Multi-carboxyl modified loofah sponge heavy metal trapping agent as well as preparation method and application thereof
By modifying the loofah pulp with multiple carboxyl groups, a heavy metal trapping agent for polycarboxyl group modified loofah pulp was prepared, which solved the problems of unstable and high cost of heavy metal wastewater treatment in the prior art, and achieved efficient and environmentally friendly heavy metal adsorption effect.
Patent Information
- Application Number
- CN202411724609.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-04-08
AI Technical Summary
In the prior art, when treating heavy metal wastewater, conventional methods such as chemical methods and ion exchange methods have problems such as unstable treatment effects, high operating costs and secondary pollution. Polymer heavy metal trapping agents are difficult to be accepted by the market due to their high toxicity, difficulty in degradation, and expensive raw materials.
By modifying the loofah pulp with polycarboxyl groups, using potassium permanganate and thiourea as initiator, a large amount of carboxyl groups were introduced to prepare a heavy metal trap of polycarboxyl modified loofah pulp by grafting glycidyl methacrylate and ring-opening reaction of butane tetracarboxylic acid.
The adsorption capacity of loofah pulp to Pb(II) is significantly improved, with an adsorption capacity of up to 476mg·g-1, and the raw material is cheap, the preparation method is simple and efficient, and there is no secondary pollution.
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Figure CN119771381A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of heavy metal wastewater treatment, and particularly relates to a polycarboxyl-modified loofah heavy metal scavenger and a preparation method and application thereof. Background Art
[0002] my country is a major agricultural producer. Agricultural technology is constantly innovating, the degree of agricultural modernization is getting higher and higher, the output of crops is increasing, and the total amount of agricultural waste is gradually increasing. For environmental protection, agricultural waste is prohibited from burning, resulting in the accumulation of a large amount of agricultural waste. On the other hand, although chemical equipment is constantly improving, it still cannot guarantee the reduction of discharged sewage. The discharge of industrial sewage from various factories has seriously affected our daily life and our health. It is urgent to seek an effective treatment method to reduce the concentration of heavy metals in wastewater.
[0003] The conventional method for treating heavy metal wastewater at present - chemical method (lime neutralization method and sulfide precipitation method) is easy to operate, simple in process and low in treatment cost, but the treatment effect is unstable, the discharged wastewater is difficult to meet the discharge standards, and secondary pollution will also occur. The ion exchange method has a large capacity for removing heavy metal ions and good effluent quality, but the ion exchanger is easily oxidized and ineffective, regenerated frequently, and has high operating costs. Although polymer heavy metal scavengers have strong scavenging ability with heavy metal ions and can selectively capture and precipitate heavy metal ions, their monomers are highly toxic, difficult to degrade, the raw materials are expensive, and the treatment cost is too high, making them difficult to be accepted by the market.
[0004] More and more scientific researchers are turning their attention to agricultural waste, which has easy-to-obtain raw materials, low cost and is environmentally friendly. They prepare heavy metal scavengers by functionally modifying agricultural waste to achieve waste utilization and practice the concept of environmental protection and energy conservation. Summary of the invention
[0005] In order to solve the above technical problems, the present invention provides a polycarboxyl modified sponge gourd heavy metal scavenger and a preparation method thereof, the purpose of which is to enhance the adsorption capacity of sponge gourd for heavy metal ions through chemical modification.
[0006] The technical solution of the present invention is as follows:
[0007] The first aspect of the present invention provides a method for preparing a polycarboxyl-modified heavy metal scavenger of loofah, which comprises: using potassium permanganate and dithiocarbamide as initiators, grafting loofah with glycidyl methacrylate to obtain epoxy loofah; using butanetetracarboxylic acid and the epoxy loofah to carry out a ring-opening reaction, and performing a carboxylate treatment to obtain a polycarboxyl-modified heavy metal scavenger of loofah. By free radical graft copolymerization of glycidyl methacrylate (GMA), epoxy groups are introduced into the loofah to obtain epoxy loofah, and further a ring-opening reaction is carried out with butanetetracarboxylic acid.
[0008] Furthermore, the method specifically comprises: (1) preparing the sponge gourd into sponge gourd powder, treating the sponge gourd powder in an alkali solution and then drying it to obtain treated sponge gourd; adding the treated sponge gourd into water, adding potassium permanganate, dioxythiourea and glycidyl methacrylate in sequence to obtain a reaction system, heating the reaction system to 60°C to 100°C and reacting for 0.5h to 2.5h; after the reaction, filtering the obtained solid product, pouring it into anhydrous ethanol for immersion and washing, then removing the homopolymer in the solid product by extraction with an extraction solvent, and then drying it to obtain the epoxy sponge gourd; (2) dissolving butanetetracarboxylic acid in N,N-dimethylformamide, adding the epoxy sponge gourd after the dissolution is completed to react; after the reaction is completed, washing and drying the obtained product, and performing carboxylation treatment with sodium hydroxide to obtain the polycarboxyl-modified sponge gourd heavy metal scavenger.
[0009] Furthermore, the step (1) specifically includes the following steps: the mass ratio of the sponge gourd and glycidyl methacrylate is 1:1 to 1:5, and the mass ratio of the dithiocarbamide and potassium permanganate is 4:1 to 4:7; the sponge gourd is washed, dried, crushed, sieved to obtain sponge gourd powder, the sponge gourd powder is soaked in 1 mol / L sodium hydroxide solution for 24 hours, then filtered, dried, ground, and set aside; 0.5 g of the treated sponge gourd is added to a reaction container containing 50 mL of distilled water, potassium permanganate, dithiocarbamide, and glycidyl methacrylate are added in sequence, and the reaction is carried out at a constant temperature of 60°C to 100°C for 0.5h to 2.5h; after the reaction is completed, the solid product obtained by the reaction is filtered and poured into anhydrous ethanol for soaking and washing, and then the homopolymer is extracted with acetone for 2 to 3 times, and then dried to obtain the epoxy sponge gourd, which is ground and set aside.
[0010] Furthermore, the screening is specifically screening through a 200-mesh sieve.
[0011] Furthermore, the step (2) specifically includes the following steps: the mass ratio of the epoxy sponge gourd to butane tetracarboxylic acid is 1:3 to 1:7; butane tetracarboxylic acid is weighed and placed in a reaction container containing 30 mL of N,N-dimethylformamide, and after the butane tetracarboxylic acid is completely dissolved at a constant temperature of 100°C to 150°C, 1 g of the epoxy sponge gourd is added; after the reaction is completed, the obtained product is washed in acetone, dried to constant weight, ground, and carboxylated with sodium hydroxide to obtain the polycarboxyl-modified sponge gourd heavy metal scavenger.
[0012] Furthermore, the washing specifically includes washing the obtained product in acetone for 2 to 3 times.
[0013] The second aspect of the present invention provides a polycarboxyl-modified loofah heavy metal scavenger prepared by the method for preparing the polycarboxyl-modified loofah heavy metal scavenger as described above.
[0014] Furthermore, the polycarboxyl-modified sponge gourd heavy metal scavenger has a 2+ The saturated adsorption capacity can reach 476 mg·g -1 .
[0015] The third aspect of the present invention provides the use of the above-mentioned polycarboxyl-modified loofah heavy metal scavenger in the field of heavy metal wastewater.
[0016] Compared with the prior art, the present invention has the following advantages:
[0017] Through the modification process route of the present invention, a large number of carboxyl groups are introduced on the surface of the sponge gourd, and the prepared polycarboxyl modified sponge gourd heavy metal scavenger significantly improves the adsorption capacity of the sponge gourd for Pb(II). The raw material cost is low, and the preparation method is simple and efficient. The polycarboxyl modified sponge gourd heavy metal scavenger prepared by the present invention is applied to heavy metal wastewater. When the pH of the adsorption solution is 6 and the initial concentration of Pb(II) is 800 mg·L -1 The adsorption capacity is as high as 476 mg g -1 . BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is the adsorption amount of loofah powder and polycarboxyl-modified loofah heavy metal scavenger at different initial Pb(Ⅱ) concentrations (25℃, solution pH 6). DETAILED DESCRIPTION
[0019] In view of this, the present invention utilizes the adsorption function of the carboxyl group in butanetetracarboxylic acid on heavy metal ions to achieve carboxyl modification of agricultural waste, giving it a higher adsorption capacity, and is widely used in the field of heavy metal wastewater treatment. The present application utilizes free radical graft copolymerization to achieve epoxylation of sponge gourd sponge through glycidyl methacrylate (GMA), and further performs a ring-opening reaction with butanetetracarboxylic acid to introduce a large number of carboxyl groups on the surface of the sponge gourd sponge, thereby enhancing the adsorption capacity of the sponge gourd sponge for heavy metal ions.
[0020] The present invention is described in detail below in conjunction with specific implementation modes.
[0021] Example 1
[0022] Wash, dry and crush the sponge gourd, and sieve out the powder that passes through a 200-mesh sieve for later use. Soak the sponge gourd powder in a 1mol / L sodium hydroxide solution for 24 hours, then filter it, dry it, grind it, and set it aside. Add 0.5g of the treated sponge gourd into a four-necked flask with 50mL of distilled water, wait until the temperature rises to 80°C, add 0.05mol / L potassium permanganate, 0.08mol / L dithiocarbamide, and 4mL GMA in sequence, and stir at a constant temperature for 1 hour. After the reaction is completed, the solid product obtained by the reaction is filtered and poured into anhydrous ethanol for soaking and washing, and then extracted with acetone to remove the homopolymer 2 to 3 times, and then dried to obtain epoxy sponge gourd, which is ground and set aside.
[0023] Weigh 7g of butanetetracarboxylic acid and place it in a four-necked flask containing 30mL of N,N-dimethylformamide (DMF), heat it to 130°C, and add 1g of epoxy loofah after the butanetetracarboxylic acid is completely dissolved. After the reaction is completed, wash the obtained sample in acetone for 2 to 3 times, dry it in a drying oven to constant weight, grind it, and perform carboxylation treatment with sodium hydroxide to obtain a polycarboxyl-modified loofah heavy metal scavenger.
[0024] The adsorption performance of the polycarboxyl-modified sponge gourd heavy metal scavenger for Pb(Ⅱ) at different initial concentrations
[0025] Specific steps: measure different concentrations (50 mg·L -1 、100mg·L -1 , 200mg·L -1 、300mg·L -1 , 400mg·L -1 , 500mg·L -1 、600mg·L -1 、700mg·L -1 、800mg·L -140 mL of Pb(Ⅱ) solution was added to each reaction container, and 0.02 g of the polycarboxyl-modified sponge gourd heavy metal scavenger was added. The temperature was kept at 25°C and the oscillator speed was 160 r·min. -1 After shaking for 2 hours, a portion of the solution was taken out and centrifuged for 30 minutes. The supernatant was taken and the Pb(Ⅱ) concentration was measured by atomic absorption spectrometer, and the adsorption capacity was calculated. Figure 1 As shown, (a) is a polycarboxyl-modified loofah heavy metal scavenger, and (b) is loofah original powder.
[0026] from Figure 1 It can be seen that the adsorption capacity of the polycarboxyl-modified sponge gourd heavy metal scavenger increased with the increase of the initial concentration of Pb(Ⅱ). When the initial concentration was 800 mg·L -1 When the adsorption capacity reaches 476 mg·g -1 , showing its strong adsorption capacity.
[0027] Example 2
[0028] Wash, dry and crush the sponge gourd, and sieve out the powder that passes through a 200-mesh sieve for later use. Soak the sponge gourd powder in a 1mol / L sodium hydroxide solution for 24 hours, then filter it, dry it, grind it, and set it aside. Add 0.5g of the treated sponge gourd into a four-necked flask with 50mL of distilled water, wait until the temperature rises to 60°C, add 0.03mol / L potassium permanganate, 0.04mol / L dithiocarbamide, and 2mL GMA in sequence, and stir at a constant temperature for 0.5h. After the reaction is completed, the solid product obtained by the reaction is filtered and poured into anhydrous ethanol for soaking and washing, and then extracted with acetone to remove the homopolymer 2 to 3 times, and then dried to obtain epoxy sponge gourd, which is ground and set aside.
[0029] 3g of butanetetracarboxylic acid was weighed and placed in a four-necked flask containing 30ml of DMF, heated to 110°C, and after the butanetetracarboxylic acid was completely dissolved, 1g of epoxy loofah was added. After the reaction was completed, the obtained sample was washed in acetone for 2 to 3 times, dried in a drying oven to constant weight, ground, and subjected to carboxylate treatment to obtain a polycarboxyl-modified loofah heavy metal scavenger.
[0030] Example 3
[0031] Wash, dry and crush the sponge gourd, and sieve out the powder that passes through a 200-mesh sieve for later use. Soak the sponge gourd powder in a 1mol / L sodium hydroxide solution for 24 hours, then filter it, dry it, grind it, and set it aside. Add 0.5g of the treated sponge gourd into a four-necked flask with 50mL of distilled water, wait until the temperature rises to 70°C, add 0.04mol / L potassium permanganate, 0.06mol / L dithiocarbamide, and 3mL GMA in sequence, and stir at a constant temperature for 1 hour. After the reaction is completed, the solid product obtained by the reaction is filtered and poured into anhydrous ethanol for soaking and washing, and then extracted with acetone to remove the homopolymer 2 to 3 times, and then dried to obtain epoxy sponge gourd, which is ground and set aside.
[0032] 5 g of butane tetracarboxylic acid was weighed and placed in a four-necked flask containing 30 mL of DMF, heated to 120°C, and after the butane tetracarboxylic acid was completely dissolved, 1 g of epoxy loofah was added. After the reaction was completed, the obtained sample was washed 2 to 3 times in acetone, dried to constant weight in a drying oven, ground, and subjected to carboxylate treatment to obtain a polycarboxyl-modified loofah heavy metal scavenger.
[0033] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in practical applications, various changes may be made to the embodiments in form and detail without departing from the spirit and scope of the present application. Any person skilled in the art may make their own changes and modifications without departing from the spirit and scope of the present application, and therefore the scope of protection of the present application shall be subject to the scope defined in the claims.
Claims
1. A method for preparing a polycarboxyl-modified sponge gourd heavy metal scavenger, characterized in that: The method comprises: using potassium permanganate and dioxythiourea as initiators, grafting loofah sponge through glycidyl methacrylate to obtain epoxy loofah sponge; using butane tetracarboxylic acid and the epoxy loofah sponge to carry out ring-opening reaction, and performing carboxylate treatment to obtain a polycarboxyl-modified loofah sponge heavy metal scavenger.
2. The method for preparing the polycarboxyl-modified sponge gourd heavy metal scavenger according to claim 1, characterized in that: The method specifically includes: (1) making the sponge gourd into sponge gourd powder, and treating the sponge gourd powder in an alkali solution and then drying it to obtain the treated sponge gourd; After adding the treated sponge gourd into water, potassium permanganate, dioxythiourea and glycidyl methacrylate are added in sequence to obtain a reaction system, and the reaction system is heated to 60° C. to 100° C. and reacted for 0.5 h to 2.5 h; After the reaction is completed, the obtained solid product is filtered and poured into anhydrous ethanol for immersion and washing, and then the homopolymer in the solid product is removed by extraction with an extraction solvent, and then the solid product is dried to obtain the epoxy sponge gourd; (2) dissolving butanetetracarboxylic acid in N,N-dimethylformamide, and adding the epoxy sponge gourd to react after the dissolution is completed; After the reaction is completed, the obtained product is washed and dried, and then carboxylated with sodium hydroxide to obtain the polycarboxyl-modified sponge gourd heavy metal scavenger.
3. The method for preparing the polycarboxyl-modified sponge gourd heavy metal scavenger according to claim 2, characterized in that: The step (1) specifically comprises the following steps: the mass ratio of the sponge gourd to glycidyl methacrylate is 1:1 to 1:5, and the mass ratio of the dioxythiourea to potassium permanganate is 4:1 to 4:7; Wash, dry, and crush the sponge gourd, sieve to obtain sponge gourd powder, soak the sponge gourd powder in a 1 mol / L sodium hydroxide solution for 24 h, then filter, dry, and grind it for later use; Add 0.5 g of the treated sponge gourd into a reaction vessel containing 50 mL of distilled water, and then add potassium permanganate, dioxythiourea, and glycidyl methacrylate in sequence, and react at a constant temperature of 60°C to 100°C for 0.5h to 2.5h; After the reaction is completed, the solid product obtained by the reaction is filtered and poured into anhydrous ethanol for soaking and washing, and then extracted with acetone to remove the homopolymer 2 to 3 times, and then dried to obtain the epoxy sponge gourd, which is ground and set aside.
4. The method for preparing the polycarboxyl-modified sponge gourd heavy metal scavenger according to claim 3, characterized in that: The screening specifically includes screening through a 200-mesh sieve.
5. The method for preparing the polycarboxyl-modified sponge gourd heavy metal scavenger according to claim 3, characterized in that: The step (2) specifically comprises the following steps: the epoxy sponge gourd and butane tetracarboxylic acid are used in a mass ratio of 1:3 to 1:7; Weigh butanetetracarboxylic acid and place it in a reaction container containing 30 mL of N,N-dimethylformamide, at a constant temperature of 100° C. to 150° C., until the butanetetracarboxylic acid is completely dissolved, then add the epoxy sponge gourd; After the reaction is completed, the obtained product is washed in acetone, dried to constant weight, ground, and subjected to carboxylation treatment with sodium hydroxide to obtain the polycarboxyl-modified sponge gourd heavy metal scavenger.
6. The method for preparing the polycarboxyl-modified sponge gourd heavy metal scavenger according to claim 5, characterized in that: The washing specifically comprises washing the obtained product in acetone for 2 to 3 times. 7 . The polycarboxyl-modified loofah heavy metal scavenger prepared by the method for preparing the polycarboxyl-modified loofah heavy metal scavenger according to claim 1 .
8. The polycarboxyl-modified sponge gourd heavy metal scavenger according to claim 7, characterized in that: The polycarboxyl modified sponge gourd heavy metal scavenger has good activity against Pb 2+ The saturated adsorption capacity can reach 476 mg·g -1 .
9. Use of the polycarboxyl-modified loofah heavy metal scavenger as claimed in claim 7 in the field of heavy metal wastewater.