Preparation method of environment-friendly macromolecular organic flocculant by taking tannic acid and quaternary phosphonium salt as raw materials

Abstract

The invention discloses a preparation method of an environment-friendly macromolecular organic flocculant by taking tannic acid and quaternary phosphonium salt as raw materials, and relates to the technical field of solid waste resource utilization and water treatment medicaments. A natural polyphenol compound tannic acid and allyltributylphosphonium bromide are subjected to an addition polymerization reaction under the action of an initiator ceric ammonium nitrate to generate the environment-friendly polymeric flocculant with a branched structure, and the environment-friendly polymeric flocculant is high in charge density and large in molecular weight, has a branched long-chain structure, and can be used for preparing the environment-friendly polymeric flocculant. The sewage treatment agent can efficiently remove pollutants in water under the condition of low dosage, can adapt to various wastewater treatment scenes, is wide in application range, and has higher economical efficiency and environmental friendliness.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste resource utilization and water treatment agents, and in particular to a method for preparing an environmentally friendly high-molecular organic flocculant using tannic acid and quaternary phosphonium salt as raw materials. Background Art

[0002] Flocculants play a key role in the water treatment process, effectively removing pollutants such as suspended matter and colloids from water, thereby significantly improving water quality. Their performance directly affects coagulation efficiency, process operating costs, and the ultimate quality of water purification. Traditional flocculants mainly include inorganic flocculants such as aluminum salts and iron salts, and organic polymers such as polyacrylamide. However, these traditional flocculants have some limitations in practical applications: inorganic flocculants may introduce metal ion residues, while organic polymer flocculants may face problems such as poor biodegradability and potential environmental toxicity. Therefore, the development of new, efficient and environmentally friendly flocculants has become an important research direction in the field of water treatment.

[0003] Currently, environmentally friendly organic polymer flocculants are divided into two main categories: biodegradable synthetic flocculants and flocculants based on modified natural polymer materials. Biodegradable synthetic flocculants are prepared through polymerization reactions using renewable monomers such as lactic acid and caprolactone. They offer advantages such as widespread availability, renewable availability, biodegradability, and environmental friendliness. However, these flocculants also suffer from issues such as poor product stability, significant susceptibility to environmental factors, and high cost, which to some extent limit their large-scale application.

[0004] With growing environmental awareness, modified natural polymers have become a research hotspot due to their low toxicity, wide availability of raw materials, biodegradability, and low cost. These flocculants are typically obtained by modifying biomass (especially industrial and agricultural waste) through etherification, esterification, sulfonation, or graft copolymerization. This not only achieves comprehensive utilization of waste resources but also effectively reduces the cost of flocculant preparation and application. Therefore, research on biomass-based flocculants has important practical significance and application value for promoting the development of water treatment technologies.

[0005] Tannins are natural polyphenolic compounds found widely in plants. They possess abundant phenolic hydroxyl groups, which can form complexes or cross-linking reactions with metal ions, proteins, and other substances. Tannins are widely used in water treatment, leather tanning, medicine, and other fields due to their broad availability, renewable nature, and good biodegradability. However, while the phenolic hydroxyl groups in tannin molecules possess high reactivity, their solubility and flocculation properties in water are limited, making their direct use as efficient flocculants difficult. Therefore, chemical modification of tannins to introduce functional groups with flocculation properties has become an effective approach to improve their performance in applications.

[0006] Quaternary phosphonium salts are a class of organic compounds containing phosphorus cations. They possess strong positive charge and good water solubility, neutralizing negatively charged colloidal particles and promoting their aggregation and sedimentation. Introducing quaternary phosphonium groups into tannin molecules not only increases the tannin's water solubility but also enhances its interaction with negatively charged colloidal particles in water, thereby improving the flocculation effect. Furthermore, as organic flocculants, quaternary phosphonium tannins possess the advantages of good biodegradability and environmental friendliness, aligning with the development trend of green chemistry.

[0007] Currently, there are reports on quaternary phosphonium tannin flocculants. Studies have shown that quaternary phosphonium tannins have excellent flocculation effects on oily wastewater, dye wastewater, and other wastewaters, effectively removing suspended matter and colloidal particles from the water. However, existing methods for preparing quaternary phosphonium tannins still have some shortcomings, such as difficult to control reaction conditions, uneven product structure, and high costs, which limit their large-scale application. Therefore, developing a method for preparing quaternary phosphonium tannin organic flocculants with mild reaction conditions, simple operation, and low cost has important theoretical significance and practical application value. Summary of the Invention

[0008] The purpose of the present invention is to provide a method for preparing an environmentally friendly high-molecular organic flocculant using tannic acid and quaternary phosphonium salt as raw materials, so as to solve the problems existing in the above-mentioned prior art.

[0009] To achieve the above object, the present invention provides the following solutions:

[0010] The present invention provides a method for preparing a polymer organic flocculant, comprising the following steps:

[0011] Tannic acid and quaternary phosphonium salt are used as raw materials, and addition polymerization reaction is carried out in the presence of an initiator under a protective atmosphere to obtain the high molecular organic flocculant.

[0012] As a further preferred embodiment of the present invention, the pH of the addition polymerization reaction is 4-10; and the addition polymerization reaction is subjected to composite ultraviolet irradiation treatment.

[0013] As a further preferred embodiment of the present invention, the preparation method includes the following steps: mixing tannic acid and a quaternary phosphonium salt at 40-90°C in a protective atmosphere in the presence of an initiator, and then subjecting the reaction system to ultraviolet irradiation treatment; after the ultraviolet irradiation treatment is completed, reacting at 40-90°C to obtain the polymer organic flocculant.

[0014] As a further preferred embodiment of the present invention, the initiator is cerium ammonium nitrate; and the quaternary phosphonium salt is allyltributylphosphonium bromide.

[0015] Wherein, the mass ratio of the initiator to tannic acid is (0.01-0.1) g:1 g.

[0016] The quaternary phosphonium salt used in the present invention is allyltributylphosphonium bromide. The double bond in its allyl group is highly reactive. Under the action of an initiator, the double bond opens to create an active site. Simultaneously, the phenolic hydroxyl group on the tannic acid also generates an O-active site under the action of the initiator. Under anaerobic conditions, the two can be grafted and copolymerized.

[0017] As a further preferred embodiment of the present invention, the mass ratio of tannic acid to allyltributylphosphonium bromide is 1:(0.5-5).

[0018] As a further preference of the present invention, the mixing reaction time is 15 min-1 h.

[0019] In the present invention, the protective atmosphere is an inert atmosphere, preferably a nitrogen protective atmosphere.

[0020] As a further preferred embodiment of the present invention, the intensity of the ultraviolet irradiation treatment is 5-50 mw / cm 2 ; The ultraviolet light irradiation treatment time is 10-30min.

[0021] As a further preferred embodiment of the present invention, after the ultraviolet light irradiation is completed, the reaction time at 40-90° C. is 2-5 hours.

[0022] The present invention also provides a high-molecular organic flocculant prepared by the above preparation method.

[0023] The present invention further provides application of the above-mentioned high molecular organic flocculant in water treatment.

[0024] The present invention provides a method for preparing an environmentally friendly high-molecular-weight organic flocculant using tannic acid and a quaternary phosphonium salt as raw materials. The core principle is to utilize the functional groups (phenolic hydroxyl groups) on tannic acid, a natural polyphenolic compound, to react with allyltributylphosphonium bromide in the presence of an initiator (ceric ammonium nitrate) to undergo an addition polymerization reaction. The high-molecular-weight organic flocculant has a zeta potential of 69.3±1.3 mV, a charge density of 4500-4763 μeq / L, and a molecular weight of 100,000 kDa to 200,000 kDa.

[0025] The flocculant produced by this invention generates larger flocs, significantly increasing their contact rate with pollutant particles. Its adsorption and bridging effects on tiny flocs are superior to those of traditional flocculants, demonstrating excellent flocculation performance. Furthermore, this product is environmentally friendly and suitable for wastewater treatment, demonstrating particularly remarkable results in the treatment of simulated reactive blue dye wastewater.

[0026] The present invention helps to improve water treatment efficiency, conforms to the concept of green environmental protection, and has broad application prospects.

[0027] The present invention discloses the following technical effects:

[0028] The invention utilizes a natural polyphenol compound, tannic acid, and allyltributylphosphonium bromide in the presence of an initiator, ceric ammonium nitrate, to form an environmentally friendly high-molecular-weight flocculant with a branched structure through an addition polymerization reaction. This environmentally friendly high-molecular-weight flocculant has a high charge density, a large molecular weight, and a branched long-chain structure, enabling efficient removal of pollutants from water.

[0029] The flocculant prepared by this invention has a larger floc particle size, which increases the probability of contact with pollutant particles. Its adsorption and bridging effect on tiny flocs is significantly superior to that of traditional flocculants. Furthermore, due to its high charge density and strong adsorption and charge neutralization ability, it is more effective at removing anionic impurities in water than non-cationic flocculants. Furthermore, its high viscosity and high cationicity make it suitable for a variety of wastewater treatment scenarios and has a wide range of applications.

[0030] The flocculant product obtained by the present invention can achieve a high chroma removal rate (up to 96% or more) under low dosage conditions, and its flocculation efficiency is significantly better than that of existing tannin-based flocculant products. Its efficient pollutant removal ability gives it a significant advantage in industrial wastewater treatment, while reducing operating costs.

[0031] The preparation method of the present invention features simple process, mild reaction conditions, few byproducts, and low equipment requirements, making it easy to implement industrial production. Furthermore, tannic acid, as a natural renewable resource, is widely available and inexpensive, meeting the requirements of green chemistry and sustainable development. Compared with traditional flocculant preparation processes, the present invention is more economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 This is a TEM image of the environmentally friendly polymer organic flocculant prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0035] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0036] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0037] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0038] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0039] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0040] The present invention provides a method for preparing a polymer organic flocculant, comprising the following steps:

[0041] Tannic acid and quaternary phosphonium salt are used as raw materials, and addition polymerization reaction is carried out in the presence of an initiator under a protective atmosphere to obtain the high molecular organic flocculant.

[0042] Preferably, the pH of the addition polymerization reaction is 4-10; and the addition polymerization reaction is subjected to composite ultraviolet irradiation treatment.

[0043] Preferably, the preparation method comprises the following steps: mixing tannic acid and quaternary phosphonium salt at 40-90°C in a protective atmosphere in the presence of an initiator, and then subjecting the reaction system to ultraviolet irradiation treatment; after the ultraviolet irradiation treatment is completed, reacting at 40-90°C to obtain the polymer organic flocculant.

[0044] Preferably, the initiator is cerium ammonium nitrate; and the quaternary phosphonium salt is allyltributylphosphonium bromide.

[0045] Preferably, the mass ratio of the initiator to tannic acid is (0.01-0.1) g:1 g.

[0046] The quaternary phosphonium salt used in the present invention is allyltributylphosphonium bromide. The double bond in its allyl group is highly reactive. Under the action of an initiator, the double bond opens to create an active site. Simultaneously, the phenolic hydroxyl group on the tannic acid also generates an O-active site under the action of the initiator. Under anaerobic conditions, the two can be grafted and copolymerized.

[0047] Preferably, the mass ratio of the tannic acid to allyltributylphosphonium bromide is 1:(0.5-5).

[0048] Preferably, the mixing reaction time is 15 min-1 h.

[0049] In the present invention, the protective atmosphere is an inert atmosphere, preferably a nitrogen protective atmosphere.

[0050] Preferably, the intensity of the ultraviolet irradiation treatment is 5-50 mw / cm 2 ; The ultraviolet light irradiation treatment time is 10-30min.

[0051] Preferably, after the ultraviolet irradiation is completed, the reaction time at 40-90° C. is 2-5 hours.

[0052] More preferably, the preparation method of the environmentally friendly polymer organic flocculant of the present invention specifically comprises the following steps:

[0053] (1) Add tannic acid to deionized water, adjust the pH of the solution to 4-10 using NaOH solution, and stir thoroughly to mix;

[0054] (2) While the tannic acid was stirred for 20 minutes, nitrogen gas was introduced at a high flow rate and continued to be introduced for 30 minutes to remove air from the tannic acid solution. Cerium ammonium nitrate dissolved in ultrapure water was quickly added to the mixture as an initiator;

[0055] (3) Under continuous stirring and nitrogen protection, an aqueous solution of allyltributylphosphonium bromide is added dropwise to the reaction system;

[0056] (4) placing the reaction system in an ultraviolet light reactor, and irradiating the reaction system with ultraviolet light under nitrogen protection and continuous stirring;

[0057] (5) The reaction system was transferred to a water bath and the reaction was continued under continuous stirring and nitrogen protection;

[0058] (6) After the reaction is completed, the mixture is cooled to room temperature, and the obtained product is purified, frozen, and dried to obtain the polymer organic flocculant.

[0059] The present invention also provides a high-molecular organic flocculant prepared by the above preparation method.

[0060] The present invention further provides application of the above-mentioned high molecular organic flocculant in water treatment.

[0061] The present invention will be further described in detail below with reference to the examples. It should be noted that the parts not described in detail in the present invention are conventional operating methods in the art and are not the focus of the present invention.

[0062] Example 1

[0063] Preparation of environmentally friendly polymer organic flocculants:

[0064] (1) Weigh 1 g of tannic acid powder and add it to 100 mL of deionized water. Adjust the pH of the solution to 4 with 0.1 M NaOH solution and stir thoroughly to mix. Place the resulting solution in a three-necked flask and heat it in a water bath at 50°C. Stir continuously for 30 min.

[0065] (2) After the tannic acid solution was stirred for 20 min, nitrogen gas was introduced at a high flow rate and continued for 30 min to remove air from the solution. Subsequently, 0.5 g of cerium ammonium nitrate was dissolved in 10 mL of ultrapure water as an initiator and quickly added to the mixture. Stirring was continued for 10 min to ensure that the initiator was fully dispersed.

[0066] (3) Continuing under nitrogen protection and stirring conditions, the aqueous solution of allyltributylphosphonium bromide was added dropwise to the reaction system three times, wherein the mass ratio of tannic acid to allyltributylphosphonium bromide was 1:1.

[0067] (4) The three-necked flask was transferred to a UV reactor and the UV light was irradiated at 20 mW / cm2 under nitrogen protection and continuous stirring. 2 The reaction system was irradiated with ultraviolet light for 20 min.

[0068] (5) The three-necked flask was transferred to a 50°C water bath again and the reaction was continued for 3 h under nitrogen protection and stirring to ensure that the reaction was complete.

[0069] (6) After the reaction is completed, the reaction system is cooled to room temperature; the resulting product is then purified and freeze-dried to finally obtain an environmentally friendly high molecular weight organic flocculant.

[0070] Figure 1 This is a TEM image of the environmentally friendly high molecular organic flocculant prepared in Example 1 of the present invention. It can be seen that it presents a branched long chain structure.

[0071] The preparation steps of the simulated reactive blue dye wastewater in the present invention are as follows:

[0072] Weigh 70 mg of Reactive Blue powder, dissolve it in 7 L of water, and stir thoroughly to prepare the experimental water sample. The characteristic parameters of this experimental water sample were measured: pH: 7.40 ± 0.02; Zeta potential: -8.36 ± 1.0 mV; and absorbance: 1.101 ± 0.02.

[0073] In the following application examples, the above-mentioned simulated reactive blue dye wastewater is used for experimental research, and the treatment effect is evaluated by the chroma removal rate (%).

[0074] Chroma removal rate (%) = (1-Ce / C0) × 100;

[0075] Among them, Ce refers to the chromaticity value of the water sample before treatment, and C0 refers to the chromaticity value of the water sample after treatment.

[0076] Application Example 1

[0077] The mass ratios of tannic acid and allyltributylphosphonium bromide in Example 1 were adjusted to 1:0.5, 1:1, 1:2, 1:3, 1:4, and 1:5, respectively. The environmentally friendly polymer organic flocculants prepared according to these different mass ratios were named a1, b1, c1, d1, e1, and f1, respectively.

[0078] Subsequently, the prepared environmentally friendly polymeric organic flocculants a1, b1, c1, d1, e1, and f1 were subjected to zeta potential testing. The test results are detailed in Table 1-1. Furthermore, these environmentally friendly polymeric organic flocculants a1, b1, c1, d1, e1, and f1 were used in a treatment experiment simulating reactive blue dye wastewater. The treatment effects at different dosages (coagulation for 30 minutes and sedimentation for 30 minutes) were examined. The treatment results are shown in Table 1-2.

[0079] Table 1-1 Zeta potential, molecular weight and charge density (mV)

[0080]

[0081]

[0082] Table 1-2. Chroma removal rate (%)

[0083]

[0084] Application Example 2

[0085] Based on Example 1, the addition amount of ammonium cerium nitrate was adjusted to 0.03g, 0.04g, 0.05g, 0.06g, 0.07mg, and 0.08g, respectively. The environmentally friendly polymer organic flocculants prepared according to the above different addition amounts were labeled a2, b2, c2, d2, e2, and f2, respectively.

[0086] Subsequently, the prepared environmentally friendly polymeric organic flocculants a2, b2, c2, d2, e2, and f2 were subjected to zeta potential testing. The specific test results are detailed in Table 2-1. Furthermore, the environmentally friendly polymeric organic flocculants a2, b2, c2, d2, e2, and f2 were used in a treatment experiment simulating reactive blue dye wastewater. The treatment effects at different dosages (coagulation for 30 minutes and sedimentation for 30 minutes) were examined. The specific treatment results are shown in Table 2-2.

[0087] Table 2-1. Zeta potential, molecular weight and charge density

[0088]

[0089]

[0090] Table 2-2. Chroma removal rate (%)

[0091]

[0092] Application Example 3

[0093] Based on Example 1, the effect of varying the order of addition of ammonium cerium nitrate on flocculant performance was studied. The specific order of addition is as follows: Option 1: Add all of the ammonium cerium nitrate at once before adding allyltributylphosphonium bromide. Option 2: Add all of the ammonium cerium nitrate simultaneously with the addition of allyltributylphosphonium bromide. Option 3: Add all of the ammonium cerium nitrate after the addition of allyltributylphosphonium bromide. Option 4: Add half of the ammonium cerium nitrate before adding allyltributylphosphonium bromide; add the remaining half after the addition of allyltributylphosphonium bromide. Option 5: Divide the ammonium cerium nitrate into three equal parts, and add one-third of the ammonium cerium nitrate before, simultaneously with, and after the addition of allyltributylphosphonium bromide. The flocculants prepared according to the above different addition orders were named a3, b3, c3, d3, and e3, respectively. Zeta potential tests were then performed on these flocculants, and the results are detailed in Table 3-1. In addition, a3, b3, c3, d3 and e3 were used to treat simulated reactive blue dye wastewater, and the treatment effects at different dosages were investigated (coagulation for 30 minutes, sedimentation for 30 minutes). The specific results are shown in Table 3-2.

[0094] Table 3-1. Zeta potential, molecular weight and charge density

[0095]

[0096]

[0097] Table 3-2. Chroma removal rate (%)

[0098]

[0099] Application Example 4

[0100] Based on Example 1, the water bath temperature was changed to 40°C, 50°C, 60°C, 70°C, 80°C, and 90°C, respectively, to prepare different environmentally friendly polymeric organic flocculants, which were labeled a4, b4, c4, d4, e4, and f4, respectively. Subsequently, the prepared environmentally friendly polymeric organic flocculants a4, b4, c4, d4, e4, and f4 were subjected to Zeta potential testing. The specific test results are shown in Table 4-1. In addition, the above-mentioned environmentally friendly polymeric organic flocculants a4, b4, c4, d4, e4, and f4 were used in a treatment experiment simulating reactive blue dye wastewater, and the treatment effects at different dosages were examined (coagulation for 30 minutes, sedimentation for 30 minutes). The specific treatment results are shown in Table 4-2.

[0101] Table 4-1. Zeta potential, molecular weight and charge density

[0102]

[0103]

[0104] Table 4-2. Chroma removal rate (%)

[0105]

[0106] Application Example 5:

[0107] Based on Example 1, the pH value of the solution system was adjusted to 3, 4, 5, 6, 7, and 8, respectively, to prepare different environmentally friendly polymeric organic flocculants, labeled a5, b5, c5, d5, e5, and f5, respectively. Subsequently, the prepared environmentally friendly polymeric organic flocculants a5, b5, c5, d5, e5, and f5 were subjected to zeta potential testing. The specific test results are detailed in Table 5-1. Furthermore, the environmentally friendly polymeric organic flocculants a5, b5, c5, d5, e5, and f5 were used in a treatment experiment simulating reactive blue dye wastewater, and the treatment effects at different dosages were examined (coagulation for 30 minutes, sedimentation for 30 minutes). The specific treatment results are shown in Table 5-2.

[0108] Table 5-1 Zeta potential, molecular weight and charge density

[0109]

[0110]

[0111] Table 5-2. Chroma removal rate (%)

[0112]

[0113] Application Example 6:

[0114] Based on Example 1, the addition method of allyltributylphosphonium bromide was changed to a single, rapid addition, resulting in the preparation of a corresponding environmentally friendly polymeric organic flocculant. Subsequently, the environmentally friendly polymeric organic flocculant prepared under these conditions was subjected to zeta potential testing, with the specific test results shown in Table 6-1. Furthermore, the environmentally friendly polymeric organic flocculant prepared under these conditions was used in a treatment experiment simulating reactive blue dye wastewater, and the treatment effects at different dosages (coagulation for 30 minutes and sedimentation for 30 minutes) were examined. The specific treatment results are shown in Table 6-2.

[0115] Table 6-1. Zeta potential, molecular weight and charge density

[0116]

[0117]

[0118] Table 6-2. Chroma removal rate Removal rate (%)

[0119]

[0120] Comparative Example 1 Preparation of Tannin-[2-(Methacryloyloxy)ethyl]trimethylammonium chloride flocculant

[0121] (1) Weigh 1 g of tannic acid powder and dissolve it in 100 mL of deionized water. Adjust the pH to 7 with 0.1 M NaOH and stir thoroughly to mix. Place the resulting solution in a three-necked flask and heat it in a water bath at 50°C. Stir continuously for 30 min.

[0122] (2) After the tannic acid solution was stirred for 20 min, nitrogen was introduced at a high flow rate and continued for 30 min to remove air from the solution. Subsequently, 0.3 g of KPS was dissolved in 10 mL of ultrapure water as an initiator, and the temperature was raised to 70 °C to initiate the reaction.

[0123] (3) Continue to add 1 g of DMC aqueous solution dropwise three times under nitrogen protection and stirring, maintaining nitrogen protection and stirring at 70°C.

[0124] (4) The reaction was continued at 70°C for 4 h.

[0125] (5) Cool to room temperature, precipitate with ethanol, and freeze-dry to obtain a white powder product.

[0126] Comparative Example 2 The flocculant prepared in the comparative example was used to treat simulated dye wastewater (coagulation for 30 min, sedimentation for 30 min), and the treatment effects are listed in Table 7 below.

[0127] Table 7 Chroma removal rate (%)

[0128]

[0129]

[0130] Compared to the coagulation effluent indicators of the comparative flocculant, the environmentally friendly polymer organic flocculant of the present invention, made from tannic acid and quaternary phosphonium salt, showed a significantly higher chroma removal rate, significantly improving the removal rate at the same dosage. The flocculant of the present invention has a higher charge density and a stronger coagulation effect.

[0131] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a polymer organic flocculant, characterized in that: The following steps are involved: Tannic acid and quaternary phosphonium salt are used as raw materials, and addition polymerization reaction is carried out in the presence of an initiator under a protective atmosphere to obtain the high molecular organic flocculant.

2. The preparation method according to claim 1, characterized in that The pH of the addition polymerization reaction is 4-10; and the addition polymerization reaction is subjected to composite ultraviolet irradiation treatment.

3. The preparation method according to claim 1, characterized in that The following steps are involved: In the presence of an initiator in a protective atmosphere, tannic acid and a quaternary phosphonium salt are mixed and reacted at 40-90° C., and then the reaction system is subjected to ultraviolet irradiation treatment; after the ultraviolet irradiation treatment is completed, the reaction system is placed at 40-90° C. for reaction to obtain the polymer organic flocculant.

4. The preparation method according to claim 3, characterized in that The initiator is cerium ammonium nitrate; and the quaternary phosphonium salt is allyltributylphosphonium bromide.

5. The preparation method according to claim 4, characterized in that The mass ratio of the tannic acid to allyltributylphosphonium bromide is 1:(0.5-5).

6. The preparation method according to claim 3, characterized in that The mixing reaction time is 15 min-1 h.

7. The preparation method according to claim 3, characterized in that The intensity of the ultraviolet radiation treatment is 5-50 mw / cm 2 ; The ultraviolet light irradiation treatment time is 10-30min.

8. The preparation method according to claim 3, characterized in that After the ultraviolet irradiation treatment is completed, the reaction time at 40-90° C. is 2-5 hours.

9. The high molecular weight organic flocculant prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the high molecular organic flocculant according to claim 9 in water treatment.

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