A method for repairing heavy metal polluted water

Abstract

The present invention discloses a method for repairing heavy metal contaminated water bodies, which belongs to the field of water body repair, including the preparation of a heavy metal water body repair agent and its use method. Plant wood fiber powder is dissolved to obtain a wood fiber solution, and then titanium tetrachloride and a mixed solution prepared by a surfactant, water-soluble chitosan, sodium tripolyphosphate, and 1.0g / L zinc chloride solution are added in sequence, and then heated and stirred to obtain a chitosan gel-coated heavy metal water body repair agent. The chitosan gel-coated heavy metal water body repair agent is calcined to obtain a heavy metal water body repair agent for repairing heavy metal contaminated water bodies. The repaired water body Pb 2+ ions, Cr 6+ ions, Cu 2+ ions and Cd 2+ The concentrations of these ions dropped to 0.12 mg / L, 0.21 mg / L, 0.94 mg / L, and 0.03 mg / L, respectively. The preparation process for the heavy metal water remediation agent features mild conditions, simple steps, high wastewater treatment efficiency, and the ability to simultaneously treat multiple heavy metal ion contaminations, providing a feasible approach for large-scale remediation of heavy metal-contaminated waters.

Description

Technical Field

[0001] The present invention relates to the field of contaminated water restoration, and in particular to a method for restoring heavy metal contaminated water. Background Art

[0002] Once heavy metals enter water bodies, they can be distributed throughout various components of aquatic ecosystems, impacting them. Heavy metal pollutants are non-biodegradable, highly toxic, carcinogenic, long-lasting, and prone to bioaccumulation. They can accumulate in animals and plants, gradually enriching through the food chain and causing serious harm to the environment, organisms, and human health.

[0003] The main methods for heavy metal treatment include chemical precipitation, redox, electrolysis, membrane osmosis, and adsorption. Chemical precipitation requires strict control of chemical dosage. Excessive addition can cause secondary contamination of the water, necessitating secondary treatment. However, this method is incomplete, complex, and requires high investment. Redox, commonly used as a pre-treatment method for heavy metal wastewater treatment, can only treat water heavily contaminated by heavy metals. Furthermore, redox methods are often sparse and cannot simultaneously treat multiple heavy metal ions. Electrolysis can separate mixed metal ions in a stepwise manner, recovering and purifying each metal to a relatively high purity, facilitating direct heavy metal recovery. However, this method consumes significant power and requires complex processes, requiring strict control of solution conditions, pH, and air agitation speed to prevent anode passivation and improve separation efficiency. Membrane osmosis, however, does not require the addition of chemical reagents and therefore avoids secondary contamination. However, its membranes are expensive and prone to contamination, which reduces flux and treatment effectiveness.

[0004] Adsorption is the most common treatment method for heavy metal pollution, and its key point lies in the adsorption performance of the adsorbent. Adsorbents with good adsorption properties are often characterized by small specific surface area and small particle size, but these characteristics also lead to high production costs and difficulties in secondary utilization. There is competitive adsorption between multiple heavy metals in water bodies, and the same adsorbent cannot adsorb multiple heavy metal ions at the same time. At the same time, the large amount of water and the high production cost of the adsorbent make it impossible to achieve industrial application. Therefore, it is urgent to find a method for repairing heavy metal water pollution with higher repair efficiency, the ability to adsorb multiple heavy metal ions at the same time, low adsorbent production cost, and simple heavy metal water pollution treatment steps. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for repairing heavy metal contaminated water bodies, adding heavy metal water body repair agent during the repair process to solve the problems of low adsorption efficiency and difficulty in simultaneously treating multiple heavy metal ions during the repair process of heavy metal contaminated water bodies.

[0006] The present invention solves the above technical problems through the following technical means:

[0007] A method for repairing heavy metal polluted water is as follows:

[0008] A. Pass the heavy metal wastewater into the sedimentation tank, and discharge the treated wastewater after the sedimentation is completed;

[0009] B. Passing the wastewater after the primary treatment into the activated carbon pool for adsorption to obtain the second treatment liquid;

[0010] C. Pass the treated liquid into the sewage treatment reaction tank, then add the heavy metal water body repair agent, stir and adsorb for 30-40 minutes, let it stand and separate to obtain the repaired water body.

[0011] Furthermore, the raw materials for preparing the heavy metal water body repair agent include: plant wood fiber powder, choline chloride solution, urea, water-soluble chitosan, sodium tripolyphosphate, surfactant, titanium tetrachloride and 1.0 g / L zinc chloride solution.

[0012] Furthermore, the surfactant is dodecyldimethylbenzylammonium chloride or hexadecyltrimethylammonium chloride.

[0013] The present invention also provides a preparation method of a heavy metal water body repair agent, which is as follows:

[0014] S1. After the urea and choline chloride solution are mixed evenly, the plant wood fiber powder is added and stirred to fully dissolve to obtain a wood fiber solution for use;

[0015] S2. Add surfactant, water-soluble chitosan, and sodium tripolyphosphate to 1.0 g / L zinc chloride solution and stir at room temperature for 20-30 minutes to obtain a mixed solution;

[0016] S3, adding titanium tetrachloride dropwise to the wood fiber solution at a rate of 40-60 d / min, and then adding the mixed solution dropwise at a rate of 80-120 d / min. After the addition is complete, the temperature is increased and stirring is continued. After stirring is complete, the mixture is cooled to room temperature, filtered and separated, and the precipitate is placed in a blower dryer and dried at 50-70°C to obtain a gel-coated heavy metal water body repair agent;

[0017] S4. The gel-coated heavy metal water body repair agent is calcined under nitrogen protection to obtain a heavy metal water body repair agent.

[0018] Furthermore, in step S1, the mass ratio of plant wood fiber powder, urea and choline chloride is (1-2): (2-4): (1-2).

[0019] Furthermore, in step S2, the mass volume ratio of the surfactant, water-soluble chitosan, sodium tripolyphosphate and 1.0 g / L zinc chloride solution is: (0.3-0.5) kg: (0.6-0.8) kg: (0.1-0.2) kg: (1-2) L.

[0020] Furthermore, in step S3, the volume ratio of titanium tetrachloride, the mixed solution and the wood fiber solution is: (0.1-0.3): (1-2): (1-2).

[0021] Furthermore, the heating and continued stirring operation in step S3 is specifically: heating to 60-80° C. and stirring at a speed of 180-220 rpm for 10-20 minutes.

[0022] Furthermore, in step S4, the calcination temperature is 400-500° C. and the calcination time is 1-2 hours.

[0023] Wood fiber has the characteristics of loose structure, rich functional groups, stable chemical properties, large specific surface area, and strong adsorption properties. It can adsorb and fix pollutants such as heavy metals, dyes, pesticides, and antibiotics, but its adsorption performance for low-concentration heavy metal pollutants is poor. TiO2 and ZnO, as metal oxides, can adsorb low-concentration heavy metal pollutants, but a single TiO2 or ZnO can only adsorb a limited variety of heavy metal ions, making it difficult to apply to water bodies contaminated with multiple heavy metal ions. Therefore, combining TiO2 and ZnO with wood fiber to produce a heavy metal water remediation agent allows the advantages of both to be combined, increasing the variety of heavy metal ions adsorbed while also being able to adsorb low-concentration heavy metal ions.

[0024] Simply adsorbing TiO2 and ZnO on the surface of wood fiber will reduce the adsorption performance of wood fiber, and the adsorption performance and range of TiO2 and ZnO are limited. Therefore, it is necessary to effectively combine TiO2 and ZnO with wood fiber, while maintaining the adsorption performance of wood fiber, and increase TiO2 and ZnO to achieve the adsorption of low concentrations of heavy metal ions.

[0025] The present invention dissolves plant wood fiber powder in a mixed solution of urea and choline chloride to prepare a wood fiber solution, sequentially adds titanium tetrachloride and a mixed solution prepared from a surfactant, water-soluble chitosan, sodium tripolyphosphate, and a 1.0 g / L zinc chloride solution to the wood fiber solution, and then heats and stirs. After heating, urea decomposes to produce a large amount of ammonium ions, which increases the pH value of the solution and produces a large amount of mixed metal precipitates. Choline chloride quaternizes the water-soluble chitosan and then cross-links it into a water-soluble chitosan gel under the action of sodium tripolyphosphate. Simultaneously, due to the reduction of urea and choline chloride content, wood fiber gradually precipitates out, and together with the mixed metal precipitate and the water-soluble chitosan gel, a gel-coated heavy metal water body repair agent is obtained. Subsequently, the heavy metal water body repair agent is calcined under nitrogen protection to obtain the heavy metal water body repair agent.

[0026] Mixed metal precipitation requires high-temperature calcination to lose water before obtaining metal oxides. However, wood fiber is prone to pyrolysis reactions above 400°C. In order to obtain metal oxides while preventing the wood fiber from pyrolysis, the present invention coats chitosan gel with a heavy metal water remediation agent. Because chitosan preferentially pyrolyzes at 500°C, a large amount of monomeric glucose is produced during the pyrolysis process and binds to the surface of the wood fiber under the action of metal oxides, which increases the pyrolysis temperature of the wood fiber and only pyrolyzes above 600°C, effectively protecting the integrity of the wood fiber. The result is a heavy metal water remediation agent formed by the effective combination of TiO2 and ZnO with wood fiber. The obtained heavy metal water remediation agent is highly efficient in the remediation of heavy metal water contaminated water and can simultaneously adsorb multiple heavy metal ions.

[0027] Beneficial effects:

[0028] 1. The present invention successfully prepared a heavy metal water body repair agent by combining TiO2 and ZnO with wood fiber. While maintaining the adsorption performance of wood fiber, the removal rate of the heavy metal water body repair agent for heavy metal ions is increased, so that it can simultaneously adsorb multiple heavy metal water ions.

[0029] 2. Under the protection of chitosan gel, the heavy metal water body repair agent successfully obtained TiO2 and ZnO after calcination. At the same time, the wood fiber did not undergo thermal decomposition. TiO2 and ZnO were effectively combined with the wood fiber to produce a heavy metal water body repair agent with high repair efficiency and can effectively adsorb low concentrations of heavy metal ions.

[0030] 3. Heavy metal water body repair agent can be used to simultaneously adsorb Pb in water bodies 2+ Cr 6+ 、Cu 2+ and Cd 2+ The ions achieve efficient remediation of heavy metal water bodies. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the embodiments:

[0032] Example 1: Preparation of water body repair agent

[0033] S1. Weigh 3 kg of urea and 1.5 kg of choline chloride respectively, dissolve them in 5 L of water and mix them evenly. Add 1.5 kg of plant wood fiber powder and stir until fully dissolved to obtain a wood fiber solution for later use.

[0034] S2 were weighed 0.4kg dodecyl dimethyl benzyl ammonium chloride, 0.7kg water-soluble chitosan and 0.15kg sodium tripolyphosphate were added to 1.5L of 1.0g / L zinc chloride solution and stirred at room temperature for 25min to obtain a mixed solution;

[0035] S3. 0.2 L of titanium tetrachloride was added dropwise to 1.5 L of the wood fiber solution at a rate of 50 d / min. Then, 1.5 L of the mixed solution was added dropwise at a rate of 100 d / min. The mixture was heated to 70°C and stirred at 200 rpm for 15 min. After stirring, the mixture was cooled to room temperature, filtered, and the precipitate was separated and placed in a blower dryer and dried at 60°C to obtain a gel-coated heavy metal water remediation agent.

[0036] S4. The gel-coated heavy metal water body repair agent was calcined at 550°C for 1.5 hours under nitrogen protection to obtain a heavy metal water body repair agent.

[0037] Example 2: Preparation of water body repair agent II

[0038] S1. Weigh 2 kg of urea and 2 kg of choline chloride respectively, dissolve them in 5 L of water and mix them evenly. Add 2 kg of plant wood fiber powder and stir until fully dissolved to obtain a wood fiber solution for later use.

[0039] S2 were weighed 0.3kg cetyltrimethylammonium chloride, 0.8kg water-soluble chitosan and 0.1kg sodium tripolyphosphate were added to 1L of 1.0g / L zinc chloride solution and stirred at room temperature for 20min to obtain a mixed solution;

[0040] S3. 0.1 L of titanium tetrachloride was added dropwise to 2 L of the wood fiber solution at a rate of 60 d / min, and then 2 L of the mixed solution was added dropwise at a rate of 80 d / min. After the addition was completed, the mixture was heated to 60 ° C and stirred at 180 rpm for 20 min. After stirring, it was cooled to room temperature, filtered, and the precipitate was separated and placed in a blower dryer. It was dried at 70 ° C to obtain a gel-coated heavy metal water remediation agent;

[0041] S4. The gel-coated heavy metal water body repair agent was calcined at 400° C. for 2 h under nitrogen protection to obtain a heavy metal water body repair agent.

[0042] Example 3: Preparation of water body repair agent

[0043] S1. Weigh 4 kg of urea and 1 kg of choline chloride respectively, dissolve them in 5 L of water and mix them evenly. Add 1 kg of plant wood fiber powder and stir until fully dissolved to obtain a wood fiber solution for later use.

[0044] S2 were weighed 0.5kg dodecyl dimethyl benzyl ammonium chloride, 0.6kg water-soluble chitosan and 0.2kg sodium tripolyphosphate were added to 2L of 1.0g / L zinc chloride solution and stirred at room temperature for 30min to obtain a mixed solution;

[0045] S3. 0.3 L of titanium tetrachloride was added dropwise to 1 L of the wood fiber solution at a rate of 40 d / min, and then 1 L of the mixed solution was added dropwise at a rate of 120 d / min. After the addition was complete, the mixture was heated to 80°C and stirred at 240 rpm for 10 min. After stirring, it was cooled to room temperature, filtered, and the precipitate was separated and placed in a blower dryer. Drying at 50°C gave a gel-coated heavy metal water remediation agent.

[0046] S4. The gel-coated heavy metal water body repair agent was calcined at 500° C. for 1 h under nitrogen protection to obtain a heavy metal water body repair agent.

[0047] Example 4: Remediation of heavy metal contaminated water

[0048] This example uses the heavy metal water body repair agent prepared in Example 1 to repair heavy metal contaminated water bodies. The specific repair steps are as follows:

[0049] A. Pass the heavy metal wastewater into the sedimentation tank, let it settle for 20 minutes, and then discharge the treated wastewater;

[0050] B. Pass the wastewater after primary treatment into the activated carbon pool for adsorption for 1 hour to obtain treated liquid 2;

[0051] C. Pass 100L of treated liquid into the sewage treatment reaction tank twice, then add 5kg of heavy metal water body repair agent, stir and adsorb for 35 minutes, let it stand and separate to obtain the repaired water body.

[0052] Comparative Example 1:

[0053] This comparative example is a comparative example with Example 1, and the only difference is that the wood fiber solution in step S3 is replaced with a plant wood fiber suspension when preparing the heavy metal water body repair agent, and step S1 is changed to the preparation of the plant wood fiber suspension as follows:

[0054] S1. Weigh 1.5 kg of plant wood fiber powder and add it to 5 L of water, stirring until evenly mixed to obtain a plant wood fiber suspension for later use.

[0055] The remaining steps are the same. Step S3 of the preparation of the heavy metal water body repair agent is as follows:

[0056] S3. 0.2 L of titanium tetrachloride was added dropwise to 1.5 L of the plant wood fiber suspension at a rate of 50 d / min, and then 1.5 L of the mixed solution was added dropwise at a rate of 100 d / min. After the addition was completed, the mixture was heated to 70°C and stirred at 200 rpm for 15 min. After stirring, it was cooled to room temperature, filtered, and the precipitate was separated and placed in a blower dryer and dried at 60°C to obtain a gel-coated heavy metal water remediation agent;

[0057] Comparative Example 2:

[0058] This comparative example is a comparative example with Example 1, and the only difference is that in the preparation of the heavy metal water body repair agent, the 1.0 g / L zinc chloride solution in step S2 is replaced with deionized water. The remaining steps are the same. The specific steps of step S2 in the preparation of the heavy metal water body repair agent are as follows:

[0059] S2 were weighed 0.4kg dodecyl dimethyl benzyl ammonium chloride, 0.7kg water-soluble chitosan and 0.15kg sodium tripolyphosphate were added to 1.5L of deionized water and stirred at room temperature for 25min to obtain a mixed solution;

[0060] Comparative Example 3:

[0061] This comparative example is a comparative example with Example 1, and the only difference is that no surfactant is added in step S2 when preparing the heavy metal water body repair agent. The remaining steps are the same. Step S2 when preparing the heavy metal water body repair agent is specifically as follows:

[0062] S2 were weighed 0.7kg water-soluble chitosan and 0.15kg sodium tripolyphosphate were added to 1.5L of 1.0g / L zinc chloride solution and stirred at room temperature for 25min to obtain a mixed solution;

[0063] Comparative Example 4:

[0064] This comparative example is a comparative example with Example 1, and the only difference is that water-soluble chitosan is not added in step S2 when preparing the heavy metal water body repair agent. The remaining steps are the same. Step S2 of the heavy metal water body repair agent is specifically as follows:

[0065] S2 were weighed 0.4kg dodecyl dimethyl benzyl ammonium chloride and 0.15kg sodium tripolyphosphate were added 1.5L of 1.0g / L zinc chloride solution and stirred at room temperature for 25min to obtain a mixed solution;

[0066] Comparative Example 5:

[0067] This comparative example is a comparative example with Example 1, and the only difference is that sodium tripolyphosphate is not added in step S2 when preparing the heavy metal water body repair agent. The remaining steps are the same. Step S2 of the heavy metal water body repair agent is specifically as follows:

[0068] S2 were weighed 0.4kg dodecyl dimethyl benzyl ammonium chloride and 0.7kg water-soluble chitosan was added to 1.5L of 1.0g / L zinc chloride solution and stirred at room temperature for 25min to obtain a mixed solution;

[0069] Comparative Example 6:

[0070] This comparative example is a comparative example with Example 1, and the only difference is that titanium tetrachloride is not added in step S3 when preparing the heavy metal water body repair agent. The remaining steps are the same. The specific steps of step S3 when preparing the heavy metal water body repair agent are as follows:

[0071] S3. 1.5 L of the mixed solution was added dropwise to 1.5 L of the wood fiber solution at a rate of 100 d / min. After the addition was completed, the temperature was raised to 70 ° C and stirred at 200 rpm for 15 min. After stirring, the mixture was cooled to room temperature, filtered and separated, and the precipitate was placed in a blower dryer and dried at 60 ° C to obtain a gel-coated heavy metal water remediation agent;

[0072] Comparative Example 7:

[0073] This comparative example is a comparative example with Example 1, and the only difference is that the calcination temperature in step S4 is changed to 300° C. when preparing the heavy metal water body repair agent. The remaining steps are the same. The specific steps of step S4 when preparing the heavy metal water body repair agent are as follows:

[0074] S4. The gel-coated heavy metal water body repair agent was calcined at 300°C for 1.5h under nitrogen protection to obtain a heavy metal water body repair agent.

[0075] Comparative Example 8:

[0076] This comparative example is a comparative example with Example 1, and the only difference is that the calcination temperature in step S4 is changed to 600° C. when preparing the heavy metal water body repair agent. The remaining steps are the same. The specific steps of step S4 when preparing the heavy metal water body repair agent are as follows:

[0077] S4. The gel-coated heavy metal water body repair agent was calcined at 600°C for 1.5h under nitrogen protection to obtain a heavy metal water body repair agent.

[0078] 1. Laboratory adsorption experiment of simulated heavy metal wastewater

[0079] Weigh 300 mg of lead nitrate, 150 mg of chromium chloride, 100 mg of copper chloride and 50 mg of cadmium chloride and dissolve them in 1 L of water to prepare Pb 2+ ions, Cr 6+ ions, Cu 2+ ions and Cd 2+ The heavy metal water body repair agent prepared in Example 4 and Comparative Examples 1-8 was added to 100 mL of the heavy metal wastewater simulation solution and stirred for 35 minutes to repair the heavy metal wastewater simulation solution. The heavy metal water body repair agent prepared in Example 1 and Comparative Examples 1-8 had an effect on the Pb content of the heavy metal wastewater simulation solution after repair. 2+ ions, Cr 6+ ions, Cu 2+ ions and Cd 2+ The ion detection is shown in Table 1.

[0080] Table 1

[0081]

[0082] Data Analysis:

[0083] From the data of Example 4 in Table 1, it can be seen that the heavy metal water body repair agent prepared by the present invention can effectively adsorb and remove Pb in the heavy metal wastewater simulation solution. 2+ ions, Cr 6+ ions, Cu 2+ ions and Cd 2+ Example 4 Pb in water after repair 2+ ions, Cr 6+ ions, Cu 2+ ions and Cd 2+ The concentration of ions can be reduced to 0.22 mg / L, 0.11 mg / L, 1.19 mg / L and 0.03 mg / L respectively, indicating that the heavy metal water body remediation agent has high remediation efficiency and can adsorb heavy metal ions in low concentration solutions.

[0084] Comparing the data of Example 4 and Comparative Example 1, it can be seen that in Comparative Example 1, when preparing the heavy metal water body repair agent, the wood fiber solution in step S3 is replaced with a plant wood fiber suspension to prepare the heavy metal water body repair agent. 2+ ions, Cr 6+ ions, Cu 2+ ions and Cd 2+The ion concentration increased significantly. This shows that the heavy metal water remediation agent prepared by simply adsorbing TiO2 and ZnO on the surface of wood fiber has poor adsorption performance, reduced ability to adsorb and remove heavy metals, and low sewage treatment efficiency.

[0085] Comparing the data of Example 4 and Comparative Examples 2-6, it can be seen that when preparing the heavy metal water body repair agent, Comparative Examples 2-6 do not add 1.0g / L zinc chloride solution, surfactant, water-soluble chitosan, sodium tripolyphosphate and titanium tetrachloride, the Pb content in the repaired water will increase. 2+ ions, Cr 6+ ions, Cu 2+ ions and Cd 2+ The ion concentrations all increase and the sewage treatment efficiency decreases.

[0086] Comparing the data of Example 4 and Examples 7-8, it can be seen that the calcination temperature of the heavy metal water body repair agent is closely related to the repair effect of the heavy metal water body repair agent. The temperature of Example 4 is too high, and the wood fiber begins to pyrolyze, resulting in a weakening of the adsorption performance of the metal water body repair agent. The temperature of Example 5 is too low, and the TiO2-ZnO nanocomposite is not fully dehydrated, and cannot form a small pore size to adsorb low concentrations of heavy metal ions. Too high or too low a temperature will cause the Pb in the repaired water to 2+ ions, Cr 6 + ions, Cu 2+ ions and Cd 2+ The ion concentrations all increase, which in turn affects the adsorption effect of heavy metal water body repair agents and reduces the sewage treatment efficiency.

[0087] 2. Actual treatment experiment of heavy metal wastewater

[0088] The heavy metal wastewater was repaired according to the method of Example 4. The main heavy metal ions in the wastewater before and after repair, including Pb 2+ ions, Cr 6+ ions, Cu 2+ ions and Cd 2+ The results after ion detection are shown in Table 2:

[0089] Table 2

[0090]

[0091] Table 2 shows that after remediation of heavy metal-contaminated water using the method of Example 4, the concentrations of Pb2+, Cr6+, Cu2+, and Cd2+ ions in the water dropped to 0.12 mg / L, 0.21 mg / L, 0.94 mg / L, and 0.03 mg / L, respectively. Example 4 employed the heavy metal water remediation agent prepared in Example 1. The preparation process offers mild conditions, simple steps, high wastewater treatment efficiency, and simultaneous treatment of multiple heavy metal ion contamination, providing a viable approach for large-scale remediation of heavy metal-contaminated water.

[0092] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. A method for repairing heavy metal polluted water, characterized in that: The method for repairing the heavy metal polluted water body is as follows: A. Pass the heavy metal wastewater into the sedimentation tank, and discharge the treated wastewater after the sedimentation is completed; B. Passing the wastewater after the primary treatment into the activated carbon pool for adsorption to obtain the second treatment liquid; C. Pass the treated liquid into the sewage treatment reaction tank, then add the heavy metal water body repair agent, stir and adsorb for 30-40 minutes, let it stand and stratify to obtain the repaired water body; The raw materials for preparing the heavy metal water body repair agent include: plant wood fiber powder, choline chloride solution, urea, water-soluble chitosan, sodium tripolyphosphate, surfactant, titanium tetrachloride and 1.0g / L zinc chloride solution; The preparation method of the heavy metal water body repair agent is as follows: S1. After the urea and choline chloride solution are mixed evenly, the plant wood fiber powder is added and stirred to fully dissolve to obtain a wood fiber solution for use; S2. Add surfactant, water-soluble chitosan, and sodium tripolyphosphate to 1.0 g / L zinc chloride solution and stir at room temperature for 20-30 minutes to obtain a mixed solution; S3. Titanium tetrachloride was added dropwise to the wood fiber solution, and then the mixed solution was added dropwise, and then the temperature was raised and stirred. After stirring, the mixture was cooled to room temperature, the precipitate was separated by filtration and dried in an air dryer to obtain a gel-coated heavy metal water remediation agent; S4. The gel-coated heavy metal water body repair agent is calcined under nitrogen protection to obtain a heavy metal water body repair agent; the calcination temperature in step S4 is 400-500°C and the time is 1-2h.

2. The method for repairing a heavy metal polluted water body according to claim 1, characterized in that: The surfactant is dodecyldimethylbenzyl ammonium chloride or hexadecyltrimethylammonium chloride.

3. The method for repairing heavy metal polluted water according to claim 2, characterized in that: In step S1, the mass ratio of plant wood fiber powder, urea and choline chloride is (1-2): (2-4): (1-2).

4. The method for repairing a heavy metal polluted water body according to claim 3, characterized in that: In step S2, the mass volume ratio of the surfactant, water-soluble chitosan, sodium tripolyphosphate and 1.0 g / L zinc chloride solution is (0.3-0.5) kg: (0.6-0.8) kg: (0.1-0.2) kg: (1-2) L.

5. The method for repairing heavy metal polluted water according to claim 4, characterized in that: In step S3, the volume ratio of titanium tetrachloride, the mixed solution and the wood fiber solution is (0.1-0.3): (1-2): (1-2).

6. The method for repairing heavy metal polluted water according to claim 5, characterized in that: The heating and stirring operation in step S3 is specifically as follows: heating to 60-80° C. and stirring at a speed of 180-220 rpm for 10-20 minutes.

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