A method for synthesizing an inorganic-organic flocculant by using magnetic iron porphyrin in cooperation with titanium dioxide

Abstract

The present invention discloses a method for synthesizing an inorganic-organic flocculant by using magnetic iron porphyrin in cooperation with titanium dioxide. First, magnetite is synthesized by the coprecipitation method, and then magnetic iron porphyrin is further synthesized. Using acrylamide and sodium vinyl sulfonate as reaction monomers, aluminum sulfate hydrate and ferric chloride hydrate as co-flocculants, and magnetic iron porphyrin and titanium dioxide as a binary initiation system, an inorganic-organic flocculant is prepared under the irradiation of a metal halide visible light lamp equipped with an ultraviolet filter membrane and a filter. The present invention uses visible light initiation, with low energy consumption. By using magnetic iron porphyrin in cooperation with titanium dioxide, the initiation efficiency is high and the initiation time is short. The obtained inorganic-organic flocculant has good stability, is easy to dissolve, has a high removal efficiency for pollutants such as colloidal particles in water sources, and has good economic and social benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment agents, and particularly relates to a method for synthesizing an inorganic-organic flocculant by using magnetic iron porphyrin and titanium dioxide in a synergistic manner. Background Art

[0002] Flocculants have the advantages of low cost, excellent flocculation effect, small dosage, and high removal efficiency for most suspended particles and soluble pollutants. Currently, they have been widely used in the pretreatment of polluted water bodies. According to the raw materials for preparing flocculants, they can be divided into natural and chemically synthesized ones. According to the types of flocculants, they can be divided into inorganic, organic, and inorganic-organic composites. However, the use of inorganic flocculants will produce a large amount of sludge that is difficult to be harmlessly treated, while the synthesis cost of traditional organic polymer flocculants is relatively high, and some monomers also have certain toxicity and the disadvantage of being difficult to biodegrade.

[0003] Chinese Patent Application No. CN202210058332.X, with the invention title "A magnetic flocculant and its preparation method and application". This invention provides a magnetic flocculant and its preparation method and application. The preparation method includes the following steps: (1) Iron tailings slag, carbon material and alcohol are subjected to a first mixing, first drying, and calcination in a protective atmosphere to obtain a magnetic core; (2) A solvent, a surfactant, a flocculant and the magnetic core obtained in step (1) are subjected to a second mixing and second drying to obtain a magnetic flocculant. This invention uses iron tailings slag as a raw material, realizes the preparation of a flocculant with strong magnetism through the resource utilization of iron tailings slag and a simple preparation method, and the prepared magnetic flocculant has the characteristics of low cost, good flocculation effect and strong magnetism. However, the energy consumption is relatively high.

[0004] Chinese Patent Application No. CN202111597834.1, with the invention title "A magnetic deflocculation method and a magnetic seed recovery device". This method discloses a magnetic deflocculation method and a magnetic seed recovery device, and its main idea is to realize the dispersion and deflocculation of magnetic flocs by using the magnetic force difference. The magnetic deflocculation method and the magnetic seed recovery device provided by this invention are completely different from the deflocculation methods disclosed by traditional magnetic seed separation equipment, and overcome the problems of high energy consumption, fast impeller wear, difficult replacement and maintenance, high labor intensity, and high cost of traditional mechanical high-speed dispersion devices; it also overcomes the problems of poor magnetic seed recovery effect caused by impeller wear or high-shear machine seal failure of the dispersion impeller; the magnetic seed recovery device provided by this invention has the advantages of low energy consumption, low noise, large processing capacity and high recovery efficiency when applied to large-flow sewage treatment. However, this device occupies a large area, the operation process is cumbersome, and the maintenance cost is high. Summary of the Invention

[0005] Aiming at the above deficiencies existing in the prior art, the purpose of the present invention is to provide a method for synthesizing an inorganic-organic flocculant by using magnetic iron porphyrin and titanium dioxide in a synergistic manner.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for synthesizing an inorganic-organic flocculant by magnetic iron porphyrin and titanium dioxide. It is characterized in that first, magnetic iron oxide is synthesized by coprecipitation method, and magnetic iron porphyrin is further synthesized. Acrylamide, deionized water and sodium vinyl sulfonate are successively added to the reaction flask and rapidly stirred until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution are 12.5 - 31.3% and 0.8 - 10.4% respectively. Under a nitrogen atmosphere, aluminum sulfate hydrate and ferric chloride hydrate are respectively added to the mixed solution. After addition, the mass fractions of aluminum sulfate and ferric chloride are 13.3 - 25% and 20% - 33.3% respectively, and stirred evenly at room temperature. The pH of the reaction system is adjusted to 1 - 3 with a 0.1M hydrochloric acid solution and mixed evenly. Magnetic iron porphyrin and titanium dioxide are successively added, and their mass fractions are 0.02‰ - 0.3‰ and 0.12‰ - 1‰ respectively, and rapidly stirred until the two are evenly dispersed. Finally, it is irradiated under a metal halide visible light lamp with an optical density of 30 - 80 mW / cm 2 for 2 - 4 h; after aging and purification, an inorganic-organic flocculant is obtained.

[0008] Specifically, it includes the following steps:

[0009] 1) First, magnetic iron oxide is synthesized by coprecipitation method, and magnetic iron porphyrin is further synthesized.

[0010] 2) Acrylamide, deionized water and sodium vinyl sulfonate are successively added to the reaction flask and rapidly stirred until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution are 12.5 - 31.3% and 0.8 - 10.4% respectively.

[0011] 3) Under a nitrogen atmosphere, aluminum sulfate hydrate and ferric chloride hydrate are respectively added to the mixed solution. After addition, the mass fractions of aluminum sulfate and ferric chloride are 13.3 - 25% and 20% - 33.3% respectively, and stirred evenly at room temperature.

[0012] 4) The pH of the reaction system is adjusted to 1 - 3 with a 0.1M hydrochloric acid solution and mixed evenly.

[0013] 5) Magnetic iron porphyrin and titanium dioxide are successively added, and their mass fractions are 0.02‰ - 0.3‰ and 0.12‰ - 1‰ respectively, and rapidly stirred until the two are evenly dispersed.

[0014] 6) Finally, it is irradiated under a metal halide visible light lamp with an optical density of 30 - 80 mW / cm 2 for 2 - 4 h.

[0015] 7) After aging and purification, an inorganic-organic flocculant is obtained.

[0016] Among them: In step (2), acrylamide and sodium vinyl sulfonate with mass fractions of 12.5 - 31.3% and 0.8 - 10.4% are respectively added to the reactor. By controlling the mass of acrylamide and sodium vinyl sulfonate added, the ratio of monomers and the total monomer concentration are adjusted, thereby improving the initiation efficiency under visible light. When the mass fraction of acrylamide is too low and the mass fraction of sodium vinyl sulfonate is too high, the polymerization effect of the finally obtained flocculant is poor and uneconomical. When the mass fraction of acrylamide is too large and the mass fraction of sodium vinyl sulfonate is too low, it is not conducive to subsequent reactions.

[0017] In step (3), aluminum sulfate hydrate with a mass fraction of 13.3 - 25% and ferric chloride hydrate with a mass fraction of 20% - 33.3% are added to the reactor. When there is an excess of aluminum ions and a small amount of iron ions in the reaction system, the removal rate of particulate matter in the coagulation experiment is low. When there is an excess of iron ions and a small amount of aluminum ions in the reaction system, the adsorption capacity of the flocculant is greatly weakened.

[0018] In step (4), the pH of the reaction system is adjusted to 1 - 3. When the pH is relatively large, the hydrogen ion content in the solution is low, inhibiting the synthesis of the flocculant. When the pH is relatively small, it is not conducive to the formation of colloids by aluminum ions and iron ions, thus affecting the subsequent coagulation experiment.

[0019] In step (5), magnetic iron porphyrin with a mass fraction of 0.02‰ - 0.3‰ is added. When the addition of magnetic iron porphyrin is too low, the spectral response effect of porphyrin on titanium dioxide is weak, the polymerization efficiency is low, and the polymerization is incomplete; when the magnetic iron porphyrin is too high, a large number of reactive intermediates are generated by porphyrin, the light capture ability of titanium dioxide is rapidly enhanced, the polymerization reaction is violent, and the phenomenon of explosive polymerization will occur, and it cannot be configured into a flocculant solution with a certain concentration.

[0020] In step (5), titanium dioxide with a mass fraction of 0.12‰ - 1‰ is added. If the amount of titanium dioxide is small, the amount of reactive intermediates is small, making the chain growth slow and the polymerization reaction difficult to initiate; if the amount of titanium dioxide is large, the amount of reactive intermediates increases, the reaction rate accelerates, the molecular chain is easily broken, and the molecular weight of the prepared flocculant is low.

[0021] In step (6), the light density of the metal halide visible light lamp is 30 - 80 mW / cm 2 . When the light density is too low, the reaction time is long, the energy consumption is high, and the initiation efficiency is low; when the light density is too high, the reaction is violent and the phenomenon of explosive polymerization is likely to occur.

[0022] In step (6), the reaction is irradiated with a metal halide visible light lamp for 2 to 4 h. If the reaction time is too short, the polymerization reaction of the flocculant is incomplete, and there is a phenomenon of coexistence of solid hydrogel and a large amount of liquid; if the irradiation time is too long, although the polymerization reaction can be made more complete, the molecular weight change of the synthesized flocculant is small, which is uneconomical.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention uses visible light initiation, with low energy consumption. By using magnetic iron porphyrin in cooperation with titanium dioxide, the initiation efficiency is high and the initiation time is short. The obtained inorganic-organic flocculant has good stability, is easy to dissolve, and has good economic and social benefits. Specific embodiments

[0025] The present invention will be further described in detail below in conjunction with specific embodiments. In the embodiments, unless otherwise specified, the raw materials used are ordinary commercially available products. Example 1:

[0026] 1) First, magnetite is synthesized by the coprecipitation method, and magnetic iron porphyrin is further synthesized.

[0027] 2) Acrylamide, deionized water, and sodium vinyl sulfonate are successively added to the reaction flask and rapidly stirred until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution are 18.8% and 6.3% respectively.

[0028] 3) Under a nitrogen atmosphere, aluminum sulfate hydrate and ferric chloride hydrate are respectively added to the mixed solution. After addition, the mass fractions of aluminum sulfate and ferric chloride are 13.3% and 20% respectively, and the mixture is stirred evenly at room temperature.

[0029] 4) The pH of the reaction system is adjusted to 1 with a 0.1 M hydrochloric acid solution and mixed evenly.

[0030] 5) Magnetic iron porphyrin and titanium dioxide are successively added, and their mass fractions are 0.02‰ and 0.12‰ respectively, and rapidly stirred until the two are evenly dispersed.

[0031] 6) Finally, the reaction is irradiated for 2 h under a metal halide visible light lamp with an optical density of 30 mW / cm 2 equipped with an ultraviolet filter membrane and a filter.

[0032] 7) After aging and purification, an inorganic-organic flocculant is obtained. Example 2:

[0033] 1) First, magnetite is synthesized by the coprecipitation method, and magnetic iron porphyrin is further synthesized.

[0034] 2) Acrylamide, deionized water, and sodium vinyl sulfonate were successively added to the reaction flask and rapidly stirred until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution were 20.8% and 4.2% respectively.

[0035] 3) Aluminum sulfate hydrate and ferric chloride hydrate were respectively added to the mixed solution under a nitrogen atmosphere. After addition, the mass fractions of aluminum sulfate and ferric chloride were 18% and 22% respectively, and the mixture was stirred evenly at room temperature.

[0036] 4) The pH of the reaction system was adjusted to 1.4 with a 0.1 M hydrochloric acid solution and mixed evenly.

[0037] 5) Magnetic iron porphyrin and titanium dioxide were successively added, and their mass fractions were 0.08‰ and 0.24‰ respectively. The mixture was rapidly stirred until both were evenly dispersed.

[0038] 6) Finally, the reaction was irradiated for 2.4 h under a metal halide visible light lamp with an optical density of 40 mW / cm 2 equipped with an ultraviolet filter membrane and a filter.

[0039] 7) After aging and purification, an inorganic-organic flocculant was obtained. Example 3:

[0040] 1) First, magnetite was synthesized by the co-precipitation method, and magnetic iron porphyrin was further synthesized.

[0041] 2) Acrylamide, deionized water, and sodium vinyl sulfonate were successively added to the reaction flask and rapidly stirred until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution were 21.9% and 3.1% respectively.

[0042] 3) Under a nitrogen atmosphere, aluminum sulfate hydrate and ferric chloride hydrate were respectively added to the mixed solution. After addition, the mass fractions of aluminum sulfate and ferric chloride were 21% and 24% respectively, and the mixture was stirred evenly at room temperature.

[0043] 4) The pH of the reaction system was adjusted to 1.8 with a 0.1 M hydrochloric acid solution and mixed evenly.

[0044] 5) Magnetic iron porphyrin and titanium dioxide were successively added, and their mass fractions were 0.14‰ and 0.48‰ respectively. The mixture was rapidly stirred until both were evenly dispersed.

[0045] 6) Finally, the reaction was irradiated for 2.8 h under a metal halide visible light lamp with an optical density of 50 mW / cm 2 equipped with an ultraviolet filter membrane and a filter.

[0046] 7) After aging and purification, an inorganic-organic flocculant was obtained. Example 4:

[0047] 1) First, magnetite was synthesized by the coprecipitation method, and then magnetic iron porphyrin was further synthesized.

[0048] 2) Acrylamide, deionized water and sodium vinyl sulfonate were successively added to the reaction flask and stirred rapidly until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution were 22.5% and 2.5% respectively.

[0049] 3) Under a nitrogen atmosphere, aluminum sulfate hydrate and ferric chloride hydrate were respectively added to the mixed solution. After addition, the mass fractions of aluminum sulfate and ferric chloride were 25% and 26% respectively, and the mixture was stirred evenly at room temperature.

[0050] 4) The pH of the reaction system was adjusted to 2.2 with a 0.1 M hydrochloric acid solution and mixed evenly.

[0051] 5) Magnetic iron porphyrin and titanium dioxide were successively added, and their mass fractions were 0.2‰ and 0.6‰ respectively, and the mixture was stirred rapidly until both were evenly dispersed.

[0052] 6) Finally, the reaction was irradiated for 3.2 h under a metal halide visible light lamp with an optical density of 60 mW / cm 2 equipped with an ultraviolet filter membrane and a filter.

[0053] 7) After aging and purification, an inorganic-organic flocculant was obtained. Example 5:

[0054] 1) First, magnetite was synthesized by the coprecipitation method, and then magnetic iron porphyrin was further synthesized.

[0055] 2) Acrylamide, deionized water and sodium vinyl sulfonate were successively added to the reaction flask and stirred rapidly until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution were 23.2% and 1.8% respectively.

[0056] 3) Under a nitrogen atmosphere, aluminum sulfate hydrate and ferric chloride hydrate were respectively added to the mixed solution. After addition, the mass fractions of aluminum sulfate and ferric chloride were 28% and 28% respectively, and the mixture was stirred evenly at room temperature.

[0057] 4) The pH of the reaction system was adjusted to 2.6 with a 0.1 M hydrochloric acid solution and mixed evenly.

[0058] 5) Magnetic iron porphyrin and titanium dioxide were successively added, and their mass fractions were 0.26‰ and 0.84‰ respectively, and the mixture was stirred rapidly until both were evenly dispersed.

[0059] 6) Finally, the reaction was irradiated for a certain time under a metal halide visible light lamp with an optical density of 70 mW / cm 2Irradiate the reaction under a metal halide visible light lamp for 3.6 h.

[0060] 7) After aging and purification, an inorganic-organic flocculant is obtained. Example 6:

[0061] 1) First, synthesize magnetite by the coprecipitation method and further synthesize magnetic iron porphyrin.

[0062] 2) Sequentially add acrylamide, deionized water, and sodium vinyl sulfonate to the reaction flask, and stir rapidly until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution are 23.4% and 1.6% respectively.

[0063] 3) Under a nitrogen atmosphere, add aluminum sulfate hydrate and ferric chloride hydrate to the mixed solution respectively. After addition, the mass fractions of aluminum sulfate and ferric chloride are 31% and 30% respectively, and stir evenly at room temperature.

[0064] 4) Adjust the pH of the reaction system to 3 with a 0.1 M hydrochloric acid solution and mix evenly.

[0065] 5) Sequentially add magnetic iron porphyrin and titanium dioxide, and their mass fractions are 0.3‰ and 1‰ respectively, and stir rapidly until the two are evenly dispersed.

[0066] 6) Finally, irradiate the reaction under a metal halide visible light lamp with an optical density of 80 mW / cm 2 equipped with an ultraviolet filter membrane and a filter for 4 h.

[0067] 7) After aging and purification, an inorganic-organic flocculant is obtained.

[0068] Measure the molecular weights of the inorganic-organic flocculants prepared in Examples 1 to 6 and the removal rates of colloidal particles in the source water respectively. The data are shown in Table 1.

[0069] Table 1 Performance parameters of inorganic-organic flocculants

[0070] Product performance Molecular weight of inorganic-organic flocculant (kDa) Removal rate of colloidal particles in source water (%) Example 1 3240 84 Example 2 3560 86 Example 3 3830 92 Example 4 4290 95 Example 5 4920 94 Example 6 5470 96

[0071] As can be seen from Table 1 above, the present invention relates to a method for synthesizing an inorganic-organic flocculant with magnetic iron porphyrin and titanium dioxide in cooperation. The present invention uses visible light initiation, with low energy consumption. By using magnetic iron porphyrin and titanium dioxide in cooperation, the initiation efficiency is high and the initiation time is short. The obtained inorganic-organic flocculant has good stability, is easy to dissolve, and has good economic and social benefits.

[0072] Finally, it should be noted that the above embodiments of the present invention are merely examples for illustrating the present invention and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes and modifications can be made based on the above description. It is impossible to enumerate all the implementation manners here. Any obvious changes or modifications derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A method for synthesizing an inorganic-organic flocculant by using magnetic iron porphyrin in cooperation with titanium dioxide, which is characterized in that First, magnetite was synthesized by coprecipitation method, and magnetic iron porphyrin was further synthesized. Acrylamide, deionized water and sodium vinyl sulfonate were successively added into the reaction flask and rapidly stirred until completely dissolved to obtain a mixed solution. The mass fractions of acrylamide and sodium vinyl sulfonate in the mixed solution were 12.5 - 31.3% and 0.8 - 10.4% respectively. Under a nitrogen environment, aluminum sulfate hydrate and ferric chloride hexahydrate were respectively added into the mixed solution. After addition, the mass fractions of aluminum sulfate and ferric chloride were 13.3 - 25% and 20% - 33.3% respectively, and stirred evenly at room temperature. The pH of the reaction system was adjusted to 1 - 3 with 0.1M hydrochloric acid solution and mixed evenly. Magnetic iron porphyrin and titanium dioxide were successively added, and their mass fractions were 0.02‰ - 0.3‰ and 0.12‰ - 1‰ respectively, and rapidly stirred until the two were evenly dispersed. Finally, it was irradiated under a metal halide visible light lamp with an optical density of 30 - 80 mW / cm 2 equipped with an ultraviolet filter membrane and a filter plate for 2 - 4 h; After aging and purification, an inorganic-organic flocculant was obtained.