A polyacrylamide flocculant

Abstract

The present invention relates to the field of flocculant technology, specifically a polyacrylamide flocculant, comprising the following raw materials in parts by weight: 100 parts anionic polyacrylamide, 35-40 parts a first additive, 25-28 parts a second additive, 18-22 parts a powder additive, 15-18 parts a modified zeolite, and 12-14 parts anhydrous ethanol. In the present invention, the first additive is combined with a biomass component via a bamboo-based diatom composite carrier to capture and lock oil droplets in high-viscosity oily wastewater within seconds, significantly shortening the flocculation induction period of traditional processes and improving the flocculant's wastewater treatment efficiency. Furthermore, by adding the second additive, the flocculant system has both demulsification and heavy metal chelation functions, significantly reducing wastewater treatment energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of flocculants, in particular to a polyacrylamide flocculant. Background Art

[0002] Polyacrylamide flocculant is a high molecular weight polymer formed by the polymerization of acrylamide monomers. It is divided into three types: anionic (APAM), cationic (CPAM), and non-ionic (NPAM). Its molecular chain contains a large number of active groups (such as amide and carboxyl groups). Through electrical neutralization, adsorption bridging, and net capture and sweeping, it can quickly flocculate and settle suspended particles in water. It is widely used in sewage treatment, sludge dewatering, mining flotation, oil extraction and other fields. It has the characteristics of high efficiency, low dosage, and strong adaptability. It is one of the key chemicals in the water treatment industry.

[0003] When treating high-viscosity oily wastewater, traditional polyacrylamide flocculants, due to their simple carrier pore structure and lack of surface active sites, are unable to quickly address the negative charge repulsion of oil droplets, thick hydration layers, and the escape of tiny particles. This results in a long flocculation induction time and a lack of rapid response, which limits the overall wastewater treatment efficiency. Based on this, the present invention provides a polyacrylamide flocculant. Summary of the Invention

[0004] The purpose of the present invention is to provide a polyacrylamide flocculant. The polyacrylamide flocculant prepared by the present invention not only improves the treatment efficiency of the flocculant for wastewater, but also reduces the energy consumption of sewage treatment.

[0005] To achieve the above object, the present invention provides the following technical solution: a polyacrylamide flocculant, comprising the following raw materials in parts by weight: 100 parts of anionic polyacrylamide, 35-40 parts of a first additive, 25-28 parts of a second additive, 18-22 parts of a powder additive, 15-18 parts of a modified zeolite, and 12-14 parts of anhydrous ethanol;

[0006] The preparation method comprises the following steps:

[0007] S1: Weigh anionic polyacrylamide and powder additives as needed and add them into a double-screw mixer, premixing at 35-45 rpm for 8-12 minutes;

[0008] S2: Add the modified zeolite to the double-screw mixer in S1 and continue mixing for 4 to 6 minutes to obtain a mixture;

[0009] S3: The first additive and the second additive are sprayed into the mixture after being moistened by atomizing with anhydrous ethanol. The resulting product is aged in a constant humidity cabinet at a temperature of 32-38°C and a relative humidity of 25-35% for 40-60 hours. The resulting product is crushed and passed through a 100-140 mesh sieve to obtain a polyacrylamide flocculant.

[0010] Preferably, the modified zeolite preparation method is: boiling tea residue and deionized water in a mass ratio of 1:10 for 30 to 40 minutes, adding zeolite powder and stirring, filtering the obtained product and taking the precipitate, drying it at 100°C and then activating it at 400°C for 1 hour to obtain the modified zeolite, wherein the mass of the zeolite powder is 30 to 35% of the mass of the deionized water.

[0011] Preferably, the preparation method of the powder additive is as follows: magnesium chloride, aluminum chloride and deionized water are added to a mixer, processed at 200 rpm for 20 to 30 minutes, and then sodium hydroxide is added to adjust the pH to 9 to 10 to obtain a suspension slurry, the suspension slurry is added to a water bath, set to 55 to 65°C and kept warm for 2 to 3 hours, the resulting product is centrifuged to obtain a solid, the solid is washed with deionized water 4 to 6 times, and then sent to an oven and set at 105°C for 3 to 5 hours to obtain a powder additive, wherein the mass ratio of magnesium chloride, aluminum chloride and deionized water is (0.5 to 0.6): (0.3 to 0.4): 1000.

[0012] Preferably, the preparation method of the first additive comprises the following steps:

[0013] Step 1: Add activated diatom powder and bamboo charcoal gel liquid into a kneader at a mass ratio of 1: (0.9-1), set the speed to 25-35 rpm and stir for 10-15 minutes to prepare a primary mixed colloid;

[0014] Step 2: Add the porous reinforcing agent to the kneader in step 1, raise the temperature to 50-60°C, adjust the speed to 50-100 rpm, and continue stirring for 20-40 minutes to obtain a reinforced colloid, wherein the mass of the porous reinforcing agent is 6-9% of the mass of the initial mixed colloid;

[0015] Step 3: The reinforcing colloid is pressed into a thin sheet by a twin-roll extruder, and the thin sheet is dried at 70-80° C. for 100-150 min. The obtained product is crushed and passed through a 180-200 mesh sieve to obtain the first additive, wherein the thickness of the thin sheet is 1.5-2.5 mm.

[0016] Preferably, the preparation method of the activated diatom powder is as follows: taking a discarded diatomaceous earth filter element as a raw material, immersing it in a 5% oxalic acid solution with a solid-liquid ratio of 1:6 for 2 to 3 hours, washing the obtained product with water until neutral and then crushing it to 80 to 120 mesh, mixing it with an activation treatment liquid with a solid-liquid ratio of 1: (4 to 6), and stirring the obtained product at a constant temperature of 75 to 85°C and 180 to 220 rpm for 50 to 70 minutes to obtain a slurry, filtering the slurry under a vacuum degree of -0.08 MPa and taking a filter cake, washing the filter cake with deionized water until the conductivity is ≤50 μS / cm, and then transferring it to an oven, setting it to 100 to 110°C and drying it for 3 to 5 hours to obtain activated diatom powder.

[0017] Preferably, the preparation method of the activation treatment liquid is: calcining waste bamboo sticks and passing them through a 300-500 mesh sieve to obtain a first powder, calcining waste paper cotton to obtain a second powder, adding the first powder and the second powder into a reactor for premixing, then adding ammonium sulfate and magnesium rosinate and heating to 55-65°C, stirring at a speed of 120-180 rpm for 30-50 minutes, filtering the obtained product through a plate and frame filter press and taking the filtrate, which is the activation treatment liquid, wherein the mass ratio of the first powder, the second powder, ammonium sulfate and magnesium rosinate is (25-35): (20-30): (10-15): (20-30), and the waste paper cotton calcination temperature is 550-650°C.

[0018] Preferably, the preparation method of the bamboo charcoal gel liquid is:

[0019] Step a: crushing bamboo processing waste into 15-25 mesh, adding it into a tube furnace, heating it to 480-520° C. at 8-12° C. / min under a nitrogen atmosphere for 1-1.2 hours, and ball milling the obtained product to a particle size of 5-15 μm to obtain refined bamboo charcoal powder;

[0020] Step b: adding the refined bamboo charcoal powder to a sodium alginate solution with a mass concentration of 0.3-0.7% at a solid-liquid ratio of 1:(7-9), and ultrasonically treating the solution at a power of 250-350W for 15-25 minutes to obtain a dispersed slurry;

[0021] Step c: adding the bean dregs extract to the dispersed slurry, and then stirring at a constant temperature of 45-55° C. and 450-550 rpm for 50-70 min to obtain a bamboo charcoal gel solution, wherein the mass of the bean dregs extract is 8-12% of the mass of the dispersed slurry.

[0022] Preferably, the preparation method of the bean dregs extract is: taking waste bean dregs as raw material and drying it to a moisture content of ≤8%, adding a 5% mass concentration of sodium hydroxide solution at a solid-liquid ratio of 1:10, stirring at 80-90°C for 1-2h, letting the obtained product stand for stratification, taking the supernatant and adjusting the pH to 4-5, letting it stand for 30-40min, precipitating and filtering to obtain a protein precipitate, adding deionized water 4-6 times the mass of the protein precipitate, stirring and mixing, and treating the obtained product with a spray dryer to obtain a bean dregs extract, wherein the spray dryer is set to have an inlet air temperature of 170-190°C and an outlet air temperature of 80-90°C.

[0023] Preferably, the preparation method of the second additive comprises the following steps:

[0024] Step A: crushing dolomite into 60-100 mesh, adding it into a muffle furnace, setting it to 180-220° C. and keeping it for 0.8-1.2 hours, then heating it to 700° C. at a rate of 4-6° C. / min and keeping it for 1.8-2.2 hours, and naturally cooling the obtained product to obtain a porous matrix;

[0025] Step B: Immerse the porous substrate in a rosin zinc emulsion at a solid-liquid ratio of 1:(3-4), and perform constant temperature shaking treatment at 60-70°C for 1.2-1.5 hours to obtain a mixture;

[0026] Step C: adding the mixed material into a centrifuge and separating it at 5500-6500 rpm for 4-6 minutes, washing the precipitate until it is neutral, and vacuum drying the obtained product at 75-85° C. for 2.5-3.5 hours to obtain the second additive.

[0027] Preferably, the rosin zinc emulsion is prepared by mixing rosin glycerol ester, zinc stearate, carbon black, and sodium lauryl sulfate in a mass ratio of (35-45): (25-35): (15-20): (3-7), and the resulting product is dispersed and homogenized at high speed at 65-75° C. and 7000-9000 rpm for 15-25 minutes to obtain the rosin zinc emulsion.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. In the present invention, the first additive is combined with the biomass component through a bamboo-based diatom composite carrier, so that the waste diatomaceous earth filter element after oxalic acid activation forms a through-type mesoporous skeleton. After its surface is modified by the activation treatment liquid, abundant silanol active sites are exposed, which significantly enhances the capillary adsorption force of emulsified oil droplets. At the same time, it provides a dispersion carrier for the powder auxiliary agent and significantly enhances the electrical neutralization ability. The nanocellulose network in the bamboo charcoal gel liquid and the soybean dregs protein work synergistically to form an amphiphilic molecular film at the oil-water interface, which neutralizes the surface charge of the oil droplets and strengthens the bridging effect, thereby capturing and locking the oil droplets in the high-viscosity oily wastewater within seconds, greatly shortening the flocculation induction period of the traditional process and improving the treatment efficiency of the flocculant for wastewater.

[0030] 2. In the present invention, a flocculant is added with a second additive, a nano-calcium oxide array is formed by gradient calcination of dolomite, a micro-nano hydrophobic interface is constructed by a rosin zinc emulsion, zinc stearate and carbon black form a microemulsion structure on the surface of the calcium oxide to destroy the stability of the oil droplet interface film, the hydrophobic peptides in the dregs extract form a thermally stable cross-linked network mediated by calcium ions, inhibiting the re-emulsification of oil droplets, and synergistically with the tea polyphenols in the modified zeolite, so that the system has both demulsification and heavy metal chelation functions, which can significantly reduce the energy consumption of sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A preparation flow chart of polyacrylamide flocculant is proposed for the invention;

[0032] Figure 2 A flow chart for preparing the first additive of a polyacrylamide flocculant is proposed for the invention;

[0033] Figure 3 The invention proposes a flow chart for preparing the second additive of polyacrylamide flocculant. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] Example 1

[0036] A polyacrylamide flocculant is composed of the following raw materials in parts by weight: 100 parts of anionic polyacrylamide, 35 parts of a first additive, 25 parts of a second additive, 18 parts of a powder additive, 15 parts of a modified zeolite, and 12 parts of anhydrous ethanol;

[0037] The preparation method comprises the following steps:

[0038] S1: Weigh anionic polyacrylamide and powder additives as needed and add them into a double-screw mixer, premixing at 35 rpm for 8 minutes;

[0039] S2: Add the modified zeolite to the double-screw mixer in S1 and continue mixing for 4 minutes to obtain a mixture;

[0040] S3: The first additive and the second additive are sprayed into the mixture after being moistened by atomizing with anhydrous ethanol. The resulting product is aged in a constant humidity cabinet at a temperature of 32° C. and a relative humidity of 25% for 40 hours. The resulting product is crushed and passed through a 100-mesh sieve to obtain a polyacrylamide flocculant.

[0041] Among them, the preparation method of modified zeolite is: boil tea residue and deionized water in a mass ratio of 1:10 for 30 minutes, add zeolite powder and stir, filter the obtained product and take the precipitate, dry it at 100°C and then activate it at 400°C for 1 hour to obtain modified zeolite, wherein the mass of zeolite powder is 30% of the mass of deionized water.

[0042] Among them, the preparation method of the powder auxiliary agent is: magnesium chloride, aluminum chloride and deionized water are added to a mixer, processed at 200rpm for 20 minutes, and then sodium hydroxide is added to adjust the pH to 9 to obtain a suspension slurry, and the suspension slurry is added to a water bath, set to 55°C and kept warm for 2 hours, and the resulting product is centrifuged to obtain a solid, and the solid is washed with deionized water 4 times, and then sent to an oven, set at 105°C and processed for 3 hours to obtain a powder auxiliary agent, wherein the mass ratio of magnesium chloride, aluminum chloride and deionized water is 0.5:0.3:1000.

[0043] The preparation method of the first additive comprises the following steps:

[0044] Step 1: Add activated diatom powder and bamboo charcoal gel liquid into a kneader at a mass ratio of 1:0.9, set the speed to 25 rpm and stir for 10 minutes to prepare a primary mixed colloid;

[0045] Step 2: Add the porous reinforcing agent to the kneader in step 1, raise the temperature to 50°C, adjust the speed to 50 rpm, and continue stirring for 20 minutes to obtain a reinforced colloid, wherein the mass of the porous reinforcing agent is 6% of the mass of the initial mixed colloid;

[0046] Step 3: The reinforcing colloid is pressed into a thin sheet by a twin-roll extruder, and the thin sheet is dried at 70° C. for 100 min. The obtained product is crushed and passed through a 180-mesh sieve to obtain the first additive, wherein the thickness of the thin sheet is 1.5 mm.

[0047] Among them, the preparation method of activated diatom powder is: take the discarded diatomaceous earth filter element as the raw material, immerse it in a 5% oxalic acid solution with a solid-liquid ratio of 1:6 for 2 hours, wash the obtained product with water until neutral and then crush it to 80 mesh, mix it with the activation treatment liquid with a solid-liquid ratio of 1:4, and stir the obtained product at a constant temperature of 75°C and 180rpm for 50 minutes to obtain a slurry. The slurry is filtered under a vacuum degree of -0.08MPa and the filter cake is taken. The filter cake is washed with deionized water until the conductivity is ≤50μS / cm and then transferred to an oven and set at 100°C for drying for 3 hours to obtain activated diatom powder.

[0048] Among them, the preparation method of the activation treatment liquid is: calcining waste bamboo sticks and then passing them through a 300-mesh sieve to obtain a first powder, calcining waste paper cotton to obtain a second powder, adding the first powder and the second powder into a reactor for premixing, then adding ammonium sulfate and magnesium rosinate and heating to 55°C, stirring at a speed of 120 rpm for 30 minutes, and filtering the obtained product through a plate and frame filter press to obtain the filtrate, which is the activation treatment liquid, wherein the mass ratio of the first powder, the second powder, ammonium sulfate and magnesium rosinate is 25:20:10:20, and the calcination temperature of the waste paper cotton is 550°C.

[0049] Wherein, the preparation method of bamboo charcoal gel liquid is:

[0050] Step a: The bamboo processing waste was crushed into 15 mesh, added into a tube furnace, heated to 480°C at 8°C / min under a nitrogen atmosphere for 1 hour, and the obtained product was ball-milled to a particle size of 5 μm to obtain refined bamboo charcoal powder;

[0051] Step b: adding refined bamboo charcoal powder to a 0.3% sodium alginate solution at a solid-liquid ratio of 1:7, and ultrasonically treating the solution at a power of 250 W for 15 minutes to obtain a dispersed slurry;

[0052] Step c: adding the okara extract to the dispersed slurry, and then stirring at a constant temperature of 45° C. and 450 rpm for 50 min to obtain a bamboo charcoal gel solution, wherein the mass of the okara extract is 8% of the mass of the dispersed slurry.

[0053] Among them, the preparation method of bean dregs extract is: take waste bean dregs as raw material and dry it to a moisture content of ≤8%, add 5% mass concentration of sodium hydroxide solution at a solid-liquid ratio of 1:10, stir and treat at 80°C for 1 hour, let the obtained product stand and separate, take the supernatant and adjust the pH to 4, let it stand for 30 minutes, precipitate and filter to obtain protein precipitate, add deionized water 4 times the mass of the protein precipitate and stir and mix, and the obtained product is treated in a spray dryer to obtain bean dregs extract, wherein the spray dryer is set to have an inlet temperature of 170°C and an outlet temperature of 80°C.

[0054] The preparation method of the second additive comprises the following steps:

[0055] Step A: Dolomite was crushed into 60 mesh, added into a muffle furnace, set at 180°C and kept at that temperature for 0.8 h, then heated to 700°C at a rate of 4°C / min and kept at that temperature for 1.8 h. The obtained product was naturally cooled to obtain a porous matrix;

[0056] Step B: Immerse the porous substrate in a rosin zinc emulsion at a solid-liquid ratio of 1:3, and perform constant temperature shaking treatment at 60° C. for 1.2 h to obtain a mixture;

[0057] Step C: The mixture was added to a centrifuge and separated at 5500 rpm for 4 minutes. The precipitate was washed until neutral. The obtained product was vacuum dried at 75° C. for 2.5 hours to obtain the second additive.

[0058] The preparation method of rosin zinc emulsion is as follows: rosin glycerol ester, zinc stearate, carbon black and sodium lauryl sulfate are mixed in a mass ratio of 35:25:15:3, and the obtained product is dispersed and homogenized at high speed at 65°C and 7000 rpm for 15 minutes to obtain rosin zinc emulsion.

[0059] Example 2

[0060] A polyacrylamide flocculant, composed of the following raw materials in parts by weight: 100 parts of anionic polyacrylamide, 38 parts of a first additive, 26 parts of a second additive, 20 parts of a powder additive, 16 parts of a modified zeolite, and 13 parts of anhydrous ethanol;

[0061] The preparation method comprises the following steps:

[0062] S1: Weigh anionic polyacrylamide and powder additives as needed and add them into a double-screw mixer, premixing at 40 rpm for 10 minutes;

[0063] S2: Add the modified zeolite to the double-screw mixer in S1 and continue mixing for 5 minutes to obtain a mixture;

[0064] S3: The first additive and the second additive are sprayed into the mixture after being moistened by atomizing with anhydrous ethanol. The obtained product is aged for 50 hours in a constant humidity cabinet at a temperature of 35°C and a relative humidity of 30%. The obtained product is crushed and passed through a 120-mesh sieve to obtain a polyacrylamide flocculant.

[0065] Among them, the preparation method of modified zeolite is: boil tea residue and deionized water in a mass ratio of 1:10 for 35 minutes, add zeolite powder and stir, filter the obtained product and take the precipitate, dry it at 100°C and then activate it at 400°C for 1 hour to obtain modified zeolite, wherein the mass of zeolite powder is 32% of the mass of deionized water.

[0066] Among them, the preparation method of the powder auxiliary agent is: magnesium chloride, aluminum chloride and deionized water are added to a mixer, processed at 200rpm for 25 minutes, and then sodium hydroxide is added to adjust the pH to 9.5 to obtain a suspension slurry, and the suspension slurry is added to a water bath, set to 60°C and kept warm for 2.5 hours. The resulting product is centrifuged to obtain a solid, and the solid is washed with deionized water 5 times, and then sent to an oven, set at 105°C and processed for 4 hours to obtain a powder auxiliary agent, wherein the mass ratio of magnesium chloride, aluminum chloride and deionized water is 0.55:0.35:1000.

[0067] The preparation method of the first additive comprises the following steps:

[0068] Step 1: Add activated diatom powder and bamboo charcoal gel liquid into a kneader at a mass ratio of 1:0.95, set the speed to 30 rpm and stir for 12 minutes to prepare a primary mixed colloid;

[0069] Step 2: Add the porous reinforcing agent to the kneader in step 1, raise the temperature to 55°C, adjust the speed to 80 rpm, and continue stirring for 30 minutes to obtain a reinforced colloid, wherein the mass of the porous reinforcing agent is 8% of the mass of the initial mixed colloid;

[0070] Step 3: The reinforcing colloid is pressed into a thin sheet by a twin-roll extruder, and the thin sheet is dried at 75° C. for 125 min. The obtained product is crushed and passed through a 190-mesh sieve to obtain the first additive, wherein the thickness of the thin sheet is 2 mm.

[0071] Among them, the preparation method of activated diatom powder is as follows: take the discarded diatomaceous earth filter element as raw material, immerse it in a 5% mass concentration oxalic acid solution at a solid-liquid ratio of 1:6 for 2.5 hours, wash the obtained product with water until neutral and then crush it to 100 mesh, mix it with the activation treatment liquid at a solid-liquid ratio of 1:5, and stir the obtained product at a constant temperature of 80°C and 200rpm for 60 minutes to obtain a slurry. The slurry is filtered under a vacuum degree of -0.08MPa and the filter cake is taken. The filter cake is washed with deionized water until the conductivity is ≤50μS / cm and then transferred to an oven and set at 105°C for drying for 4 hours to obtain activated diatom powder.

[0072] Among them, the preparation method of the activation treatment liquid is: calcining waste bamboo sticks and then passing them through a 400-mesh sieve to obtain a first powder, calcining waste paper cotton to obtain a second powder, adding the first powder and the second powder into a reactor for premixing, then adding ammonium sulfate and magnesium rosinate and heating to 60°C, stirring at a speed of 150 rpm for 40 minutes, and filtering the obtained product through a plate and frame filter press to obtain the filtrate, which is the activation treatment liquid, wherein the mass ratio of the first powder, the second powder, ammonium sulfate and magnesium rosinate is 30:25:12:25, and the calcination temperature of the waste paper cotton is 600°C.

[0073] Wherein, the preparation method of bamboo charcoal gel liquid is:

[0074] Step a: The bamboo processing waste was crushed into 20 mesh, added into a tube furnace, heated to 500°C at 10°C / min under a nitrogen atmosphere for 1.1 h, and the obtained product was ball-milled to a particle size of 10 μm to obtain refined bamboo charcoal powder;

[0075] Step b: adding refined bamboo charcoal powder to a 0.5% sodium alginate solution at a solid-liquid ratio of 1:8, and ultrasonically treating the solution at a power of 300 W for 20 minutes to obtain a dispersed slurry;

[0076] Step c: adding the bean dregs extract to the dispersed slurry, and then stirring at a constant temperature of 50° C. and 500 rpm for 60 minutes to obtain a bamboo charcoal gel solution, wherein the mass of the bean dregs extract is 10% of the mass of the dispersed slurry.

[0077] Among them, the preparation method of bean dregs extract is: take waste bean dregs as raw material and dry it to a moisture content of ≤8%, add 5% mass concentration of sodium hydroxide solution at a solid-liquid ratio of 1:10, stir and treat at 85°C for 1.5 hours, let the obtained product stand for stratification, take the supernatant and adjust the pH to 4-5, let it stand for 30-40 minutes, precipitate and filter to obtain protein precipitate, add deionized water 5 times the mass of the protein precipitate and stir and mix, and the obtained product is treated in a spray dryer to obtain bean dregs extract, wherein the spray dryer is set to have an inlet air temperature of 180°C and an outlet air temperature of 85°C.

[0078] The preparation method of the second additive comprises the following steps:

[0079] Step A: Dolomite was crushed into 80 mesh, added into a muffle furnace, set at 200°C for 1 hour, then heated to 700°C at a rate of 5°C / min and kept for 2 hours. The obtained product was naturally cooled to obtain a porous matrix;

[0080] Step B: Immerse the porous substrate in a rosin zinc emulsion at a solid-liquid ratio of 1:3.5, and perform constant temperature shaking treatment at 65° C. for 1.3 h to obtain a mixture;

[0081] Step C: The mixture was added to a centrifuge and separated at 6000 rpm for 5 minutes. The precipitate was washed until neutral. The obtained product was vacuum dried at 80° C. for 3 hours to obtain the second additive.

[0082] The preparation method of rosin zinc emulsion is as follows: rosin glycerol ester, zinc stearate, carbon black and sodium lauryl sulfate are mixed in a mass ratio of 40:30:18:5, and the obtained product is dispersed and homogenized at high speed at 70°C and 8000 rpm for 20 minutes to obtain rosin zinc emulsion.

[0083] Example 3

[0084] A polyacrylamide flocculant is composed of the following raw materials in parts by weight: 100 parts of anionic polyacrylamide, 40 parts of a first additive, 28 parts of a second additive, 22 parts of a powder additive, 18 parts of a modified zeolite, and 14 parts of anhydrous ethanol;

[0085] The preparation method comprises the following steps:

[0086] S1: Weigh anionic polyacrylamide and powder additives as needed and add them into a double-screw mixer, premixing at 45 rpm for 12 minutes;

[0087] S2: Add the modified zeolite to the double-screw mixer in S1 and continue mixing for 6 minutes to obtain a mixture;

[0088] S3: The first additive and the second additive were atomized and moistened with anhydrous ethanol and then sprayed into the mixture. The resulting product was aged in a constant humidity cabinet at a temperature of 38° C. and a relative humidity of 35% for 60 hours. The resulting product was crushed and passed through a 140-mesh sieve to obtain a polyacrylamide flocculant.

[0089] Among them, the preparation method of modified zeolite is: boil tea residue and deionized water in a mass ratio of 1:10 for 40 minutes, add zeolite powder and stir, filter the obtained product and take the precipitate, dry it at 100°C and then activate it at 400°C for 1 hour to obtain modified zeolite, wherein the mass of zeolite powder is 35% of the mass of deionized water.

[0090] Among them, the preparation method of the powder additive is: magnesium chloride, aluminum chloride and deionized water are added to a mixer, processed at 200rpm for 30 minutes, and then sodium hydroxide is added to adjust the pH to 10 to obtain a suspension slurry, and the suspension slurry is added to a water bath, set at 65°C and kept warm for 3 hours. The resulting product is centrifuged to obtain a solid, and the solid is washed with deionized water 6 times, and then sent to an oven, set at 105°C and processed for 5 hours to obtain a powder additive, wherein the mass ratio of magnesium chloride, aluminum chloride and deionized water is 0.6:0.4:1000.

[0091] The preparation method of the first additive comprises the following steps:

[0092] Step 1: Add activated diatom powder and bamboo charcoal gel liquid into a kneader at a mass ratio of 1:1, set the speed to 35 rpm and stir for 15 minutes to prepare a primary mixed colloid;

[0093] Step 2: Add the porous reinforcing agent to the kneader in step 1, raise the temperature to 60°C, adjust the speed to 100 rpm, and continue stirring for 40 minutes to obtain a reinforced colloid, wherein the mass of the porous reinforcing agent is 9% of the mass of the initial mixed colloid;

[0094] Step 3: The reinforcing colloid is pressed into a thin sheet by a twin-roll extruder, and the thin sheet is dried at 80° C. for 150 min. The obtained product is crushed and passed through a 200-mesh sieve to obtain the first additive, wherein the thickness of the thin sheet is 2.5 mm.

[0095] Among them, the preparation method of activated diatom powder is: take the discarded diatomaceous earth filter element as raw material, immerse it in a 5% oxalic acid solution with a solid-liquid ratio of 1:6 for 3 hours, wash the obtained product with water until neutral and then crush it to 120 mesh, mix it with the activation treatment liquid with a solid-liquid ratio of 1:6, and stir the obtained product at a constant temperature of 85°C and 220rpm for 70 minutes to obtain a slurry. The slurry is filtered under a vacuum degree of -0.08MPa and the filter cake is taken. The filter cake is washed with deionized water until the conductivity is ≤50μS / cm and then transferred to an oven and set at 110°C for drying for 5 hours to obtain activated diatom powder.

[0096] Among them, the preparation method of the activation treatment liquid is: calcining waste bamboo sticks and then passing them through a 500-mesh sieve to obtain a first powder, calcining waste paper cotton to obtain a second powder, adding the first powder and the second powder into a reactor for premixing, then adding ammonium sulfate and magnesium rosinate and heating to 65°C, stirring at a speed of 180 rpm for 50 minutes, and filtering the obtained product through a plate and frame filter press to obtain the filtrate, which is the activation treatment liquid, wherein the mass ratio of the first powder, the second powder, ammonium sulfate and magnesium rosinate is 35:30:15:30, and the calcination temperature of the waste paper cotton is 650°C.

[0097] Wherein, the preparation method of bamboo charcoal gel liquid is:

[0098] Step a: The bamboo processing waste was crushed into 25 mesh, added into a tube furnace, heated to 520°C at 12°C / min under a nitrogen atmosphere for 1.2 h, and the obtained product was ball-milled to a particle size of 15 μm to obtain refined bamboo charcoal powder;

[0099] Step b: adding refined bamboo charcoal powder to a 0.7% sodium alginate solution at a solid-liquid ratio of 1:9, and ultrasonically treating the solution at a power of 350 W for 25 minutes to obtain a dispersed slurry;

[0100] Step c: adding the okara extract to the dispersed slurry, and then stirring at a constant temperature of 55° C. and 550 rpm for 70 minutes to obtain a bamboo charcoal gel solution, wherein the mass of the okara extract is 12% of the mass of the dispersed slurry.

[0101] Among them, the preparation method of bean dregs extract is: take waste bean dregs as raw material and dry it to a moisture content of ≤8%, add 5% mass concentration of sodium hydroxide solution at a solid-liquid ratio of 1:10, stir and treat at 90°C for 2h, let the obtained product stand for stratification, take the supernatant and adjust the pH to 5, let it stand for 40min, precipitate and filter to obtain protein precipitate, add deionized water 6 times the mass of the protein precipitate and stir and mix, and the obtained product is treated in a spray dryer to obtain bean dregs extract, wherein the spray dryer is set to have an inlet temperature of 190°C and an outlet temperature of 90°C.

[0102] The preparation method of the second additive comprises the following steps:

[0103] Step A: Dolomite was crushed into 100 mesh, added into a muffle furnace, set at 220°C for 1.2 hours, then heated to 700°C at a rate of 6°C / min and kept at that temperature for 2.2 hours. The obtained product was naturally cooled to obtain a porous matrix;

[0104] Step B: Immerse the porous substrate in a rosin zinc emulsion at a solid-liquid ratio of 1:4, and perform constant temperature shaking treatment at 70° C. for 1.5 hours to obtain a mixture;

[0105] Step C: The mixture was added to a centrifuge and separated at 6500 rpm for 6 minutes. The precipitate was washed until neutral. The obtained product was vacuum dried at 85° C. for 3.5 hours to obtain the second additive.

[0106] The preparation method of rosin zinc emulsion is as follows: rosin glycerol ester, zinc stearate, carbon black and sodium lauryl sulfate are mixed in a mass ratio of 45:35:20:7, and the obtained product is dispersed and homogenized at a high speed of 75°C and 9000 rpm for 25 minutes to obtain rosin zinc emulsion.

[0107] Comparative Example 1: This comparative example is different from Example 1 in that: this comparative example does not contain the first additive.

[0108] Comparative Example 2: This comparative example differs from Example 1 in that it does not contain the second additive.

[0109] Comparative Example 3: This comparative example differs from Example 1 in that an equal amount of zeolite powder is used in place of the powder additive.

[0110] Comparative Example 4: This comparative example differs from Example 1 in that an equal amount of zeolite raw powder is used to replace the modified zeolite.

[0111] Test method:

[0112] Flocculation response time: According to GB / T 16881-2008 "Determination of Flocculation Performance of Water Treatment Agents", 50 mg / L of flocculant was added to 500 mL of oily wastewater (300 mg / L of petroleum), and the time it took for flocs to be visible to the naked eye was recorded under magnetic stirring at 200 rpm.

[0113] Oil removal rate: tested in accordance with HJ 637-2018 "Water quality - Determination of petroleum, animal and vegetable oils" standard;

[0114] Turbidity removal rate: tested in accordance with HJ1075-2019 "Determination of Turbidity in Water" standard;

[0115] Performance test: The polyacrylamide flocculants prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests, and the test data obtained are recorded in the following table:

[0116] Table 1:

[0117]

[0118] By analyzing the data in the comparison table, it can be seen that the flocculation time, oil removal rate and turbidity removal rate of the flocculants prepared in Examples 1-3 are better than those prepared in Comparative Examples 1-4;

[0119] This shows that: by adding the first additive to the polyacrylamide flocculant, the first additive is combined with the biomass component through the bamboo-based diatom composite carrier, so that the waste diatomaceous earth filter element activated by oxalic acid forms a through-type mesoporous skeleton. After its surface is modified by the activation treatment liquid, abundant silanol active sites are exposed, which significantly enhances the capillary adsorption force of emulsified oil droplets. At the same time, it provides a dispersion carrier for the powder additive and significantly enhances the electrical neutralization ability. The nanocellulose network in the bamboo charcoal gel liquid and the soybean dregs protein work synergistically to form an amphiphilic molecular membrane at the oil-water interface, which neutralizes the surface charge of the oil droplets and strengthens the bridging effect. This composite structure allows the oil droplets in the high-viscosity oily wastewater to be captured and locked within seconds, significantly shortening the flocculation induction period of the traditional process and improving the wastewater treatment efficiency of the flocculant.

[0120] The flocculant is prepared by adding a second additive. The nano-calcium oxide array formed by the gradient calcination of dolomite, the micro-nano hydrophobic interface is constructed by the rosin zinc emulsion, zinc stearate and carbon black form a microemulsion structure on the surface of calcium oxide to destroy the stability of the oil droplet interface film, and the hydrophobic peptides in the soybean dregs extract form a thermally stable cross-linked network mediated by calcium ions, inhibiting the re-emulsification of oil droplets, and synergistically modifying the tea polyphenols in the zeolite, so that the system has both demulsification and heavy metal chelation functions, which can significantly reduce the energy consumption of sewage treatment.

[0121] By comparing and analyzing the relevant data in the table, it can be seen that the polyacrylamide flocculant prepared by the present invention not only improves the wastewater treatment efficiency of the flocculant, but also reduces the energy consumption of sewage treatment. This shows that the polyacrylamide flocculant provided by the present invention has a broader market prospect and is more suitable for promotion.

[0122] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these 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 any one or more embodiments or examples.

[0123] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A polyacrylamide flocculant, characterized in that: The invention is composed of the following raw materials in parts by weight: 100 parts of anionic polyacrylamide, 35-40 parts of a first additive, 25-28 parts of a second additive, 18-22 parts of a powder auxiliary agent, 15-18 parts of a modified zeolite, and 12-14 parts of anhydrous ethanol; The preparation method comprises the following steps: S1: Weigh anionic polyacrylamide and powder additives as needed and add them into a double-screw mixer, premixing at 35-45 rpm for 8-12 minutes; S2: Add the modified zeolite to the double-screw mixer in S1 and continue mixing for 4 to 6 minutes to obtain a mixture; S3: The first additive and the second additive are atomized and moistened with anhydrous ethanol and then sprayed into the mixture. The resulting product is aged in a constant humidity cabinet at a temperature of 32-38° C. and a relative humidity of 25-35% for 40-60 hours. The resulting product is crushed and passed through a 100-140 mesh sieve to obtain a polyacrylamide flocculant. The preparation method of the first additive comprises the following steps: Step 1: Add activated diatom powder and bamboo charcoal gel liquid into a kneader at a mass ratio of 1: (0.9-1), set the speed to 25-35 rpm and stir for 10-15 minutes to prepare a primary mixed colloid; Step 2: Add the porous reinforcing agent to the kneader in step 1, raise the temperature to 50-60°C, adjust the speed to 50-100 rpm, and continue stirring for 20-40 minutes to obtain a reinforced colloid, wherein the mass of the porous reinforcing agent is 6-9% of the mass of the initial mixed colloid; Step 3: Pressing the reinforcing colloid into a sheet using a twin-roll extruder, drying the sheet at 70-80° C. for 100-150 minutes, crushing the resulting product and passing it through a 180-200 mesh sieve to obtain the first additive, wherein the sheet has a thickness of 1.5-2.5 mm; The preparation method of the second additive comprises the following steps: Step A: crushing dolomite into 60-100 mesh, adding it into a muffle furnace, setting it to 180-220° C. and keeping it for 0.8-1.2 hours, then heating it to 700° C. at a rate of 4-6° C. / min and keeping it for 1.8-2.2 hours, and naturally cooling the obtained product to obtain a porous matrix; Step B: Immerse the porous substrate in a rosin zinc emulsion at a solid-liquid ratio of 1:(3-4), and perform constant temperature shaking treatment at 60-70°C for 1.2-1.5 hours to obtain a mixture; Step C: adding the mixed material to a centrifuge and separating it at 5500-6500 rpm for 4-6 minutes, washing the precipitate until it is neutral, and vacuum drying the obtained product at 75-85° C. for 2.5-3.5 hours to obtain a second additive; The modified zeolite preparation method comprises the following steps: boiling tea residue and deionized water at a mass ratio of 1:10 for 30 to 40 minutes, adding zeolite powder and stirring, filtering the resulting product, collecting the precipitate, drying it at 100°C, and then activating it at 400°C for 1 hour to obtain the modified zeolite, wherein the mass of the zeolite powder is 30 to 35% of the mass of the deionized water; The powder auxiliary agent preparation method comprises the following steps: adding magnesium chloride, aluminum chloride, and deionized water into a mixer, processing at 200 rpm for 20 to 30 minutes, then adding sodium hydroxide to adjust the pH to 9 to 10 to obtain a suspension slurry, adding the suspension slurry into a water bath, setting the temperature at 55 to 65° C. and keeping the temperature for 2 to 3 hours, centrifuging the obtained product to obtain a solid, washing the solid with deionized water for 4 to 6 times, then placing the solid into an oven, setting the temperature at 105° C. and processing the solid for 3 to 5 hours to obtain the powder auxiliary agent, wherein the mass ratio of magnesium chloride, aluminum chloride, and deionized water is (0.5 to 0.6):(0.3 to 0.4):1000.

2. The polyacrylamide flocculant according to claim 1, characterized in that The preparation method of the activated diatom powder comprises the following steps: taking a discarded diatomaceous earth filter element as a raw material, immersing the filter element in a 5% oxalic acid solution at a solid-liquid ratio of 1:6 for 2-3 hours, washing the obtained product with water until neutral, crushing the obtained product to 80-120 meshes, mixing the obtained product with an activation treatment liquid at a solid-liquid ratio of 1:(4-6), and stirring the obtained product at a constant temperature of 75-85° C. and 180-220 rpm for 50-70 minutes to obtain a slurry, filtering the slurry under a vacuum degree of -0.08 MPa, and obtaining a filter cake, washing the filter cake with deionized water until the conductivity is ≤50 μS / cm, and then transferring the filter cake to an oven, setting the temperature at 100-110° C. and drying for 3-5 hours to obtain the activated diatom powder.

3. The polyacrylamide flocculant according to claim 2, characterized in that The preparation method of the activation treatment liquid is as follows: calcining waste bamboo sticks and then passing them through a 300-500 mesh sieve to obtain a first powder, calcining waste paper cotton to obtain a second powder, adding the first powder and the second powder into a reactor for premixing, then adding ammonium sulfate and magnesium rosinate, heating to 55-65° C., stirring at a speed of 120-180 rpm for 30-50 minutes, filtering the obtained product through a plate and frame filter press, and collecting the filtrate, which is the activation treatment liquid, wherein the mass ratio of the first powder, the second powder, ammonium sulfate and magnesium rosinate is (25-35): (20-30): (10-15): (20-30), and the waste paper cotton is calcined at a temperature of 550-650° C.

4. The polyacrylamide flocculant according to claim 1, characterized in that The preparation method of the bamboo charcoal gel liquid is: Step a: crushing bamboo processing waste into 15-25 mesh, adding it into a tube furnace, heating it to 480-520° C. at 8-12° C. / min under a nitrogen atmosphere for 1-1.2 hours, and ball milling the obtained product to a particle size of 5-15 μm to obtain refined bamboo charcoal powder; Step b: adding the refined bamboo charcoal powder to a sodium alginate solution with a mass concentration of 0.3-0.7% at a solid-liquid ratio of 1:(7-9), and ultrasonically treating the solution at a power of 250-350W for 15-25 minutes to obtain a dispersed slurry; Step c: adding the bean dregs extract to the dispersed slurry, and then stirring at a constant temperature of 45-55° C. and 450-550 rpm for 50-70 min to obtain a bamboo charcoal gel solution, wherein the mass of the bean dregs extract is 8-12% of the mass of the dispersed slurry.

5. The polyacrylamide flocculant according to claim 4, characterized in that The bean dregs extract preparation method comprises the following steps: taking waste bean dregs as raw material and drying them to a moisture content of ≤8%, adding a 5% sodium hydroxide solution by mass at a solid-liquid ratio of 1:10, stirring the solution at 80-90° C. for 1-2 hours, allowing the obtained product to stand for stratification, taking the supernatant, adjusting the pH to 4-5, allowing the product to stand for 30-40 minutes, and filtering to obtain a protein precipitate, adding deionized water 4-6 times the mass of the protein precipitate, stirring and mixing, and subjecting the obtained product to treatment in a spray dryer to obtain the bean dregs extract, wherein the spray dryer is set with an inlet air temperature of 170-190° C. and an outlet air temperature of 80-90° C.

6. The polyacrylamide flocculant according to claim 5, characterized in that The preparation method of the rosin zinc emulsion comprises the following steps: selecting rosin glycerol ester, zinc stearate, carbon black, and sodium lauryl sulfate in a mass ratio of (35-45): (25-35): (15-20): (3-7); and homogenizing the obtained product at a high speed at 65-75° C. and 7000-9000 rpm for 15-25 minutes to obtain the rosin zinc emulsion.

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