Efficient flocculant for sewage treatment and preparation method thereof
By constructing a high-efficiency flocculant with multiple flocculation networks, the problems of simple structure and few adsorption sites of existing flocculants are solved, enabling efficient treatment of complex wastewater, improving flocculation rate and floc strength, and increasing wastewater treatment efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-02
- Publication Date
- 2026-04-14
AI Technical Summary
Existing flocculants for wastewater treatment have a simple flocculation network structure and few adsorption sites, resulting in low overall treatment efficiency for complex wastewater.
A high-efficiency flocculant composed of inorganic components, organic components, composite additives, silane coupling agents, and framework materials is adopted. The first and second additives in the composite additives form a highly efficient synergistic system, and combined with the interfacial coupling effect of the silane coupling agent, a multi-layer flocculation network is constructed to enhance floc strength and adsorption sites, thereby improving the flocculation rate.
It improves the efficiency of wastewater treatment, enhances the ability to capture phosphate, heavy metal ions and fine suspended particles in water, promotes the rapid formation of flocculation intermediates and the rapid growth of flocs, improves the sedimentation effect of flocculants, and increases the flocculation rate and solid-liquid separation efficiency.
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Figure CN121850170A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wastewater treatment materials technology, specifically to a high-efficiency flocculant for wastewater treatment and its preparation method. Background Technology
[0002] Wastewater treatment flocculants are chemical agents that achieve solid-liquid separation by neutralizing charges and bridging dissolved pollutants in water to aggregate into large flocs. Their core functions include rapidly reducing turbidity and removing COD and heavy metal ions. They are suitable for various scenarios such as industrial wastewater and domestic sewage.
[0003] In existing technologies, flocculants used for wastewater treatment have simple flocculation network structures and few adsorption sites, resulting in low efficiency in the comprehensive treatment of complex wastewater. Therefore, this invention provides a high-efficiency flocculant for wastewater treatment and its preparation method. Summary of the Invention
[0004] The purpose of this invention is to provide a high-efficiency flocculant for wastewater treatment and its preparation method. The high-efficiency flocculant for wastewater treatment prepared by this invention has high wastewater treatment efficiency and effectively improves the performance of flocculants for wastewater treatment.
[0005] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a high-efficiency flocculant for wastewater treatment, characterized in that it is made from the following raw materials in parts by weight: 40-60 parts inorganic components, 20-35 parts organic components, 5-10 parts composite additives, 0.5-1.5 parts silane coupling agent, and 5-10 parts skeleton material.
[0006] Furthermore, the inorganic component is composed of polyaluminum chloride, polyferric sulfate and nano silica gel in a mass ratio of (13-15):(4-6):(1-3).
[0007] Furthermore, the organic component is composed of corn starch and polyacrylamide in a mass ratio of (14-17):(3-6), wherein the corn starch is pretreated before preparing the high-efficiency flocculant for wastewater treatment.
[0008] Furthermore, the composite additive is prepared from a first additive and a second additive.
[0009] Further, the preparation method of the composite additive is as follows: the first additive and the second additive are mixed at a mass ratio of 1:(2-4), potassium persulfate is added, and the mixture is stirred at 300 rpm for 1.5-2.5 h at 60-70℃. The inlet air temperature is set to 185-195℃, the outlet air temperature to 80-90℃, and the atomization pressure to 0.2-0.4 MPa. The mixture is then spray-dried for 20-30 min to obtain the composite additive, wherein the mass of potassium persulfate is 0.1-0.3% of the total mass of the first additive and the second additive.
[0010] Furthermore, the preparation method of the first additive is as follows: (1) Heat the composite to 60°C, add sodium dodecyl sulfate at 0.1-0.3% of the composite mass, stir at 500 rpm for 20-30 min to obtain the pretreated composite; (2) Prepare a 1-3 wt% aqueous solution of the powder and disperse it by ultrasonication at 300W for 20-40 min to obtain a suspension; (3) Mix the pretreated complex with the suspension at a mass ratio of (2-4):1, stir at 500 rpm for 1 h at 55-65℃, let stand at 3-5℃ for 10-15 h, centrifuge at 8000 rpm for 5-15 min, freeze dry to obtain the first additive.
[0011] Further, the preparation method of the complex is as follows: first, cerium nitrate is mixed with 4-6% oxalic acid solution at a mass ratio of 1:(2-4), stirred at 40℃ for 30 min, the mixture is vacuum filtered, the filter membrane pore size is 0.45 μm, the filtered cerium nitrate is mixed with citric acid at a mass ratio of 1:(2-4), the pH of the system is adjusted to 3-4, and the reaction is carried out at 60℃ for 1.5-2.5 h to obtain the complex.
[0012] Further, the preparation method of the powder is as follows: oyster shells are cleaned and crushed to 100-200μm, 10wt% hydrochloric acid solution is added at a solid-liquid ratio of 1:(9-11), stirred at 200-300rpm for 24h at 25℃, filtered, and the filter residue is washed with water until neutral. The filter residue is added with 5wt% sodium hydroxide solution at a solid-liquid ratio of 1:(7-9), stirred in a water bath at 200-300rpm for 6h at 90℃, filtered, and the filter residue is washed with water until neutral. The powder is vacuum dried at 55-65℃ to constant weight. The dried powder is mixed with 85wt% concentrated phosphoric acid at a mass ratio of 1:(14-16), hydrolyzed at 80-90℃ for 30min, centrifuged at 8000rpm for 10-20min, and freeze-dried to obtain the powder.
[0013] Further, the preparation method of the second additive is as follows: acrylamide and dimethyl diallyl ammonium chloride are mixed in a molar ratio of (3-5):1, and initiator V50 is added. The mixture is polymerized at 55-65°C for 4-6 hours to obtain the second additive. The mass of initiator V50 is 0.04-0.06% of the total mass of acrylamide and dimethyl diallyl ammonium chloride monomer.
[0014] Furthermore, the pretreatment method for the corn starch is as follows: first, prepare a 15wt% aqueous solution of corn starch, add cationic etherifying agent QA-188, adjust the pH of the system to 10, and react at 60-70℃ for 3-5 hours to obtain pretreated corn starch, wherein the mass of cationic etherifying agent QA-188 is 10-20% of the mass of corn starch.
[0015] Furthermore, the silane coupling agent is KH-570.
[0016] Furthermore, the skeleton material is a mixture of diatomaceous earth, perlite and zeolite in a mass ratio of 5:3:2, and the particle size of the three is 50 μm.
[0017] Secondly, the present invention provides a high-efficiency flocculant for wastewater treatment, characterized by comprising the following steps: S1: Mix polyaluminum chloride, polyferric sulfate and nano silica gel, and ultrasonically disperse at 300W for 1 hour at 35-45℃ to obtain the inorganic component. Then mix corn starch and polyacrylamide, and stir at 400rpm for 1 hour at 65-75℃ to obtain the organic component. S2: Mix the inorganic and organic components, adjust the pH of the system to 4.5-5.5, and stir at 400 rpm for 1-2 hours at 65-75℃ to obtain the composite component; S3: Add composite additives, silane coupling agents and pretreated diatomaceous earth to the composite components, stir at 100-200 rpm for 1-2 hours at 50℃, spray dry at 185-195℃ and 80-90℃ for 20-30 minutes, and pass through a 100-mesh sieve to obtain a high-efficiency flocculant for wastewater treatment.
[0018] Compared with the prior art, the beneficial effects of the present invention are: In this invention, a highly efficient synergistic system is formed by the first and second additives in the composite additive. The first additive, with a cerium-containing complex and modified oyster shell powder as the active center, has a strong chelating and adsorption effect on phosphate, heavy metal ions and fine suspended particles in water, and quickly forms a stable flocculation intermediate. The second additive is a cationic copolymer, which can increase the charge density of the system, enhance charge neutralization and adsorption bridging capabilities, and promote the rapid growth and compaction of flocs. Combined with the interfacial coupling effect of silane coupling agent, it improves the compatibility and dispersion stability of inorganic and organic components. Pre-treated corn starch further enhances water solubility and bridging effect. Loaded on a framework of diatomaceous earth, perlite and zeolite, it forms a multi-layer flocculation network, increases adsorption sites and floc strength, and improves the defects of conventional flocculants such as slow settling and loose flocs, effectively improving the flocculation rate and further improving the wastewater treatment efficiency. Attached Figure Description
[0019] Figure 1 The present invention provides a flowchart of a high-efficiency flocculant for wastewater treatment and its preparation method. Detailed Implementation
[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0021] It should be noted that the raw materials used in the following embodiments are all commercially available.
[0022] Example 1: Prepare the following raw materials by weight: 40 parts inorganic components, 20 parts organic components, 5 parts composite additives, 0.5 parts silane coupling agent, and 5 parts skeleton material; The silane coupling agent is KH-570; The skeleton material is a mixture of diatomaceous earth, perlite and zeolite in a mass ratio of 5:3:2, with a particle size of 50 μm.
[0023] Preparation of the complex: First, cerium nitrate and 4% oxalic acid solution were mixed at a mass ratio of 1:2 and stirred at 40℃ for 30 min. The mixture was then vacuum filtered with a filter membrane with a pore size of 0.45 μm. The filtered cerium nitrate was then mixed with citric acid at a mass ratio of 1:2. The pH of the system was adjusted to 3 and the mixture was reacted at 60℃ for 1.5 h to obtain the complex.
[0024] Preparation of powder: Oyster shells were cleaned and crushed to 100 μm. 10 wt% hydrochloric acid solution was added at a solid-liquid ratio of 1:9. The mixture was stirred at 200 rpm for 24 h at 25 °C. After filtration, the filter residue was washed with water until neutral. 5 wt% sodium hydroxide solution was added to the filter residue at a solid-liquid ratio of 1:7. The mixture was stirred in a water bath at 200 rpm for 6 h at 90 °C. After filtration, the filter residue was washed with water until neutral. The mixture was vacuum dried at 55 °C to constant weight. The resulting dry powder was mixed with 85 wt% concentrated phosphoric acid at a mass ratio of 1:14. The mixture was hydrolyzed at 80 °C for 30 min, centrifuged at 8000 rpm for 10 min, and freeze-dried to obtain the powder.
[0025] Preparation of the first additive: (1) Heat the composite to 60°C, add sodium dodecyl sulfate at 0.1% of the composite mass, stir at 500 rpm for 20 min to obtain the pretreated composite; (2) Prepare a 1wt% aqueous solution of the powder and disperse it by ultrasonication at 300W for 20min to obtain a suspension; (3) The pretreated complex and the suspension were mixed at a mass ratio of 2:1, stirred at 500 rpm for 1 h at 55 °C, then allowed to stand at 3 °C for 10 h, centrifuged at 8000 rpm for 5 min, and freeze-dried to obtain the first additive.
[0026] Preparation of composite additive: The first additive and the second additive are mixed at a mass ratio of 1:2, and then potassium persulfate is added. The mixture is stirred at 300 rpm for 1.5 h at 60 °C. The inlet air temperature is set to 185 °C, the outlet air temperature to 80 °C, and the atomization pressure to 0.2 MPa. The mixture is then spray-dried for 20 min to obtain the composite additive. The mass of potassium persulfate is 0.1% of the total mass of the first additive and the second additive.
[0027] Preparation of the second additive: Acrylamide and dimethyl diallyl ammonium chloride were mixed in a molar ratio of 3:1, and then initiator V50 was added. The mixture was polymerized at 55°C for 4 hours to obtain the second additive. The mass of initiator V50 was 0.04% of the total mass of acrylamide and dimethyl diallyl ammonium chloride monomer.
[0028] Pretreated corn starch: First, prepare a 15wt% aqueous solution of corn starch, add cationic etherifying agent QA-188, adjust the pH of the system to 10, and react at 60℃ for 3h to obtain pretreated corn starch. The mass of cationic etherifying agent QA-188 is 10% of the mass of corn starch.
[0029] Preparation of high-efficiency flocculants for wastewater treatment: S1: Polyaluminum chloride, polyferric sulfate and nano silica gel are mixed and ultrasonically dispersed at 300W for 1 hour at 35°C to obtain the inorganic component. Then, corn starch and polyacrylamide are mixed and stirred at 400rpm for 1 hour at 65°C to obtain the organic component. S2: Mix the inorganic and organic components, adjust the pH of the system to 4.5, and stir at 400 rpm for 1 hour at 65°C to obtain the composite component; S3: Add composite additives, silane coupling agents and pretreated diatomaceous earth to the composite components, stir at 100 rpm for 1 hour at 50°C, spray dry at 185°C inlet air temperature and 80°C outlet air temperature for 20 minutes, and pass through a 100-mesh sieve to obtain a high-efficiency flocculant for wastewater treatment.
[0030] Example 2: Prepare the following raw materials by weight: 50 parts inorganic components, 28 parts organic components, 8 parts composite additives, 1 part silane coupling agent, and 8 parts skeleton material. The silane coupling agent is KH-570; The skeleton material is a mixture of diatomaceous earth, perlite and zeolite in a mass ratio of 5:3:2, with a particle size of 50 μm.
[0031] Preparation of the complex: First, cerium nitrate and 5% oxalic acid solution were mixed at a mass ratio of 1:3 and stirred at 40℃ for 30 min. The mixture was then vacuum filtered with a filter membrane with a pore size of 0.45 μm. The filtered cerium nitrate was then mixed with citric acid at a mass ratio of 1:3. The pH of the system was adjusted to 3.5 and reacted at 60℃ for 2 h to obtain the complex.
[0032] Preparation of powder: Oyster shells were cleaned and crushed to 150 μm. 10 wt% hydrochloric acid solution was added at a solid-liquid ratio of 1:10. The mixture was stirred at 250 rpm for 24 h at 25 °C. After filtration, the filter residue was washed with water until neutral. 5 wt% sodium hydroxide solution was added to the filter residue at a solid-liquid ratio of 1:8. The mixture was stirred in a water bath at 250 rpm for 6 h at 90 °C. After filtration, the filter residue was washed with water until neutral. The mixture was vacuum dried at 60 °C to constant weight. The resulting dry powder was mixed with 85 wt% concentrated phosphoric acid at a mass ratio of 1:15. The mixture was hydrolyzed at 85 °C for 30 min, centrifuged at 8000 rpm for 15 min, and freeze-dried to obtain the powder.
[0033] Preparation of the first additive: (1) Heat the composite to 60°C, add sodium dodecyl sulfate at 0.2% of the composite mass, stir at 500 rpm for 25 min to obtain the pretreated composite; (2) Prepare a 2wt% aqueous solution of the powder and disperse it by ultrasonication at 300W for 30min to obtain a suspension; (3) The pretreated complex and the suspension were mixed at a mass ratio of 3:1, stirred at 500 rpm for 1 h at 60 °C, then allowed to stand at 4 °C for 12 h, centrifuged at 8000 rpm for 10 min, and freeze-dried to obtain the first additive.
[0034] Preparation of composite additive: The first additive and the second additive are mixed at a mass ratio of 1:3, and then potassium persulfate is added. The mixture is stirred at 300 rpm for 2 hours at 65°C. The inlet air temperature is set to 190°C, the outlet air temperature to 85°C, and the atomization pressure to 0.3 MPa. The mixture is then spray-dried for 25 minutes to obtain the composite additive. The mass of potassium persulfate is 0.2% of the total mass of the first additive and the second additive.
[0035] Preparation of the second additive: Acrylamide and dimethyl diallyl ammonium chloride were mixed in a molar ratio of 4:1, and initiator V50 was added. The mixture was polymerized at 60°C for 5 hours to obtain the second additive. The mass of initiator V50 was 0.05% of the total mass of acrylamide and dimethyl diallyl ammonium chloride monomer.
[0036] Pretreated corn starch: First, prepare a 15wt% aqueous solution of corn starch, add cationic etherifying agent QA-188, adjust the pH of the system to 10, and react at 65℃ for 4 hours to obtain pretreated corn starch. The mass of cationic etherifying agent QA-188 is 15% of the mass of corn starch.
[0037] Preparation of high-efficiency flocculants for wastewater treatment: S1: Polyaluminum chloride, polyferric sulfate and nano silica gel are mixed and ultrasonically dispersed at 300W for 1 hour at 40℃ to obtain the inorganic component. Then, corn starch and polyacrylamide are mixed and stirred at 400rpm for 1 hour at 70℃ to obtain the organic component. S2: Mix the inorganic and organic components, adjust the pH of the system to 5, and stir at 400 rpm for 1.5 h at 70°C to obtain the composite component; S3: Add composite additives, silane coupling agents and pretreated diatomaceous earth to the composite components, stir at 150 rpm for 1.5 h at 50 °C, spray dry at 190 °C and 85 °C for 25 min, and pass through a 100-mesh sieve to obtain a high-efficiency flocculant for wastewater treatment.
[0038] Example 3: Prepare the following raw materials by weight: 60 parts inorganic components, 35 parts organic components, 10 parts composite additives, 1.5 parts silane coupling agent, and 10 parts skeleton material. The silane coupling agent is KH-570; The skeleton material is a mixture of diatomaceous earth, perlite and zeolite in a mass ratio of 5:3:2, with a particle size of 50 μm.
[0039] Preparation of the complex: First, cerium nitrate and 6% oxalic acid solution were mixed at a mass ratio of 1:4 and stirred at 40℃ for 30 min. The mixture was then vacuum filtered with a filter membrane with a pore size of 0.45 μm. The filtered cerium nitrate was then mixed with citric acid at a mass ratio of 1:4. The pH of the system was adjusted to 4, and the mixture was reacted at 60℃ for 2.5 h to obtain the complex.
[0040] Preparation of powder: Oyster shells were cleaned and crushed to 200 μm. 10 wt% hydrochloric acid solution was added at a solid-liquid ratio of 1:11. The mixture was stirred at 300 rpm for 24 h at 25 °C. After filtration, the filter residue was washed with water until neutral. 5 wt% sodium hydroxide solution was added to the filter residue at a solid-liquid ratio of 1:9. The mixture was stirred in a water bath at 300 rpm for 6 h at 90 °C. After filtration, the filter residue was washed with water until neutral. The mixture was vacuum dried at 65 °C to constant weight. The resulting dry powder was mixed with 85 wt% concentrated phosphoric acid at a mass ratio of 1:16. The mixture was hydrolyzed at 90 °C for 30 min, centrifuged at 8000 rpm for 20 min, and freeze-dried to obtain the powder.
[0041] Preparation of the first additive: (1) Heat the composite to 60°C, add sodium dodecyl sulfate at 0.3% of the composite mass, stir at 500 rpm for 30 min to obtain the pretreated composite; (2) Prepare a 3wt% aqueous solution of the powder and disperse it by ultrasonication at 300W for 40 minutes to obtain a suspension; (3) The pretreated complex and the suspension were mixed at a mass ratio of 4:1, stirred at 500 rpm for 1 h at 65°C, then allowed to stand at 5°C for 15 h, centrifuged at 8000 rpm for 15 min, and freeze-dried to obtain the first additive.
[0042] Preparation of composite additive: The first additive and the second additive are mixed at a mass ratio of 1:4, and then potassium persulfate is added. The mixture is stirred at 300 rpm for 2.5 h at 70 °C. The inlet air temperature is set to 195 °C, the outlet air temperature to 90 °C, and the atomization pressure to 0.4 MPa. The mixture is then spray-dried for 30 min to obtain the composite additive. The mass of potassium persulfate is 0.3% of the total mass of the first additive and the second additive.
[0043] Preparation of the second additive: Acrylamide and dimethyl diallyl ammonium chloride were mixed in a molar ratio of 5:1, and initiator V50 was added. The mixture was polymerized at 65°C for 6 hours to obtain the second additive. The mass of initiator V50 was 0.06% of the total mass of acrylamide and dimethyl diallyl ammonium chloride monomer.
[0044] Pretreated corn starch: First, prepare a 15wt% aqueous solution of corn starch, add cationic etherifying agent QA-188, adjust the pH of the system to 10, and react at 70℃ for 5h to obtain pretreated corn starch. The mass of cationic etherifying agent QA-188 is 20% of the mass of corn starch.
[0045] Preparation of high-efficiency flocculants for wastewater treatment: S1: Polyaluminum chloride, polyferric sulfate and nano silica gel were mixed and ultrasonically dispersed at 300W for 1 hour at 45°C to obtain the inorganic component. Then, corn starch and polyacrylamide were mixed and stirred at 400rpm for 1 hour at 75°C to obtain the organic component. S2: Mix the inorganic and organic components, adjust the pH of the system to 5.5, and stir at 75°C and 400 rpm for 2 hours to obtain the composite component; S3: Add composite additives, silane coupling agents and pretreated diatomaceous earth to the composite components, stir at 200 rpm for 2 hours at 50°C, spray dry at 195°C inlet air temperature and 90°C outlet air temperature for 30 minutes, and pass through a 100-mesh sieve to obtain a high-efficiency flocculant for wastewater treatment.
[0046] Comparative Example 1: The difference between this comparative example and Example 1 is that this comparative example does not contain any compound additives.
[0047] Comparative Example 2 differs from Example 1 in that the first additive was not added during the preparation of the composite additive in this comparative example.
[0048] Comparative Example 3 differs from Example 1 in that the skeleton material of this comparative example is a single diatomaceous earth.
[0049] Performance testing: The high-efficiency flocculants for wastewater treatment prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance testing, and the test data are recorded in the table below: Table 1
[0050] In the performance test, the wastewater treatment efficiency was tested by measuring the transmittance of heavy metal ion solution, flocculation rate, and total phosphorus removal rate. For the transmittance test of heavy metal ion solutions, a 0.5% Pb solution was first prepared using deionized water. 2+ Ionic solutions were used to simulate wastewater. After shaking and mixing, 100 mL of the above wastewater was added to a 200 mL stoppered conical flask. Then, 0.05 g of the flocculant prepared in each group was added dropwise using a syringe. The mixture was stirred at 25 °C and 200 rpm for 30 min, filtered, and allowed to stand for 10 min. 70 mL of the supernatant was taken and its transmittance was measured using a spectrophotometer. For the flocculation rate test, first weigh 2g of dry kaolin into a beaker, add 1000mL of deionized water and stir well to prepare a simulated water sample. Measure 100mL of the simulated water sample into a graduated cylinder, add 0.1g of the flocculant prepared in each group, stir rapidly for 1min, then stir slowly for 3min, let stand for 10min, and use a pipette to draw 2mL of the supernatant 20mm below the liquid surface in the graduated cylinder. Use a spectrophotometer to measure the absorbance at 550nm. Flocculation rate = (absorbance value of the original kaolin solution - absorbance value of the supernatant after flocculant treatment) / absorbance value of the original kaolin solution × 100%; For the total phosphorus removal rate test, domestic sewage with a total phosphorus concentration of 5 mg / L was collected. 10 g of the flocculant prepared in each group was added to a 1000 mL beaker containing the domestic sewage. After stirring evenly, the mixture was allowed to settle for 30 min. The test was conducted in accordance with GB 3838-2002.
[0051] The transmittance test results of the high-efficiency flocculants for wastewater treatment prepared in Examples 1-3 and Comparative Examples 1-3 were 79.2%, 83.1%, 81.5%, 45.3%, 56.5%, and 67.4%, respectively.
[0052] The flocculation rates of the high-efficiency flocculants for wastewater treatment prepared in Examples 1-3 and Comparative Examples 1-3 were 93.1%, 96.4%, 94.8%, 71.2%, 76.8%, and 89.3%, respectively.
[0053] The total phosphorus removal rates of the high-efficiency flocculants for wastewater treatment prepared in Examples 1-3 and Comparative Examples 1-3 were 89.2%, 93.1%, 91.5%, 63.2%, 71.4%, and 79.6%, respectively.
[0054] It is evident that the wastewater treatment efficiency of the high-efficiency flocculants prepared in Comparative Examples 1-3 is lower than that in Examples 1-3. This indicates that: in the composite additive, the first additive forms a dual active center with the oyster shell powder through the cerium-based complex. The strong chelating property of the cerium group and the porous adsorption property of the oyster shell powder work synergistically to efficiently capture phosphate, heavy metal ions and fine suspended particles in the water, quickly forming stable flocculation intermediates, increasing light transmittance and flocculation rate, and effectively removing phosphate. The second additive is a cationic copolymer, which can increase the charge density of the system, enhance charge neutralization and adsorption bridging ability, and promote the rapid aggregation of flocculation intermediates into dense large flocs. The silane coupling agent KH-570 realizes the interfacial bonding of inorganic and organic components, improving the system compatibility and dispersion stability. Pretreated corn starch enhances water solubility and bridging effect. The composite framework of diatomaceous earth, perlite and zeolite constructs a multi-layer flocculation network, increasing adsorption sites while improving floc strength, accelerating solid-liquid separation and improving wastewater treatment efficiency. Comparative Example 1, lacking composite additives and consisting only of simple inorganic and organic components, showed a significant decrease in transmittance, flocculation rate, and total phosphorus removal rate, resulting in poor wastewater treatment efficiency. Comparative Example 2, lacking the primary additive, lacked the cerium-based chelation and modified oyster shell powder adsorption effects, thus failing to deeply remove phosphorus and heavy metals, and exhibited poor flocculation effects, leading to a decrease in various values. Comparative Example 3, lacking a composite framework, with diatomaceous earth alone lacking synergistic effects, failed to construct a multi-layered flocculation network, resulting in fewer adsorption sites and lower floc strength, which to some extent affected various values.
[0055] By comparing and analyzing the relevant data in the table, it can be seen that the high-efficiency flocculant for wastewater treatment prepared by this invention has a high wastewater treatment efficiency. This indicates that the high-efficiency flocculant for wastewater treatment provided by this invention has a broader market prospect and is more suitable for widespread application.
[0056] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0057] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A high-efficiency flocculant for wastewater treatment, characterized in that, It is made from the following raw materials in parts by weight: 40-60 parts inorganic components, 20-35 parts organic components, 5-10 parts composite additives, 0.5-1.5 parts silane coupling agent, and 5-10 parts skeleton material; The inorganic component is composed of polyaluminum chloride, polyferric sulfate and nano silica gel in a mass ratio of (13-15):(4-6):(1-3); The organic component is composed of corn starch and polyacrylamide in a mass ratio of (14-17):(3-6), wherein the corn starch is pretreated before preparing the high-efficiency flocculant for wastewater treatment; The composite additive is prepared from a first additive and a second additive.
2. The high-efficiency flocculant for wastewater treatment according to claim 1, characterized in that, The composite additive is prepared by mixing the first additive and the second additive at a mass ratio of 1:(2-4), then adding potassium persulfate, stirring at 300 rpm for 1.5-2.5 h at 60-70℃, spray drying for 20-30 min at an inlet air temperature of 185-195℃, an outlet air temperature of 80-90℃, and an atomization pressure of 0.2-0.4 MPa to obtain the composite additive, wherein the mass of potassium persulfate is 0.1-0.3% of the total mass of the first additive and the second additive.
3. The high-efficiency flocculant for wastewater treatment according to claim 1, characterized in that, The preparation method of the first additive is as follows: (1) Heat the composite to 60°C, add sodium dodecyl sulfate at 0.1-0.3% of the composite mass, stir at 500 rpm for 20-30 min to obtain the pretreated composite; (2) Prepare a 1-3 wt% aqueous solution of the powder and disperse it by ultrasonication at 300W for 20-40 min to obtain a suspension; (3) Mix the pretreated complex with the suspension at a mass ratio of (2-4):1, stir at 500 rpm for 1 h at 55-65℃, let stand at 3-5℃ for 10-15 h, centrifuge at 8000 rpm for 5-15 min, freeze dry to obtain the first additive.
4. The high-efficiency flocculant for wastewater treatment according to claim 3, characterized in that, The preparation method of the complex is as follows: first, cerium nitrate is mixed with 4-6% oxalic acid solution at a mass ratio of 1:(2-4), stirred at 40℃ for 30 min, the mixture is vacuum filtered, the filter membrane pore size is 0.45 μm, the filtered cerium nitrate is mixed with citric acid at a mass ratio of 1:(2-4), the pH of the system is adjusted to 3-4, and the reaction is carried out at 60℃ for 1.5-2.5 h to obtain the complex.
5. The high-efficiency flocculant for wastewater treatment according to claim 3, characterized in that, The powder is prepared as follows: Oyster shells are cleaned and crushed to 100-200 μm. 10 wt% hydrochloric acid solution is added at a solid-liquid ratio of 1:(9-11). The mixture is stirred at 200-300 rpm for 24 h at 25 °C. After filtration, the filter residue is washed with water until neutral. 5 wt% sodium hydroxide solution is added to the filter residue at a solid-liquid ratio of 1:(7-9). The mixture is stirred in a water bath at 200-300 rpm for 6 h at 90 °C. After filtration, the filter residue is washed with water until neutral. The mixture is vacuum dried at 55-65 °C to constant weight. The resulting dry powder is mixed with 85 wt% concentrated phosphoric acid at a mass ratio of 1:(14-16). The mixture is hydrolyzed at 80-90 °C for 30 min, centrifuged at 8000 rpm for 10-20 min, and freeze-dried to obtain the powder.
6. The high-efficiency flocculant for wastewater treatment according to claim 1, characterized in that, The preparation method of the second additive is as follows: acrylamide and dimethyl diallyl ammonium chloride are mixed in a molar ratio of (3-5):1, and then initiator V50 is added. The mixture is polymerized at 55-65℃ for 4-6 hours to obtain the second additive. The mass of initiator V50 is 0.04-0.06% of the total mass of acrylamide and dimethyl diallyl ammonium chloride monomer.
7. The high-efficiency flocculant for wastewater treatment according to claim 1, characterized in that, The pretreatment method for corn starch is as follows: first, prepare a 15wt% aqueous solution of corn starch, add cationic etherifying agent QA-188, adjust the pH of the system to 10, and react at 60-70℃ for 3-5 hours to obtain pretreated corn starch. The mass of cationic etherifying agent QA-188 is 10-20% of the mass of corn starch.
8. The high-efficiency flocculant for wastewater treatment according to claim 1, characterized in that, The silane coupling agent is KH-570.
9. The high-efficiency flocculant for wastewater treatment according to claim 1, characterized in that, The skeleton material is a mixture of diatomaceous earth, perlite and zeolite in a mass ratio of 5:3:2, with a particle size of 50 μm.
10. The high-efficiency flocculant for wastewater treatment according to claim 1, characterized in that, Includes the following steps: S1: Mix polyaluminum chloride, polyferric sulfate and nano silica gel, and ultrasonically disperse at 300W for 1 hour at 35-45℃ to obtain the inorganic component. Then mix corn starch and polyacrylamide, and stir at 400rpm for 1 hour at 65-75℃ to obtain the organic component. S2: Mix the inorganic and organic components, adjust the pH of the system to 4.5-5.5, and stir at 400 rpm for 1-2 hours at 65-75℃ to obtain the composite component; S3: Add composite additives, silane coupling agents and pretreated diatomaceous earth to the composite components, stir at 100-200 rpm for 1-2 hours at 50℃, spray dry at 185-195℃ and 80-90℃ for 20-30 minutes, and pass through a 100-mesh sieve to obtain a high-efficiency flocculant for wastewater treatment.