Rare earth compound flocculant as well as preparation method and application thereof

Abstract

The invention discloses a rare earth compound flocculant and a preparation method and application thereof.The rare earth compound flocculant is composed of a gluconic acid rare earth compound, a pyrithione rare earth compound and water, the content of the gluconic acid rare earth compound is 5-15 wt%, and the gluconic acid rare earth compound is prepared by reacting sodium gluconate with first chlorinated rare earth salt in water; the content of the pyrithione rare earth compound is 0.4-0.6 wt%, and the pyrithione rare earth compound is prepared by reacting sodium pyrithione with second chlorinated rare earth salt in water. According to the invention, rare earth ions have positive electricity, and show extremely strong coordination ability and high coordination number. Meanwhile, the surface of phaeodactylum tricornutum has electronegativity; therefore, when the rare earth ions are in contact with the phaeodactylum tricornutum, the rare earth ions and the phaeodactylum tricornutum can rapidly generate charge interaction, so that the phaeodactylum tricornutum is rapidly agglomerated and forms a lump, and then the lump

Description

Technical Field

[0001] The invention belongs to the technical field of rare earth compound application, and specifically relates to a rare earth compound flocculant and a preparation method and application thereof. Background Art

[0002] P. triangularis is a single-cell marine diatom with high economic value. Due to its unique biological characteristics, it has been widely used in many fields such as food, medicine and biofuel. As an efficient oil producer, P. triangularis has an extremely high oil content, usually between 30wt% and 50wt%, which makes it show great application potential in the field of biodiesel production. Studies have shown that under specific culture conditions, the oil yield of P. triangularis can reach 2.94mg / L / d2, which shows that it has significant advantages in large-scale industrial applications.

[0003] In addition to its application value in the energy field, P. triangularis is also rich in fucoxanthin, a natural pigment with a variety of potential pharmacological activities. Fucoxanthin has antioxidant, anti-inflammatory and anti-tumor effects, so it is widely used in nutritional supplements, providing important protection for human health.

[0004] However, despite the many advantages of P. triangularis, its harvesting and separation process remains a technical problem that needs to be solved urgently. At present, the main methods for harvesting P. triangularis include centrifugation, filtration and sedimentation. Although centrifugation can provide higher separation efficiency, it is only suitable for laboratory-scale operations due to its high energy consumption and equipment requirements. In industrial production, large filters are usually used for treatment, but this method not only has a low recovery rate and high cost, but also has a certain impact on the integrity of the algae. In addition, there are relatively few studies specifically on the collection and flocculants of P. triangularis, and related reports are extremely limited.

[0005] Despite this, there are still some patent technologies that attempt to solve this problem. For example, CN 1418825A discloses a highly efficient algae flocculant and its application method in the control of red tides and water blooms. This method uses clay modified by natural high molecular polymers as a flocculant. When the input amount is 0.005g / L, after 8 hours of treatment, a flocculation rate of more than 95wt% can be achieved. This technology provides a possible solution for the industrial collection of triangular brown finger algae. In addition, Japanese patent JP57131119 proposes a method for treating clay with inorganic acid, while US patent US6071859 introduces a method for mixing unsaturated fatty acids with clay. Although these technologies have improved the flocculation effect to a certain extent, they still have many shortcomings. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and provide a rare earth compound flocculant.

[0007] Another object of the present invention is to provide a method for preparing the rare earth compound flocculant.

[0008] Another object of the present invention is to provide application of the rare earth compound flocculant.

[0009] The technical solution of the present invention is as follows:

[0010] A rare earth compound flocculant, comprising a gluconic acid rare earth compound, a pyrithione rare earth compound and water, wherein:

[0011] The content of the rare earth gluconate compound is 5-15 wt %, and the rare earth gluconate compound is prepared by reacting sodium gluconate and a first rare earth chloride salt in water;

[0012] The content of the pyrithione rare earth compound is 0.4-0.6wt%, and the pyrithione rare earth compound is prepared by reacting sodium pyrithione and a second rare earth chloride salt in water.

[0013] In a preferred embodiment of the present invention, the first rare earth chloride salt is selected from lanthanum chloride, europium chloride and gadolinium chloride.

[0014] Further preferably, the second rare earth chloride salt is selected from samarium chloride, cerium chloride and lanthanum chloride.

[0015] The preparation method of the rare earth compound flocculant comprises the following steps:

[0016] (1) preparing a gluconic acid rare earth compound solution;

[0017] (2) preparing a pyrithione rare earth compound solution;

[0018] (3) adding the pyrithione rare earth compound solution obtained in step (2) to the gluconic acid rare earth compound solution obtained in step (1), and stirring them sufficiently to obtain the rare earth compound flocculant.

[0019] In a preferred embodiment of the present invention, the step (1) comprises:

[0020] A. Add sodium gluconate into ionized water and stir to prepare a transparent solution;

[0021] B. Heat the transparent solution obtained in step A to 40° C. and stir continuously to fully extend the molecular chains of sodium gluconate;

[0022] C. stirring and dissolving the first rare earth chloride salt in deionized water to obtain a solution;

[0023] D. Slowly drop the solution obtained in step C into the material obtained in step (2) while stirring. After the dropwise addition is completed, the reaction is continued at 40° C. for 2 h, and then cooled to room temperature to obtain a gadolinium gluconate solution.

[0024] In a preferred embodiment of the present invention, the step (2) comprises:

[0025] a. Add sodium pyrithione into deionized water and stir to mix evenly;

[0026] b. stirring and dissolving the second rare earth chloride salt in deionized water to obtain a solution;

[0027] c. Add the solution obtained in step b dropwise to the material obtained in step a. After the addition is completed, react at room temperature and pressure for 3 hours to obtain a precipitate, which is filtered and washed in sequence to obtain a lanthanum pyridinethione solution.

[0028] The rare earth compound flocculant is used for collecting Pseudomonas triangularis in seawater.

[0029] In a preferred embodiment of the present invention, 20 kg of the rare earth compound flocculant is added per ton of seawater.

[0030] A method for collecting triangular lipopolysaccharide in seawater comprises adding the rare earth compound flocculant to seawater containing triangular lipopolysaccharide, stirring evenly, and collecting the precipitate.

[0031] In a preferred embodiment of the present invention, 20 kg of the rare earth compound flocculant is added per ton of seawater.

[0032] The beneficial effects of the present invention are:

[0033] 1. The rare earth ions in the present invention are positively charged, showing strong coordination ability and high coordination number. At the same time, the surface of the triangular brown finger algae is negatively charged; therefore, when the rare earth ions come into contact with the triangular brown finger algae, the two can quickly interact with each other in charge, causing the triangular brown finger algae to quickly agglomerate and form a mass, which then gradually precipitates.

[0034] 2. The pyrithione in the present invention has the function of inhibiting the growth of bacteria and algae, can provide an antibacterial effect during the storage process of the above-mentioned rare earth gluconate, and at the same time promote the release of rare earth ions, further enhancing the inhibitory effect on the triangular brown algae; therefore, the synergistic effect of pyrithione and rare earth gluconate can effectively promote the rapid flocculation of the triangular brown algae, and realize efficient, short-time, low-dose industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure is a flow chart of the preparation of the rare earth compound flocculant of the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further illustrated and described below through specific implementation modes in combination with the accompanying drawings.

[0037] The process flow of the following embodiments is as follows Figure 1 shown, and in which:

[0038] Sodium gluconate is sodium D-gluconate, and its purity is food grade;

[0039] The purity of rare earth chloride salt is 99.99%;

[0040] Sodium pyrithione is an industrial-grade solution with a concentration of 40 wt %, purchased from Guangzhou Lanfeng Chemical Co., Ltd. with a brand name of SPT-40.

[0041] Example 1

[0042] The preparation method of rare earth gluconate in this embodiment comprises the following steps:

[0043] (1) adding 0.1 mol (about 44.84 g) of sodium gluconate to 403.56 g of ionized water, stirring at 400 r / min for 10 min to prepare a transparent solution with a concentration of 10 wt%;

[0044] (2) heating the transparent solution obtained in step (1) to 40° C. and stirring continuously to allow the sodium gluconate molecular chains to fully extend, with the stirring time being about 20 min;

[0045] (3) Weigh 0.03 mol (7.35 g) of lanthanum chloride into a beaker, then add 4.90 g of deionized water, stir until completely dissolved, and prepare a solution with a concentration of 60 wt %, which is set aside;

[0046] (4) slowly adding the solution obtained in step (3) to the material obtained in step (2) while stirring, and continuing the reaction at 40° C. for 2 h after the addition is completed, and then cooling to room temperature to obtain a lanthanum gluconate solution.

[0047] Furthermore, the preparation method of the rare earth compound flocculant in this embodiment comprises the following steps:

[0048] (1) Add 0.1 mol (about 15.01 g) of sodium pyrithione into a beaker, add 45.03 g of deionized water, and stir to mix evenly at a rate of 600 r / min for 7 min;

[0049] (2) Weigh 0.03 mol (about 7.35 g) of samarium chloride into a beaker, then add deionized water and stir until completely dissolved to prepare a solution with a concentration of 60 wt%;

[0050] (3) adding the solution obtained in step (2) dropwise to the material obtained in step (1); after the addition is completed, reacting at room temperature and pressure for 3 hours to obtain a white powder precipitate, which is filtered and washed in turn to obtain a samarium pyrithione solution with a solid content of 32 wt%;

[0051] (4) Add 8.69 g of the samarium pyrithione solution obtained in step (3) to the above lanthanum gluconate solution, so that the concentration of samarium pyrithione is 0.6 wt % and the concentration of lanthanum gluconate is 10 wt %. Stir continuously to obtain a transparent light yellow solution, which is the rare earth compound flocculant.

[0052] About 20 kg of the rare earth compound flocculant prepared in this example was directly added to the seawater containing the triangular liposome per ton of seawater, and the mixture was stirred and mixed evenly. After 1 hour, the triangular liposome was found to be precipitated in the water, and the collection rate of the triangular liposome was 94.2 wt %.

[0053] Example 2

[0054] The preparation method of rare earth gluconate in this embodiment comprises the following steps:

[0055] (1) adding 0.1 mol (about 44.84 g) of sodium gluconate to 254.09 g of ionized water, stirring at 600 r / min for 10 min to prepare a transparent solution with a concentration of 15 wt%;

[0056] (2) heating the transparent solution obtained in step (1) to 40° C. and stirring continuously to allow the sodium gluconate molecular chains to fully extend, with the stirring time being about 25 min;

[0057] (3) Weigh 0.03 mol (7.35 g) of europium chloride into a beaker, then add 4.90 g of deionized water, stir until completely dissolved, and prepare a solution with a concentration of 60 wt %, which is set aside;

[0058] (4) Slowly adding the solution obtained in step (3) to the material obtained in step (2) while stirring, and continuing the reaction at 40° C. for 2 h, and then cooling to room temperature to obtain a europium gluconate solution.

[0059] Furthermore, the preparation method of the rare earth compound flocculant in this embodiment comprises the following steps:

[0060] (1) Add 0.1 mol (about 15.01 g) of sodium pyrithione into a beaker, add 60.04 g of deionized water, and stir to mix evenly at a rate of 400 r / min for 10 min;

[0061] (2) Weigh 0.03 mol (about 7.35 g) of cerium chloride into a beaker, then add deionized water and stir until completely dissolved to prepare a solution with a concentration of 60 wt%;

[0062] (3) adding the solution obtained in step (2) dropwise to the material obtained in step (1); after the addition is completed, reacting at room temperature and pressure for 3 hours to obtain a white powder precipitate, which is filtered and washed in turn to obtain a cerium pyrithione solution with a solid content of 28 wt%;

[0063] (4) Add 4.46 g of the cerium pyrithione solution obtained in step (3) to the europium gluconate solution, so that the concentration of cerium pyrithione is 0.4 wt % and the concentration of europium gluconate is 14.9 wt %. Stir continuously to obtain a transparent light yellow solution, which is the rare earth compound flocculant.

[0064] (5) About 20 kg of the rare earth compound flocculant prepared in this example was directly added to the seawater containing P. triangularis per ton of seawater, and the mixture was stirred and mixed evenly. After 1 hour, the P. triangularis was found to be precipitated in the water, and the collection rate of P. triangularis was 97.5 wt%.

[0065] Example 3

[0066] The preparation method of rare earth gluconate in this embodiment comprises the following steps:

[0067] (1) adding 0.1 mol (about 44.84 g) of sodium gluconate to 851.96 g of ionized water, stirring at 200 r / min for 10 min to prepare a transparent solution with a concentration of 5 wt%;

[0068] (2) heating the transparent solution obtained in step (1) to 40° C. and stirring continuously to allow the sodium gluconate molecular chains to fully extend, with the stirring time being about 30 min;

[0069] (3) Weigh 0.03 mol (about 7.35 g) of gadolinium chloride into a beaker, then add 4.90 g of deionized water, stir until completely dissolved, and prepare a solution with a concentration of 60 wt %, which is set aside;

[0070] (4) slowly adding the solution obtained in step (3) to the material obtained in step (2) while stirring; after the addition is completed, the reaction is continued at 40° C. for 2 h, and then cooled to room temperature to obtain a gadolinium gluconate solution.

[0071] Furthermore, the preparation method of the rare earth compound flocculant in this embodiment comprises the following steps:

[0072] (1) Add 0.1 mol (about 15.01 g) of sodium pyrithione into a beaker, add 45.03 g of deionized water, and stir to mix evenly at a rate of 600 r / min for 7 min;

[0073] (2) Weigh 0.03 mol (about 7.35 g) of lanthanum chloride into a beaker, then add deionized water and stir until completely dissolved to prepare a solution with a concentration of 60 wt %;

[0074] (3) adding the solution obtained in step (2) dropwise to the material obtained in step (1); after the addition is completed, reacting at room temperature and pressure for 3 hours to obtain a white powder precipitate, which is filtered and washed in turn to obtain a lanthanum pyridinethione solution with a solid content of 41 wt%;

[0075] (4) Add 11.97 g of the lanthanum pyridinethione solution obtained in step (3) to the gadolinium gluconate solution, so that the concentration of lanthanum pyridinethione is 0.5 wt % and the concentration of gadolinium gluconate is 5 wt %. Stir continuously to obtain a transparent light yellow solution, which is the rare earth compound flocculant.

[0076] About 20 kg of the rare earth compound flocculant prepared in this example was directly added to the seawater containing the triangular liposome per ton of seawater, and the mixture was stirred and mixed evenly. After 1 hour, the triangular liposome was found to be precipitated in the water, and the collection rate of the triangular liposome was 95.7 wt %.

[0077] Comparative Example 1

[0078] The preparation method of rare earth gluconate in this comparative example comprises the following steps:

[0079] (1) adding 0.1 mol (about 44.84 g) of sodium gluconate to 2197.169 g of ionized water, stirring at 600 r / min for 10 min to prepare a transparent solution with a concentration of 2 wt%;

[0080] (2) heating the transparent solution obtained in step (1) to 40° C. and stirring continuously to allow the sodium gluconate molecular chains to fully extend, with the stirring time being about 25 min;

[0081] (3) Weigh 0.03 mol (7.35 g) of europium chloride into a beaker, then add 4.90 g of deionized water, stir until completely dissolved, and prepare a solution with a concentration of 60 wt %, which is set aside;

[0082] (4) Slowly adding the solution obtained in step (3) to the material obtained in step (2) while stirring, and continuing the reaction at 40° C. for 2 h, and then cooling to room temperature to obtain a europium gluconate solution.

[0083] Furthermore, the preparation method of the comparative flocculant in this comparative example comprises the following steps:

[0084] (1) Add 0.1 mol (about 15.01 g) of sodium pyrithione into a beaker, add 60.04 g of deionized water, and stir to mix evenly at a rate of 400 r / min for 10 min;

[0085] (2) Weigh 0.03 mol (about 7.35 g) of cerium chloride into a beaker, then add deionized water and stir until completely dissolved to prepare a solution with a concentration of 60 wt%;

[0086] (3) adding the solution obtained in step (2) dropwise to the material obtained in step (1); after the addition is completed, reacting at room temperature and pressure for 3 hours to obtain a white powder precipitate, which is filtered and washed in turn to obtain a cerium pyrithione solution with a solid content of 28 wt%;

[0087] (4) Add 97.25 g of the cerium pyrithione solution obtained in step (3) to the europium gluconate solution so that the concentration of cerium pyrithione is 1.2 wt % and the concentration of europium gluconate is 2 wt %. Stir continuously to obtain a transparent light yellow solution, which is the comparative flocculant.

[0088] In the seawater containing triangular brown algae, about 20 kg of the comparative flocculant prepared in this comparative example was directly added per ton of seawater, and the mixture was stirred and mixed evenly. After 1 hour, the triangular brown algae was found to be precipitated in the water, and the collection rate of the triangular brown algae was 85.5wt%.

[0089] Comparative Example 2

[0090] The preparation method of rare earth gluconate in this comparative example comprises the following steps:

[0091] (1) adding 0.1 mol (about 44.84 g) of sodium gluconate to 134.52 g of ionized water, stirring at 600 r / min for 10 min to prepare a transparent solution with a concentration of 25 wt%;

[0092] (2) heating the transparent solution obtained in step (1) to 40° C. and stirring continuously to allow the sodium gluconate molecular chains to fully extend, with the stirring time being about 25 min;

[0093] (3) Weigh 0.03 mol (7.35 g) of europium chloride into a beaker, then add 4.90 g of deionized water, stir until completely dissolved, and prepare a solution with a concentration of 60 wt %, which is set aside;

[0094] (4) Slowly adding the solution obtained in step (3) to the material obtained in step (2) while stirring, and continuing the reaction at 40° C. for 2 h, and then cooling to room temperature to obtain a europium gluconate solution.

[0095] Furthermore, the preparation method of the comparative flocculant in this comparative example comprises the following steps:

[0096] (1) Add 0.1 mol (about 15.01 g) of sodium pyrithione into a beaker, add 60.04 g of deionized water, and stir to mix evenly at a rate of 400 r / min for 10 min;

[0097] (2) Weigh 0.03 mol (about 7.35 g) of cerium chloride into a beaker, then add deionized water and stir until completely dissolved to prepare a solution with a concentration of 60 wt%;

[0098] (3) adding the solution obtained in step (2) dropwise to the material obtained in step (1); after the addition is completed, reacting at room temperature and pressure for 3 hours to obtain a white powder precipitate, which is filtered and washed in turn to obtain a cerium pyrithione solution with a solid content of 28 wt%;

[0099] (4) Add 1.58 g of the cerium pyrithione solution obtained in step (3) to the europium gluconate solution, so that the concentration of cerium pyrithione is 0.2 wt % and the concentration of europium gluconate is 24.8 wt %. Stir continuously to obtain a transparent light yellow solution, which is the comparative flocculant.

[0100] In the seawater containing triangular brown algae, about 20 kg of the comparative flocculant prepared in this comparative example was directly added per ton of seawater, and stirred and mixed evenly. After 1 hour, the triangular brown algae was found to be precipitated in the water, and the collection rate of the triangular brown algae was 74.8wt%.

[0101] Comparative Example 3

[0102] The preparation method of rare earth gluconate in this comparative example comprises the following steps:

[0103] (1) adding 0.1 mol (about 44.84 g) of sodium gluconate to 254.09 g of ionized water, stirring at 600 r / min for 3 min to prepare a transparent solution with a concentration of 15 wt%;

[0104] (2) heating the transparent solution obtained in step (1) to 30° C. and stirring continuously to allow the sodium gluconate molecular chains to fully extend, with the stirring time being about 25 min;

[0105] (3) Weigh 0.03 mol (7.35 g) of europium chloride into a beaker, then add 4.90 g of deionized water, stir until completely dissolved, and prepare a solution with a concentration of 60 wt %, which is set aside;

[0106] (4) slowly dropping the solution obtained in step (3) into the material obtained in step (2) while stirring, and cooling to room temperature after the dropping is completed to obtain a europium gluconate solution.

[0107] Furthermore, the preparation method of the comparative flocculant in this comparative example comprises the following steps:

[0108] (1) Add 0.1 mol (about 15.01 g) of sodium pyrithione into a beaker, add 60.04 g of deionized water, and stir to mix evenly at a rate of 200 r / min for 10 min;

[0109] (2) Weigh 0.03 mol (about 7.35 g) of cerium chloride into a beaker, then add deionized water and stir until completely dissolved to prepare a solution with a concentration of 60 wt%;

[0110] (3) adding the solution obtained in step (2) dropwise to the material obtained in step (1); after the addition is completed, reacting at room temperature and pressure for 3 hours to obtain a white powder precipitate, which is filtered and washed in turn to obtain a cerium pyrithione solution with a solid content of 28 wt%;

[0111] (4) Add 4.46 g of the cerium pyrithione solution obtained in step (3) to the europium gluconate solution so that the concentration of cerium pyrithione is 0.4 wt % and the concentration of europium gluconate is 14.9 wt %. Stir continuously to obtain a transparent light yellow solution, which is the comparative flocculant.

[0112] In the seawater containing triangular brown algae, about 20 kg of the comparative flocculant prepared in this comparative example was directly added per ton of seawater, and the mixture was stirred and mixed evenly. After 1 hour, the triangular brown algae was found to be precipitated in the water, and the collection rate of the triangular brown algae was 81.6 wt%.

[0113] Table 2 Comparison of flocculation effects of flocculants in different embodiments

[0114] Serial number name Flocculation rate / wt% 1 Example 1 94.2 2 Example 2 97.5 3 Example 3 95.7 4 Comparative Example 1 85.5 5 Comparative Example 2 74.8 6 Comparative Example 3 81.6

[0115] The above description is only a preferred embodiment of the present invention, and therefore cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the patent scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A rare earth compound flocculant, characterized in that: It is composed of a rare earth gluconic acid compound, a pyrithione rare earth compound and water, wherein: The content of the gluconate rare earth compound is 5-15wt%, and the gluconate rare earth compound is prepared by reacting sodium gluconate and a first rare earth chloride salt in water; The content of the pyrithione rare earth compound is 0.4-0.6wt%, and the pyrithione rare earth compound is prepared by reacting sodium pyrithione and a second rare earth chloride salt in water.

2. A rare earth compound flocculant as claimed in claim 1, characterized in that: The first rare earth chloride salt is selected from lanthanum chloride, europium chloride and gadolinium chloride.

3. A rare earth compound flocculant as claimed in claim 2, characterized in that: The second rare earth chloride salt is selected from samarium chloride, cerium chloride and lanthanum chloride.

4. The method for preparing a rare earth compound flocculant according to any one of claims 1 to 3, characterized in that: The steps include: (1) preparing a gluconic acid rare earth compound solution; (2) preparing a pyrithione rare earth compound solution; (3) adding the pyrithione rare earth compound solution obtained in step (2) to the gluconic acid rare earth compound solution obtained in step (1), and stirring them sufficiently to obtain the rare earth compound flocculant.

5. The preparation method according to claim 4, characterized in that: The step (1) comprises: A. Add sodium gluconate into ionized water and stir to prepare a transparent solution; B. Heat the transparent solution obtained in step A to 40° C. and stir continuously to fully extend the molecular chains of sodium gluconate; C. stirring and dissolving the first rare earth chloride salt in deionized water to obtain a solution; D. Slowly drop the solution obtained in step C into the material obtained in step (2) while stirring. After the dropwise addition is completed, the reaction is continued at 40° C. for 2 h, and then cooled to room temperature to obtain a gadolinium gluconate solution.

6. The preparation method according to claim 4, characterized in that: The step (2) comprises: a. Add sodium pyrithione into deionized water and stir to mix evenly; b. stirring and dissolving the second rare earth chloride salt in deionized water to obtain a solution; c. Add the solution obtained in step b dropwise to the material obtained in step a. After the addition is completed, react at room temperature and pressure for 3 hours to obtain a precipitate, which is filtered and washed in sequence to obtain a lanthanum pyridinethione solution.

7. Use of the rare earth compound flocculant according to any one of claims 1 to 3 in collecting Pseudomonas triangularis in seawater.

8. The use according to claim 7, characterized in that: 20 kg of the rare earth compound flocculant is added per ton of seawater.

9. A method for collecting Pseudomonas triangularis in seawater, characterized in that: include: The rare earth compound flocculant according to any one of claims 1 to 3 is added to seawater containing triangular brown algae, stirred evenly, and then the precipitate is collected.

10. The collection method according to claim 9, characterized in that: 20 kg of the rare earth compound flocculant is added per ton of seawater.

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