1 in that:
the mol ratio of the acrylamide to the functional monomer is 1:4; the amount of initiator added was 1wt% of the total amount of the polymerization monomers.
The floating auxiliary agent comprises a modified polyacrylamide polymer and polyaluminium chloride, and the mass ratio of the modified polyacrylamide polymer to the polyaluminium chloride is 1:0.5.
example 3:
the above functional monomers were prepared as in example 1.
The preparation of the above-mentioned modified polyacrylamide-based polymer is different from example 1 in that:
the mol ratio of the acrylamide to the functional monomer is 1:2; the amount of initiator added was 0.6wt% of the total amount of the polymerization monomers.
The floating auxiliary agent comprises a modified polyacrylamide polymer and polyaluminium chloride, and the mass ratio of the modified polyacrylamide polymer to the polyaluminium chloride is 1:0.8.
example 4:
the above functional monomers were prepared as in example 1.
The preparation of the above-mentioned modified polyacrylamide-based polymer is different from that of example 1 in that:
the mol ratio of the acrylamide to the functional monomer is 1:2.5; the amount of initiator added was 0.9wt% of the total amount of the polymerization monomers.
The floating auxiliary agent comprises a modified polyacrylamide polymer and polyaluminium chloride, and the mass ratio of the modified polyacrylamide polymer to the polyaluminium chloride is 1:0.6.
example 5:
the above functional monomers were prepared as in example 1.
The modified polyacrylamide-based polymer was prepared in the same manner as in example 1.
The difference between the floating assistant and the floating assistant in the embodiment 1 is that: the modified polyaluminum chloride is adopted to replace polyaluminum chloride.
The preparation of the modified polyaluminum chloride comprises the following steps:
taking a 25wt% polyaluminum chloride aqueous solution, adding N, N '-methylene-bisacrylamide (the mass ratio of the N, N' -methylene-bisacrylamide to the polyaluminum chloride is 0.17; then precipitating with ethanol, washing with acetone, and drying at constant temperature of 50 ℃ to obtain the modified polyaluminum chloride.
Example 6:
the preparation of the above-mentioned modified polyacrylamide-based polymer is different from example 5 in that:
instead of the functional monomer, an equimolar amount of acrylamide is used.
The difference between one floating assistant and example 5 is that: the modified polyacrylamide-based polymer was prepared in this example.
The modified polyaluminum chloride was prepared in the same manner as in example 5.
Example 7:
the above-mentioned modified polyacrylamide-based polymer was prepared in the same manner as in example 6.
The difference between one floating assistant and example 6 is that: modified polyaluminum chloride was prepared in this example.
The preparation of the modified polyaluminum chloride described above is different from example 6 in that: an equimolar amount of N, N' -methylenebisacrylamide was used instead of acryloyloxyethyldimethylbenzylammonium chloride.
Comparative example 1:
the preparation of the above-mentioned modified polyacrylamide-based polymer is different from example 1 in that:
an equimolar amount of acrylamide was used instead of the functional monomer.
The difference between the floating assistant and the floating assistant in the embodiment 1 is that: the modified polyacrylamide-based polymer was prepared in this example.
Test example 1:
infrared characterization
Testing by potassium bromide tabletting methodThe infrared spectrometer is carried out by a transform infrared spectrometer, the model of the spectrometer is MB154S of Bomen company of Canada, and the wavelength range is 4000 to 500cm -1 。
The intermediate product a and the functional monomer prepared in example 1 were subjected to the above test, and the results are shown in fig. 1. From the analysis in the figure, 3100cm was observed in the IR spectrum of intermediate A -1 ~2900cm -1 Characteristic absorption peaks of methyl and methylene appear in the range; 1720cm -1 A characteristic absorption peak of C = O in the ester group appeared in the vicinity, 1625cm -1 A characteristic absorption peak of C = C, 1500cm, appears nearby -1 ~1400cm -1 Characteristic absorption peaks of the benzene rings appear in the range, indicating successful preparation of intermediate a in example 1. In the infrared spectrum of the prepared functional monomer, 1350cm -1 、1170cm -1 Nearby newly appeared SO 2 Indicating successful preparation of the functional monomer in example 1.
The modified polyacrylamide-based polymer prepared in example 1 was subjected to the above-described test, and the results are shown in FIG. 2. As can be seen from the analysis in the figure, 1654cm of infrared spectrum of the modified polyacrylamide polymer -1 Nearby absorption bands of the primary amide; 1806cm -1 A characteristic absorption peak of C = O in the ester group, 1335cm, appeared in the vicinity -1 、1143cm -1 In the vicinity of SO 2 Characteristic absorption peak of (5), 965cm -1 The characteristic absorption peak of quaternary ammonium salt appears nearby, indicating that the modified polyacrylamide polymer in example 1 was successfully prepared.
The modified polyaluminum chloride prepared in example 5 was subjected to the above-mentioned test, and the results are shown in FIG. 3. As can be seen from the analysis in the figure, 1718cm are found in the infrared spectrum of the modified polyacrylamide polymer -1 A characteristic absorption peak of C = O in the ester group appeared in the vicinity, 1625cm -1 The vicinity is the variable angle vibration of the crystal water-OH in the sample structure; 1680cm -1 、1535cm -1 A characteristic absorption peak of 1500cm around the amide group -1 ~1400cm -1 The characteristic absorption peak of benzene ring appears in the range of 1143cm -1 A characteristic absorption peak of C-N bond appears nearby, indicating that the modified polyaluminum chloride in example 5 was successfully prepared.
Determination of molecular weight
The test was performed by the viscosity method. Determination of intrinsic viscosity of Polymer: a solution with a certain concentration is prepared according to the specified conditions, the flowing time t of the solvent and the solution is measured by a gas-supported liquid column type Ubbelohde viscometer at the temperature of 30 ℃, and then the intrinsic viscosity (mL/g) is calculated according to the measured t value, which is specifically carried out according to the method specified in GB 17514. The final calculation formula is as follows:
η r =t/t 0
in the formula (I), the compound is shown in the specification,η r represents the relative viscosity; t represents the flow time of the sample solution, s; t is t 0 Represents the flow-through time, s, of 1mol of sodium chloride solution.
η sp =η r -1
In the formula (I), the compound is shown in the specification,η sp representing the specific viscosity increase.
In the formula (2)η]Represents the intrinsic viscosity.
Calculation of the results, when the polymer, solvent and temperature are determined, the intrinsic viscosity is determined only by the relative molecular mass of the sample, which is related by the following equation:
[η]=KM a
the above formula is Mark-Houwink equation, wherein K and a are related to temperature, polymer type and solvent property, and are generally between 0.5 to 1.0.
Test example 2:
determination of flocculation Capacity
Experimental preparation of a 1wt% kaolin suspension as a simulated waste liquid, mixing uniformly, standing for 10min, adding 50mL into a 50mL measuring cylinder with a plug, adding a 2mg/L test sample, turning and mixing the measuring cylinder at a constant speed for 5 times, standing, taking a supernatant 10mm away from the liquid surface after 40min, and measuring the light transmittance by using a spectrophotometer (distilled water is used as a reference and is recorded as 100%).
The above test was carried out on the floating aids prepared in comparative example 1 and examples 1 to 7, and the results are shown in table 1:
TABLE 1 flocculation Capacity test results
| Sample (I) | Light 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 |
As can be seen from data analysis in Table 1, after the floating assistant prepared in example 1 is used for treatment, the light transmittance is obviously higher than that of comparative example 1, and the effects of examples 2 to 4 are equivalent to those of example 1, which shows that the floating assistant prepared by compounding the functional monomer prepared from the barley malt alkali and the N- (3-chloropropyl) methanesulfonamide with other components can be used for preparing the modified polyacrylamide polymer, and then the modified polyacrylamide polymer is compatible with the polyaluminum chloride to obtain the floating assistant with 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 assistant can be further enhanced by chemically modifying polyaluminum chloride with N, N' -methylene bisacrylamide and acryloyloxyethyldimethylbenzyl ammonium 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 flotation microscopic observation system
The system for the experiment mainly comprises a dissolved air floatation system and a fiber observation system. Wherein, the dissolved air floatation process consists of a water inlet system, a dosing system, a dissolved air system and a counter-flow dissolved air floatation separation column; the microscopic observation system is a system structure consisting of a body type microscope, a computer and an observation container.
The dissolved air flotation separation column is a counter-flow organic glass column with the height of 40cm and the inner diameter of 20cm, the effective volume is 12.5L, and the upper part is open. The experimental water is mixed and stirred uniformly and then pumped into a pipeline system by a water pump, the floating auxiliary agent is added after the pump, the experimental water is fully mixed in the pipeline and then enters from the bottom of a dissolved air floatation column, meanwhile, the backflow water enters the bottom of the dissolved air floatation column through the pressurization of a dissolved air pump, a large amount of micro bubbles are generated after the pressure is released, tiny flocs are generated after the coagulation of raw water to form air-borne flocs in the column, and the air-borne flocs rise to the top for solid-liquid separation. In the ascending process of the air-borne flocs, a part of the air-borne floc mixed liquid enters an observation container through the dissolved air floatation 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 dosage of the floating auxiliary agent is 1mg/L. The turbidity of the test water sample was (45. + -. 0.5) NTU.
Index testing
(1) Particle size of air bubbles and air-borne flocs
In the air flotation reaction, compared with the large-size bubbles, when the reaction is carried out in the contact area, the smaller bubbles can more easily enter flocs and are wrapped, and the rising speed of the bubbles is calculated according to the Stokes formula. The sizes of the air bubbles and airborne flocs captured were measured, counted, and analyzed using NIS-Elements D3.2 software.
(2) Two-dimensional fractal dimension
The fractal dimension can truly and accurately characterize the character characteristics of the flocs. The smaller the numerical value is, the more open and loose the structure of the floc is, the larger the porosity is, and the compaction degree is poor; otherwise, the more dense the floc structure. In the experimental test, a logarithmic graph of lnA-lnL is drawn on the maximum outer diameter L by obtaining the projection area A of the flocs to obtain a straight line 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 flocs under the coagulation condition 2 。
(3) Turbidity removal rate
For sewage, turbidity is an important physical index that can characterize the concentration of light-tight floating impurities and colloids in water. The experiment was carried out using a turbidity meter type HI 93703-1.
The above test was performed on the floating aids prepared in comparative example 1 and examples 1 to 7, and the results are shown in table 2:
TABLE 2 index test results
| Sample(s) | Average particle diameter (mm) | D 2 | Turbidity removal Rate (%) |
| 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 can be seen that after the floating assistant prepared in example 1 is added, the average particle size of the floc is significantly higher than that of comparative example 1, and the effects of examples 2 to 4 are equivalent to those of example 1, which indicates that the functional monomer prepared from barley malt alkali and N- (3-chloropropyl) methanesulfonamide is used in combination with other components to prepare a modified polyacrylamide polymer, and then the modified polyacrylamide polymer is combined with polyaluminum chloride to obtain a floating assistant with better flocculation effect, and the particle size of the formed floc 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 flocculation effect of the floating assistant and fine solids in water can be further enhanced and the particle size distribution of the obtained flocs is further improved by chemically modifying the polyaluminum chloride with N, N' -methylenebisacrylamide and acryloyloxyethyldimethylbenzylammonium chloride.
Meanwhile, after the treatment of adding the floating assistant prepared in example 1, D 2 The value of the modified polyacrylamide is obviously lower than that of the comparative example 1, the turbidity clearance rate is obviously higher than that of the comparative example 1, and the effects of the examples 2 to 4 are equivalent to those of the example 1, so that the modified polyacrylamide is prepared by compounding the functional monomer prepared from the barley malt alkali and the N- (3-chloropropyl) methanesulfonamide with other components, and then the modified polyacrylamide is compatible with the polyaluminum chloride, so that the obtained floating auxiliary agent has better flocculation capability, the formed floc has a looser structure, the combination of bubbles and the floc is better, and the removal effect through air flotation 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 flocculation effect of the floating assistant and fine solids in water can be further enhanced by chemically modifying polyaluminum chloride with N, N' -methylene bisacrylamide and acryloyloxyethyldimethylbenzyl ammonium chloride, and the obtained floc has better and firmer characteristicsThe liquid separation effect is better.
(4) Time required for flocs to float completely
The test results are shown in table 3:
TABLE 3 floc flotation time test results
| Sample(s) | Time required for upward 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 can be seen that the time required for forming floes to float completely is less than that of comparative example 1 after the floe floating assistant prepared in example 1 is added, and the effects of examples 2 to 4 are equivalent to those of example 1, which indicates that the functional monomer prepared from barley malt alkali and N- (3-chloropropyl) methanesulfonamide is compounded with other components to prepare the modified polyacrylamide polymer, and then the modified polyacrylamide polymer is compatible with polyaluminium chloride to obtain the floe floating assistant with better flocculation capability, so that the formed floes can be better combined with bubbles, the time required for 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 flocculation effect of the floating assistant and fine solids in water can be further enhanced by chemically modifying the polyaluminum chloride with N, N' -methylene bisacrylamide and acryloyloxyethyldimethylbenzyl ammonium chloride, so that the obtained floc has better characteristics and higher water treatment efficiency.
Conventional techniques in the above embodiments are known to those skilled in the art, and thus will not be described in detail herein.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (9)
1. An ascent aid comprising: a modified polyacrylamide-based polymer comprising at least one ethylenically unsaturated monomer, and a functional monomer; the ethylenically unsaturated monomer includes an acrylamide-based compound; the functional monomer is obtained by connecting acryloyl chloride and barley malt alkali through a chemical bond and then performing quaternization reaction on the acryloyl chloride and the barley malt alkali and N- (3-chloropropyl) methanesulfonamide.
2. The buoyant adjuvant of claim 1, wherein the buoyant adjuvant is selected from the group consisting of: the molecular weight of the modified polyacrylamide polymer is 3 x 10 7 ~5×10 7 。
3. The buoyant adjuvant according to claim 1, wherein: the polyacrylamide compound includes acrylamide.
4. The buoyant adjuvant according to claim 1, wherein: the floating auxiliary agent also comprises polyaluminium chloride.
5. The buoyant adjuvant according to claim 4, wherein: the mass ratio of the modified polyacrylamide polymer to the polyaluminum chloride is 1:0.5 to 0.8.
6. A process for producing a modified polyacrylamide polymer according to claim 1, which comprises: taking an acrylamide compound and a functional monomer for compounding, and carrying out free radical polymerization reaction under the condition of an initiator to prepare the modified polyacrylamide polymer.
7. Use of the modified polyacrylamide-based polymer according to claim 1 in the preparation of a floating aid.
8. Use of the buoyant adjuvant of claim 1 in the field of water treatment.
9. Use according to claim 8, characterized in that: the dosage of the floating auxiliary agent is 0.5 to 5mg/L.
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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 |
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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 |
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