A hydrophobic organic-inorganic hybrid flocculant and preparation method thereof

Abstract

The present invention provides a hydrophobic organic-inorganic hybrid flocculant and a preparation method thereof. The flocculant has the following structural formula: The flocculant of the present invention is a hybrid flocculant that can combine the electrical neutralization ability of an inorganic polymer with the adsorption bridging effect of an organic polymer. The organic component and the inorganic component are combined in a covalent bond through the action of a silane coupling agent, and the flocculation performance is stable and good. At the same time, the present invention provides a method for preparing the above flocculant.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to a hydrophobic organic-inorganic hybrid high-efficiency flocculant and a preparation method thereof. Background Art

[0002] The key to using flocculants to treat sewage and condition sludge lies in the selection of flocculants. At present, there are two main types of flocculants used in water treatment: inorganic flocculants and organic flocculants. Inorganic flocculants are mainly polyaluminum and polyiron flocculants, which have the advantages of good coagulation effect, wide application range, strong electrical neutralization ability, low unit price, etc., but they also have many problems such as large dosage, toxic residual metals, and certain corrosion to pipeline equipment. There are many types of inorganic flocculants, usually with a small dosage, fast floc formation speed, and very excellent adsorption and bridging ability, but their electrical neutralization ability is weak and their ability to remove organic matter is poor, especially in the conditioning and dehydration of residual sludge, and they cannot reach the level of deep treatment.

[0003] Organic-inorganic hybrid flocculants not only have uniform inorganic ion dispersion and uniform overall material structure, but also can combine in the form of chemical bonds under appropriate conditions to maintain the stability of the performance of each component, and can also give full play to the synergistic effect between inorganic and organic components to obtain a better flocculation effect than a single flocculant component. And compared with compound flocculants, organic-inorganic hybrid flocculants save the tedious work of finding the optimal compounding ratio for different water qualities. However, the bonding strength between the organic polymer and the inorganic component interface has a significant impact on the flocculation effect. If the strength of the interface bonding is weak, phase separation occurs under strong hydraulic shear, and the performance advantage is lost. At present, most simple physical compound flocculants are usually combined by van der Waals force or hydrogen bond between the components, while inorganic-organic hybrid flocculants connect the organic phase and the inorganic phase by ionic bond or covalent bond through a modifier to achieve molecular-level compounding, improve product stability, and to a certain extent improve the inorganic ion morphology structure and charge distribution, and improve the comprehensive adsorption bridging and electrical neutralization capabilities.

[0004] Organic-inorganic hybrid flocculants are combined by ionic bonding: organic monomers are 2 O 8 2- ) The ionic free radicals decomposed by heat initiate polymerization, and the organic polymer chain segments rely on -SO 4 2- It is connected to the positively charged inorganic components by ionic bonding. Ionic bonds are stronger than hydrogen bonds, and to destroy their structure, higher temperatures and energy are required. However, when the concentration of hybrid flocculants connected by ionic bonds is too low, the -SO 4 2-Ionization will occur, causing the structure of the hybrid polymer product to change and reducing the flocculation stability. Therefore, in order to ensure the stability of the hybrid product system, the interface between the organic phase and the inorganic phase is generally connected by covalent bonds in the prior art.

[0005] Usually, organic polymers are polymerized from acrylamide and cationic monomers, and the cationic degree is difficult to exceed 80%, resulting in weak electrical neutralization ability of organic polymers. However, polymers homopolymerized with dimethyldiallylammonium chloride as a monomer are strong cationic polyelectrolytes with a cationic degree of 100%. Therefore, in recent years, the research on polyaluminium chloride-polydimethyldiallylammonium chloride hybrid flocculants has become a hot topic among scholars.

[0006] In addition, whether it is an inorganic flocculant or an organic polymer, the flocs obtained by flocculation have strong hydrophilicity, and the density of the flocs is difficult to further improve, thereby affecting the dewatering effect of the sludge. Existing technicians have tried to add hydrophobic monomers during the polymerization process of hybrid flocculants. The carbon chain length of the selected hydrophobic monomers is greater than 12 carbons. At a concentration higher than the critical micelle concentration, this type of flocculant will produce intermolecular hydrophobic association, thereby making the viscosity of the aqueous solution much greater than that of ordinary polymers of the same molecular weight. However, in the field of water treatment, the actual use concentration of the flocculant is usually lower than the critical concentration when the hydrophobic association phenomenon occurs, and the hydrophobic association effect cannot be exerted. Therefore, how to obtain an organic-inorganic hybrid flocculant with good hydrophobic effect, good flocculation performance and high floc density by reasonably selecting raw materials is a problem that needs to be solved by technicians in this field. Summary of the invention

[0007] The main purpose of the present invention is to provide a hydrophobic organic-inorganic hybrid flocculant to overcome the deficiencies in the prior art.

[0008] A hydrophobic organic-inorganic hybrid flocculant, the chemical formula of the flocculant is:

[0009]

[0010] Among them, R 1 is an inorganic polymer, R 2 is an organic group, the value of m is 0 to 3, and the value of n is 6 to 10. The value range of x:y is (1.5 to 4): 1. x:y is a molar ratio.

[0011] Preferably, R 1 It is at least one of polyaluminium chloride, polyferric chloride, polyferric sulfate, polyaluminium sulfate and polyaluminium ferric sulfate.

[0012] Preferably, R 2 It is any one of a vinyl group, an epoxy group, an amino group, a methacryloxy group, a mercapto group, an acid anhydride group, and an alkyl group.

[0013] According to a second aspect of an embodiment of the present invention, a method for preparing the above-mentioned hydrophobic organic-inorganic hybrid flocculant is provided.

[0014] A method for preparing a hydrophobic organic-inorganic hybrid flocculant comprises the following steps:

[0015] S1, add 2-8 parts of silane coupling agent, 200-600 parts of inorganic polymer, and 200-600 parts of distilled water into a reaction kettle by mass, pass nitrogen to deoxygenate under stirring, and raise the temperature to 60-90°C, keep the temperature constant for 4-8 hours, and then cool it down to 5-10°C;

[0016] S3, adding 200-600 parts by mass of a mixed solution of dimethyldiallyl ammonium chloride and alkyldimethylallyl ammonium chloride to the reactor, mixing and dissolving them thoroughly, stirring and passing nitrogen to deoxygenate, and then adding 0.1-0.5 parts of a chelating agent and stirring evenly;

[0017] S3, adding 0.1 to 0.5 parts by mass of an initiator to the reactor to initiate polymerization, and after the temperature of the reactor is raised to 50 to 60° C., the temperature is maintained for 2 to 6 hours to obtain a polymer gel;

[0018] S4, cutting and granulating the polymer gel, drying and then crushing to obtain flocculant powder.

[0019] Preferably, the molecular structure of the silane coupling agent is R 3 -(CH 2 ) a -Si-B (3-a) , where a is a value of 0 to 3, R 3 is any organic functional group selected from vinyl, epoxy, amino, methacryloyloxy, mercapto, anhydride, and alkyl, and B is Cl, OCH 3 , OC 2 H 5 , OOCR, NR, any hydrolyzable group.

[0020] Preferably, the inorganic polymer is one or more of polyaluminium chloride, polyferric chloride, polyferric sulfate, polyaluminium sulfate and polyaluminium ferric sulfate.

[0021] Preferably, the alkyl dimethyl allyl ammonium chloride is one or more of hexaalkyl dimethyl allyl ammonium chloride, octaalkyl dimethyl allyl ammonium chloride, and decanyl dimethyl allyl ammonium chloride.

[0022] Preferably, the mass concentration of the mixed solution of dimethyldiallyl ammonium chloride and alkyldimethylallyl ammonium chloride is 65%, and the molar ratio of dimethyldiallyl ammonium chloride to alkyldimethylallyl ammonium chloride in the mixed solution is 1:0.25-0.66.

[0023] Preferably, the chelating agent is a mixture of disodium ethylenediaminetetraacetic acid and diethylenetriaminepenta(methylenephosphonic acid).

[0024] Preferably, the mass ratio of disodium ethylenediaminetetraacetate to diethylenetriaminepenta(methylenephosphonic acid) in the chelating agent is 1:(1.5-3).

[0025] Compared with the prior art, the advantages of the present invention include:

[0026] First, the hydrophobic organic-inorganic hybrid flocculant disclosed in the present invention has a specific molecular structure, and is a hybrid flocculant that can combine the electrical neutralization ability of inorganic polymers (such as polyaluminium chloride, etc.) with the adsorption bridging effect of organic polymers. Among them, the organic component and the inorganic component are combined in a covalent bond through the action of a silane coupling agent, and the flocculation performance is stable and good. At the same time, the flocculant of the present invention has a large number of hydrophobic groups, which can greatly reduce the hydrophilicity of the flocs and tightly bind the flocs. The structure and performance of the flocculant of the present invention can be highly designed. Furthermore, on each molecular chain of the flocculant of the present invention, whether it is the inorganic component part or the organic component part, each polymer repeating unit is cationic, thereby providing cationic charges, so that it has a strong electrical neutralization adsorption ability, and improves the flocculation effect. In the process of sewage treatment and sludge conditioning, especially in the process of residual sludge conditioning, the amount of flocculant added is small, the deep dehydration effect is good, and thus cost reduction and efficiency improvement are achieved.

[0027] Secondly, the present invention discloses a preparation method of the hydrophobic organic-inorganic hybrid flocculant. In the preparation method, polyaluminium chloride, polyferric chloride, polyferric sulfate, polyaluminium sulfate, polyaluminium ferric sulfate are used as inorganic components, disodium ethylenediaminetetraacetate and a mixture of diethylenetriaminepenta(methylenephosphonic acid) are used as chelating agents, potassium sulfate, ammonium persulfate, cerium ammonium nitrate, and azobisisobutylamidine hydrochloride are used as initiators, and dimethyldiallylammonium chloride is polymerized with hexaalkyldimethylallylammonium chloride, octaalkyldimethylallylammonium chloride, and decaalkyldimethylallylammonium chloride, and is combined with the inorganic components by covalent bonds under the action of a silane coupling agent to form a hydrophobic organic-inorganic hybrid high-efficiency flocculant. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0029] Figure 1 It is the Fourier infrared spectrum of the hydrophobic organic-inorganic hybrid flocculant prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0031] The present invention provides a hydrophobic organic-inorganic hybrid high-efficiency flocculant, the structural formula of which is as follows:

[0032]

[0033] Among them, R 1 The inorganic polymer may be at least one of polyaluminium chloride, polyferric chloride, polyferric sulfate, polyaluminium sulfate and polyaluminium ferric sulfate.

[0034] R 2 is an organic group, and the organic group may be any one of a vinyl group, an epoxy group, an amino group, a methacryloxy group, a mercapto group, an acid anhydride, and an alkyl group.

[0035] In addition, the value of m is 0 to 3, and the value of n is 6 to 10. x:y is a molar ratio, and the value range is (1.5 to 4):1.

[0036] The hydrophobic organic-inorganic hybrid flocculant disclosed in the present invention has the above-mentioned specific molecular structure, and is a hybrid flocculant that can combine the electrical neutralization ability of inorganic polymers (such as polyaluminium chloride, etc.) with the adsorption bridging effect of organic polymers. Among them, the organic component and the inorganic component are combined in a covalent bond through the action of a silane coupling agent, and the flocculation performance is stable and good. At the same time, the flocculant of the present invention has a large number of hydrophobic groups, which can greatly reduce the hydrophilicity of the flocs and tightly bind the flocs. The structure and performance of the flocculant of the present invention can be highly designed. Furthermore, on each molecular chain of the flocculant of the present invention, whether it is the inorganic component part or the organic component part, each polymer repeating unit is cationic, thereby providing cationic charges, so that it has a strong electrical neutralization adsorption capacity, and improves the flocculation effect. In the process of sewage treatment and sludge conditioning, especially in the process of residual sludge conditioning, the amount of flocculant added is small, the deep dehydration effect is good, and thus cost reduction and efficiency improvement are achieved.

[0037] The present invention also provides a method for preparing the above-mentioned hydrophobic organic-inorganic hybrid high-efficiency flocculant, which is specifically as follows.

[0038] S1, add 2-8 parts of silane coupling agent, 200-600 parts of inorganic polymer, and 200-600 parts of distilled water into a reaction kettle by mass, pass nitrogen to deoxygenate under stirring, and raise the temperature to 60-90°C, keep the temperature constant for 4-8 hours, and then cool it down to 5-10°C;

[0039] S3, adding 200-600 parts by mass of a mixed solution of dimethyldiallyl ammonium chloride and alkyldimethylallyl ammonium chloride to the reactor, mixing and dissolving them thoroughly, stirring and passing nitrogen to deoxygenate, and then adding 0.1-0.5 parts of a chelating agent and stirring evenly;

[0040] S3, slowly adding 0.1 to 0.5 parts of initiator by mass into the reactor to initiate polymerization, and after the temperature of the reactor is raised to 50 to 60° C., the temperature is maintained for 2 to 6 hours to obtain a polymer gel;

[0041] S4, cutting and granulating the polymer gel, drying and then crushing to obtain flocculant powder.

[0042] Among them, the molecular structure of the silane coupling agent is R 3 -(CH 2 ) a -Si-B (3-a) , where a is a value of 0 to 3, R 3 is any organic functional group selected from vinyl, epoxy, amino, methacryloyloxy, mercapto, anhydride, and alkyl, and B is Cl, OCH 3 , OC 2 H 5, OOCR, NR, etc. A hydrolyzable group. Preferably, the silane coupling agent is one of vinyl trioxy silane, vinyl tri (β-methoxyethoxy) silane, γ-aminopropyl triethoxy silane, γ-(2,3-epoxypropoxy) propyl trimethoxy silane, γ-mercaptopropyl trimethoxy silane, N-(β-aminoethyl)-γ-aminopropyl methyl dimethoxy silane, N-(β-aminoethyl)-γ-aminopropyl trimethoxy silane, and aniline methyl triethoxy silane.

[0043] The inorganic polymer is one or more of polyaluminium chloride, polyferric chloride, polyferric sulfate, polyaluminium sulfate and polyaluminium ferric sulfate.

[0044] The alkyl dimethyl allyl ammonium chloride is one or more of hexaalkyl dimethyl allyl ammonium chloride, octaalkyl dimethyl allyl ammonium chloride, and decaalkyl dimethyl allyl ammonium chloride. Preferably, the mass concentration of the mixed solution of dimethyl diallyl ammonium chloride and alkyl dimethyl allyl ammonium chloride is 65%, and the molar ratio of dimethyl diallyl ammonium chloride to alkyl dimethyl allyl ammonium chloride is 1:0.25-0.66.

[0045] The chelating agent is a mixture of disodium ethylenediaminetetraacetate and diethylenetriaminepenta(methylenephosphonic acid). Preferably, the chelating agent is a mixture of disodium ethylenediaminetetraacetate and diethylenetriaminepenta(methylenephosphonic acid) in a mass ratio of 1:(1.5-3).

[0046] The initiator is one or more of potassium persulfate, ammonium persulfate, ammonium cerium nitrate, and azobisisobutylamidine hydrochloride.

[0047] Example 1

[0048] 3 parts of γ-aminopropyltriethoxysilane, 300 parts of polyaluminium chloride and 300 parts of distilled water were added to the reaction kettle by mass, nitrogen was passed through the reaction kettle for deoxygenation under stirring, and the temperature was raised to 65°C, kept at this temperature for 4 hours, and then lowered to 5°C;

[0049] In the reaction kettle, add 600 parts by mass of a mixed solution of dimethyldiallyl ammonium chloride and hexaalkyldimethylallyl ammonium chloride, wherein the molar ratio of dimethyldiallyl ammonium chloride to hexaalkyldimethylallyl ammonium chloride is 2:1. Mix and dissolve thoroughly, pass nitrogen gas to deoxygenate under stirring, then add 0.1 parts of disodium ethylenediaminetetraacetate and 0.2 parts of diethylenetriaminepenta(methylenephosphonic acid), and stir evenly;

[0050] Slowly add 0.15 parts of azobisisobutylamidine hydrochloride by mass into the reactor to initiate polymerization, and after the temperature of the reactor is raised to 50° C., keep the temperature for 3 hours to obtain a polymer gel;

[0051] The polymer gel is cut into granules, placed in an oven for drying, and crushed to obtain white to light yellow hydrophobic organic-inorganic hybrid flocculant powder.

[0052] See also Figure 1 , Figure 1 This is the Fourier infrared spectrum of the hydrophobic organic-inorganic hybrid flocculant prepared in Example 1. The wave number is 3408.6 cm -1 and 1641.2cm -1 The two obvious characteristic peaks are the stretching vibration peaks of -OH of polyaluminium chloride, with a wave number of 2988.8cm -1 and 1482.3cm -1 The absorption peak of methyl is at 2527.9cm -1 The group is the absorption peak of quaternary ammonium salt, and the wave number is 1641.2cm -1 The group is a double bond stretching vibration peak at a wave number of 611.5 cm -1 The stretching peak at 475.2 cm corresponds to the Al-O bond. -1 The peak at is the absorption peak of O-Si-O, and it can be seen that the organic part is connected to the inorganic component through a covalent bond. This proves that the specific hydrophobic organic-inorganic hybrid flocculant of the present invention is successfully synthesized.

[0053] Please refer to Table 1, the elemental analysis of the product obtained in Example 1 was carried out, and the results were as follows: It can be seen that the actual measured value of the flocculant obtained by the above preparation method has a small deviation from the theoretical value.

[0054] Table 1 Element analysis results of organic-inorganic hybrid flocculants

[0055]

[0056] Example 2

[0057] According to mass parts, 3 parts of vinyltrioxysilane, 400 parts of polyaluminium chloride and 300 parts of distilled water were added into the reaction kettle, nitrogen was passed through the reaction kettle for deoxygenation under stirring, and the temperature was raised to 75°C, kept at this temperature for 5 hours, and then lowered to 10°C;

[0058] In the reaction kettle, add 225 parts by mass of a mixed solution of dimethyldiallyl ammonium chloride and hexaalkyldimethylallyl ammonium chloride, wherein the molar ratio of dimethyldiallyl ammonium chloride to hexaalkyldimethylallyl ammonium chloride is 2.5:1. Mix and dissolve thoroughly, pass nitrogen gas to deoxygenate under stirring, then add 0.1 parts of disodium ethylenediaminetetraacetate and 0.3 parts of diethylenetriaminepenta(methylenephosphonic acid), and stir evenly;

[0059] Slowly add 0.15 parts of potassium persulfate by mass into the reactor to initiate polymerization, and after the temperature of the reactor is raised to 50°C, keep the temperature for 3 hours to obtain a polymer gel;

[0060] The polymer gel is cut into granules, placed in an oven for drying, and crushed to obtain white to light yellow hydrophobic organic-inorganic hybrid flocculant powder.

[0061] Example 3

[0062] 3 parts of γ-mercaptopropyltrimethoxysilane, 400 parts of polyferric chloride, and 300 parts of distilled water were added to the reaction kettle by mass, nitrogen was passed through the reaction kettle for deoxygenation under stirring, and the temperature was raised to 75°C, kept at this temperature for 5 hours, and then lowered to 10°C;

[0063] In the reaction kettle, add 500 parts by mass of a mixed solution of dimethyldiallyl ammonium chloride and hexaalkyldimethylallyl ammonium chloride, wherein the molar ratio of dimethyldiallyl ammonium chloride to hexaalkyldimethylallyl ammonium chloride is 4:1. Mix and dissolve thoroughly, pass nitrogen gas to deoxygenate under stirring, then add 0.1 parts of disodium ethylenediaminetetraacetate and 0.3 parts of diethylenetriaminepenta(methylenephosphonic acid), and stir evenly;

[0064] Slowly add 0.15 parts of potassium persulfate by mass into the reactor to initiate polymerization, and after the temperature of the reactor is raised to 50°C, keep the temperature for 3 hours to obtain a polymer gel;

[0065] The polymer gel is cut into granules, placed in an oven for drying, and crushed to obtain hydrophobic organic-inorganic hybrid flocculant powder.

[0066] Example 4

[0067] 3 parts of γ-mercaptopropyltrimethoxysilane, 600 parts of polyferric sulfate, and 300 parts of distilled water were added to the reaction kettle by mass, nitrogen was passed through the reaction kettle for deoxygenation under stirring, and the temperature was raised to 75°C, kept at this temperature for 5 hours, and then lowered to 10°C;

[0068] In the reaction kettle, add 600 parts by mass of a mixed solution of dimethyldiallyl ammonium chloride and dodecyldimethylallyl ammonium chloride, wherein the molar ratio of dimethyldiallyl ammonium chloride to dodecyldimethylallyl ammonium chloride is 4:1. Mix and dissolve thoroughly, pass nitrogen gas to deoxygenate under stirring, then add 0.1 parts of disodium ethylenediaminetetraacetate and 0.3 parts of diethylenetriaminepenta(methylenephosphonic acid), and stir evenly;

[0069] Slowly add 0.15 parts of potassium persulfate by mass into the reactor to initiate polymerization, and after the system temperature rises to 60°C, keep the temperature for 4 hours to obtain a polymer gel;

[0070] The polymer gel is cut into granules, placed in an oven for drying, and crushed to obtain white to light yellow hydrophobic organic-inorganic hybrid flocculant powder.

[0071] Example 5

[0072] 3 parts of aniline methyl triethoxysilane, 400 parts of polyferric chloride, and 300 parts of distilled water were added to the reaction kettle by mass, nitrogen was passed through the reaction kettle for deoxygenation under stirring, and the temperature was raised to 75°C, kept at this temperature for 5 hours, and then cooled to 10°C;

[0073] In the reaction kettle, add 600 parts by mass of a mixed solution of dimethyldiallyl ammonium chloride and octaalkyldimethylallyl ammonium chloride, wherein the molar ratio of dimethyldiallyl ammonium chloride to octaalkyldimethylallyl ammonium chloride is 2:1. Mix and dissolve thoroughly, pass nitrogen gas to deoxygenate under stirring, then add 0.1 parts of disodium ethylenediaminetetraacetate and 0.3 parts of diethylenetriaminepenta(methylenephosphonic acid), and stir evenly;

[0074] Slowly add 0.15 parts of ammonium persulfate by mass into the reactor to initiate polymerization, and after the temperature of the reactor is raised to 50°C, keep the temperature for 3 hours to obtain a polymer gel;

[0075] The polymer gel is cut into granules, placed in an oven for drying, and crushed to obtain white to light yellow hydrophobic organic-inorganic hybrid flocculant powder.

[0076] Experimental example

[0077] The flocculant products synthesized in the above five embodiments were used to compare the sludge dehydration effect with commercially available polydimethyldiallyl ammonium chloride (PDADMAC), polyaluminium chloride and polyferric sulfate products. The sludge was taken from the residual sludge of Beijing Daoxiang Water Purification Plant. After adding the same amount of flocculant at 3.5kg / t of absolute dry sludge, the sludge was treated with a pressure of about 1.5MPa in the same plate and frame filter press, and the moisture content of the mud cake was compared to compare the sludge dehydration effect of different flocculants. The specific comparison is shown in Table 2.

[0078] Table 2 Water content of mud cake after sludge conditioning with conventional flocculants and the product of the embodiment

[0079]

[0080] It can be seen from Table 2 that the flocculants synthesized in the five embodiments of the present invention have better sludge dewatering effects than similar products on the market.

[0081] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A hydrophobic organic-inorganic hybrid flocculant, characterized in that: The chemical formula of the flocculant is: Among them, R1 is an inorganic polymer, R2 is an organic group, the value of m is 0~3, the value of n is 6~10, and the value range of x:y is (1.5~4):

1.

2. A hydrophobic organic-inorganic hybrid flocculant as claimed in claim 1, characterized in that: The R1 is at least one of polyaluminium chloride, polyferric chloride, polyferric sulfate, polyaluminium sulfate and polyaluminium ferric sulfate.

3. A hydrophobic organic-inorganic hybrid flocculant as claimed in claim 1, characterized in that: The R2 is any one of vinyl, epoxy, amino, methacryloyloxy, mercapto, acid anhydride, and alkyl.

4. A method for preparing a hydrophobic organic-inorganic hybrid flocculant as claimed in claim 1, characterized in that: The steps include: S1, add 2-8 parts of silane coupling agent, 200-600 parts of inorganic polymer, and 200-600 parts of distilled water into a reaction kettle by mass, pass nitrogen to deoxygenate under stirring, and raise the temperature to 60-90°C, keep the temperature constant for 4-8 hours, and then cool it down to 5-10°C; S3, adding 200-600 parts by mass of a mixed solution of dimethyldiallyl ammonium chloride and alkyldimethylallyl ammonium chloride to the reactor, mixing and dissolving them thoroughly, stirring and passing nitrogen to deoxygenate, and then adding 0.1-0.5 parts of a chelating agent and stirring evenly; S3, adding 0.1-0.5 parts of initiator by mass to the reactor to initiate polymerization, and after the temperature of the reactor is raised to 50-60° C., the temperature is maintained for 2-6 hours to obtain a polymer gel; S4, cutting and granulating the polymer gel, drying and then crushing to obtain flocculant powder.

5. A method for preparing a hydrophobic organic-inorganic hybrid flocculant as claimed in claim 4, characterized in that: The molecular structure of the silane coupling agent is R3-(CH2) a -Si-B (3-a) , wherein the value of a is 0-3, R3 is any organic functional group selected from vinyl, epoxy, amino, methacryloyloxy, mercapto, anhydride, and alkyl, and B is any hydrolyzable group selected from Cl, OCH3, OC2H5, OOCR, and NR.

6. A method for preparing a hydrophobic organic-inorganic hybrid flocculant as claimed in claim 4, characterized in that: The inorganic polymer is one or more of polyaluminium chloride, polyferric chloride, polyferric sulfate, polyaluminium sulfate and polyaluminium ferric sulfate.

7. A method for preparing a hydrophobic organic-inorganic hybrid flocculant as claimed in claim 4, characterized in that: The alkyl dimethyl allyl ammonium chloride is one or more of hexaalkyl dimethyl allyl ammonium chloride, octaalkyl dimethyl allyl ammonium chloride, and decanyl dimethyl allyl ammonium chloride.

8. A method for preparing a hydrophobic organic-inorganic hybrid flocculant as claimed in claim 4, characterized in that: The mass concentration of the mixed solution of dimethyldiallyl ammonium chloride and alkyldimethylallyl ammonium chloride is 65%, and the molar ratio of dimethyldiallyl ammonium chloride to alkyldimethylallyl ammonium chloride in the mixed solution is 1:0.25-0.

66.

9. A method for preparing a hydrophobic organic-inorganic hybrid flocculant as claimed in claim 4, characterized in that: The chelating agent is a mixture of disodium ethylenediaminetetraacetate and diethylenetriaminepenta(methylenephosphonic acid).

10. A method for preparing a hydrophobic organic-inorganic hybrid flocculant as claimed in claim 9, characterized in that: The mass ratio of disodium ethylenediaminetetraacetate to diethylenetriaminepenta(methylenephosphonic acid) in the chelating agent is 1:(1.5-3).

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