A multifunctional safe water purification coagulant aid, its preparation process and application

Abstract

The present invention relates to a multifunctional safe water purification coagulant aid, its preparation process and application. The water purification coagulant aid includes components A, B, and C. Component A includes anionic PAM and a first multifunctional additive. Component B includes sodium sulfate, an acid-base regulator, a second multifunctional additive, and a stabilizer. Component C includes a low-molecular-weight flocculant, sodium silicate, sodium carbonate, and a dispersant. When using the water purification coagulant aid of the present invention, the technical product of the present invention is used in combination with a suitable coagulant represented by PAC for water treatment. Generally, the dosage of PAC can be reduced by 70-80%, the sedimentation time is shortened by about 70%, and the turbidity of the supernatant in the sedimentation tank can reach below 0.1 NTU after secondary purification by filtration. Moreover, the residual AM monomer in the dry powder of the technical product of the present invention is less than 12 ppm, and there is a major breakthrough in safety compared with similar water purification coagulant aids, having huge technical advantages, a wider application field, and important practical economic significance and far-reaching social significance.

Description

Technical Field

[0001] The present invention relates to the field of water treatment for purification, and particularly to a multifunctional safe water purification coagulant aid, its preparation process and application. Background Art

[0002] At present, the vast majority of water purification agents use coagulants represented by PAC for water purification reactions. By adding a certain amount of PAC to the raw water to be treated, harmful substances are removed and flocculated, generating fine floccules and sedimenting to achieve the purpose of water purification. There are also cases where PAC is added first and then an anionic PAM solution is added to achieve solid-liquid separation and accelerate precipitation. A polyacrylamide sewage treatment agent and its preparation method disclosed in CN201410481611.2 contain PAC in its components. In the preparation process, an intermediate one is obtained through a temperature-rising reaction; the remaining components are mixed to obtain an intermediate two, and finally the intermediate one and the intermediate two are mixed to obtain the product. The technical effect of this patent is to provide a treatment agent that is convenient to use and can efficiently reduce COD, SS, and chromaticity in sewage. However, its disadvantage is that its application scenario is relatively single and it cannot be effective for raw water in complex situations such as surface water, reservoir water, and different temperatures and turbidities. Moreover, the combination of other components except polyaluminum chloride itself cannot achieve good water purification effects. Summary of the Invention

[0003] The technical objective of the present invention is to solve the problems in the background art and provide a multifunctional safe water purification coagulant aid, its preparation process and application.

[0004] The above technical objective of the present invention is achieved through the following technical solutions:

[0005] A multifunctional safe water purification coagulant aid, wherein the water purification coagulant aid includes components A, B, and C;

[0006] Among them, component A includes anionic PAM and a first multifunctional additive; component B includes sodium sulfate, an acid-base regulator, a second multifunctional additive, and a stabilizer; component C includes a low-molecular flocculant, sodium silicate, sodium carbonate, and a dispersant.

[0007] The prior art has the following deficiencies: When using only PAC as a water purifying agent, 1. Since it is an endothermic reaction, during the low-temperature period in winter, when treating water, due to the low external heat, its reaction is slow and the coagulation reaction cannot be fully carried out, and perhaps only a small part of the original effect of PAC can be exerted; 2. Using a single PAC as a water purifying agent, the aluminum content in the final treated water is too high, which is harmful to the human body and cannot meet the current requirements for environmental green health; 3. If after adding PAC for coagulation reaction, then adding an anionic PAM solution for water purification, although the solid-liquid separation and precipitation are fast, but the premise is that after PAC fully exerts its water purification effect, then the aggregation size of flocs, etc. is improved by anionic PAM, and the essential water purification effect cannot be achieved. Moreover, in this application process, the application of anionic PAM is currently restricted by the residual acrylamide monomer, resulting in secondary pollution and the water quality safety cannot be guaranteed; 4. For the annual cyanobacteria-containing water, using only PAC, as the cyanobacteria and fine flocs are not easy to settle in the sedimentation tank, the water purification effect is greatly reduced; 5. For type III surface water, it is very difficult to reach the drinking water standard by simply using PAC for purification; 6. Using only PAC to purify and improve landscape water has a relatively poor effect and is rather difficult; 7. Currently, using biochemical technology to improve river water has a high cost, a slow speed, and a long time; 8. There is also a process of using a reverse osmosis membrane for water purification treatment in the current technology, but there are still problems of too high operation and maintenance costs, a large one-time investment cost, and its process is too complex.

[0008] The inventor found that: The existing anionic PAM only plays a single role in solid-liquid separation in water treatment, so it does not have its own water purification function during the coagulation aid process.

[0009] Anionic PAM produces electrostatic adsorption, adsorption bridging and enveloping effects on tiny particles in the water system, thereby aggregating tiny particles to form flocculent precipitation. In other words, the role of anionic PAM is to precipitate loose and tiny alum flowers that have not settled after PAC treatment. It cannot be ionized into a double-layer micelle structure in water like PAC polyaluminium chloride. It aggregates with impurities in water to form large-volume particles through adsorption neutralization, adsorption bridging, net capture and sweeping mechanisms, thereby precipitating. In addition, most of the anionic PAMs in the prior art use a single molecular weight. When performing coagulant aid, according to different water purification needs, it is necessary to use a single molecular weight anionic PAM that can solve the problem to prepare a coagulant aid product, and the effect is not good. It is relatively not ideal (because it cannot form a denser network structure, more fine alum flowers are missed in the sedimentation tank), and the water purification type water purification coagulant prepared by the present invention naturally forms a denser network structure in the coagulant process, and organically cooperates with many effective parameters of components B and C to target some pain points in water treatment, so as to play a better water purification role, and adopts anionic PAM with a molecular weight range of 12-20 million as raw materials to prepare products. The products can be used in many different scenarios, such as purifying surface water, reservoir water, low-temperature and low-turbidity water, blue algae water, normal-temperature and high-turbidity water, industrial wastewater, etc. When in use, only the dosage ratio needs to be changed to achieve excellent water purification effect.

[0010] In the design of components A, B, and C in the solution of the present invention, the obtained water purification coagulant aid itself has the function of purifying water, and its multifunctionality is reflected in: (1) For high-turbidity raw water, normal-temperature or high-temperature raw water, and low-temperature and low-turbidity raw water below 5°C, the water purification coagulant aid in this solution can reduce the turbidity of the raw water to 0.1-0.2 NTU when used in combination with PAC, and can basically reach 0 NTU after subsequent secondary filtration and purification; (2) For highly polluted and highly toxic surface water (Class III water source) that cannot be treated by the existing technology, using the water purification coagulant aid of the present invention in combination with PAC for purification treatment and then filtering and disinfecting can make the treated surface water meet the drinking water standard, with a turbidity lower than 0.2 NTU, being safe and non-toxic, and not causing secondary pollution (if necessary, surface water cannot be used as a tap water source according to the existing water purification agent technology, while the technical product of the present invention can solve such problems); (3) For the problem of cyanobacteria in reservoir water, by using the water purification coagulant aid prepared according to the solution of the present invention in combination with PAC, the cyanobacteria in the water can precipitate together with the flocs, solving the problem that cyanobacteria are difficult to settle, and the turbidity of the supernatant in the sedimentation tank reaches 0.1 NTU; (4) For the aerobic end water, when using PAC dry powder alone, 20-40 kg per thousand tons of water is required, and after sedimentation in the secondary sedimentation tank for more than 2 hours, the turbidity of the supernatant is about 1.2-2.8 NTU; when using the present invention, the dosage can be reduced by 50-70%, the sedimentation time only needs about 15 minutes, and the turbidity of the supernatant can be reduced to 0.2 NTU. The multifunctional use of the water purification coagulant aid designed in the above solution of the present invention not only greatly improves the efficiency of flocculation and sedimentation in water treatment, but also reduces the PAC usage by 50-70% and improves the final purification effect of the raw water, and the sedimentation time is shortened by 70%; (5) Since the present invention also has a targeted water purification function for low-temperature and low-turbidity water and high-temperature and high-turbidity water, it is suitable for treating the raw water to be treated throughout the year; (6) The safety index of the technical product of the present invention, the residual amount of AM monomer, is less than 12 ppm; (7) For highly polluted and highly toxic surface water at high temperature, PAC alone cannot purify the water quality. Because the surface water in this season is oxygen-deficient and will cause cyanobacteria, using the product of the present invention in combination with PAC can achieve an ideal water purification effect, and the turbidity can reach 0.3 NTU in 15 minutes of sedimentation time.

[0011] Preferably, the molecular weight of the anionic PAM in component A is 12 million - 20 million, and the first multifunctional additive is a pectin biosurfactant.

[0012] Preferably, the mass fraction of the anionic PAM in component A is 25-35 parts, and the mass fraction of the first multifunctional additive is 1-3 parts.

[0013] By adopting the present invention, the advantage lies in that in component A, high-molecular-weight anionic PAMs with different molecular weights are mixed and stirred. The molecular weight of anionic PAM refers to the length of the molecular chain in the molecule. Selecting high-molecular-weight anionic PAM with a molecular weight of 12 million - 20 million as the raw material for component A can make the flocculation of raw water and the water to be treated after biochemical treatment more comprehensive and sufficient.

[0014] When using the product of the present technology in combination with PAC, PAC can be added first and then stirred with a mixer at a rotation speed of 200 rpm for 30 seconds or more to break up the cyanobacteria. After PAC reacts for a certain period of time, the purified water working solution dissolving the product of the present technology is added for the purification and coagulation aid reaction. During the reaction process, the broken cyanobacteria and the adsorbed harmful substances are packed into the alum flower net. The quality of this alum flower is particularly heavy, so it precipitates rapidly in the sedimentation tank.

[0015] By adopting the present invention, the advantage lies in that a first multifunctional additive pectin biosurfactant is added to component A, and its preparation method is further proposed later; the pectin biosurfactant with a limited preparation ratio of the raw materials added in the present invention is not only biodegradable, but also can play a very good environmental protection and water purification effect when added to the raw material components of the water purification coagulant aid.

[0016] By adopting the present invention, the advantage lies in selecting sodium silicate as the stabilizer. Sodium silicate has a strong adsorption ability and can adsorb Fe 2+ and block HOO - , and can combine with Ca 2+ , Mg 2+ in the bleaching solution to form highly dispersed calcium silicate and magnesium silicate colloids, making them lose their activity, thus playing a stabilizing role; and sodium silicate itself is an alkaline agent and can buffer the pH.

[0017] Preferably, the component B further includes serpentine powder and modified porous zeolite. The mass fraction of serpentine powder is 0.1 - 1 part, and the mass fraction of modified porous zeolite is 0.5 - 2 parts; the acid-base regulator in component B is sodium carbonate, and the mass fraction of the acid-base regulator is 3 - 8 parts; the mass fraction of sodium sulfate is 10 - 30 parts; the second multifunctional additive is a glycolipid biosurfactant extracted from yeast taken from a low-temperature environment, and its mass fraction is 0.5 - 1.5 parts; the stabilizer is sodium silicate, and the mass fraction of sodium silicate is 3 - 8 parts.

[0018] By adopting the present invention, the advantage lies in that the glycolipid biosurfactant extracted from yeast (isolated strain of Antarctic bacteria) taken from a low-temperature environment added to component B is very suitable for decontamination and purification of low-temperature raw water in a low-temperature environment because it comes from a cold environment.

[0019] Adopting the present invention, the advantages are as follows: Using serpentine and modified inorganic porous materials as raw materials promotes the use of PAC to achieve electro-neutralization, destabilize colloids and suspended pollutants in water bodies, and form fine floccules. At the same time, the electric double layer of colloidal particles in water is compressed or electrically neutralized, the potential is reduced, colloidal ions are attracted to each other, the stability of the micelle is destroyed, and colloidal particles collide to form flocculation precipitation, so as to achieve the effect of destabilization and coagulation, and achieve the purification treatment effect.

[0020] Preferably, the low-molecular flocculant in the C component is a lignin flocculant, and its mass fraction is 1-3 parts; the mass fraction of sodium silicate is 13-18 parts, and the mass fraction of sodium carbonate is 3-10 parts; the dispersant is talcum powder, and the mass fraction is 1.5-3 parts.

[0021] Preferably, a preparation process of a multifunctional safe water purification coagulant aid includes the following process steps:

[0022] Step S1 Preparation of component A: Mix and stir different molecular weight anionic PAM solids in a blender according to the specified amounts, add the first multifunctional additive and stir to mix evenly, and finally sieve and dry the obtained product to obtain component A;

[0023] Step S2 Preparation of component B: Mix the raw materials of component B and stir evenly, add the second multifunctional additive, continue to stir evenly in the blender, and then sieve and dry to obtain component B;

[0024] Step S3 Preparation of component C: Mix the raw materials of component C and stir evenly to obtain component C;

[0025] Step S4 Preparation of the water purification coagulant aid: Mix components A, B, and C in proportion in a blender and stir evenly, and then bag them to obtain a multifunctional safe water purification coagulant aid.

[0026] Preferably, the preparation method of the pectin biosurfactant is as follows: (1) Add alkylamine to pectin, and the mass ratio of pectin to alkylamine is 1:(8.5-10.5); (2) React the mixture in (1) in a silicone oil bath at 60-80 °C for 45-60 min; (3) Wash the heated reaction mixture with chloroform and dialyze the above mixture through a dialysis membrane for 2-4 days, and keep the pH value of the dialysis water at 4.0; (4) Remove the water in the solution and dry it to obtain a biosurfactant derived from pectin.

[0027] Furthermore, the mass ratio of pectin to alkylamine is 1:9, react at 70 °C in a silicone oil bath for 60 min, and dialyze the mixture for 3 days.

[0028] As a further preference, in the component B, the modified porous zeolite is obtained by reacting a modifier with an inorganic porous zeolite, and the modifier is dodecyl dimethyl betaine; the preparation process is to add 1.5 - 2.5 parts of the modifier dodecyl dimethyl betaine and 0.5 - 1 part of porous zeolite into a reaction kettle after stirring, and at the same time add water and dilute sulfuric acid, and carry out a heat preservation reaction for 3 - 5 h. After the reaction, it is washed, centrifuged and dried to obtain the modified porous zeolite.

[0029] Adopting the present invention, the advantage is that the surface of the inorganic porous material is modified by using dodecyl dimethyl betaine. Dodecyl dimethyl betaine has a long alkyl chain and no other branched chains, and can form a bridge between the inorganic porous materials during the adsorption and flocculation processes, making the adsorbed volume larger, the bridge more dense, and further making the floc density larger and the aggregated impurities more. Under the action of gravity, the precipitation speed is faster and the flocculation time is shorter.

[0030] As a further preference, the component A further includes an epichlorohydrin trimethyl ammonium CNC - EPTMAC polymer flocculant, and the epichlorohydrin trimethyl ammonium is prepared by sodium hydroxide, CNCs dispersion and 3 - chloro - 2 - hydroxypropyl trimethyl ammonium chloride CHPTAC: adding the cellulose nanocrystal CNC dispersion into the sodium hydroxide solution to obtain a CNC dispersion solution with a CNC dispersion concentration of 0.1 - 0.5 mol / L, and stirring the obtained CNC dispersion solution at room temperature for 15 - 40 min; adding 3 - chloro - 2 - hydroxypropyl trimethyl ammonium chloride CHPTAC into the above - mentioned CNC dispersion solution while stirring, so that the molar concentration of CHPTAC in the solution is 1.5 - 3 mol / L. After stirring for 5 - 10 h, the reactant is dialyzed with distilled water for 3 days, and finally the obtained product is dried to obtain cellulose nanocrystal - epichlorohydrin trimethyl ammonium; the mass fraction of the epichlorohydrin trimethyl ammonium is 0.1 - 1 part.

[0031] Adopting the present invention, the advantage is that CNC - EPTMAC has great flocculant potential in water treatment and has remarkable stability in the range of 2 - 12 pH. In addition, at a concentration of only 2 ppm, it can effectively reduce the turbidity by 99.7%, and it is a natural and environmentally sustainable commercial flocculant.

[0032] As a preference, the water purification coagulant aid is dissolved indoors at room temperature, and the proportions of components A, B, and C can be adjusted according to the use scenario.

[0033] Adopting the present invention, the advantage is that components A, B, and C are mixed adjustably to prepare a multifunctional and safe water purification type coagulant aid, which can effectively combine the active raw materials in the components, analyze specific problems specifically, and remove harmful substances in water treatment to the greatest extent by flocculation and precipitation.

[0034] Preferably, for low-temperature and low-turbidity raw water, surface water, reservoir water treatment, aerobic end water after biochemical treatment in urban sewage plants, supernatant of secondary sedimentation tanks, and industrial wastewater such as papermaking wastewater; first add an appropriate amount of PAC for uniform mixing reaction, and then add an appropriate amount of the working solution of the technical product of the present invention for water purification and coagulation aid reaction, and precipitate for 15 - 30 minutes; the turbidity of the supernatant of the precipitated water can reach 0.1 NTU - 0.5 NTU; after filtration and purification through a filter tank, it can reach 0.0 NTU - 0.2 NTU.

[0035] Adopting the present invention, the advantage is that the technical product of the present invention's solution also has a great effect on removing scale and softening hard water, and the water purification and coagulation aid are safe and reliable without secondary pollution.

[0036] Adopting the present invention, the advantage is that for low-temperature and low-turbidity raw water, the product produced by this technology can be used in combination with PAC to obtain a sufficient and rapid water purification reaction, thus achieving the effects of comprehensive water purification and rapid precipitation; for surface water across the country, when the technical product of this technology is used in combination with PAC, the turbidity of the supernatant of the sedimentation tank can reach 0.1 - 0.2 NTU, making it possible for surface water sources in any region to be used as tap water sources; for reservoir water, when the technical product of this technology is used in combination with PAC, the dosage can be reduced by 70 - 80%, greatly reducing the cost of water purification agents, shortening the sedimentation time by 70%, and the turbidity of the supernatant of the sedimentation tank reaching 0.1 NTU.

[0037] In summary, the present invention has the following beneficial effects:

[0038] 1. By using the products of components A, B, and C of the present invention's solution in combination with PAC, cyanobacteria can settle together with flocs, the sedimentation time is shortened by 70%, the turbidity of the supernatant of the sedimentation tank is 0.1 - 0.3 NTU, greatly improving the efficiency of flocculation and sedimentation in water treatment, reducing the usage amount of PAC, and improving the water purification efficiency while reducing the water purification cost;

[0039] 2. The water purification and coagulation aid prepared by this solution can remove scale and soften hard water, and is safe and reliable in water purification and coagulation aid without secondary pollution; when the water purification and coagulation aid prepared by the present invention's solution is used in combination with PAC for water purification treatment, the dosage can be reduced by 70 - 80%, the sedimentation time is shortened by about 70%, the turbidity of the supernatant of the sedimentation tank can reach below 0.1 NTU after purification through a filter tank, and there is basically no residual AM monomer;

[0040] 3. Using the water purification and coagulation aid prepared by this solution can solve the problem of excessive fixed investment in water treatment plants, save floor space, reduce energy consumption, greatly reduce the dosage of subsequent disinfectants, and greatly reduce the side effects brought by disinfectants, greatly reducing the existing comprehensive water purification cost;

[0041] 4. For the water body of the papermaking wastewater that meets the discharge standards after water treatment using this solution, additional reaction facilities, sedimentation tanks, and filtration tanks are added. An appropriate amount of PAC is added to the reaction facilities for sludge mixing reaction, and then the water purification coagulant prepared according to the solution of the present invention is added for water purification coagulation reaction. Then, it is sedimented in the sedimentation tank for 15 minutes and then reaches a turbidity of 0.00 NTU in the filtration tank, and other indicators can all meet the standards available for the paper mill.

[0042] 5. For raw water with low temperature and low turbidity, the water purification coagulant prepared according to the solution of the present invention is used in combination with an appropriate amount of PAC for water purification treatment. The sedimentation time is shortened by about 70%, and the supernatant of the sedimentation tank can reach below 0.1 NTU after being purified by the filtration tank.

[0043] 6. For surface water with high temperature, high toxicity, and high pollution, the water purification coagulant prepared according to the solution of the present invention is used in combination with an appropriate amount of PAC for water purification treatment. The sedimentation time is shortened by about 70%, and the supernatant of the sedimentation tank can reach below 0.1 NTU after being purified by the filtration tank.

[0044] 7. In some existing technologies for reusing reclaimed water in the sewage field, the operating cost is high. The water purification coagulant prepared according to the solution of the present invention is used in combination with an appropriate amount of PAC for water purification treatment. The sedimentation time is 15 minutes, and it can reach the reclaimed water reuse standard after filtration, purification, and disinfection.

[0045] 8. Comparing the safety of the water purification coagulant prepared according to the solution of the present invention with the coagulant represented by anionic PAM, in the existing technology, the residual amount of AM monomer in anionic PAM (dry basis) is less than 200 ppm, while the residual amount of AM monomer in the water purification coagulant product (dry basis) prepared according to the solution of the present invention is less than 12 ppm.

[0046] 9. The water purification coagulant prepared according to the solution of the present invention is used in combination with an appropriate amount of PAC for water purification treatment, which can be used for the rapid purification of river water and enable the river water to achieve the self-purification function earlier. Description of the Drawings

[0047] Figure 1 is a process flow chart of the preparation of a multifunctional safe water purification type coagulant. Detailed Embodiments

[0048] The following specific embodiments are only explanations of the present invention and are not limitations thereof. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0049] The raw water in the following examples and comparative examples is collected from the water to be treated in the water treatment plant, the raw water to be treated after biochemical treatment, and the water discharged up to the standard in papermaking. And the total number of parts by mass of the components of the present invention is not calculated based on 100 parts; the first multifunctional additive in the following examples and comparative examples is a pectin biosurfactant, and the second multifunctional additive is a glycolipid biosurfactant derived from Antarctic yeast. And the preparation method of the pectin biosurfactant is: (1) adding alkylamine to pectin, and the mass ratio of pectin to alkylamine is 1:9; (2) reacting the mixture in (1) in a silicone oil bath at 70 °C for 60 min; (3) washing the heated reaction mixture with chloroform and dialyzing the above mixture through a dialysis membrane for 3 days, and the pH value of the dialysis water is kept at 4.0; (4) removing the water in the solution and drying to obtain a biosurfactant derived from pectin, which will not be elaborated in the examples.

[0050] It should also be noted that: PAC mentioned in the content of this article, the full Chinese name is polyaluminum chloride; anionic PAM, the full Chinese name is anionic polyacrylamide; AM, the full Chinese name is acrylamide; PAC mentioned in this article is used as a representative of coagulants, but the coagulant aids of the present invention can be conditionally used in combination with other existing coagulants in addition to being used in combination with PAC. In the above table of our experiments, the comparison list of the use of PAC and anionic PAM in combination and the use of PAC and the coagulant aid of the present invention is not listed. The reason is that the AM residue contained in the coagulant aid of the present invention is less than 12 ppm, and there is no comparability in terms of the water quality safety after use and the secondary pollution to the environment, so it is not used as a comparative example. Example 1

[0051] Step S1 Preparation of component A: Epoxypropyltrimethylammonium is prepared by sodium hydroxide, CNC dispersion and 3-chloro-2-hydroxypropyltrimethylammonium chloride CHPTAC: adding cellulose nanocrystal CNC dispersion to sodium hydroxide solution to obtain a CNC dispersion solution with a CNC dispersion concentration of 0.1 mol / L, and stirring the obtained CNC dispersion solution at room temperature for 15 min; adding 3-chloro-2-hydroxypropyltrimethylammonium chloride CHPTAC to the above CNC dispersion solution while stirring, so that the molar concentration of CHPTAC in the solution is 1.5 mol / L, stirring for 5 h, and then dialyzing the reactant with distilled water for 3 days, and finally drying the obtained product to obtain cellulose nanocrystal-epoxypropyltrimethylammonium;

[0052] After mixing and stirring 35 parts of anionic PAM and 1 part of epoxypropyltrimethylammonium CNC-EPTMAC polymer flocculant evenly in a blender, adding 1 part of the first multifunctional additive and stirring and mixing evenly, and finally sieving and drying the obtained product to obtain component A.

[0053] Step S2 Preparation of Component B: The modified porous zeolite is obtained by reacting a modifier with an inorganic porous zeolite. The modifier is dodecyl dimethyl betaine. The preparation process is as follows: 1.5 parts of the modifier dodecyl dimethyl betaine and 0.5 parts of porous zeolite are added to a reaction kettle after stirring, and water and dilute sulfuric acid are added simultaneously, followed by a heat preservation reaction for 3 h. After the reaction, washing, centrifuging, and drying are carried out to obtain the modified porous zeolite.

[0054] 1 part of serpentine powder, 2 parts of modified porous zeolite, 30 parts of sodium sulfate, 3 parts of sodium carbonate, and 3 parts of sodium silicate are mixed and stirred evenly, then 0.5 part of the second multifunctional additive is added. After the mixer continues to stir evenly, it is sieved and dried to obtain Component B.

[0055] Step S3 Preparation of Component C: 1 part of low molecular weight flocculant, 14 parts of sodium silicate, 7 parts of sodium carbonate, and 1.5 parts of talc powder are mixed and stirred evenly to obtain Component C.

[0056] Step S4 Preparation of the water purification coagulant aid: Components A, B, and C are mixed and stirred evenly with a mixer and then bagged to obtain a multifunctional safe water purification coagulant aid.

[0057] Taking surface water during the period of 20°C - 30°C as the raw water for tap water, with the turbidity of the raw water being 105 NTU, PAC is first added to three beakers and stirred for 5 min, with the dosing amounts being 10 mg / L, 20 mg / L, and 30 mg / L respectively; subsequently, the above-mentioned multifunctional safe water purification coagulant aid is added and stirred for 5 min, with a unified dosing amount of 1 mg / L each, and then wait for complete precipitation. Example 2

[0058] Step S1 Preparation of Component A: Epoxypropyltrimethylammonium is prepared from sodium hydroxide, CNC dispersion, and 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC). The cellulose nanocrystal (CNC) dispersion is added to a sodium hydroxide solution to obtain a CNC dispersion solution with a CNC dispersion concentration of 0.1 mol / L, and the obtained CNC dispersion solution is stirred at room temperature for 15 min; 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) is added to the above-mentioned CNC dispersion solution while stirring, so that the molar concentration of CHPTAC in the solution is 1.5 mol / L. After stirring for 5 h, the reactants are dialyzed with distilled water for 3 days, and finally the obtained product is dried to obtain cellulose nanocrystal-epoxypropyltrimethylammonium.

[0059] 35 parts of anionic PAM and 1 part of the epoxypropyltrimethylammonium CNC-EPTMAC high molecular flocculant are mixed and stirred evenly in a mixer, then 1 part of the first multifunctional additive is added and stirred and mixed evenly. Finally, the obtained product is sieved and dried to obtain Component A.

[0060] Step S2 Preparation of Component B: The modified porous zeolite is obtained by reacting a modifier with an inorganic porous zeolite. The modifier is dodecyl dimethyl betaine. The preparation process is as follows: 1.5 parts of the modifier dodecyl dimethyl betaine and 0.5 parts of porous zeolite are added to a reaction kettle after stirring. At the same time, water and dilute sulfuric acid are added, and a heat preservation reaction is carried out for 3 h. After the reaction, washing, centrifuging, and drying are carried out to obtain the modified porous zeolite.

[0061] 1 part of serpentine powder, 2 parts of modified porous zeolite, 30 parts of sodium sulfate, 3 parts of sodium carbonate, and 3 parts of sodium silicate are mixed and stirred evenly, and then 0.5 part of the second multifunctional additive is added. After the mixer continues to stir evenly, it is sieved and dried to obtain Component B.

[0062] Step S3 Preparation of Component C: 1 part of low molecular weight flocculant, 14 parts of sodium silicate, 7 parts of sodium carbonate, and 1.5 parts of talc powder are mixed and stirred evenly to obtain Component C.

[0063] Step S4 Preparation of the water purification coagulant aid: Components A, B, and C are mixed and stirred evenly with a mixer and then bagged to obtain a multifunctional safe water purification coagulant aid.

[0064] In the high-temperature season (40 °C), the surface water with cyanobacteria is used as the raw water for tap water. The turbidity of the raw water is 80 NTU. In three beakers, PAC is first added and stirred for 5 min, and the dosage is 30 mg / L, 40 mg / L, and 50 mg / L. Subsequently, the above-mentioned multifunctional safe water purification coagulant aid is added and stirred for 5 min, and the unified dosage is 2 mg / L each. Wait for complete precipitation. Example 3

[0065] Step S1 Preparation of Component A: Glycidyl trimethylammonium is prepared by sodium hydroxide, CNCs dispersion, and 3-chloro-2-hydroxypropyl trimethylammonium chloride CHPTAC: The cellulose nanocrystal CNC dispersion is added to the sodium hydroxide solution to obtain a CNC dispersion solution with a CNC dispersion concentration of 0.5 mol / L. The obtained CNC dispersion solution is stirred at room temperature for 40 min; 3-chloro-2-hydroxypropyl trimethylammonium chloride CHPTAC is added to the above-mentioned CNC dispersion solution while stirring, so that the molar concentration of CHPTAC in the solution is 1.5 - 3 mol / L. After stirring for 5 - 10 h, the reactant is dialyzed with distilled water for 3 days, and finally the obtained product is dried to obtain cellulose nanocrystal - glycidyl trimethylammonium.

[0066] 25 parts of anionic PAM and 0.1 part of glycidyl trimethylammonium CNC-EPTMAC polymer flocculant are mixed and stirred evenly in a mixer, and then a first multifunctional additive containing 3 parts of pectin biosurfactant is added and stirred and mixed evenly. Finally, the obtained product is sieved and dried to obtain Component A.

[0067] Step S2 Preparation of Component B: The modified porous zeolite is obtained by reacting a modifier with an inorganic porous zeolite. The modifier is dodecyl dimethyl betaine. The preparation process is as follows: 2.5 parts of the modifier dodecyl dimethyl betaine and 1 part of porous zeolite are added to a reaction kettle after stirring, and water and dilute sulfuric acid are added simultaneously, followed by a heat preservation reaction for 5 h. After the reaction, washing, centrifugation, and drying are carried out to obtain the modified porous zeolite.

[0068] 0.1 part of serpentine powder, 0.5 part of modified porous zeolite, 33.3 parts of sodium sulfate, 8 parts of sodium carbonate, and 8 parts of sodium silicate are mixed and stirred evenly, and then 1.5 parts of a second multifunctional additive are added. After the mixer continues to stir evenly, it is sieved and dried to obtain Component B.

[0069] Step S3 Preparation of Component C: 1.5 parts of a low-molecular flocculant, 13 parts of sodium silicate, 10 parts of sodium carbonate, and 3 parts of talc powder are mixed and stirred evenly to obtain Component C.

[0070] Step S4 Preparation of a water purification coagulant aid: Components A, B, and C are mixed and stirred evenly with a mixer and then bagged to obtain a multifunctional safe water purification coagulant aid.

[0071] At a temperature below 10°C, reservoir water is used as the raw water for tap water, and the water body is flowing. The turbidity of the raw water is 1 NTU. In three beakers, PAC is first added and stirred for 5 min, with dosages of 2 mg / L, 4 mg / L, and 6 mg / L. Subsequently, the above-mentioned multifunctional safe water purification coagulant aid is added and stirred for 5 min, with a unified dosage of 0.2 mg / L each, and then wait for complete precipitation. Example 4

[0072] Step S1 Preparation of Component A: Epoxypropyltrimethylammonium is prepared from sodium hydroxide, CNCs dispersion, and 3-chloro-2-hydroxypropyltrimethylammonium chloride CHPTAC: The cellulose nanocrystal CNC dispersion is added to a sodium hydroxide solution to obtain a CNC dispersion solution with a CNC dispersion concentration of 0.25 mol / L. The obtained CNC dispersion solution is stirred at room temperature for 30 min. 3-Chloro-2-hydroxypropyltrimethylammonium chloride CHPTAC is added to the above CNC dispersion solution while stirring, so that the molar concentration of CHPTAC in the solution is 2 mol / L. After stirring for 8 h, the reactants are dialyzed with distilled water for 3 days, and finally the obtained product is dried to obtain cellulose nanocrystal-epoxypropyltrimethylammonium.

[0073] 28 parts of anionic PAM and 0.3 part of epoxypropyltrimethylammonium CNC-EPTMAC high-molecular flocculant are mixed and stirred evenly in a mixer, and then 1.8 parts of a pectin biosurfactant-containing first multifunctional additive are added and stirred and mixed evenly. Finally, the obtained product is sieved and dried to obtain Component A.

[0074] Step S2 Preparation of Component B: The modified porous zeolite is obtained by reacting a modifier with inorganic porous zeolite. The modifier is dodecyldimethylbetaine. The preparation process is as follows: 2 parts of the modifier dodecyldimethylbetaine and 0.8 part of porous zeolite are added to a reaction kettle after stirring, and at the same time, water and dilute sulfuric acid are added, and a heat preservation reaction is carried out for 3 - 5 h. After the reaction, washing, centrifuging, and drying are carried out to obtain the modified porous zeolite;

[0075] 0.4 part of serpentine powder, 1 part of modified porous zeolite, 28 parts of sodium sulfate, 4.5 parts of sodium carbonate, and 4.5 parts of sodium silicate are mixed and stirred evenly, then 1.3 parts of a second multifunctional additive are added. After the mixer continues to stir evenly, it is sieved and dried to obtain Component B.

[0076] Step S3 Preparation of Component C: 1.3 parts of a low - molecular - weight flocculant, 18 parts of sodium silicate, 7.5 parts of sodium carbonate, and 2.4 parts of talc powder are mixed and stirred evenly to obtain Component C.

[0077] Step S4 Preparation of the water purification coagulant aid: Components A, B, and C are mixed and stirred evenly with a mixer and then bagged to obtain a multifunctional safe water - purification type coagulant aid.

[0078] When the temperature is below 10°C, surface water is used as the raw water for tap water, the water body is flowing, the turbidity of the raw water is 10 NTU. In three beakers, PAC is first added and stirred for 5 min, and the dosages are 10 mg / L, 15 mg / L, and 20 mg / L. Subsequently, the above - mentioned multifunctional safe water - purification type coagulant aid is added and stirred for 5 min, and the unified dosage is 1 mg / L each. Wait for complete precipitation. Example 5

[0079] Step S1 Preparation of Component A: Glycidyltrimethylammonium is prepared by sodium hydroxide, CNCs dispersion, and 3 - chloro - 2 - hydroxypropyltrimethylammonium chloride CHPTAC: The cellulose nanocrystal CNC dispersion is added to a sodium hydroxide solution to obtain a CNC dispersion solution with a CNC dispersion concentration of 0.25 mol / L. The obtained CNC dispersion solution is stirred at room temperature for 30 min; 3 - chloro - 2 - hydroxypropyltrimethylammonium chloride CHPTAC is added to the above - mentioned CNC dispersion solution while stirring, so that the molar concentration of CHPTAC in the solution is 2 mol / L. After stirring for 8 h, the reactants are dialyzed with distilled water for 3 days, and finally the obtained product is dried to obtain cellulose nanocrystal - glycidyltrimethylammonium;

[0080] After mixing 31 parts of anionic PAM and 0.4 parts of epoxypropyltrimethylammonium CNC-EPTMAC polymer flocculant evenly in a blender, 1.7 parts of pectin biosurfactant as the first multifunctional additive was added and stirred evenly. Finally, the obtained product was sieved and dried to obtain Component A.

[0081] Step S2 Preparation of Component B: The modified porous zeolite is obtained by reacting a modifier with inorganic porous zeolite. The modifier is dodecyldimethylbetaine. The preparation process is as follows: 2 parts of the modifier dodecyldimethylbetaine and 0.8 parts of porous zeolite are added to a reaction kettle after stirring, and water and dilute sulfuric acid are added simultaneously, and a heat preservation reaction is carried out for 3 - 5 h. After the reaction, washing, centrifuging and drying are carried out to obtain the modified porous zeolite.

[0082] 0.5 parts of serpentine powder, 0.9 parts of modified porous zeolite, 27 parts of sodium sulfate, 5 parts of sodium carbonate and 5 parts of sodium silicate are mixed and stirred evenly, then 1.3 parts of the second multifunctional additive is added. After the blender continues to stir evenly, it is sieved and dried to obtain Component B.

[0083] Step S3 Preparation of Component C: 1.3 parts of low molecular weight flocculant, 15 parts of sodium silicate, 7.5 parts of sodium carbonate and 2.4 parts of talc powder are mixed and stirred evenly to obtain Component C.

[0084] Step S4 Preparation of the water purification coagulant aid: Components A, B and C are mixed and stirred evenly in a blender and then bagged to obtain a multifunctional safe water purification coagulant aid.

[0085] At room temperature, the supernatant of the secondary sedimentation tank of urban domestic sewage is used as the raw water, and the water body is flowing. The turbidity of this raw water is 1.2 - 2.8 NTU. In three beakers, PAC is first added and stirred for 5 min, and the dosage is 10 mg / L, 15 mg / L, 20 mg / L. Subsequently, the above-mentioned multifunctional safe water purification coagulant aid is added and stirred for 5 min, and the unified dosage is 1 mg / L each. Wait for the precipitation to be complete. Example 6

[0086] In this example, Components A, B and C are the same as those in Example 5 above. The difference is that: at room temperature, the water body is flowing, and the water that meets the discharge standard of papermaking wastewater is used as the raw water. The turbidity of this raw water is 20 - 30 NTU. In three beakers, PAC is first added and stirred for 5 min, and the dosage is 12 mg / L, 20 mg / L, 25 mg / L. Subsequently, the above-mentioned multifunctional safe water purification coagulant aid is added and stirred for 5 min, and the unified dosage is 1 mg / L each. Wait for the precipitation to be complete. Example 7

[0087] In this embodiment, the components A, B, and C are the same as those in the above-mentioned Embodiment 2. The difference is that at normal temperature, the water body is flowing, and the supernatant of the secondary sedimentation tank of urban industrial sewage is used as the raw water. The turbidity of this raw water is 10 NTU. In three beakers, PAC is first added and stirred for 5 minutes, and the dosage is 20 mg / L, 25 mg / L, and 30 mg / L. Subsequently, one of the above-mentioned multifunctional safe water purification coagulant aids is added and stirred for 5 minutes, and the unified dosage is 1 mg / L for each, and then wait for complete precipitation. Example 8

[0088] In this embodiment, the components A, B, and C are the same as those in the above-mentioned Embodiment 3. The difference is that in spring and autumn, the reservoir water with cyanobacteria is used as the raw water. The turbidity of this raw water is 2 NTU. In three beakers, PAC is first added and rapidly stirred for 30 seconds (200 revolutions per minute), and then slowly stirred for 4.5 minutes. The dosage is 3 mg / L, 5 mg / L, and 7 mg / L. Subsequently, one of the above-mentioned multifunctional safe water purification coagulant aids is added and stirred for 5 minutes, and the unified dosage is 0.3 mg / L for each, and then wait for complete precipitation. Comparative Example 1

[0089] Different from Embodiment 1, in three beakers, PAC is added alone and stirred for 10 minutes, and the dosages are 10 mg / L, 20 mg / L, and 30 mg / L respectively, and then wait for complete precipitation. Comparative Example 2

[0090] Different from Embodiment 2, in three beakers, PAC is added alone and stirred for 10 minutes, and the dosages are 30 mg / L, 40 mg / L, and 50 mg / L respectively, and then wait for complete precipitation. Comparative Example 3

[0091] Different from Embodiment 3, in three beakers, PAC is added alone and stirred for 10 minutes, and the dosages are 2 mg / L, 4 mg / L, and 6 mg / L respectively, and then wait for complete precipitation. Comparative Example 4

[0092] Different from Embodiment 4, in three beakers, PAC is added alone and stirred for 10 minutes, and the dosages are 10 mg / L, 15 mg / L, and 20 mg / L respectively, and then wait for complete precipitation. Comparative Example 5

[0093] Different from Embodiment 5, in three beakers, PAC is added alone and stirred for 10 minutes, and the dosages are 10 mg / L, 15 mg / L, and 20 mg / L respectively, and then wait for complete precipitation. Comparative Example 6

[0094] Different from Example 6, PAC was added singly into three beakers and stirred for 10 min, with the dosages being 12 mg / L, 20 mg / L, and 25 mg / L respectively, and then waited for complete precipitation. Comparative Example 7

[0095] Different from Example 7, PAC was added singly into three beakers and stirred for 10 min, with the dosages being 20 mg / L, 25 mg / L, and 30 mg / L respectively, and then waited for complete precipitation. Comparative Example 8

[0096] Different from Example 8, PAC was added singly into three beakers and stirred for 10 min, with the dosages being 3 mg / L, 5 mg / L, and 7 mg / L respectively, and then waited for complete precipitation.

[0097] The test results obtained from the above examples and comparative examples are as follows:

[0098] For the above water purification and flocculation situations, the turbidity of the supernatant in the sedimentation tank, sedimentation time, residual monomer of AM in the supernatant, COD removal rate and other index parameters were detected respectively.

[0099] The test results are as follows:

[0100] Table 1 Water treatment results of Example 1 and Comparative Example 1

[0101]

[0102] Table 2 Water treatment results of Example 2 and Comparative Example 2

[0103]

[0104] Table 3 Water treatment results of Example 3 and Comparative Example 3

[0105]

[0106] Table 4 Water treatment results of Example 4 and Comparative Example 4

[0107]

[0108] Table 5 Water treatment results of Example 5 and Comparative Example 5

[0109]

[0110] Table 6 Water treatment results of Example 6 and Comparative Example 6

[0111]

[0112] Table 7 Water treatment results of Example 7 and Comparative Example 7

[0113]

[0114] Table 8 Water treatment results of Example 8 and Comparative Example 8

[0115]

[0116] Table 9 Regarding the supernatant of the secondary sedimentation tank of a domestic sewage treatment plant in a southern city in Example 5 as raw water with a turbidity of 1.2 NTU, first adding 20 mg / L of PAC, stirring for 5 min, then adding 1 mg / L of the coagulant aid of the present invention and stirring for 5 min, and the supernatant obtained after precipitation for 15 min was tested for specific indicators as follows:

[0117]

[0118] From the results of the above 9 tables, the following conclusions can be drawn. The advantages of the coagulant aid of the present invention are mainly reflected in:

[0119] 1. Solved the problem of purifying low-temperature and low-turbidity water.

[0120] 2. Can solve the problem of purifying cyanobacteria water caused by oxygen-deficient water bodies in surface water during the continuous high-temperature season.

[0121] 3. Solved the problem that the existing technology for reusing intermediate water after biochemical treatment of raw water has high input and operating costs and cannot be popularized by physical and chemical methods.

[0122] 4. The coagulant aid of the present invention can greatly reduce the turbidity of the water before membrane treatment, thereby greatly reducing the subsequent membrane treatment operation cost and significantly increasing the water yield rate.

[0123] 5. At around 20 °C, using the coagulant aid of the present invention in combination with PAC in water treatment can reduce PAC by 70%-80% compared with using only PAC for water purification, and the water quality is further improved instead.

[0124] 6. The safety of the product of the present invention in the field of coagulant aids is the most ideal because the residual amount of dry-based AM monomer in the product is less than 12 PPm.

[0125] 7. Since the coagulant aid of the present invention will not cause secondary pollution, it is possible to also try to rapidly purify river water, enabling the river water to achieve self-purification function as soon as possible.

[0126] 8. For industrial wastewater (such as papermaking water) to meet the discharge standards of water quality, using the coagulant aid of the present invention in combination with PAC, and then through filtration and disinfection, it can be safely reused. In short, it provides a powerful technical means to save water resources, protect water resources, and enable the water ecosystem to quickly enter a virtuous cycle.

[0127] 9. Since the coagulant aid of the present invention can significantly improve the quality of the precipitated water, the disinfectant after filtration can be significantly reduced, thereby significantly reducing the side effects associated with the disinfectant.

[0128] 10. It can solve the problem of high fixed investment in newly built water treatment plants.

[0129] 11. It enables existing water treatment plants to improve water quality, water output efficiency and reduce comprehensive energy consumption.

Claims

1. A multifunctional safe water purification coagulant aid, characterized in that, The water purification coagulant aid includes components A, B, and C; Among them, component A includes anionic PAM and a first multifunctional additive; component B includes sodium sulfate, an acid-base regulator, a second multifunctional additive, and a stabilizer; component C includes a low-molecular-weight flocculant, sodium silicate, sodium carbonate, and a dispersant; In component A, the molecular weight of the anionic PAM is 12 million - 20 million, and the first multifunctional additive is a pectin biosurfactant; In component A, the mass fraction of the anionic PAM is 25 - 35 parts, and the mass fraction of the first multifunctional additive is 1 - 3 parts; Component B also includes serpentine powder and modified porous zeolite. The mass fraction of the serpentine powder is 0.1 - 1 part, and the mass fraction of the modified porous zeolite is 0.5 - 2 parts; the acid-base regulator in component B is sodium carbonate, and the mass fraction of the acid-base regulator is 3 - 8 parts; the mass fraction of sodium sulfate is 10 - 30 parts; the second multifunctional additive is a glycolipid biosurfactant extracted from yeast in a low-temperature environment, and its mass fraction is 0.5 - 1.5 parts; the stabilizer is sodium silicate, and the mass fraction of sodium silicate is 3 - 8 parts; in component B, the modified porous zeolite is obtained by reacting an inorganic porous zeolite with a modifier, and the modifier is dodecyldimethylbetaine; In component C, the low-molecular-weight flocculant is a lignin flocculant, and its mass fraction is 1 - 3 parts; the mass fraction of the sodium silicate is 13 - 18 parts, and the mass fraction of the sodium carbonate is 3 - 10 parts; the dispersant is talc powder, and the mass fraction is 1.5 - 3 parts.

2. The multifunctional safety water purification type coagulant aid according to claim 1, characterized in that: The preparation of the multifunctional safe water purification coagulant aid includes the following technological steps: Step S1 Preparation of component A: Mix and stir different molecular weight anionic PAM solids in a specified amount evenly in a blender, then add the first multifunctional additive and stir and mix evenly. Finally, sieve and dry the obtained product to obtain component A; Step S2 Preparation of component B: Mix the raw materials of component B evenly in a blender, add the second multifunctional additive, continue to stir and mix evenly in the blender, then sieve and dry to obtain component B; Step S3 Preparation of component C: Mix the raw materials of component C evenly to obtain component C; Step S4 Preparation of the water purification coagulant aid: Mix components A, B, and C in proportion in a blender, stir and mix evenly, and then bag to obtain a multifunctional safe water purification coagulant aid.

3. A multifunctional safety water purification type coagulant aid according to claim 1, characterized in that: The preparation method of the pectin biosurfactant is as follows: (1) Add alkylamine to pectin, and the mass ratio of pectin to alkylamine is 1:(8.5 - 10.5); (2) React the mixture in (1) in a silicone oil bath at 60 - 80 °C for 45 - 60 min; (3) Wash the heated reaction mixture with chloroform, and dialyze the above mixture through a dialysis membrane for 2 - 4 days, and keep the pH value of the dialysis water at 4.0; (4) Remove the water in the solution and dry to obtain a biosurfactant derived from pectin.

4. A multifunctional safe water purification type coagulant aid according to claim 1, characterized in that: Further, in the component B, the preparation process of the modified porous zeolite is as follows: 1.5 - 2.5 parts of the modifier dodecyl dimethyl betaine and 0.5 - 1 part of porous zeolite are added into a reaction kettle after stirring, and at the same time, water and dilute sulfuric acid are added, and a heat preservation reaction is carried out for 3 - 5 h. After the reaction, washing, centrifuging and drying are carried out to obtain the modified porous zeolite.

5. Application of a multifunctional safety water purification coagulant aid, characterized in that First, an appropriate amount of PAC is added for a uniform mixing reaction, and then an appropriate amount of the working solution formed by the multifunctional safety water purification type coagulant aid described in any one of claims 1 - 4 is added for a water purification coagulant aid reaction, and precipitation is carried out for 15 - 30 min; the turbidity of the supernatant of the precipitated water can reach 0.1 NTU - 0.5 NTU; after filtration and purification through a filter tank, it can reach 0.0 NTU - 0.2 NTU.

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