63 results about "Polydimethyl diallylammonium chloride" patented technology

The invention relates to the technical field of emergency treatment of marine ecological disasters, and provides an algae remover for emergency treatment of red tide and a preparation method of the algae remover. The algae remover comprises the following raw materials in parts by weight: 70-90 parts of clay, 10-40 parts of an inorganic flocculant and 0.02-1 part of an organic flocculant. The organic flocculating agent comprises poly dimethyl diallyl ammonium chloride and polyvinyl alcohol; the mass ratio of the poly dimethyl diallyl ammonium chloride to the polyvinyl alcohol is 10: (1-8). According to the technical scheme, the problem of low red tide organism removal rate of an algae remover in related technologies is solved.

The invention discloses a gradient chelation-free radical activation synergistic eucalyptus chemithermomechanical pulp wastewater composite coagulant and a preparation method thereof, and belongs to the technical field of eucalyptus chemithermomechanical pulp wastewater treatment. Ferrous sulfate heptahydrate, aluminum hydroxide and magnesium sulfate are used as raw materials, and the water purifying agent with the viscosity of 35-45 mPa.s is prepared through gradient chelation reaction, free radical activating treatment, functional component composite reaction, pH and specific gravity regulation and control and curing treatment. By utilizing the synergistic effect of the polydimethyldiallylammonium chloride and the formaldehyde dicyandiamide resin, the electric neutralization capability on macromolecular colloidal substances in the wastewater is remarkably enhanced, and macromolecular substances which are difficult to biodegrade in the water are effectively removed; when the compound coagulant is used for treating the eucalyptus chemithermomechanical pulp wastewater, the addition amount of the compound coagulant is small, and the compound coagulant has excellent COD (Chemical Oxygen Demand) reduction and decolorization effects.

The invention provides modified activated carbon for removing perchlorate in water of a sheep farm and a preparation method of the modified activated carbon, and relates to the field of water treatment.The method comprises the steps that activated carbon reacts in a citric acid aqueous solution, a carboxyl layer is evenly loaded on the surface of the activated carbon, and preliminarily modified activated carbon is obtained; reacting the primarily modified activated carbon in an alkaline polydimethyldiallylammonium chloride aqueous solution, and adsorbing strong cation quaternary ammonium salt on the surface of a carboxyl layer through electrostatic interaction to obtain re-modified activated carbon; the activated carbon modified again reacts in a triethylene tetramine aqueous solution, triethylene tetramine molecules are further combined to the strong cation quaternary ammonium salt through the electrostatic adsorption effect, the modified activated carbon for removing perchlorate in the water of the sheep farm is obtained, the adsorption capacity of the activated carbon to negatively charged solutes is remarkably enhanced, and the perchlorate in the water of the sheep farm is removed. The perchlorate treatment efficiency of the whole farm environment is improved.

The invention relates to an iron removal agent suitable for a water treatment system and application of the iron removal agent. The iron removal agent is prepared from the following components in percentage by weight: 15-35% of poly dimethyl diallyl ammonium chloride, 1-5% of alkyl dimethyl benzyl ammonium halide, 0-0.5% of isothiazolinone and 60-80% of deionized water. Compared with the prior art, the invention overcomes the defects of low iron removal efficiency, large amount of generated mud and the like in the raw water conveying process of a water treatment system or the concentration process of the water system in a common iron removal technology. The iron removal agent is excellent in performance, good in stability and low in use dosage, has general applicability to iron removal in the raw water conveying or water treatment system concentration process, and has the characteristics of no phosphorus, environment friendliness and high efficiency.

The invention discloses a high-performance true nanoscale fiber membrane as well as a preparation method and application thereof, and belongs to the technical field of nanofiber air filtering materials. The preparation method comprises the following steps: by taking water as a solvent, dissolving a dimethyl diallyl ammonium chloride monomer in deionized water, adding ammonium persulfate and azodiisobutyronitrile as initiators to prepare poly dimethyl diallyl ammonium chloride, then dissolving the poly dimethyl diallyl ammonium chloride and nylon 66 particles in an organic solvent 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 A spinning precursor solution is prepared in 1, 2, 2-trifluoroethanol, and the fiber membrane with a real nanoscale fiber structure is prepared from the spinning precursor solution through an electrostatic spinning technology and a one-step method. Compared with an existing preparation process, the preparation method has the advantages that the process is simple and easy to operate, the production efficiency is high, and the fibrous membrane with the real nanoscale fibers shows excellent filtering performance on fine particulate matters with different particle sizes and shows excellent application potential in the fields of air purification, environmental protection, industrial waste gas treatment and the like.

The invention relates to the technical field of sewage treatment, and discloses a quick-setting agent for coal mine sewage treatment and a treatment method, the quick-setting agent comprises the following components by weight: 1-4 parts of a Schiff base aid, 2-3 parts of modified lignin, 3-5 parts of poly dimethyl diallyl ammonium chloride, 4-8 parts of polyacrylamide, and 10-14 parts of aluminum sulfate. The quick-setting agent for coal mine sewage treatment provided by the invention has a relatively good quick-setting effect and can effectively remove heavy metal ions in sewage.

The invention discloses a coal washing water efficient solid-water separating agent and method, and belongs to the technical field of coal washing water treatment. The solid-water separation agent comprises a solid-water separation agent A and a solid-water separation agent B. The solid-water separation agent A comprises 20% by mass of poly dimethyl diallyl ammonium chloride with the effective content of 40%; the mass fraction of polyaluminum chloride with the effective content of 10% is 20%; the effective content of the polyferric trichloride is 30%, and the mass fraction is 5%. The solid-water separating agent B comprises polyacrylamide, and the mass fraction of the polyacrylamide is 45%; magnesium chloride with a mass fraction of 25%; magnesium chloride with a mass fraction of 15%; sodium sulfate with a mass fraction of 10%; and isopropanol with a mass fraction of 5%. Rapid separation of coal washing water solid-water can be achieved, and the dosage of the coal washing water solid-water separating agent A is 7-20 g, and the dosage of the coal washing water solid-water separating agent B is 2-8 g. The efficient solid-water separating agent for coal washing water has the advantages of being small in dosage, fast in solid-water separation, short in separation time, high in separation efficiency, clear in upper-layer water after precipitation, good in water recycling effect and the like.

The invention discloses a nano flocculant as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing a protein amyloid fiber solution; adding a zirconium salt compound, and mixing to obtain a zirconium ion-loaded protein amyloid fiber composite solution; and mixing with a poly dimethyl diallyl ammonium chloride solution. The nano flocculant provided by the invention can be stored for a long time at normal temperature, is simple and convenient to use, is suitable for double improvement of sedimentation efficiency and dephosphorization effect in municipal and industrial sewage treatment processes, and has wide engineering application prospects and environmental friendliness.

The invention discloses a clay stabilizer for a polymer dry powder direct distribution variable-viscosity fracturing fluid. The clay stabilizer is prepared from quaternary ammonium salt, an alcohol amine compound and a polyamine compound as raw materials in a solvent. The quaternary ammonium salt is quaternary ammonium salt with the carbon chain length of C12-C18; the alcohol amine compound is selected from at least one of ethanolamine, dimethyl propanolamine, hydroxyethyl piperazine, piperidine, isopropanolamine, triisopropanolamine, aminomethyl propanolate, hydroxyethyl ammonium salt and the like; the polyamine compound is selected from any one of poly dimethyl diallyl ammonium chloride, polyquaternary ammonium salt, poly allylamine, polyurea, polybutanediamine, polyethyleneimine, polyethylene polyamine and a polyethyleneimine cross-linked substance. The clay stabilizer disclosed by the invention is particularly suitable for polymer dry powder direct distribution variable-viscosity fracturing fluid, the stability of clay can be remarkably improved, particularly, excellent inhibition performance can still be kept under high-temperature and high-salt conditions, stratum damage is reduced, and the application requirements in complex environments of oil fields are met.

The application provides a modified activated carbon for removing perchlorate in water for sheep farms and a preparation method thereof, relates to the field of water treatment, and the method carries out reaction on activated carbon in a citric acid aqueous solution, uniformly loads a carboxyl layer on the surface of the activated carbon, and obtains preliminarily modified activated carbon; carries out reaction on the preliminarily modified activated carbon in an alkaline polydimethyl diallyl ammonium chloride aqueous solution, and strong cation quaternary ammonium salt is adsorbed on the surface of the carboxyl layer through electrostatic action, thereby obtaining secondarily modified activated carbon; and carries out reaction on the secondarily modified activated carbon in a triethylenetetramine aqueous solution, so that triethylenetetramine molecules are further combined to the strong cation quaternary ammonium salt through electrostatic adsorption, thereby obtaining the modified activated carbon for removing perchlorate in water for sheep farms, the adsorption capacity of the activated carbon for solutes with negative charges is significantly enhanced, and the treatment efficiency of the overall farm environment on perchlorate is improved.

The invention belongs to the technical field of medical supplies, and discloses a weakly ionized colloidal gold immunochromatography test strip based on a cationic polymer as a quality control line and a preparation method thereof. The weak ionized colloidal gold immunochromatography test strip comprises a substrate, a nitrocellulose membrane, a combination pad and a water absorption pad, the nitrocellulose membrane, the combination pad and the water absorption pad are all distributed on the surface of the substrate; the combination pad is lapped on the nitrocellulose membrane, the water absorption pad is lapped on the nitrocellulose membrane, and the combination pad and the water absorption pad are distributed on two sides of the nitrocellulose membrane; a detection line and a quality control line are arranged on the nitrocellulose membrane; the quality control line is coated with poly dimethyl diallyl ammonium chloride; the weak ionized colloidal gold immunochromatography test strip further comprises a CEA monoclonal antibody Ab1-weak ionized colloidal gold compound. Directional charge adsorption synergy is formed through weak ionized colloidal gold and a PDDA quality control line with strong positive electricity, and gt is still kept in a high-salt environment; the capture stability is 95%, and the production cost of the C line is reduced by 90%.

The invention discloses polycation modified meta-aramid insulating paper and a preparation method thereof, and relates to the technical field of insulating materials. Meta-aramid chopped fibers are modified through polydimethyldiallylammonium chloride, then acrylamide is added for cross-linking enhancement, then the modified meta-aramid chopped fibers and meta-aramid fibrids are mixed and molded, and the polycation modified meta-aramid insulating paper is obtained. The polycation modified meta-aramid insulation paper is obtained. According to the invention, through a polycation modification technology, the interface bonding force between the meta-aramid chopped fiber and the fibrid is obviously enhanced. The modified insulation paper is excellent in mechanical performance, the tensile strength is greatly improved, the pore defects are reduced, and the compactness is enhanced, so that the strict requirements of the high-voltage insulation paper are met. Besides, the breakdown field strength of the modified insulation paper is remarkably improved, the deep trapped charge trapping capacity is enhanced, energy accumulation in the electric breakdown process is effectively inhibited, and higher reliability is shown in a complex electric field environment.

The invention relates to the technical field of textile fabrics, in particular to a preparation method of a bio-based flame-retardant antibacterial textile fabric, which comprises the following steps: step 1, cleaning the textile fabric and then drying for later use; 2, sequentially preparing a solution A, a solution B and a solution C; wherein the solution A is a poly dimethyl diallyl ammonium chloride aqueous solution with the mass fraction of 3-7%; the solution B is a nucleotide salt flame retardant aqueous solution with the mass fraction of 15-30%; the solution C is a polyhexamethylene guanidine salt antibacterial agent aqueous solution with the mass fraction of 4-9%; 3, the standby textile fabric in the step 1 is sequentially subjected to A solution dipping, B solution dipping, C solution dipping and B solution dipping to form a cycle, roll compacting is conducted after each time of dipping till the pick-up rate is 90-100%, and the total number of cycles is 3-7; and drying the textile fabric to obtain the bio-based flame-retardant antibacterial textile fabric.

The invention relates to the technical field of stabilizers, and relates to a water-washable clay stabilizer. The stabilizer comprises the following components in parts by weight: 0.1-0.5 parts by weight of a composite stabilizer, 0.5-1.5 parts by weight of polydimethyldiallylammonium chloride, 1-5 parts by weight of hexadecyltrimethylammonium bromide, 3-5 parts by weight of potassium chloride, 2-4 parts by weight of ethylene glycol, 0.2-0.4 parts by weight of xanthan gum, and 0.05-0.09 parts by weight of a sodium hydroxide pH regulator; wherein the composite stabilizer is obtained by mixing hexamethylenediaminetetramethylenephosphoric acid and oleoyl chloride in a molar ratio of 1:1.1-1.3, and the composite stabilizer is used to introduce hydrophobic oleoyl chloride into the hexamethylenediaminetetramethylenephosphoric acid, so that the composite stabilizer can not only form a stable complex with metal ions on the surface of clay, but also form a dense covering layer on the surface of clay particles through hydrophobic groups, thereby significantly improving the water-washing resistance of the clay stabilizer, reducing the hydration expansion phenomenon of the clay particles, and improving the stability of the composite stabilizer under different pH conditions.

The present invention discloses a method for treating the full amount of sludge from a municipal sewage treatment plant as a resource, and relates to the technical field of environmental engineering. The present invention uses ozone to oxidize the contents of sludge cells, uses black soldier fly pupa shell slurry and polydimethyldiallyl ammonium chloride as conditioning materials and materials for improving the water retention performance of residues, thereby achieving the degradation of volatile organic matter in the sludge and the efficient removal of heavy metals in the sludge, and then preparing the dehydrated product into a soil water retention material, and the heavy metals separated from the sludge are recovered in the form of ferrites, and the organic carbon in the liquid phase is used as a carbon source for the sewage treatment plant, thereby achieving the full amount of sludge as a resource.

This invention discloses a nano-flocculator, its preparation method, and its applications. The preparation method includes: preparing a protein amyloid cellulose solution; adding a zirconium salt compound and mixing to obtain a zirconium-loaded protein amyloid cellulose composite solution; and mixing with a polydimethyldiallyl ammonium chloride solution. The nano-flocculator provided by this invention can be stored for a long time at room temperature, is easy to use, and is suitable for improving both sedimentation efficiency and phosphorus removal in municipal and industrial wastewater treatment processes, showing broad engineering application prospects and environmental friendliness.

The application discloses a flocculant for coking wastewater and a preparation method and application thereof, and comprises the following raw materials in parts by weight: 1-5 parts of polydimethyl diallyl ammonium chloride and 6-12 parts of a composite, wherein the composite is prepared from kaolin loaded N-succinyl-O-carboxymethyl chitosan and konjac glucomannan. The application aims at solving the technical problem that coking wastewater cannot reach the discharge standard.

This invention discloses a red pigment paste for color photoresist and its preparation method, relating to the field of photoresist technology. The red pigment paste for photoresist comprises the following materials: modified pigment red 177, propylene glycol methyl ether acetate, poly(methacrylic acid-co-acrylate) copolymer, acrylate resin, styrene-maleic anhydride copolymer, and antioxidant. This invention, by adding modified pigment red 177, works synergistically with the poly(methacrylic acid-co-acrylate) copolymer and polydimethyldiallyl ammonium chloride to inhibit pigment particle agglomeration, ensuring uniform dispersion of the pigment in the propylene glycol methyl ether acetate solvent, thus guaranteeing uniform and fine dispersion of the pigment paste. The antioxidant in this invention includes β-cyclodextrin, which can coat pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and UV-327, improving the compatibility of the pigment paste system and extending the storage life of the pigment paste.

The invention relates to the field of functional materials technology, specifically to a preparation method, product, and application of hydrophobic melamine resin foam. The preparation method of hydrophobic melamine resin foam includes the following steps: Vacuum-impregnate the melamine resin foam with a solution of poly(dimethyl diallyl ammonium chloride). Subsequently, immerse the cationic-coated melamine resin foam in a sodium polyacrylate solution. Next, immerse the anionic-coated melamine resin foam in a titanium dioxide mixed solution for cross-linking. After cross-linking, immerse the melamine resin foam in a solution of tridecafluoro-octyl triethoxysilane. After impregnation, dry the foam to obtain hydrophobic melamine resin foam. The preparation method of the invention is simple, cost-effective, and easy to scale up for industrial applications. The hydrophobic melamine resin foam prepared using this method can achieve a hydrophobic contact angle of up to 150° and exhibits excellent oil absorption performance.

This invention belongs to the technical field of stirring equipment, and specifically relates to a stirring device for dissolving high-viscosity polydimethyldiallyl ammonium chloride, which includes an isolating stirring element, a stirring assembly, and a stirring tank; the internal space of the stirring tank is a main chamber for storing materials; the isolating stirring element divides the main chamber into a first sub-chamber and a second sub-chamber, and the stirring assembly is disposed in the first sub-chamber, so that the stirring assembly can fully stir the materials in the first sub-chamber; the isolating stirring element has different working states, and by changing the working state of the isolating stirring element, the materials in the first sub-chamber and the second sub-chamber can be interchanged, so that the materials in the main chamber are fully stirred.

The invention provides a conditioner for deep dehydration of sludge as well as a preparation method and application of the conditioner, and belongs to the technical field of sludge treatment. The conditioner for deep dehydration of the sludge, provided by the invention, is prepared from the following components in parts by mass: 5 to 10 parts of persulfate, 23 to 35 parts of composite flocculant, 3 to 12 parts of activated carbon, 7 to 16 parts of poly dimethyl diallyl ammonium chloride, 4 to 11 parts of bentonite, 12 to 23 parts of zeolite and 5 to 8 parts of fiber, the composite flocculant comprises polyaluminum chloride and polyferric chloride. Results of the embodiment show that after the conditioner for deep dehydration of the sludge provided by the invention is used for dehydrating the sludge, when the addition amount of the conditioner for deep dehydration of the sludge is 1-8%, the moisture content of the sludge can be reduced to 45.8% at most, and meanwhile, the peculiar smell can be reduced.

The present application relates to the field of environmental management technology, and more particularly to a composite coagulant for landfill leachate treatment and a preparation method thereof.The composite coagulant comprises inorganic coagulant, organic flocculant and nano coagulant aid; the inorganic coagulant is a mixture of polymeric aluminum ferric silicate and basic aluminum chloride; the organic flocculant is polydimethyl diallyl ammonium chloride; and the nano coagulant aid is a mixture of nano calcium oxide, nano ferric oxide and activated carbon.The composite coagulant has the characteristics of high efficiency in removing solid suspended matter and soluble organic matter in water, fast precipitation speed, one-step flocculation and sedimentation, formation of stable flocculation large particles in sewage, and effective reduction of the load of subsequent leachate treatment equipment.

The invention provides an oily sewage purifier system and a preparation method thereof, and belongs to the field of sewage treatment. The oily sewage purifying agent system is composed of a composite coagulant and an organic polymeric flocculant. Wherein the composite coagulant is prepared from the following components in parts by mass: 20-25 parts of polyferric sulfate; 25 to 30 parts of concentrated sulfuric acid; 3-5 parts of aluminum sulfate; 2-5 parts of ferric trichloride; 3 to 5 parts of poly dimethyl diallyl ammonium chloride; the organic polymeric flocculant is a cationic polyacrylamide aqueous solution. By adopting the multi-component coagulant, the components and the synergistic effect of the components can be utilized. Colloids in the sewage lose stability by adding a composite coagulant, a particle condensation phenomenon is generated, tiny flocs are formed, then cationic polyacrylamide is added, the tiny flocs are combined into dense flocs, the treatment effect is improved, and various organic wastes in the sewage are effectively flocculated and removed.

The invention discloses a one-dose type flocculation and solidification double-effect environment-friendly material and a preparation method thereof. The method comprises the following steps: by taking metakaolin as an inorganic core, firstly carrying out hydrophobic modification with gamma-aminopropyltriethoxysilane, then carrying out reflux covalent grafting with polydimethyldiallylammonium chloride under the condition that the pH is approximately equal to 9, and then carrying out spray drying to obtain spherical composite particles taking PDADMAC as a shell. The material is simple in process, low in dosage and high in adaptability, can reduce dehydration energy consumption and secondary pollution risks at the same time, and is suitable for reduction and recycling solidification treatment of complex wastewater.

The invention discloses a treating agent and a treating method for waste water-based drilling fluid, and belongs to the technical field of oil field waste drilling fluid treatment. Wherein the treating agent is composed of a gel breaker and a flocculating agent; the gel breaker is prepared from the following raw materials: 25wt%-30wt% of polyaluminum chloride, 0.1 wt%-0.2 wt% of cationic polyacrylamide and the balance of water. The flocculant is prepared from the following raw materials in percentage by weight: 1wt%-3wt% of poly dimethyl diallyl ammonium chloride, 0.5 wt% of a heavy metal stabilizer and the balance of water. According to the method, the waste drilling fluid can be quickly treated, the production requirements of an offshore drilling platform or a limited space can be met, meanwhile, the requirements of safety, environmental protection, water compatibility and the like are met, the problems of space occupation and cost caused by long-term storage and transportation of the waste drilling fluid are solved, and a method and a way are provided for green and quick offshore drilling. The method is suitable for treating the waste water-based drilling fluid in an offshore platform or other limited spaces.

The invention discloses an environment-friendly medicament for sewage treatment and a preparation method thereof, and belongs to the technical field of water treatment. The environment-friendly medicament for sewage treatment is prepared from the following raw materials in parts by weight: 15 to 20 parts of modified cellulose, 10 to 15 parts of layered double hydroxides, 25 to 30 parts of diatomite, 1 to 3 parts of 2-mercaptobenzothiazole, 20 to 25 parts of polyaluminum chloride, 5 to 8 parts of poly dimethyl diallyl ammonium chloride and 5 to 8 parts of ferrous sulfate. Wherein the modified cellulose is subjected to dual modification of quaternization and amino grafting. According to the environment-friendly sewage treatment agent, through innovative compounding of the modified cellulose, the layered double hydroxides and the 2-mercaptobenzothiazole, the diatomite is taken as a carrier and has a synergistic effect with other substances, so that suspended matters in water are rapidly reduced, an excellent removal effect on COD (Chemical Oxygen Demand), total phosphorus and heavy metal ions is also achieved, and the sewage treatment efficiency is remarkably improved. The sewage treatment environment-friendly medicament disclosed by the invention realizes the purpose of efficient and comprehensive sewage treatment, is environment-friendly and has a remarkable application value.

The invention relates to the technical field of degreasing agents, in particular to a long-acting circulating degreasing agent for preventing secondary pollution of cold-rolled silicon steel and a preparation method of the long-acting circulating degreasing agent. The invention discloses a long-acting circulating degreasing agent for preventing secondary pollution of cold-rolled silicon steel. The degreasing agent comprises the following raw materials in percentage by mass: 7-10% of sodium hydroxide, 3-5% of sodium carbonate, 1-3% of a non-phosphorus builder, 2-4% of a chelating agent, 10-12% of a neutral surfactant, 1-3% of a corrosion inhibitor, 0.5-2% of a composite flocculant, 1-3% of a defoaming agent and the balance of deionized water. The composite flocculant is composed of cationic polymer poly dimethyl diallyl ammonium chloride and silicon magnesium based nanosheets in a mass ratio of (1: 2)-(1: 10). The degreasing agent disclosed by the invention can realize high-efficiency degreasing (the degreasing rate gt is 90%) under a normal-temperature condition, and the clarity and the cycling stability of the degreasing fluid are greatly improved.

The invention discloses a preparation method of a rapid settling agent with a phosphorus removal effect for sludge settling, and belongs to the technical field of environment and chemistry. The invention specifically comprises main components and application scenes, and the components comprise an effective component, namely, 40% of polydimethyldiallylammonium chloride with the mass fraction of 10.2%, and an auxiliary component, namely 40% of polydimethyldiallylammonium chloride with the mass fraction of 10.2%. The effective content of the polyaluminum ferric chloride is 30%, and the mass fraction is 30.5%; the mass fraction of the biomass pyrolytic activated carbon is 1%, and the solid content of the biomass pyrolytic activated carbon is 90%; isopropyl alcohol with the mass fraction of 0.57% is compounded; the solid content of the polyacrylamide is 90%, and the mass fraction of the polyacrylamide is 0.75%. The rapid settling agent is small in dosage, rapid in sludge descending and wide in sludge application range, has the effects of removing phosphorus, being not prone to deterioration and the like, can remarkably improve the sludge settling performance of a secondary sedimentation tank and improve the sewage treatment capacity or the sludge running phenomenon caused by poor settling performance, synchronously has the phosphorus removal and dirt removal performance, and ensures that the treated water amount and the treated water quality of a sewage plant exceed the standard risk.

This invention discloses a composite cationic flocculant based on a dual gradient of molecular weight and charge density, along with its preparation and application methods. The flocculant is composed of a medium-molecular-weight, high-charge-density poly(diallylammonium chloride)-acrylamide copolymer (PDA) and a high-molecular-weight, medium-low-charge-density cationic polyacrylamide (CPAM), with an effective mass ratio of 10:1 to 20:1. The mass charge density of PDA is 2 to 3 times that of CPAM. A gradient shear mixing preparation process and a time-sequential synergistic flocculation application method based on differences in diffusion kinetics are employed. Through a relay effect of rapid charge neutralization (0-30 seconds) and slow bridging (30-180 seconds), the flocculant can form a skeleton-filled floc structure, achieving adaptive interception of dissolved organic matter and complexation-encapsulation and fixation of heavy metals. This invention can significantly shorten plate and frame filter press time and reduce the moisture content of the filter cake and the concentration of pollutants in the effluent.

The application discloses a one-dose flocculation solidification double-effect environment-friendly material and a preparation method thereof. The method takes metakaolin as an inorganic core, is subjected to hydrophobic modification through gamma-aminopropyl triethoxysilane, is subjected to reflux covalent grafting with polydimethyl diallyl ammonium chloride under the condition that pH is about 9, and is then subjected to spray drying to obtain spherical composite particles with a PDADMAC shell. The material has simple process flow, low dose and strong adaptability, can simultaneously reduce dewatering energy consumption and secondary pollution risk, and is suitable for solidification disposal of complex wastewater reduction and recycling.