A method for preparing water treatment agent in collaboration with waste acid and the agent thereof

Abstract

The present invention provides a method for cooperating with waste acid to prepare a water treatment agent, and the agent. The method comprises the following steps: mixing waste acid with iron powder, reacting, and filtering to obtain a ferrous sulfate solution; mixing the ferrous sulfate solution with activated carbon to obtain ferrous sulfate-loaded activated carbon; and uniformly mixing the ferrous sulfate-loaded activated carbon with modified titanium dioxide and modified bentonite. The method of cooperating with waste acid to prepare a water treatment agent improves the resource utilization rate of waste acid by utilizing waste acid, and achieves efficient treatment of industrial printing and dyeing wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, in particular to a method for preparing a water treatment agent in coordination with waste acid and the agent. Background Art

[0002] Industrial waste acid, a type of pollutant produced during the non-ferrous metal smelting process, is highly acidic and complex. In addition to containing high concentrations of sulfuric acid, it also contains various heavy metal ions such as nickel, cadmium, and lead, making it difficult to recycle. Prior art has been able to produce ferrous sulfate by reacting waste acid with iron, which can be used as a coagulant in wastewater treatment. However, the resulting product typically suffers from unstable flocculation, making it difficult to fully utilize the iron ions.

[0003] Industrial printing and dyeing wastewater contains difficult-to-degrade organic matter, high chroma, poor biodegradability, and complex composition. When traditional activated carbon adsorption and other methods are used for treatment, although it has a good effect on removing the chroma in the wastewater and reducing the COD value of the wastewater, the cost of activated carbon is relatively high, and its adsorption effect on dyes with strong hydrophilicity and small molecules is not ideal.

[0004] In view of this, there is an urgent need to propose a water treatment agent to achieve efficient treatment of industrial printing and dyeing wastewater and achieve a good removal effect on dyes with strong hydrophilicity and small molecules. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a water treatment agent in a coordinated manner using polluted acid and the agent thereof, so as to solve the problem that the water treatment agents in the prior art have poor removal effects on dyes with strong hydrophilicity and small molecules in industrial printing and dyeing wastewater.

[0006] The present invention provides the following technical solutions:

[0007] A method for preparing a water treatment agent by cooperating with waste acid comprises the following steps:

[0008] (1) Mixing the dirty acid with iron powder, reacting, and filtering to obtain a ferrous sulfate solution;

[0009] (2) mixing the ferrous sulfate solution in step (1) with activated carbon to obtain activated carbon loaded with ferrous sulfate;

[0010] (3) uniformly mixing the activated carbon loaded with ferrous sulfate in step (2) with modified titanium dioxide and modified bentonite to obtain;

[0011] Wherein, the modified titanium dioxide is obtained by the following method:

[0012] Adding γ-aminopropyltriethoxysilane to titanium dioxide to obtain amino titanium dioxide;

[0013] The amination titanium dioxide is mixed with 3,6-thioanthracene diamine, decanediamine, and hexamethylene diisocyanate to obtain modified titanium dioxide after reaction;

[0014] The modified bentonite is obtained by the following method:

[0015] Sodium bentonite and allyl triethylammonium bromide are mixed evenly to react to obtain intercalated bentonite, and then pentene sulfonamide and an initiator are added to the mixture to react to obtain modified bentonite.

[0016] Preferably, in step (2), the ferrous sulfate solution and activated carbon are mixed in a weight ratio of (5-10):100;

[0017] Optionally, in the ferrous sulfate solution, the concentration of ferrous sulfate is 0.1-1 mol / L.

[0018] Preferably, in step (3), the titanium dioxide is iron-doped titanium dioxide, which is obtained by the following method:

[0019] The titanium dioxide precursor solution is mixed with an acid solution of iron ions, reacted, and calcined to obtain iron-doped titanium dioxide;

[0020] Optionally, the titanium dioxide precursor solution is formed by mixing tetrabutyl titanate and ethanol in a volume ratio of (1-3):10; or, the titanium dioxide precursor solution is formed by mixing isopropyl titanate and ethanol in a volume ratio of (1-3):10;

[0021] Optionally, the acid solution of iron ions is a nitric acid solution of ferric chloride, with a pH value of 1-3 and an iron ion concentration of 50-80 mmol / L;

[0022] Optionally, the volume ratio of the titanium dioxide precursor solution to the iron ion acid solution is (15-35):1.

[0023] Preferably, in step (3), the titanium dioxide is iron-doped titanium dioxide, which is obtained by the following method:

[0024] The titanium dioxide precursor solution is added dropwise to the acid solution of iron ions, stirred and reacted at 25-45°C for 2-8 hours, then heated to 120-160°C and reacted for 10-20 hours, and calcined at 400-600°C for 2-4 hours to obtain iron-doped titanium dioxide.

[0025] Preferably, the modified titanium dioxide is obtained by the following method:

[0026] Dispersing the titanium dioxide in toluene, adding γ-aminopropyltriethoxysilane, reacting at 50-60° C. for 6-10 hours, filtering, washing, and drying to obtain amino titanium dioxide;

[0027] The amino titanium dioxide, 3,6-thioanthracene diamine and decanediamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 60-80° C. for 6-12 hours to obtain modified titanium dioxide.

[0028] Preferably, the weight ratio of titanium dioxide, γ-aminopropyltriethoxysilane, and toluene is 1: (0.6-0.8): (30-50);

[0029] Optionally, the weight ratio of the amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine, and hexamethylene diisocyanate is 1: (0.8-1.5): (0.01-0.05): (1.0-1.2);

[0030] Optionally, the concentration of the amino titanium dioxide in the N,N-dimethylformamide is 1.5-3.0 wt %.

[0031] Preferably, β-cyclodextrin is further dispersed in the N,N-dimethylformamide; and the weight ratio of the β-cyclodextrin to the amino titanium dioxide is (0.01-0.05):1.

[0032] Preferably, the modified bentonite is obtained by the following method: sodium bentonite, allyl triethylammonium bromide and water are mixed uniformly, stirred and reacted at 40-60° C. for 2-6 hours to obtain intercalated bentonite, and then pentene sulfonamide and an initiator are added thereto, stirred and reacted at 50-70° C. for 2-3 hours to obtain modified bentonite;

[0033] Optionally, the weight ratio of the sodium bentonite, allyltriethylammonium bromide, water, pentenesulfonamide, and initiator is 100:(5-10):(300-500):(2-8):(0.5-1.5);

[0034] Optionally, the initiator is azobisisobutyronitrile.

[0035] Optionally, the modified bentonite is obtained by the following method: sodium bentonite, allyl triethylammonium bromide, and water are mixed uniformly, stirred and reacted at 40-60° C. for 2-6 hours to obtain intercalated bentonite, and then pentenesulfonamide, 4-(vinyloxy)benzenesulfonamide, and an initiator are added thereto, stirred and reacted at 50-70° C. for 2-3 hours to obtain modified bentonite;

[0036] The weight ratio of the 4-(vinyloxy)benzenesulfonamide to the pentenesulfonamide is 1:(30-50).

[0037] Preferably, in step (3), the weight ratio of the activated carbon loaded with ferrous sulfate to the modified titanium dioxide and modified bentonite is 1:(2-8):(10-30).

[0038] The present invention provides a water treatment agent, which is obtained by the method for preparing the water treatment agent by cooperating with the waste acid.

[0039] The above solution of the present invention includes at least the following beneficial effects:

[0040] (1) The method of the present invention for the synergistic preparation of water treatment agents using waste acid comprises the following steps: mixing waste acid with iron powder, reacting, filtering, and obtaining a ferrous sulfate solution; mixing the ferrous sulfate solution with activated carbon to obtain activated carbon loaded with ferrous sulfate; and uniformly mixing the activated carbon loaded with ferrous sulfate with modified titanium dioxide and modified bentonite. The method of the present invention for the synergistic preparation of water treatment agents using waste acid improves the resource utilization rate of waste acid by utilizing waste acid, and achieves efficient treatment of industrial printing and dyeing wastewater. The present invention achieves efficient treatment of industrial printing and dyeing wastewater by utilizing the synergistic effects of physical adsorption, inorganic coagulation, organic flocculation, and catalytic oxidation through the mutual coordination of activated carbon loaded with ferrous sulfate, modified titanium dioxide, and modified bentonite, and achieves a good removal effect on dyes with strong hydrophilicity and small molecules.

[0041] The activated carbon loaded with ferrous sulfate of the present invention, with ferrous sulfate as an inorganic coagulant and activated carbon as an adsorbent, can remove pollutants such as dye molecules and heavy metal ions in industrial printing and dyeing wastewater. Loading ferrous sulfate on activated carbon can achieve slow release of ferrous sulfate, achieve long-term and stable treatment during continuous treatment, greatly improve the utilization rate of the reagent, and have strong adaptability in the case of large fluctuations in water quality, which can prevent Fe 2+ / Fe 3+ to prevent the pollution from exceeding the standard and reduce the risk of secondary pollution.

[0042] The modified titanium dioxide described in the present invention is obtained by the following method: adding γ-aminopropyltriethoxysilane to titanium dioxide to obtain amino titanium dioxide; mixing the amino titanium dioxide with 3,6-thioanthracene diamine, decanediamine, and hexamethylene diisocyanate, and reacting to obtain the modified titanium dioxide. The modified titanium dioxide is first grafted with amino groups on the surface of the titanium dioxide using γ-aminopropyltriethoxysilane, and then the isocyanate in the hexamethylene diisocyanate undergoes interfacial polymerization with the amino groups to form urea bonds. The amino groups grafted onto the titanium dioxide, the amino groups of the 3,6-thioanthracene diamine, and the amino groups of the decanediamine are cross-linked to form a polymer network that is anchored to the titanium dioxide surface.

[0043] The porous structure of the polymer network of the modified titanium dioxide can physically adsorb pollutants in printing and dyeing wastewater, and the titanium dioxide can play a photocatalytic role to degrade organic pollutants. The thioanthracene ring anchored on the surface of the titanium dioxide acts as a π-π conjugated structure, which can adsorb structures such as the aromatic ring of the dye molecule in the printing and dyeing wastewater under the action of π-π stacking; At the same time, the conjugated structure it has can provide strong electron-withdrawing ability and electron delocalization characteristics, which can promote the separation of photogenerated electron-hole pairs, expand the light response range of titanium dioxide, and improve the photocatalytic degradation efficiency of titanium dioxide for organic pollutants. In addition, the sulfur atom of the thioanthracene ring contains two pairs of lone pairs of electrons and has a low electronegativity, which is easy to participate in free radical reactions and can attack the chromophore of the dye, causing it to break and decompose into small molecules. The rigid conjugated structure of the thioanthracene ring makes it difficult to decompose when participating in free radical reactions, thereby achieving more sustained and stable high-efficiency decolorization.

[0044] The modified titanium dioxide is rich in urea bonds, which connect the dispersed functional groups through strong covalent bonds and introduce flexible segments through decanediamine to form a rigid-flexible alternating network structure. The segments can bend and stretch to adapt to the spatial configuration of the dye molecules, which is not only conducive to the function of the thioanthracene ring, but also conducive to the adsorption and enrichment of dye particles by the urea group through hydrogen bonding, thereby forming micro-floc aggregates, which are then connected into large flocs through bridging to accelerate sedimentation. In particular, small molecule dyes with good hydrophilicity are easily dissociated into ionic states in water due to their small size and strong polarity, making them difficult to remove. The urea group has a strong hydrogen bonding effect. The amino group of the urea group can act as a hydrogen bond donor, and the carbonyl group can act as a hydrogen bond acceptor. Multi-site hydrogen bonding can be generated with the small molecule dye with good hydrophilicity, thereby improving its adsorption selectivity.

[0045] The modified bentonite of the present invention is obtained by the following method: sodium bentonite and allyltriethylammonium bromide are uniformly mixed, reacted to obtain intercalated bentonite, and then pentenesulfonamide and an initiator are added to the mixture to obtain the modified bentonite after reaction. The main component of the sodium bentonite is layered silicate, and sodium ions are located between the layers. When allyltriethylammonium bromide is added, the quaternary ammonium salt and the sodium ions are exchanged, and the allyltriethylammonium bromide is inserted between the layers through electrostatic interaction, thereby increasing the interlayer spacing. Then, through the reaction of pentenesulfonamide and allyltriethylammonium bromide, sulfonamide groups are introduced between the layers of the modified bentonite.

[0046] Sodium bentonite has a low adsorption capacity and good hydrophilicity, and easily forms a colloidal suspension that is difficult to settle or flocculate in water. The modified bentonite increases adsorption sites through intercalation treatment, which can greatly improve its adsorption capacity. More importantly, after modification, the hydrophobic carbon chain formed by allyltriethylammonium bromide and pentenesulfonamide causes the bentonite to form a hydrophobic interface. The sulfonamide group has a good adsorption effect on phenolic organic compounds, carboxylic organic compounds, etc., which can greatly improve treatment efficiency. By replacing activated carbon with the modified bentonite, the amount of activated carbon used can be greatly reduced, reducing costs.

[0047] (2) In the method for preparing a water treatment agent in a synergistic manner using waste acid according to the present invention, β-cyclodextrin is added during the preparation of the modified titanium dioxide. β-cyclodextrin is cyclic and has the characteristics of being hydrophilic on the outside and hydrophobic on the inside. When the amino titanium dioxide, 3,6-thioanthracene diamine, and decanediamine are dispersed in N,N-dimethylformamide, the addition of β-cyclodextrin can regulate the orderly arrangement of the three. After reacting with hexamethylene diisocyanate, the microstructure of the product is optimized, thereby improving the treatment effect of the obtained water treatment agent. DETAILED DESCRIPTION

[0048] In the examples of the present invention, if specific conditions are not specified, the experiments were carried out under conventional conditions or the conditions recommended by the manufacturer. Reagents or instruments used without specifying the manufacturer are all commercially available conventional products. Raw materials of different manufacturers and types do not affect the implementation of the technical solutions of the present invention and the achievement of the technical effects.

[0049] In the following examples, the 3,6-thioanthracene diamine has the following structural formula:

[0050]

[0051] The decanediamine has the following structural formula:

[0052]

[0053] The 4-(vinyloxy)benzenesulfonamide has the following structural formula:

[0054]

[0055] The CAS number of the pentenesulfonamide is 245368-50-7, and it has the following structural formula:

[0056]

[0057] The CAS number of the allyltriethylammonium bromide is 29443-23-0.

[0058] The above raw materials are commercially available products and can be purchased.

[0059] Example 1

[0060] The method of preparing a water treatment agent in a coordinated manner using waste acid in this embodiment comprises the following steps:

[0061] (1) Mixing the dirty acid with iron powder, reacting, and filtering to obtain a ferrous sulfate solution;

[0062] It should be noted that the theoretical molar ratio of sulfuric acid in the waste acid to the iron powder is 1:1. The amount of iron powder added can be determined according to the sulfuric acid content in the waste acid, as long as the sulfuric acid can be completely or substantially consumed.

[0063] (2) mixing the ferrous sulfate solution in step (1) with activated carbon to obtain activated carbon loaded with ferrous sulfate;

[0064] The ferrous sulfate solution and activated carbon are mixed in a weight ratio of 5:100; and the concentration of ferrous sulfate in the ferrous sulfate solution is 0.5 mol / L.

[0065] (3) The activated carbon loaded with ferrous sulfate in step (2) is uniformly mixed with modified titanium dioxide and modified bentonite in a weight ratio of 1:2:20 to obtain the product.

[0066] In this embodiment, the modified titanium dioxide is obtained by the following method:

[0067] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 50°C for 8 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0068] The amino titanium dioxide, 3,6-thioanthracene diamine and decanediamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 60° C. for 8 hours to obtain modified titanium dioxide.

[0069] Among them, the weight ratio of the titanium dioxide, γ-aminopropyltriethoxysilane, and toluene is 1:0.6:40; the weight ratio of the amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine, and hexamethylene diisocyanate is 1:1.2:0.03:1.0; and the concentration of the amino titanium dioxide in the N,N-dimethylformamide is 2.4wt%.

[0070] In this embodiment, the modified bentonite is obtained by the following method:

[0071] Sodium bentonite, allyl triethylammonium bromide and water were mixed evenly, stirred and reacted at 40°C for 6 hours to obtain intercalated bentonite, and then pentene sulfonamide and initiator were added thereto, stirred and reacted at 50°C for 3 hours to obtain modified bentonite;

[0072] The weight ratio of the sodium bentonite, allyltriethylammonium bromide, water, pentenesulfonamide and initiator is 100:5:400:2:1.0; and the initiator is azobisisobutyronitrile.

[0073] Example 2

[0074] The method of preparing a water treatment agent in a coordinated manner using waste acid in this embodiment comprises the following steps:

[0075] (1) Mixing the dirty acid with iron powder, reacting, and filtering to obtain a ferrous sulfate solution;

[0076] (2) mixing the ferrous sulfate solution in step (1) with activated carbon to obtain activated carbon loaded with ferrous sulfate;

[0077] The ferrous sulfate solution and activated carbon are mixed in a weight ratio of 10:100; and the concentration of ferrous sulfate in the ferrous sulfate solution is 1 mol / L.

[0078] (3) The activated carbon loaded with ferrous sulfate in step (2) is uniformly mixed with modified titanium dioxide and modified bentonite in a weight ratio of 1:5:30 to obtain the product.

[0079] In this embodiment, the modified titanium dioxide is obtained by the following method:

[0080] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 60°C for 10 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0081] The amino titanium dioxide, 3,6-thioanthracene diamine and decanediamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 80° C. for 12 hours to obtain modified titanium dioxide.

[0082] Among them, the weight ratio of the titanium dioxide, γ-aminopropyltriethoxysilane, and toluene is 1:0.7:50; the weight ratio of the amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine, and hexamethylene diisocyanate is 1:0.8:0.05:1.2; and the concentration of the amino titanium dioxide in the N,N-dimethylformamide is 3.0wt%.

[0083] In this embodiment, the modified bentonite is obtained by the following method:

[0084] Sodium bentonite, allyl triethylammonium bromide and water were mixed evenly, stirred and reacted at 60°C for 4 hours to obtain intercalated bentonite, and then pentene sulfonamide and initiator were added thereto, stirred and reacted at 70°C for 3 hours to obtain modified bentonite;

[0085] The weight ratio of the sodium bentonite, allyltriethylammonium bromide, water, pentenesulfonamide and initiator is 100:10:500:8:1.5; and the initiator is azobisisobutyronitrile.

[0086] Example 3

[0087] The method of preparing a water treatment agent in a coordinated manner using waste acid in this embodiment comprises the following steps:

[0088] (1) Mixing the dirty acid with iron powder, reacting, and filtering to obtain a ferrous sulfate solution;

[0089] (2) mixing the ferrous sulfate solution in step (1) with activated carbon to obtain activated carbon loaded with ferrous sulfate;

[0090] The ferrous sulfate solution and activated carbon are mixed in a weight ratio of 8:100; and the concentration of ferrous sulfate in the ferrous sulfate solution is 0.1 mol / L.

[0091] (3) The activated carbon loaded with ferrous sulfate in step (2) is uniformly mixed with modified titanium dioxide and modified bentonite in a weight ratio of 1:8:10 to obtain the product.

[0092] In this embodiment, the modified titanium dioxide is obtained by the following method:

[0093] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 55°C for 6 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0094] The amino titanium dioxide, 3,6-thioanthracene diamine and decanediamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 70° C. for 6 hours to obtain modified titanium dioxide.

[0095] Among them, the weight ratio of the titanium dioxide, γ-aminopropyltriethoxysilane, and toluene is 1:0.8:30; the weight ratio of the amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine, and hexamethylene diisocyanate is 1:1.5:0.01:1.1; and the concentration of the amino titanium dioxide in the N,N-dimethylformamide is 1.5wt%.

[0096] In this embodiment, the modified bentonite is obtained by the following method:

[0097] Sodium bentonite, allyl triethylammonium bromide and water were mixed evenly, stirred and reacted at 50°C for 2 hours to obtain intercalated bentonite, and then pentene sulfonamide and initiator were added thereto, stirred and reacted at 60°C for 2 hours to obtain modified bentonite;

[0098] The weight ratio of the sodium bentonite, allyltriethylammonium bromide, water, pentenesulfonamide and initiator is 100:8:300:5:0.5; and the initiator is azobisisobutyronitrile.

[0099] Example 4

[0100] The method of preparing a water treatment agent in a coordinated manner using waste acid in this embodiment comprises the following steps:

[0101] (1) Mixing the dirty acid with iron powder, reacting, and filtering to obtain a ferrous sulfate solution;

[0102] (2) mixing the ferrous sulfate solution in step (1) with activated carbon to obtain activated carbon loaded with ferrous sulfate;

[0103] The ferrous sulfate solution and activated carbon are mixed in a weight ratio of 8:100; and the concentration of ferrous sulfate in the ferrous sulfate solution is 0.8 mol / L.

[0104] (3) The activated carbon loaded with ferrous sulfate in step (2) is uniformly mixed with modified titanium dioxide and modified bentonite in a weight ratio of 1:6:18 to obtain the product.

[0105] In this embodiment, the modified titanium dioxide is obtained by the following method:

[0106] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 50°C for 10 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0107] The amino titanium dioxide, 3,6-thioanthracene diamine and decanediamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 70° C. for 10 hours to obtain modified titanium dioxide.

[0108] Among them, the weight ratio of the titanium dioxide, γ-aminopropyltriethoxysilane, and toluene is 1:0.7:50; the weight ratio of the amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine, and hexamethylene diisocyanate is 1:1.2:0.04:1.0; and the concentration of the amino titanium dioxide in the N,N-dimethylformamide is 1.8wt%.

[0109] In this embodiment, the modified bentonite is obtained by the following method:

[0110] Sodium bentonite, allyl triethylammonium bromide and water were mixed evenly, stirred and reacted at 50°C for 5 hours to obtain intercalated bentonite, and then pentene sulfonamide and initiator were added thereto, stirred and reacted at 50°C for 3 hours to obtain modified bentonite;

[0111] The weight ratio of the sodium bentonite, allyltriethylammonium bromide, water, pentenesulfonamide and initiator is 100:8:500:3:0.8; and the initiator is azobisisobutyronitrile.

[0112] Example 5

[0113] The method for preparing a water treatment agent by cooperating with waste acid in this embodiment is the same as that in Example 4, except that the titanium dioxide is replaced by iron-doped titanium dioxide.

[0114] In this embodiment, the iron-doped titanium dioxide is obtained by the following method:

[0115] The titanium dioxide precursor solution was added dropwise to the acid solution of iron ions, stirred and reacted at 25°C for 2 hours, then heated to 140°C and reacted for 10 hours, and calcined at 400°C for 3 hours to obtain iron-doped titanium dioxide.

[0116] The titanium dioxide precursor solution is a mixture of isopropyl titanate and ethanol in a volume ratio of 1:10. The iron ion acid solution is a nitric acid solution of ferric chloride with a pH of 1 and an iron ion concentration of 80 mmol / L. The volume ratio of the titanium dioxide precursor solution to the iron ion acid solution is 15:1.

[0117] Example 6

[0118] The method for preparing a water treatment agent by cooperating with waste acid in this embodiment is the same as that in Example 4, except that the titanium dioxide is replaced by iron-doped titanium dioxide.

[0119] In this embodiment, the iron-doped titanium dioxide is obtained by the following method:

[0120] The titanium dioxide precursor solution was added dropwise to the acid solution of iron ions, stirred and reacted at 45°C for 8 hours, then heated to 160°C and reacted for 20 hours, and calcined at 600°C for 2 hours to obtain iron-doped titanium dioxide.

[0121] The titanium dioxide precursor solution is a mixture of tetrabutyl titanate and ethanol in a volume ratio of 2:10. The iron ion acid solution is a nitric acid solution of ferric chloride with a pH of 3 and an iron ion concentration of 50 mmol / L. The volume ratio of the titanium dioxide precursor solution to the iron ion acid solution is 35:1.

[0122] Example 7

[0123] The method for preparing a water treatment agent by cooperating with waste acid in this embodiment is the same as that in Example 4, except that the titanium dioxide is replaced by iron-doped titanium dioxide.

[0124] In this embodiment, the iron-doped titanium dioxide is obtained by the following method:

[0125] The titanium dioxide precursor solution was added dropwise to the acid solution of iron ions, stirred and reacted at 30°C for 5 hours, then heated to 120°C and reacted for 12 hours, and calcined at 550°C for 4 hours to obtain iron-doped titanium dioxide.

[0126] The titanium dioxide precursor solution is a mixture of tetrabutyl titanate and ethanol in a volume ratio of 3:10. The iron ion acid solution is a nitric acid solution of ferric chloride with a pH of 2 and an iron ion concentration of 65 mmol / L. The volume ratio of the titanium dioxide precursor solution to the iron ion acid solution is 26:1.

[0127] Example 8

[0128] The method for co-preparing a water treatment agent with waste acid in this embodiment is the same as that in Example 7, except that: during the preparation of the modified titanium dioxide, β-cyclodextrin is also dispersed in the N,N-dimethylformamide; and the weight ratio of the β-cyclodextrin to the amino titanium dioxide is 0.01:1.

[0129] In this embodiment, the modified titanium dioxide is obtained by the following method:

[0130] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 50°C for 10 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0131] The amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine and β-cyclodextrin are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise with stirring, and the mixture is reacted at 70° C. for 10 hours. After the reaction, the mixture is filtered, washed with water and dried to obtain modified titanium dioxide.

[0132] Example 9

[0133] The method for co-preparing a water treatment agent with waste acid in this embodiment is the same as that in Example 7, except that: during the preparation of the modified titanium dioxide, β-cyclodextrin is also dispersed in the N,N-dimethylformamide; and the weight ratio of the β-cyclodextrin to the amino titanium dioxide is 0.05:1.

[0134] In this embodiment, the modified titanium dioxide is obtained by the following method:

[0135] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 50°C for 10 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0136] The amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine and β-cyclodextrin are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise with stirring, and the mixture is reacted at 70° C. for 10 hours. After the reaction, the mixture is filtered, washed with water and dried to obtain modified titanium dioxide.

[0137] Example 10

[0138] The method for co-preparing a water treatment agent with waste acid in this embodiment is the same as that in Example 7, except that: during the preparation of the modified titanium dioxide, β-cyclodextrin is also dispersed in the N,N-dimethylformamide; and the weight ratio of the β-cyclodextrin to the amino titanium dioxide is 0.03:1.

[0139] In this embodiment, the modified titanium dioxide is obtained by the following method:

[0140] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 50°C for 10 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0141] The amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine and β-cyclodextrin are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise with stirring, and the mixture is reacted at 70° C. for 10 hours. After the reaction, the mixture is filtered, washed with water and dried to obtain modified titanium dioxide.

[0142] Example 11

[0143] The method for preparing a water treatment agent using waste acid in this embodiment is the same as that in Example 10, except that 4-(vinyloxy)benzenesulfonamide is added during the preparation of the modified bentonite. The weight ratio of 4-(vinyloxy)benzenesulfonamide to the modified bentonite is 1:30.

[0144] In this embodiment, the modified bentonite is obtained by the following method:

[0145] Sodium bentonite, allyl triethylammonium bromide and water were mixed evenly, stirred and reacted at 40°C for 4 hours to obtain intercalated bentonite, and then pentenesulfonamide, 4-(vinyloxy)benzenesulfonamide and initiator were added thereto, stirred and reacted at 50°C for 2 hours to obtain modified bentonite.

[0146] Example 12

[0147] The method for preparing a water treatment agent using waste acid in this embodiment is the same as that in Example 10, except that 4-(vinyloxy)benzenesulfonamide is added during the preparation of the modified bentonite. The weight ratio of 4-(vinyloxy)benzenesulfonamide to pentenesulfonamide is 1:50.

[0148] In this embodiment, the modified bentonite is obtained by the following method:

[0149] Sodium bentonite, allyl triethylammonium bromide and water were mixed evenly, stirred and reacted at 60°C for 2 hours to obtain intercalated bentonite, and then pentenesulfonamide, 4-(vinyloxy)benzenesulfonamide and initiator were added thereto, stirred and reacted at 70°C for 3 hours to obtain modified bentonite.

[0150] Example 13

[0151] The method for preparing a water treatment agent using waste acid in this embodiment is the same as that in Example 10, except that 4-(vinyloxy)benzenesulfonamide is added during the preparation of the modified bentonite. The weight ratio of 4-(vinyloxy)benzenesulfonamide to pentenesulfonamide is 1:40.

[0152] In this embodiment, the modified bentonite is obtained by the following method:

[0153] Sodium bentonite, allyl triethylammonium bromide and water were mixed evenly, stirred and reacted at 50°C for 6 hours to obtain intercalated bentonite, and then pentenesulfonamide, 4-(vinyloxy)benzenesulfonamide and initiator were added thereto, stirred and reacted at 60°C for 2 hours to obtain modified bentonite.

[0154] Comparative Example 1

[0155] The method for preparing a water treatment agent by cooperating with waste acid in this comparative example is the same as that in Example 4, except that step (3) is not included, and the activated carbon loaded with ferrous sulfate obtained in step (2) is used as the product.

[0156] Comparative Example 2

[0157] The method for preparing a water treatment agent in a coordinated manner using waste acid in this comparative example is the same as that in Example 4, with the only difference being that the modified titanium dioxide is not included in step (3).

[0158] Comparative Example 3

[0159] The method for preparing a water treatment agent in a coordinated manner using waste acid in this comparative example is the same as that in Example 4, except that the modified bentonite is not included in step (3).

[0160] Comparative Example 4

[0161] The method for preparing a water treatment agent in a coordinated manner using waste acid in this comparative example is the same as that in Example 4, with the only difference being that in step (3), the modified titanium dioxide is replaced by titanium dioxide.

[0162] Comparative Example 5

[0163] The method for preparing a water treatment agent in a coordinated manner using waste acid in this comparative example is the same as that in Example 4, with the only difference being that in step (3), the modified bentonite is replaced with sodium bentonite.

[0164] Comparative Example 6

[0165] The method for preparing a water treatment agent in a coordinated manner using waste acid in this comparative example is the same as that in Example 4, with the only difference being that in step (3), the modified titanium dioxide is prepared by a different method, and the titanium dioxide is directly used for polymerization without amino treatment.

[0166] In this comparative example, the modified titanium dioxide is obtained specifically by the following method:

[0167] Titanium dioxide, 3,6-thioanthracene diamine, and decanediamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 70° C. for 10 hours to obtain modified titanium dioxide.

[0168] Comparative Example 7

[0169] The method for preparing a water treatment agent in a coordinated manner using waste acid in this comparative example is the same as that in Example 4, with the only difference being that in step (3), the preparation method of the modified titanium dioxide is different, and the 3,6-thioanthracene diamine is not added for the polymerization reaction.

[0170] The modified titanium dioxide is specifically obtained by the following method:

[0171] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 50°C for 10 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0172] The amino titanium dioxide and decanediamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 70° C. for 10 hours to obtain modified titanium dioxide.

[0173] Comparative Example 8

[0174] The method for preparing a water treatment agent in a coordinated manner using waste acid in this comparative example is the same as that in Example 4, with the only difference being that in step (3), the preparation method of the modified titanium dioxide is different, and the 3,6-thioanthracene diamine is replaced by 2,6-diaminoanthracene.

[0175] The 2,6-diaminoanthracene has the structure shown below:

[0176]

[0177] Comparative Example 9

[0178] The method for preparing a water treatment agent in coordination with waste acid in this comparative example is the same as that in Example 4, with the only difference being that in step (3), the preparation method of the modified titanium dioxide is different, and the decanediamine is not added for the polymerization reaction.

[0179] The modified titanium dioxide is specifically obtained by the following method:

[0180] Titanium dioxide was dispersed in toluene, γ-aminopropyltriethoxysilane was added, and the mixture was reacted at 50°C for 10 hours, filtered, washed, and dried to obtain amino titanium dioxide;

[0181] The amino titanium dioxide and 3,6-thioanthracene diamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 70° C. for 10 hours to obtain modified titanium dioxide.

[0182] Comparative Example 10

[0183] The method for preparing a water treatment agent in a coordinated manner using waste acid in this comparative example is the same as that in Example 4, with the only difference being that in step (3), the modified bentonite is prepared by a different method and is not subjected to intercalation treatment.

[0184] The modified bentonite is specifically obtained by the following method:

[0185] Sodium bentonite and water were mixed evenly, stirred and reacted at 50° C. for 5 h, and then pentenesulfonamide and initiator were added thereto, stirred and reacted at 50° C. for 3 h to obtain modified bentonite.

[0186] Comparative Example 11

[0187] The method for preparing a water treatment agent in a coordinated manner with waste acid in this comparative example is the same as that in Example 4, with the only difference being that in step (3), the modified bentonite is prepared by a different method, namely, intercalated bentonite, and does not react with pentenesulfonamide.

[0188] The modified bentonite is specifically obtained by the following method:

[0189] Sodium bentonite, allyl triethylammonium bromide and water were mixed evenly, and stirred at 50° C. for 5 h to obtain intercalated bentonite.

[0190] Effect Experiment Example

[0191] In order to verify the technical effect of the method for preparing water treatment agents in a coordinated manner using waste acid according to the present invention, the following experiments were conducted:

[0192] The water treatment agent prepared by the method of cooperating with the waste acid obtained in Examples 1-13 and Comparative Examples 1-11 was added to industrial printing and dyeing wastewater at a dosage of 1 g / L. Under visible light radiation conditions (filter cutoff wavelength of λ>420 nm), aeration and stirring were carried out for 1 hour. The CODcr, BOD5, turbidity and chromaticity in the treated water were measured, and the removal rates of CODcr, BOD5, turbidity and chromaticity were calculated.

[0193] Methylene blue, acid red G, and sulfide blue CV were prepared as 100 mg / L aqueous solutions, 10 mg / L aqueous solutions, and 60 mg / L aqueous solutions, respectively, as the water samples to be treated. A water treatment agent prepared using the method for preparing a water treatment agent using waste acid as described in Examples 1-13 and Comparative Examples 1-11 was added to the water samples at a dosage of 1 g / L. The water samples were aerated and stirred for 1 hour under visible light irradiation (with a filter cutoff wavelength of λ > 420 nm). The concentration of each dye molecule in the treated water was measured, and the removal rate was calculated.

[0194] After testing, the results are as follows:

[0195]

[0196] According to the above results, the method for preparing water treatment agents by synergistic use of polluted acid described in the present invention utilizes the synergistic effects of physical adsorption, inorganic coagulation, organic flocculation, and catalytic oxidation to achieve efficient treatment of industrial printing and dyeing wastewater, and achieves good removal effects on dyes with strong hydrophilicity and smaller molecules.

[0197] According to the results of Examples 1-4 and 5-7, when the raw material titanium dioxide of the modified titanium dioxide is replaced with iron-doped titanium dioxide, the resulting agent, when treating industrial printing and dyeing wastewater, has different degrees of improvement in CODcr removal rate, BOD5 removal rate, and chroma removal rate, while the turbidity removal rate is slightly reduced or basically stable. The removal effect of methylene blue, acid red G, and sulfide blue CV is also improved to a certain extent. This is because the introduction of iron into the lattice of iron-doped titanium dioxide increases the photocatalytic activity, which is beneficial to the decomposition and removal of organic pollutants.

[0198] According to the results of Example 7 and Example 8-10, beta-cyclodextrin, as a template added in the process of preparing the modified titanium dioxide, can regulate the microstructure of the modified titanium dioxide and have an impact on the distribution of functional groups. Therefore, the removal rates of CODcr, BOD5, turbidity, and chromaticity are all significantly improved, especially BOD5 and turbidity, which are significantly improved. This is because the distribution of the thioanthracene ring and urea group not only affects the process of photocatalytic degradation, but also affects the performance of flocculation. The removal rates of methylene blue, acid red G, and sulfide blue CV are improved to varying degrees, among which the removal effect of acid red G is significantly improved, while methylene blue and sulfide blue CV are only slightly improved. This may be because acid red G is an anionic dye with good hydrophilicity and small molecular weight, and the arrangement of groups such as urea bonds of the modified titanium dioxide and the flexible chain can be more exposed under the action of beta-cyclodextrin, as adsorption sites, greatly improving the adsorption selectivity of acid red G. Methylene blue is a cationic dye with good hydrophilicity and low molecular weight, so it is relatively less affected. Sulfur blue CV is an anionic dye with poor hydrophilicity and high molecular weight, which mainly relies on hydrophobic interactions and chemical adsorption with the thioanthracene ring and is relatively less affected.

[0199] According to the result of embodiment 10 and embodiment 11-13, compared to the embodiment 10 of only introducing amylenesulfonamide in described modified bentonite, the embodiment 11-13 of introducing amylenesulfonamide, 4-(vinyloxy) benzenesulfonamide, can achieve better overall performance.Especially, BOD5 removal rate obviously improves, and the removal effect for sulfide blue CV is also significantly improved.As can be seen, a small amount of introducing benzene ring between bentonite layers, compared to only introducing sulfonamide, can increase the hydrophobic surface of modified bentonite, is conducive to capturing amphiphilic organic matter, and this class material is the important component of BOD5.For the printing and dyeing wastewater of complex component, by the coordination of modified bentonite and the activated carbon of load ferrous sulfate, modified titanium dioxide, can realize better comprehensive treatment effect to the pollutant of more different properties.

[0200] According to the results of Example 4 and Comparative Example 1, the use of only the activated carbon loaded with ferrous sulfate resulted in a relatively small decrease in the turbidity removal and chroma removal effects, while a significant decrease in the removal effect of Acid Red G. It can be seen that the activated carbon loaded with ferrous sulfate has relatively good turbidity removal and decolorization effects, but a poor removal effect on Acid Red G.

[0201] The results of Example 4 and Comparative Examples 2, 4, 6, 7, 8, and 9 show that the addition of unmodified titanium dioxide (Comparative Example 4) not only fails to improve the performance of the water treatment agent, but also results in a decrease in many indicators compared to the absence of titanium dioxide (Comparative Example 2). This is due to the reduced proportion of activated carbon and bentonite in the water treatment agent. Titanium dioxide that has not been aminated (Comparative Example 6) is difficult to combine with other polymer monomers, and the performance is also unsatisfactory. Modified titanium dioxide (Comparative Example 7), which was not polymerized with 3,6-thioanthracene diamine, showed significant improvements in turbidity and Acid Red G removal, but lacked the thioanthracene ring, resulting in poor CODcr, BOD5, and chroma removal. The performance was comparable to that of Comparative Example 8, where 3,6-thioanthracene diamine was replaced with 2,6-diaminoanthracene. This shows that simply introducing the anthracene ring does not significantly improve CODcr, BOD5, or chroma removal. In the modified titanium dioxide to which the decanediamine was not added for polymerization (Comparative Example 9), although the thioanthracene ring can improve various properties to a certain extent, its spatial configuration is not good, the CODcr, BOD5, and chroma removal effects are limited, and the flocculation effect is difficult to be effectively exerted, resulting in poor turbidity removal effect.

[0202] The results of Example 4 and Comparative Examples 3, 5, 10, and 11 show that without the addition of modified bentonite (Comparative Example 3), the BOD5 removal efficiency decreased significantly, and the removal of Sulfur Blue CV and Acid Red G was unsatisfactory. The addition of unmodified sodium bentonite (Comparative Example 5) significantly deteriorated the turbidity removal efficiency, and the removal of BOD5 and Sulfur Blue CV also decreased. Bentonite without intercalation treatment (Comparative Example 10) not only failed to improve the removal of CODcr and BOD5, but also may have introduced organic pollutants from the polymer monomers. Bentonite that was only intercalated (Comparative Example 11) showed some improvement in various properties, but the overall performance was still poor.

[0203] It is understood from common knowledge in the art that the present invention may be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the embodiments disclosed above are, in all respects, illustrative only and not exclusive. All modifications within the scope of the present invention or equivalent to the scope of the present invention are intended to be encompassed by the present invention.

Claims

1. A method for preparing water treatment agents by cooperating with waste acid, characterized in that: The steps include: (1) Mixing the dirty acid with iron powder, reacting, and filtering to obtain a ferrous sulfate solution; (2) mixing the ferrous sulfate solution in step (1) with activated carbon to obtain activated carbon loaded with ferrous sulfate; (3) uniformly mixing the activated carbon loaded with ferrous sulfate in step (2) with modified titanium dioxide and modified bentonite to obtain; Wherein, the modified titanium dioxide is obtained by the following method: Adding γ-aminopropyltriethoxysilane to titanium dioxide to obtain amino titanium dioxide; The amination titanium dioxide is mixed with 3,6-thioanthracene diamine, decanediamine, and hexamethylene diisocyanate to obtain modified titanium dioxide after reaction; The modified bentonite is obtained by the following method: Sodium bentonite and allyl triethylammonium bromide are mixed evenly to react to obtain intercalated bentonite, and then pentene sulfonamide and an initiator are added to the mixture to react to obtain modified bentonite.

2. The method for preparing water treatment agents by synergistic use of waste acid according to claim 1, characterized in that: In step (2), the ferrous sulfate solution and activated carbon are mixed in a weight ratio of (5-10):

100.

3. The method for preparing water treatment agents by using polluted acid according to claim 2, characterized in that: In the ferrous sulfate solution, the concentration of ferrous sulfate is 0.1-1 mol / L.

4. The method for preparing water treatment agents by synergistic use of waste acid according to claim 1, characterized in that: In step (3), the titanium dioxide is iron-doped titanium dioxide, which is obtained by the following method: The titanium dioxide precursor solution is mixed with an acid solution of iron ions, reacted, and calcined to obtain iron-doped titanium dioxide.

5. The method for preparing water treatment agents by synergistic use of waste acid according to claim 4, characterized in that: The titanium dioxide precursor solution is formed by mixing tetrabutyl titanate and ethanol in a volume ratio of (1-3):10; or the titanium dioxide precursor solution is formed by mixing isopropyl titanate and ethanol in a volume ratio of (1-3):

10.

6. The method for preparing water treatment agents by using waste acid according to claim 5, characterized in that: The acid solution of iron ions is a nitric acid solution of ferric chloride, with a pH value of 1-3 and an iron ion concentration of 50-80 mmol / L.

7. The method for preparing water treatment agents by using waste acid according to claim 6, characterized in that: The volume ratio of the titanium dioxide precursor solution to the iron ion acid solution is (15-35):

1.

8. The method for preparing water treatment agents by synergistic use of waste acid according to claim 1, characterized in that: In step (3), the titanium dioxide is iron-doped titanium dioxide, which is obtained by the following method: The titanium dioxide precursor solution is added dropwise to the acid solution of iron ions, stirred and reacted at 25-45°C for 2-8 hours, then heated to 120-160°C and reacted for 10-20 hours, and calcined at 400-600°C for 2-4 hours to obtain iron-doped titanium dioxide.

9. The method for preparing water treatment agents by synergistic use of waste acid according to claim 1, characterized in that: The modified titanium dioxide is specifically obtained by the following method: Dispersing the titanium dioxide in toluene, adding γ-aminopropyltriethoxysilane, reacting at 50-60° C. for 6-10 hours, filtering, washing, and drying to obtain amino titanium dioxide; The amino titanium dioxide, 3,6-thioanthracene diamine and decanediamine are dispersed in N,N-dimethylformamide, hexamethylene diisocyanate is added dropwise thereto with stirring, and the mixture is reacted at 60-80° C. for 6-12 hours to obtain modified titanium dioxide.

10. The method for preparing water treatment agents by using waste acid according to claim 9, characterized in that: The weight ratio of the titanium dioxide, gamma-aminopropyltriethoxysilane and toluene is 1:(0.6-0.8):(30-50).

11. The method for preparing water treatment agents by using waste acid according to claim 10, characterized in that: The weight ratio of the amino titanium dioxide, 3,6-thioanthracene diamine, decanediamine and hexamethylene diisocyanate is 1: (0.8-1.5): (0.01-0.05): (1.0-1.2).

12. The method for preparing water treatment agents by using waste acid according to claim 11, characterized in that: The concentration of the amino titanium dioxide in the N,N-dimethylformamide is 1.5-3.0 wt %.

13. The method for preparing water treatment agents by using waste acid according to claim 12, characterized in that: β-cyclodextrin is also dispersed in the N,N-dimethylformamide; the weight ratio of the β-cyclodextrin to the amino titanium dioxide is (0.01-0.05):

1.

14. The method for preparing water treatment agents by using waste acid according to claim 1, characterized in that: The modified bentonite is obtained by the following method: sodium bentonite, allyl triethylammonium bromide and water are uniformly mixed, stirred and reacted at 40-60°C for 2-6 hours to obtain intercalated bentonite, and then pentene sulfonamide and an initiator are added thereto, stirred and reacted at 50-70°C for 2-3 hours to obtain modified bentonite.

15. The method for preparing water treatment agents by using waste acid according to claim 14, characterized in that: The weight ratio of the sodium bentonite, allyl triethylammonium bromide, water, pentene sulfonamide and initiator is 100: (5-10): (300-500): (2-8): (0.5-1.5).

16. The method for preparing water treatment chemicals by using waste acid according to claim 15, characterized in that: The initiator is azobisisobutyronitrile.

17. The method for preparing water treatment chemicals by using waste acid according to claim 1, characterized in that: In step (3), the weight ratio of the activated carbon loaded with ferrous sulfate to the modified titanium dioxide and modified bentonite is 1:(2-8):(10-30).

18. A water treatment agent obtained by the method for preparing a water treatment agent by synergistically using waste acid as claimed in any one of claims 1 to 17.

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