A high-efficiency sewage treatment agent and preparation method thereof

Abstract

The present invention belongs to the field of sewage treatment technology and specifically relates to a high-efficiency sewage treatment agent and a preparation method thereof. The high-efficiency sewage treatment agent comprises the following components by weight: 20-30 parts of a CaWO4 / ZIF-67 composite material, 10-20 parts of Al2(SO4)3, 5-10 parts of Fe2O3, 0.5-2 parts of NaHSO3, 1-5 parts of Na2SiO3, and 3-15 parts of MnO2. ZIF-67 has a high adsorption efficiency due to its high porosity and adjustable properties. ZIF-67 is compounded with CaWO4 and endowed with magnetic properties, enabling the composite material to rapidly adsorb pollutants to the surface. Furthermore, the problem of ZIF-67 alone being easily agglomerated and difficult to recycle is solved. Combined with flocculation and reduction, the COD of the sewage is further reduced, achieving the effect of efficiently purifying the sewage.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and particularly relates to a high-efficiency sewage treatment agent and a preparation method thereof. Background Art

[0002] Water pollution is a rapidly growing environmental problem that requires effective management. Wastewater contains a wide variety of pollutants that can accumulate and remain in the environment for long periods, posing potential environmental hazards and making them difficult to treat. Therefore, effective wastewater treatment methods are needed to remove or reduce their concentrations.

[0003] While existing wastewater treatment technologies can remove pollutants to a certain extent, they still face the following challenges: low treatment efficiency: some traditional wastewater treatment agents have low removal rates for pollutants such as COD (chemical oxygen demand), BOD (biochemical oxygen demand), and suspended solids, resulting in treated water quality failing to meet reuse or discharge standards; high cost: the high cost of some highly effective wastewater treatment agents limits their practical application; and secondary pollution: some wastewater treatment agents may produce toxic and harmful byproducts during use, posing a potential threat to the environment and human health. Therefore, it is necessary to research and develop a highly efficient, environmentally friendly, low-cost, and easy-to-use wastewater treatment agent to provide a new, highly effective solution for wastewater treatment. Summary of the Invention

[0004] In response to the shortcomings of the prior art, the present invention provides a high-efficiency sewage treatment agent and a preparation method thereof. The high-efficiency sewage treatment agent prepared by the present invention utilizes a CaWO4 / ZIF-67 composite material, combined with the strong flocculation effect of Al2(SO4)3 and the catalytic effect of MnO2. ZIF-67 has a high adsorption efficiency due to its high porosity and adjustable properties. The inherent microporosity of ZIF-67 enables heavy metal ions to diffuse efficiently and quickly into the framework. ZIF-67 is composited with CaWO4, and Fe3O4 is added during the synthesis process, which imparts magnetic properties to the composite material, enabling the composite material to rapidly adsorb heavy metal ions to the surface. The composite of CaWO4 and ZIF-67 solves the problem of ZIF-67 being easily agglomerated, difficult to use and recycle, and increases the amount of surfactant, thereby improving adsorption performance. Combined with the flocculation effect of Al2(SO4)3 and the reduction effect of NaHSO3, the COD of sewage is further reduced. The high-efficiency sewage treatment agent prepared by the present invention has good flocculation and adsorption capabilities, can quickly adsorb pollutants, has good stability, can be easily separated by a magnetic field, can be recycled multiple times, and has good economic practicality.

[0005] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0006] The present invention provides a high-efficiency sewage treatment agent, which is composed of the following raw materials in parts by weight: 20-30 parts of CaWO4 / ZIF-67 composite material, 10-20 parts of Al2(SO4)3, 5-10 parts of Fe2O3, 1-5 parts of Na2SiO3, 0.5-2 parts of NaHSO3, and 3-15 parts of MnO2;

[0007] Furthermore, the raw materials for preparing the CaWO4 / ZIF-67 composite material are: Ca(NO3)2·4H2O, Na2WO4·2H2O, Co(NO3)2·6H2O, CTAB (hexadecyltrimethylammonium bromide), C4H6N2 (2-methylimidazole) and Fe3O4;

[0008] The preparation method of the CaWO4 / ZIF-67 composite material specifically comprises the following steps:

[0009] S1, weighing Ca(NO3)2·4H2O and dissolving it in ethylene glycol to form a first solution, weighing Na2WO4·2H2O and dissolving it in deionized water to form a second solution, then slowly pouring the second solution into the first solution, placing the mixture in a magnetic stirrer and stirring at 180-300 rpm at 70°C to form a mixture;

[0010] S2, subjecting the mixture obtained in step S1 to a hydrothermal reaction at a reaction temperature of 180°C for 24 hours. After the reaction is completed, the mixture is cooled to room temperature to obtain a white precipitate. The obtained white precipitate is washed alternately with ethanol and deionized water three times, dried in an oven at 70°C for 12 hours, and then taken out and ground to obtain CaWO4;

[0011] S3: CTAB and Co(NO3)2·6H2O were added to deionized water and ultrasonicated at 240 W for 15 min to form a uniform solution A. C4H6N2 and Fe3O4 were added to anhydrous ethanol to obtain solution B. Solution A was slowly poured into solution B and mixed to form a mixed solution.

[0012] S4, adding the CaWO4 prepared in step S2 to the mixed solution, ultrasonically mixing, drying to obtain a composite material precursor, and then calcining at 400 ° C for 4-6 h to obtain a CaWO4 / ZIF-67 composite material.

[0013] Furthermore, the dosage ratio of Ca(NO3)2·4H2O to ethylene glycol is 0.1 g:7 mL, the dosage ratio of Na2WO4·2H2O to deionized water is 0.1 g:15 mL, the molar ratio of Ca(NO3)2·4H2O to Na2WO4·2H2O is 1:1, and the volume ratio of solution A to solution B is 1:12.

[0014] Furthermore, the usage ratio of CTAB, Co(NO3)2·6H2O and deionized water is 1 mg:0.15 g:2.5 mL, and the usage ratio of C4H6N2, Fe3O4 and anhydrous ethanol is 1 g:0.5 g:10 mL.

[0015] Furthermore, the usage ratio of CaWO4 to the mixed solution is 0.1-0.5 g:25 mL.

[0016] The present invention also provides a method for preparing a high-efficiency sewage treatment agent, which specifically comprises the following steps:

[0017] Y1, weigh Al2(SO4)3 and Fe2O3 by weight, dissolve them in deionized water, and stir at 200-500 rpm to form a mixed solution;

[0018] Y2, weighing the CaWO4 / ZIF-67 composite material and NaHSO3 in parts by weight, adding them to the mixed solution obtained in step Y1, and mixing them at 70-90°C and 200 rpm with magnetic stirring to form a suspension;

[0019] Y3. Add Na2SiO3 and MnO2 to the suspension obtained in step Y2, stir and mix at 300 rpm, let it stand for 30-60 minutes, then centrifuge and dry to obtain a high-efficiency sewage treatment agent.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The high-efficiency sewage treatment agent prepared by the present invention adopts CaWO4 / ZIF-67 composite material, combined with the strong flocculation effect of Al2(SO4)3 and the catalytic effect of MnO2, so that the prepared sewage treatment agent has the characteristics of high efficiency, stability, and environmental protection. Due to its high porosity and adjustable properties, ZIF-67 has a high adsorption efficiency and can effectively remove heavy metal ions and organic pollutants in water bodies. The inherent microporosity of ZIF-67 allows heavy metal ions to diffuse into the framework efficiently and quickly. ZIF-67 is compounded with calcium tungstate, and Fe3O4 is added during the synthesis process to give the composite material magnetism, so that the magnetic composite material can adsorb heavy metal ions such as Pb 2+ Cr 6+Plasma and organic dyes are rapidly adsorbed to the surface, then enter the interior of the material and combine with the active centers of the CaWO4 / ZIF-67 composite material until adsorption saturation is reached. After CaWO4 is compounded with ZIF-67, the characteristics of ZIF-67 that are easy to agglomerate, difficult to use and recycle are solved, and the surfactant is increased, and the adsorption performance is improved, so that the adsorption mechanism of the CaWO4 / ZIF-67 composite material is attributed to electrostatic attraction and surface complexation of oxygen-containing functional groups, rather than relying solely on the interaction of CN in ZIF-67, which greatly enhances the purification effect of sewage; CaWO4 has good chemical stability and can remain stable under different pH values and chemical environments. The combination of ZIF-67 and CaWO4 improves the overall stability of the composite material. At the same time, the composite material is magnetic and can be easily separated by a magnetic field, solving the problem that traditional powdered functional materials are difficult to recycle, thereby avoiding secondary pollution. Al2(SO4)3 hydrolyzes in water to form aluminum hydroxide colloid, which has excellent flocculation properties. Combined with the flocculation and adsorption properties of Fe2O3, and supplemented by Na2SiO3, it promotes the formation of flocs from suspended particles in wastewater, accelerating the aggregation and sedimentation of suspended matter and colloidal particles in the water. Al2(SO4)3 can regulate the pH value of the water body, while Na2SiO3 partially hydrolyzes into silicic acid and sodium hydroxide in the wastewater, assisting Al2(SO4)3 in regulating the wastewater pH and jointly maintaining the pH stability of the water body. The catalytic oxidation of MnO2 helps decompose organic pollutants in the water, while calcium tungstate / ZIF-67 can adsorb these decomposition products and heavy metal ions, achieving comprehensive removal of pollutants. The catalytic effect of MnO2 accelerates the efficient adsorption and separation of pollutants by CaWO4 / ZIF-67, improving wastewater treatment efficiency. The CaWO4 / ZIF-67 composite provides mechanical support for MnO2, protecting it from wear during the wastewater treatment process and maintaining its catalytic activity. The magnetic properties of Fe2O3 facilitate the recovery of MnO2 and Al2(SO4)3, preventing their loss during water treatment. NaHSO3 sterilizes and disinfects wastewater, reducing oxidative pollutants in it, lowering its color and COD, and further purifying it. The highly efficient sewage treatment agent prepared by the present invention exhibits excellent flocculation and adsorption capabilities, rapidly adsorbing pollutants, exhibits excellent stability, can be easily separated by magnetic fields, can be recycled multiple times, is low in cost, and does not cause secondary pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of heavy metal ion removal rate and BOD removal rate of the high-efficiency sewage treatment agent prepared in Examples 1-3 of the present invention and Comparative Examples 1-3;

[0023] Figure 2Schematic diagram of the adsorption amount of the high-efficiency sewage treatment agent prepared in Example 1 and Comparative Examples 1-3 of the present invention over time;

[0024] Figure 3 Schematic diagram of the stability of the high-efficiency sewage treatment agents prepared in Examples 1-3 of the present invention and Comparative Examples 1-3. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solution of the present invention and to make the above-mentioned features, purposes and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with examples. The examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0026] It should be noted that, unless otherwise specified, all chemical reagents involved in the present invention were purchased through commercial channels.

[0027] Example 1: This example provides a high-efficiency sewage treatment agent, which is composed of the following raw materials in parts by weight: 20 parts of CaWO4 / ZIF-67 composite material, 20 parts of Al2(SO4)3, 5 parts of Fe2O3, 1 part of Na2SiO3, 0.5 parts of NaHSO3, and 3 parts of MnO2;

[0028] The preparation method of the CaWO4 / ZIF-67 composite material specifically comprises the following steps:

[0029] S1. Weigh Ca(NO3)2·4H2O and dissolve it in ethylene glycol at a ratio of 0.1 g:7 mL to form a first solution. Weigh Na2WO4·2H2O and dissolve it in deionized water at a ratio of 0.1 g:15 mL to form a second solution at a molar ratio of 1:1 to Ca(NO3)2·4H2O. Then, slowly pour the second solution into the first solution and stir it in a magnetic stirrer at 180 rpm and 70°C to form a mixture.

[0030] S2, the mixture obtained in step S1 was transferred to a 100 mL polytetrafluoroethylene-lined reactor for hydrothermal reaction at a temperature of 180°C for 24 h. After the reaction was completed, the mixture was cooled to room temperature to obtain a white precipitate. The obtained white precipitate was washed alternately with ethanol and deionized water three times, dried in an oven at 70°C for 12 h, and then taken out and ground to obtain CaWO4;

[0031] S3, CTAB and Co(NO3)2·6H2O were added to deionized water in a ratio of 1 mg:0.15 g:2.5 mL. Ultrasonic treatment was performed at 240 W for 15 min to form a uniform solution A. C4H6N2 and Fe3O4 were added to anhydrous ethanol to obtain solution B in a ratio of 1 g:0.5 g:10 mL. Solution A was slowly poured into solution B and mixed to form a mixed solution.

[0032] S4, adding CaWO4 prepared in step S2 to the mixed solution obtained in step S3, with the amount ratio of CaWO4 to the mixed solution being 0.1 g:25 mL, treating with an ultrasonic cleaner at 240 W for 30 min to mix, drying to obtain a composite material precursor, and then calcining at 400 ° C for 4 h to obtain a CaWO4 / ZIF-67 composite material.

[0033] This embodiment also provides a method for preparing a high-efficiency sewage treatment agent, which specifically includes the following steps:

[0034] Y1, weigh 20 parts of Al2(SO4)3 and 5 parts of Fe2O3, dissolve them in deionized water, and stir at 200 rpm to form a mixed solution;

[0035] Y2, weighing 20 parts of CaWO4 / ZIF-67 composite material and 0.5 parts of NaHSO3, adding them to the mixed solution obtained in step Y1, and mixing them at 70°C and 200 rpm with magnetic stirring to form a suspension;

[0036] Y3. Add 1 part of Na2SiO3 and 3 parts of MnO2 to the suspension obtained in step Y2, stir and mix at 300 rpm, let it stand for 30 minutes, then centrifuge and dry to obtain a high-efficiency sewage treatment agent.

[0037] Example 2: This example provides a high-efficiency sewage treatment agent, which is composed of the following raw materials in parts by weight: 25 parts of CaWO4 / ZIF-67 composite material, 15 parts of Al2(SO4)3, 8 parts of Fe2O3, 3 parts of Na2SiO3, 1.2 parts of NaHSO3, and 9 parts of MnO2;

[0038] The preparation method of the CaWO4 / ZIF-67 composite material specifically comprises the following steps:

[0039] S1. Weigh Ca(NO3)2·4H2O and dissolve it in ethylene glycol at a ratio of 0.1 g:7 mL to form a first solution. Weigh Na2WO4·2H2O and dissolve it in deionized water at a ratio of 0.1 g:15 mL to form a second solution at a molar ratio of 1:1 to Ca(NO3)2·4H2O. Then, slowly pour the second solution into the first solution and stir it in a magnetic stirrer at 240 rpm and 70°C to form a mixture.

[0040] S2, the mixture obtained in step S1 was transferred to a 100 mL polytetrafluoroethylene-lined reactor for hydrothermal reaction at a temperature of 180°C for 24 h. After the reaction was completed, the mixture was cooled to room temperature to obtain a white precipitate. The obtained white precipitate was washed alternately with ethanol and deionized water three times, dried in an oven at 70°C for 12 h, and then taken out and ground to obtain CaWO4;

[0041] S3, CTAB and Co(NO3)2·6H2O were added to deionized water in a ratio of 1 mg:0.15 g:2.5 mL. Ultrasonic treatment was performed at 240 W for 15 min to form a uniform solution A. C4H6N2 and Fe3O4 were added to anhydrous ethanol to obtain solution B in a ratio of 1 g:0.5 g:10 mL. Solution A was slowly poured into solution B and mixed to form a mixed solution.

[0042] S4, adding CaWO4 prepared in step S2 to the mixed solution obtained in step S3, with the amount ratio of CaWO4 to the mixed solution being 0.3 g:25 mL, treating with an ultrasonic cleaner at 240 W for 30 min to mix, drying to obtain a composite material precursor, and then calcining at 400 ° C for 5 h to obtain a CaWO4 / ZIF-67 composite material.

[0043] This embodiment also provides a method for preparing a high-efficiency sewage treatment agent, which specifically includes the following steps:

[0044] Y1, weigh 15 parts of Al2(SO4)3 and 8 parts of Fe2O3, dissolve them in deionized water, and stir at 400 rpm to form a mixed solution;

[0045] Y2, weighing 25 parts of CaWO4 / ZIF-67 composite material and 1.2 parts of NaHSO3, adding them to the mixed solution obtained in step Y1, and mixing them at 80°C and 200 rpm with magnetic stirring to form a suspension;

[0046] Y3. Add 3 parts of Na2SiO3 and 9 parts of MnO2 to the suspension obtained in step Y2, stir and mix at 300 rpm, let it stand for 45 minutes, then centrifuge and dry to obtain a high-efficiency sewage treatment agent.

[0047] Example 3: This example provides a high-efficiency sewage treatment agent, which is composed of the following raw materials in parts by weight: 30 parts of CaWO4 / ZIF-67 composite material, 10 parts of Al2(SO4)3, 10 parts of Fe2O3, 5 parts of Na2SiO3, 2 parts of NaHSO3, and 15 parts of MnO2;

[0048] The preparation method of the CaWO4 / ZIF-67 composite material specifically comprises the following steps:

[0049] S1. Weigh Ca(NO3)2·4H2O and dissolve it in ethylene glycol at a ratio of 0.1 g:7 mL to form a first solution. Weigh Na2WO4·2H2O and dissolve it in deionized water at a ratio of 0.1 g:15 mL to form a second solution at a molar ratio of 1:1 to Ca(NO3)2·4H2O. Then, slowly pour the second solution into the first solution and stir the mixture in a magnetic stirrer at 300 rpm and 70°C to form a mixture.

[0050] S2, the mixture obtained in step S1 was transferred to a 100 mL polytetrafluoroethylene-lined reactor for hydrothermal reaction at a temperature of 180°C for 24 h. After the reaction was completed, the mixture was cooled to room temperature to obtain a white precipitate. The obtained white precipitate was washed alternately with ethanol and deionized water three times, dried in an oven at 70°C for 12 h, and then taken out and ground to obtain CaWO4;

[0051] S3, CTAB and Co(NO3)2·6H2O were added to deionized water in a ratio of 1 mg:0.15 g:2.5 mL. Ultrasonic treatment was performed at 240 W for 15 min to form a uniform solution A. C4H6N2 and Fe3O4 were added to anhydrous ethanol to obtain solution B in a ratio of 1 mg:0.15 g:2.5 mL. Solution A was slowly poured into solution B and mixed uniformly to form a mixed solution.

[0052] S4, adding CaWO4 prepared in step S2 to the mixed solution obtained in step S3, with the amount ratio of CaWO4 to the mixed solution being 0.5 g:25 mL, treating with an ultrasonic cleaner at 240 W for 30 min to mix, drying to obtain a composite material precursor, and then calcining at 400 ° C for 4-6 h to obtain a CaWO4 / ZIF-67 composite material.

[0053] This embodiment also provides a method for preparing a high-efficiency sewage treatment agent, which specifically includes the following steps:

[0054] Y1, weigh 10 parts of Al2(SO4)3 and 10 parts of Fe2O3, dissolve them in deionized water, and stir at 500 rpm to form a mixed solution;

[0055] Y2, weighing 30 parts of CaWO4 / ZIF-67 composite material and 2 parts of NaHSO3, adding them to the mixed solution obtained in step Y1, and mixing them at 90°C and 200 rpm with magnetic stirring to form a suspension;

[0056] Y3. Add 5 parts of Na2SiO3 and 15 parts of MnO2 to the suspension obtained in step Y2, stir and mix at 300 rpm, let it stand for 60 minutes, then centrifuge and dry to obtain a high-efficiency sewage treatment agent.

[0057] The difference between Comparative Example 1 and Example 1 is that no CaWO4 / ZIF-67 composite material is added, and the rest is the same as Example 1.

[0058] The difference between Comparative Example 2 and Example 1 is that no Al2(SO4)3 is added, and the rest is the same as Example 1.

[0059] The difference between Comparative Example 3 and Example 1 is that no MnO2 is added, and the rest is the same as Example 1.

[0060] Experimental Example Industrial wastewater discharged from the same batch was divided into 6 groups for testing, namely Examples 1-3 and Comparative Examples 1-3, with a dosage of 0.2 g / L, and the COD removal rate, suspended solids removal rate and ammonia nitrogen removal rate of the high-efficiency sewage treatment agent prepared by the present invention were measured.

[0061] Experimental Example 1: The chemical oxygen demand (COD) content in wastewater was determined using the national standard GB11914-89 "COD Determination by Dichromate Method." 20 mL of each sample was placed in a glass bottle for testing. 10.0 mL of potassium dichromate standard solution and several explosion-proof glass beads were added to each sample and shaken thoroughly. The conical flask was connected to the lower end of the condenser of a reflux system and connected to the condenser water. 30 mL of silver sulfate-sulfuric acid reagent was slowly added from the upper end of the condenser to prevent the escape of low-boiling-point organic matter, swirling the conical flask continuously to ensure uniform mixing. Refluxed for two hours from the time the solution began to boil. After cooling, the condenser was rinsed from the upper end with 30 mL of water, the conical flask was removed, and the solution was diluted to approximately 140 mL with water. After the solution cooled to room temperature, 3 drops of 1,10-phenanthroline indicator solution were added and titrated with ferrous ammonium sulfate standard titrant. The endpoint was reached when the solution's color changed from yellow to blue-green to reddish-brown. Record the number of milliliters (V2) of standard ammonium sulfate titration solution consumed. The chemical oxygen demand (COD) of the water sample, expressed in mg / L, is calculated using the following formula: COD (mg / L) = c × (V1-V2) × 8000 / V0. Where: C is the concentration of standard ammonium sulfate titration solution (4.6), mol / L; V1 is the volume of standard ammonium sulfate titration solution consumed in the blank test, mL; V2 is the volume of standard ammonium sulfate titration solution consumed in the sample determination, mL; V0 is the volume of the sample, mL; and 8000 is the conversion value of 1 / 4 the molar mass of O2 in mg / L. The COD removal rate is calculated based on the calculated chemical oxygen demand, and the results are recorded in Table 1.

[0062] Experimental Example 2: Suspended solids were determined according to the weight method specified in the national standard GB11901-89. The test steps are as follows: (1) Preparation of the filter membrane: Place the filter membrane in a weighing bottle and place it in an oven at 105°C for drying. After drying for half an hour, place the filter membrane in a desiccator and weigh the filter membrane after cooling to room temperature. Repeat the above steps until the difference between the two weighings of the filter membrane is less than 0.2 mg. Place the filter membrane on the filter tray, moisten the filter membrane with distilled water, and continue to filter. (2) Determination of suspended solids: Filter 100 mL of thoroughly shaken water sample to allow all water to pass through the filter membrane. Wash the filter membrane with distilled water three times, 10 mL each time, and continue to filter to remove excess water. After the filtration stops, place the filter membrane containing suspended solids in the original weighing bottle, then dry it in an oven at 105°C for one hour, then place it in a desiccator to cool, and weigh the total weight of the filter membrane, suspended solids, and weighing bottle. Repeat the steps in (2) until the difference between the two weighed total weights is less than 0.4 mg. The content of suspended matter is calculated according to the following formula: C = (AB) × 10 4 / V, where C is the concentration of suspended solids in water, in mg / L; A is the total weight of the filter membrane, suspended solids, and weighing bottle, in g; E is the weight of the filter membrane and weighing bottle, in g; V6 is the volume of the water sample, in mL. The removal rate of suspended solids is calculated based on the results, and the results are recorded in Table 1.

[0063] Experimental Example 3: According to the Nessler reagent colorimetric method specified in the national standard GB-T 7479-1987, the ammonia nitrogen content in sewage was determined. 10 mg / L ammonia nitrogen standard solution was accurately pipetted at 0, 0.50, 1.00, 2.00, 6.00, 8.00, and 10.00 mL using a pipette. 1.00 mL KNaC4H4O6 solution and 1.5 mL Nessler reagent were added. The volume was made up to 50 mL with ultrapure water. The mixture was evenly mixed and allowed to stand for 10 min. The mixture was then heated at 420°C for 10 min. The absorbance was measured at 400 nm, with ultrapure water as the blank sample. The difference between the measured absorbance in the water sample and the blank sample was used to obtain the ammonia nitrogen mass (mg) from the calibration standard curve. The ammonia nitrogen content was calculated using the following formula: ammonia nitrogen (NH3-N, mg / L) = m / V×1000, where m is the ammonia nitrogen compound content on the calibration standard curve, mg; V is the volume of the test water sample, mL. The ammonia nitrogen removal rate was calculated by measuring the ammonia nitrogen content, and the calculation results are recorded in Table 1.

[0064] Table 1

[0065]

[0066] The results in Table 1 show that the COD removal rates of Examples 1-3 of the present invention are significantly higher than those of the comparative example, indicating that the present invention successfully prepares a high-efficiency sewage treatment agent, and the removal rate of suspended solids reaches 99.5%, indicating that the sewage treatment agent can quickly separate suspended solids from sewage. From the results of ammonia nitrogen removal, the high-efficiency sewage treatment agent prepared by the present invention can effectively remove ammonia nitrogen and purify sewage, indicating that the sewage treatment agent prepared by the present invention has a good sewage decomposition effect through the interaction between materials.

[0067] Figure 1 The results showed that the high-efficiency sewage treatment agent prepared by the present invention had a removal rate of 99.6% for heavy metal ions and a BOD removal rate of 95.8%, indicating that the sewage treatment agent prepared by the present invention has a good function of removing heavy metal ions in sewage. Figure 2 It shows that adsorption saturation is reached at approximately 60 minutes, indicating that the sewage treatment agent prepared by the present invention can quickly adsorb pollutants in water and purify sewage; Figure 3 The high-efficiency sewage treatment agent prepared by the present invention has a heavy metal removal rate of 93.2% after 5 repeated experiments, indicating that the sewage treatment agent prepared by the present invention has good stability and can be reused many times.

[0068] In summary, it can be seen from the examples and comparative examples that the present invention increases active substances, improves adsorption efficiency, and improves overall stability through the compounding of CaWO4 and ZIF-67. At the same time, combined with the strong flocculation effect of Al2(SO4)3 and Fe2O3, the suspended matter in the sewage can be quickly settled and separated, and MnO2 helps to catalyze the composite material and accelerate the adsorption efficiency. The CaWO4 / ZIF-67 composite material provides mechanical support for MnO2, protecting it from continuing to play a role in the sewage treatment process. The high-efficiency sewage treatment agent prepared by the present invention has good flocculation and adsorption capacity, can quickly adsorb pollutants, has good stability, and has potential promotion value in the treatment of domestic sewage, industrial wastewater, etc.

[0069] The present invention and its embodiments are described above. Such description is not restrictive. The drawings show only one embodiment of the present invention, and actual applications are not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, any method and embodiment similar to the technical solution without creative design shall fall within the scope of protection of the present invention.

Claims

1. A high-efficiency sewage treatment agent, characterized in that: The high-efficiency sewage treatment agent is composed of the following raw materials in parts by weight: 20-30 parts of CaWO4 / ZIF-67 composite material, 10-20 parts of Al2(SO4)3, 5-10 parts of Fe2O3, 1-5 parts of Na2SiO3, 0.5-2 parts of NaHSO3, and 3-15 parts of MnO2; The raw materials for preparing the CaWO4 / ZIF-67 composite material are: Ca(NO3)2·4H2O, Na2WO4·2H2O, Co(NO3)2·6H2O, CTAB, C4H6N2 and Fe3O4; The preparation method of the CaWO4 / ZIF-67 composite material specifically comprises the following steps: S1, weighing Ca(NO3)2·4H2O and dissolving it in ethylene glycol to form a first solution, weighing Na2WO4·2H2O and dissolving it in deionized water to form a second solution, then pouring the second solution into the first solution, stirring and mixing to form a mixture; S2, subjecting the mixture obtained in step S1 to a hydrothermal reaction, cooling the mixture to room temperature after the reaction is complete to obtain a white precipitate, washing the obtained white precipitate, drying it, and grinding it to obtain CaWO4; S3, CTAB and Co(NO3)2·6H2O were added to deionized water and ultrasonically treated to form a uniform solution A. C4H6N2 and Fe3O4 were added to anhydrous ethanol to obtain solution B. Solution A was slowly poured into solution B and mixed to form a mixed solution; S4, adding the CaWO4 prepared in step S2 to the mixed solution obtained in step S3, ultrasonically mixing, and drying to obtain a composite material precursor, and then calcining the composite material precursor to obtain a CaWO4 / ZIF-67 composite material.

2. A high-efficiency sewage treatment agent according to claim 1, characterized in that: In step S1, the molar ratio of Ca(NO3)2·4H2O to Na2WO4·2H2O is 1:1, the amount ratio of Ca(NO3)2·4H2O to ethylene glycol is 0.1 g:7 mL, and the amount ratio of Na2WO4·2H2O to deionized water is 0.1 g:15 mL. The stirring is magnetic stirring at a speed of 180-300 rpm, and the temperature is set to 70 °C.

3. A high-efficiency sewage treatment agent according to claim 1, characterized in that: In step S2, the hydrothermal reaction is carried out in a 100 mL polytetrafluoroethylene-lined reactor, the temperature is set to 180° C., and the reaction time is set to 24 h.

4. A high-efficiency sewage treatment agent according to claim 1, characterized in that: In step S3, the usage ratio of CTAB, Co(NO3)2·6H2O and deionized water is 1 mg:0.15 g:2.5 mL, the usage ratio of C4H6N2, Fe3O4 and anhydrous ethanol is 1 g:0.5 g:10 mL, and the volume ratio of solution A to solution B is 1:

12.

5. A high-efficiency sewage treatment agent according to claim 1, characterized in that: In step S4, the ratio of CaWO4 to the mixed solution is 0.1-0.5 g:25 mL.

6. A high-efficiency sewage treatment agent according to claim 1, characterized in that: In step S4, the calcination is carried out by uniformly heating to 400° C. at a heating rate of 5° C. / min at room temperature, and maintaining the calcination at this temperature for 2-4 hours.

7. A method for preparing a high-efficiency sewage treatment agent according to any one of claims 1 to 6, characterized in that: The specific steps include: Y1, weigh Al2(SO4)3 and Fe2O3 by weight, dissolve them in deionized water, and stir at 200-500 rpm to form a mixed solution; Y2, weighing the CaWO4 / ZIF-67 composite material and NaHSO3 in parts by weight, adding them to the mixed solution obtained in step Y1, and mixing them at 70-90°C and 200 rpm with magnetic stirring to form a suspension; Y3. Add Na2SiO3 and MnO2 to the suspension obtained in step Y2, stir and mix at 300 rpm, let it stand for 30-60 min, then centrifuge and dry to obtain a high-efficiency sewage treatment agent.

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