Method for harvesting cyanobacterial bloom by using polyglutamic acid modified attapulgite

Abstract

The invention discloses a method for harvesting cyanobacterial bloom by using polyglutamic acid modified attapulgite, which is characterized by comprising the following steps: preparing a flocculating agent and flocculating cyanobacterial bloom, and the flocculating agent is prepared by using polyglutamic acid modified attapulgite. The method for modifying the attapulgite by the polyglutamic acid comprises the following steps: mixing the polyglutamic acid with hydrochloric acid to obtain a mixed material, mixing the mixed material with the attapulgite for modification, drying, and grinding. According to the technical method, cyanobacterial bloom can be efficiently harvested, and meanwhile safety and no secondary pollution can be guaranteed. The method is suitable for efficient, safe and economical harvesting of cyanobacterial blooms, and has the advantages that (1) harmful substances are not remained after the polymeric glutamic acid is used; (2) the flocculant is larger in surface area, more compact in floc, faster in sedimentation and free of secondary pollution; (3) raw materials are easy to obtain, the cost is low, and the process is simple; and (4) the method has a use value and a good application prospect.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis of polymer materials, in particular to a method for harvesting cyanobacteria blooms by using polymerized glutamic acid-modified attapulgite, and belongs to the field of cyanobacteria bloom management. Background Art

[0002] Cyanobacteria, also known as blue-green algae, have cell walls and are single-celled organisms. They are larger than bacteria, with a diameter of about 3 to 15 microns. Usually, cyanobacteria tend to aggregate to form filamentous or single-cell aggregates.

[0004] With the increasing attention paid to water environment quality, the technology of collecting and treating cyanobacteria has attracted more and more attention from researchers and has been put into practical application in many lake management projects. The use of reasonable, economical and efficient technical means to achieve rapid separation and resource utilization of cyanobacteria in water is a new development direction for the research on eutrophication management of water bodies. It is worth noting that in the process of management and resource utilization, in addition to economical and efficient technical methods, how to ensure safe and non-secondary pollution technical methods should also be a key research direction. Summary of the invention

[0005] The present invention aims to provide a method for harvesting cyanobacteria blooms by using polyglutamic acid modified attapulgite, so as to solve the technical problem that cyanobacteria blooms can be harvested efficiently while ensuring safety and no secondary pollution.

[0006] The technical solution adopted by the present invention is as follows: A method for harvesting blue algae blooms by using polymerized glutamic acid modified attapulgite comprises: preparation of a flocculant and flocculation of the blue algae blooms, wherein the flocculant is prepared by using polymerized glutamic acid modified attapulgite.

[0007] Further, the polymerized glutamic acid modified attapulgite comprises the following steps: (1) Mixing of polyglutamic acid and hydrochloric acid; (2) Modification of the mixture of the polymerized glutamic acid and the hydrochloric acid with attapulgite; (3) Drying; (4) Grinding.

[0008] Furthermore, the polyglutamic acid is 20,000 to 70,000 Daltons, the hydrochloric acid is 5 mol / L, the ratio of the polyglutamic acid to the hydrochloric acid is 0.2 (g):10 (ml), and the polyglutamic acid and the hydrochloric acid are mixed and then fully stirred.

[0009] Furthermore, the purity of the attapulgite is ≥ 80%, the ratio of the attapulgite to the polyglutamic acid is 12 (g): 1 (g), and the attapulgite is added to the polyglutamic acid and the hydrochloric acid mixture for mixing and modification.

[0010] Furthermore, the mixing modification is carried out with continuous stirring at a rotation speed of 160 RPM for 12 hours.

[0011] Furthermore, the grinding requires that the powder particles be ≥200 mesh and account for less than 8%.

[0012] The flocculation steps of the blue algae bloom are as follows: The flocculant and the coagulant aid CaCL2 solution are mixed and then added into the cyanobacteria bloom solution. The pH of the cyanobacteria bloom solution is adjusted to 7.0-9.0, stirred at 300 rpm for 5 minutes, and allowed to stand for 3 hours to perform flocculation of the cyanobacteria bloom.

[0013] Furthermore, the concentration of the flocculant in the cyanobacteria bloom liquid is 0.3 g / L, and the coagulant aid is preferably CaCL2, and the concentration of the flocculant in the cyanobacteria bloom liquid is 0.2 g / L.

[0014] The beneficial effects of the present invention are: (1) The polymerized glutamic acid of the present invention does not leave any harmful substances after use and is safe, efficient and non-toxic; (2) The present invention uses the polymerized glutamic acid to modify the attapulgite, thereby making the specific surface area larger, the flocs tighter, the sedimentation faster, and no secondary pollution; (3) The raw materials of the flocculant preparation method provided by the present invention are easily available, the cost is low, and the process is simple; (4) The present invention has high use value and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a process flow chart of the present invention.

[0016] Figure 2 This is a diagram showing the experimental effects of different proportions of polyglutamic acid and attapulgite in Experiment 1 of the present invention.

[0017] Figure 3 This is a diagram showing the experimental effects of different amounts of flocculant in Experiment 2 of the present invention.

[0018] Figure 4 This is a diagram showing the experimental effects of different pH values ​​of the cyanobacteria bloom liquid in Experiment 3 of the present invention.

[0019] Figure 5 This is an experimental effect diagram of the amount of coagulant aid used in Experiment 4 of the present invention.

[0020] Figure 6 This is an experimental effect diagram comparing the use of a coagulant aid and the use of no coagulant aid in Experiment 5 of the present invention. Implementation

[0021] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. The accompanying drawings are simplified schematic diagrams, which only illustrate the basic process of the present invention in a schematic manner, and therefore only show processes related to the present invention. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Example

[0023] The following is combined with Figure 1 The process flow chart for implementing the first technical solution of the present invention is described in detail. In this embodiment, the flocculant of polymerized glutamic acid-modified attapulgite and the method of harvesting cyanobacteria blooms using the flocculant are implemented as follows: A method for harvesting blue algae blooms by using polymerized glutamic acid modified attapulgite comprises: preparation of a flocculant and flocculation of the blue algae blooms, wherein the flocculant is prepared by using polymerized glutamic acid modified attapulgite.

[0024] Further, the polymerized glutamic acid modified attapulgite comprises the following steps: (1) Mixing of polyglutamic acid and hydrochloric acid; (2) Modification of the mixture of the polymerized glutamic acid and the hydrochloric acid with attapulgite; (3) Drying; (4) Grinding.

[0025] Furthermore, the polyglutamic acid is 20,000 to 70,000 Daltons, the hydrochloric acid is 5 mol / L, the ratio of the polyglutamic acid to the hydrochloric acid is 0.2 (g):10 (ml), and the polyglutamic acid and the hydrochloric acid are mixed and then fully stirred.

[0026] Furthermore, the purity of the attapulgite is ≥ 80%, the ratio of the attapulgite to the polyglutamic acid is 12 (g): 1 (g), and the attapulgite is added to the polyglutamic acid and the hydrochloric acid mixture for mixing and modification.

[0027] Furthermore, the mixing modification is carried out with continuous stirring at a rotation speed of 160 RPM for 12 hours.

[0028] Furthermore, the grinding requires that the powder particles be ≥200 mesh and account for less than 8%.

[0029] The flocculation steps of the blue algae bloom are as follows: The flocculant is added to the cyanobacteria bloom liquid, the concentration of the flocculant in the cyanobacteria bloom liquid is 0.3 g / L, the pH of the cyanobacteria bloom liquid is adjusted to 7.0-9.0, stirred at a speed of 300 rpm for 5 minutes, and allowed to stand for 3 hours to perform flocculation of the cyanobacteria bloom.

[0030] Further experimental comparison: Experiment 1, with the same total mass, the polymerized glutamic acid and attapulgite were mixed in a ratio of 1:6, 1:8, 1:10, 1:12, and 1:14 to prepare the flocculant. Figure 2 It can be seen that when the ratio is 1:12, the flocculation rate is about 89%.

[0031] Experiment 2: The cyanobacteria bloom solution was the same, and the dosage of flocculant was 0.1g / L, 0.2g / L, 0.3g / L, 0.4g / L, 0.5g / L, 0.6g / L respectively. Figure 3 It can be seen that when the flocculation dosage is 0.3g / L, the flocculation rate is about 89%.

[0032] Experiment 3: The flocculants were the same, and the pH of the cyanobacteria bloom solution was flocculated at pH 2.0, pH 4.0, pH 6.0, pH 8.0, pH 9.0, pH 10.0, and pH 12.0. Figure 4 It can be seen that when the pH of the cyanobacteria bloom liquid is 6.0 to 12.0, the flocculation rate of the cyanobacteria bloom can reach more than 90%. Example

[0033] This embodiment is a further improvement on the above-mentioned embodiment 1. In this embodiment, a coagulant is added during the flocculation of the cyanobacteria bloom, and the coagulant is preferably CaCL2.

[0034] Before the flocculant is added to the cyanobacteria bloom liquid, the flocculant and the coagulant aid are first mixed. The concentration of the coagulant aid in the cyanobacteria bloom liquid is 0.2 g / L. The coagulant aid helps flocculation, and its mechanism is to bridge the solid suspended particles, thereby causing the suspended matter to sink rapidly.

[0035] Further experimental comparison: Experiment 4: The cyanobacteria bloom liquid and the flocculant were the same, and flocculation was performed at 0.1 g / L, 0.2 g / L, 0.3 g / L, and 0.4 g / L, respectively. Figure 5 It can be seen that when the concentration of the coagulant aid is 0.2 g / L, the flocculation rate of the cyanobacteria bloom can reach more than 90%.

[0036] Experiment 5: The same algae bloom liquid and flocculant were used. The flocculation was compared with the addition of 0.2 g / L of the coagulant and without the addition of the coagulant. The values ​​were compared every 30 minutes. Figure 6 It can be seen that at 30 minutes of flocculation, the flocculation rate of the coagulant-aided solution was significantly higher than that of the solution without coagulant-aided solution by nearly 10%. The solution was completely flocculated and precipitated at 90 minutes, thus saving flocculation time.

[0037] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for harvesting cyanobacteria blooms by using attapulgite modified with polyglutamic acid, comprising: The invention discloses a flocculant and flocculation of cyanobacteria bloom, wherein the flocculant is prepared by modifying attapulgite with polymerized glutamic acid.

2. The method for harvesting cyanobacteria blooms by using polyglutamic acid-modified attapulgite according to claim 1, characterized in that: The polymerized glutamic acid modified attapulgite comprises the following steps: (1) Mixing of polyglutamic acid and hydrochloric acid; (2) Modification of the mixture of the polymerized glutamic acid and the hydrochloric acid with attapulgite; (3) Drying; (4) Grinding.

3. The method for harvesting blue algae blooms by using polyglutamic acid-modified attapulgite according to claim 2, characterized in that: The polyglutamic acid is 20,000 to 70,000 Daltons, the hydrochloric acid is 5 mol / L, the ratio of the polyglutamic acid to the hydrochloric acid is 0.2 (g): 10 (ml), and the polyglutamic acid and the hydrochloric acid are mixed and then fully stirred; The purity of the attapulgite is ≥ 80%, and the ratio of the attapulgite to the polyglutamic acid is 12 (g): 1 (g); The mixing modification is carried out at a speed of 160 RPM and continuous stirring for 12 hours; The grinding requires that the powder particles be ≥200 mesh and account for less than 8%.

4. The method for harvesting blue algae blooms by using polyglutamic acid-modified attapulgite according to claim 1, characterized in that: The flocculation steps of the blue algae bloom are as follows: The flocculant and the coagulant aid CaCL2 solution are mixed and then added into the cyanobacteria bloom solution. The pH of the cyanobacteria bloom solution is adjusted to 7.0-9.0, stirred at 300 rpm for 5 minutes, and allowed to stand for 3 hours to perform flocculation of the cyanobacteria bloom.

5. The method for harvesting blue algae blooms by using polyglutamic acid-modified attapulgite according to claim 4, characterized in that: The concentration of the flocculant in the cyanobacteria bloom liquid is 0.3 g / L, and the coagulant aid is preferably CaCL2, and the concentration of the flocculant in the cyanobacteria bloom liquid is 0.2 g / L.

Images