Algae remover for red tide emergency treatment and preparation method thereof

Abstract

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

Description

Technical Field

[0001] The invention relates to the technical field of emergency disposal of marine ecological disasters, and in particular to an algae remover for emergency disposal of red tides and a preparation method thereof. Background Art

[0002] In recent years, under the dual pressure of human activities and climate change, red tides have occurred frequently, and the intensity, scope and duration of outbreaks have continued to increase. Harmful red tides can not only destroy marine ecosystems and affect the economic development of coastal areas, but also threaten human health and public safety. It has become one of the world's marine disasters. The outbreak of red tides is significantly correlated with the aggravation of eutrophication in offshore waters. The presence of nutrients such as N and P provides a nutritional basis for the large-scale growth of red tide microalgae. Controlling the input of nutrients and regulating the output of nutrients can effectively reduce the frequency and intensity of red tide outbreaks.

[0003] Although prevention has been carried out against nutrients and exogenous organisms at the source, which has reduced the frequency and affected area of ​​offshore red tide outbreaks, the hazards caused by some toxic and harmful red tides still exist. Therefore, once a threatening red tide disaster occurs, emergency response must be carried out immediately to achieve the purpose of disaster elimination and mitigation and minimize the hazards caused by the red tide.

[0004] As early as the 1980s and 1990s, the natural clay sedimentation method was widely used in the emergency treatment of red tides in Japan, South Korea and other countries. Due to its wide source, low cost and pollution-free characteristics, it is considered to be the most promising emergency treatment method for red tides. However, the colloidal properties of natural clay are relatively poor, and the efficiency in removing red tide algae is relatively low. In the process of large-scale red tide algae treatment, a large amount of clay is often required for sedimentation, which increases costs and produces a large amount of sludge. The low flocculation efficiency of natural clay has become the biggest bottleneck restricting the clay sedimentation method to control red tides. Therefore, improving the removal rate of red tide algae is a problem that needs to be solved at present. Summary of the invention

[0005] The invention provides an algae remover for emergency disposal of red tide and a preparation method thereof, which solves the problem of low removal rate of red tide organisms by algae removers in the related art.

[0006] The technical solution of the present invention is as follows: The present invention provides an algae remover for emergency disposal of red tides, comprising the following raw materials in parts by weight: 70-90 parts of clay, 10-40 parts of inorganic flocculants, and 0.02-1 parts of organic flocculants; the organic flocculants include polydimethyldiallyl ammonium chloride and polyvinyl alcohol; the mass ratio of the polydimethyldiallyl ammonium chloride to the polyvinyl alcohol is 10:1-8.

[0007] As a further technical solution, the mass ratio of the polydimethyldiallylammonium chloride to the polyvinyl alcohol is 10:2-5.

[0008] In the present invention, the removal rate of the algae remover is further improved by limiting the mass ratio of polydimethyldiallylammonium chloride to polyvinyl alcohol to 10:2-5.

[0009] As a further technical solution, the alcoholysis degree of the polyvinyl alcohol is 87-94.5 mol%.

[0010] In the present invention, the removal rate of the algae remover is further improved by limiting the alcoholysis degree of polyvinyl alcohol to 87-94.5 mol%.

[0011] As a further technical solution, the clay is an organic composite clay, and the organic composite clay is obtained by compounding clay and sodium 5-sulfoisophthalic acid.

[0012] In the present invention, the organic composite clay is obtained by compounding clay and 5-sodium sulfoisophthalic acid, thereby further improving the removal rate of the algae remover.

[0013] As a further technical solution, the method for preparing the organic composite clay comprises the following steps: mixing sodium 5-sulfoisophthalate and clay in methanol, and drying to obtain the organic composite clay.

[0014] As a further technical solution, the mixing time is 1 to 2 hours.

[0015] As a further technical solution, the addition amount of 5-sodium sulfoisophthalate is 2% to 5% of the mass of the clay.

[0016] As a further technical solution, the clay includes one or more of kaolin, bentonite, coal gangue, and fly ash.

[0017] As a further technical solution, the inorganic flocculant includes one or both of an aluminum-containing inorganic flocculant and an iron-containing inorganic flocculant.

[0018] As a further technical solution, the inorganic flocculant is composed of the following components in parts by weight: 10 to 30 parts of an aluminum-containing inorganic flocculant and 0 to 10 parts of an iron-containing inorganic flocculant.

[0019] In the present invention, by adding an aluminum-containing inorganic flocculant and an iron-containing inorganic flocculant, a good flocculation effect can be exerted in a wider pH value range, and the adaptability to different types of water sources is strong.

[0020] As a further technical solution, the aluminum-containing inorganic flocculant includes one or more of polyaluminum chloride, polyaluminum sulfate, aluminum sulfate, and aluminum chloride.

[0021] As a further technical solution, the iron-containing inorganic flocculant includes one or both of polymerized ferric sulfate and ferric chloride.

[0022] The present invention also provides a method for preparing an algae remover for emergency treatment of red tides, comprising the following steps: S1, dissolving an organic flocculant in a solvent to obtain a mixed solution, adding clay to the mixed solution, stirring, aging, and drying to obtain a solid mixture; S2. Compounding the solid mixture and an inorganic flocculant to obtain an algae remover.

[0023] As a further technical solution, the mass ratio of the clay to the solvent is 1:2-5.

[0024] As a further technical solution, the solvent is water.

[0025] As a further technical solution, the aging temperature is 20-45° C., and the aging time is 1-24 hours.

[0026] As a further technical solution, in step S1, grinding is performed after drying.

[0027] As a further technical solution, in step S1, the drying temperature is 80°C.

[0028] The working principle and beneficial effects of the present invention are: In the present invention, the algae removal agent uses clay as the main raw material, and adds inorganic flocculants and organic flocculants to modify the clay. After the inorganic flocculant modifies the clay, the surface electrical properties of the clay particles are reversed, from negative charge to positive charge, so that the electrostatic repulsion between the clay particles and the algae cells is converted into electrostatic attraction, and then adsorption and electrical neutralization occur to improve the efficiency of removing red tide organisms. The organic flocculant is an organic polymer with a long chain structure, which can improve the bridging ability of natural clay-red tide organism cell flocs in the process of formation, accelerate the sedimentation speed, and has no secondary pollution. The organic flocculant includes polydimethyldiallyl ammonium chloride and polyethylene Alcohol, both have the characteristics of low cost, environmental friendliness, safety and non-toxicity. Among them, polydimethyldiallylammonium chloride can induce strong peroxidation stress, reduce the activity of red tide algae, weaken the movement ability of red tide algae, make it easier to be captured and flocculated by clay particles, and through inorganic-organic composite modification, on the basis of strong electrical neutralization ability, obtain good adsorption bridging performance, enhance the modified clay on the capture and sweeping effect of red tide algae biological cells, promote the growth of flocs and then increase the floc sedimentation rate, so that the removal effect of red tide algae is greatly improved, the amount of removal agent is reduced, and the cost of emergency disposal of red tides is greatly reduced. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the following embodiments and comparative examples: Polydimethyldiallylammonium chloride, CAS: 26062-79-3; polyvinyl alcohol of model PVA-217, alcoholysis degree of 87~89mol; polyvinyl alcohol of model PVA-613, alcoholysis degree of 92.5~94.5mol; polyvinyl alcohol of model PVA-CST, alcoholysis degree of 95.5~96.5mol; polyvinyl alcohol of model PVA-420H, alcoholysis degree of 79~81mol; kaolin, particle size of 325 mesh; bentonite, particle size of 325 mesh.

[0031] Example 1 A method for preparing an algae remover for emergency treatment of red tides comprises the following steps: S1. Add 0.02 parts of an organic flocculant to 140 parts of deionized water to obtain a mixed solution, add 70 parts of kaolin to the mixed solution and mix well, then age at 20° C. for 24 h, dry at 80° C., and grind to obtain a solid mixture; S2, mixing 10 parts of polyaluminium chloride and 10 parts of ferric chloride to obtain an inorganic flocculant; S3, compounding the solid mixture and an inorganic flocculant to obtain an algae remover; The organic flocculant is obtained by mixing polydimethyldiallyl ammonium chloride and polyvinyl alcohol PVA-CST in a mass ratio of 10:8.

[0032] Example 2 A method for preparing an algae remover for emergency treatment of red tides comprises the following steps: S1. Add 1 part of organic flocculant to 450 parts of deionized water to obtain a mixed solution, add 90 parts of bentonite to the mixed solution and mix well, then age at 45° C. for 1 h, dry at 80° C., and grind to obtain a solid mixture; S2, using 30 parts of polyaluminium chloride as an inorganic flocculant; S3, compounding the solid mixture and an inorganic flocculant to obtain an algae remover; The organic flocculant is obtained by mixing polydimethyldiallyl ammonium chloride and polyvinyl alcohol PVA-CST in a mass ratio of 10:8.

[0033] Example 3 The only difference between this embodiment and embodiment 1 is that the mass ratio of polydimethyldiallylammonium chloride to polyvinyl alcohol PVA-CST is 10:1.

[0034] Example 4 The only difference between this embodiment and embodiment 1 is that the mass ratio of polydimethyldiallylammonium chloride to polyvinyl alcohol PVA-CST is 2:1.

[0035] Example 5 The difference between this embodiment and embodiment 1 is that the mass ratio of polydimethyldiallylammonium chloride to polyvinyl alcohol PVA-CST is 5:1.

[0036] Example 6 The only difference between this embodiment and embodiment 5 is that the polyvinyl alcohol PVA-CST is replaced by an equal amount of polyvinyl alcohol PVA-420H.

[0037] Example 7 The only difference between this embodiment and embodiment 5 is that the polyvinyl alcohol PVA-CST is replaced by an equal amount of polyvinyl alcohol PVA-217.

[0038] Example 8 The only difference between this embodiment and embodiment 5 is that the polyvinyl alcohol PVA-CST is replaced by an equal amount of polyvinyl alcohol PVA-613.

[0039] Example 9 The only difference between this embodiment and embodiment 8 is that kaolin is replaced by an equal amount of modified kaolin; the preparation method of modified kaolin comprises the following steps: 40 g of kaolin and 0.8 g of sodium 5-sulfonate isophthalic acid are mixed in 400 mL of methanol for 1 hour, and then dried to obtain modified kaolin.

[0040] Example 10 The only difference between this embodiment and embodiment 8 is that kaolin is replaced by an equal amount of modified kaolin; the preparation method of modified kaolin comprises the following steps: 40 g of kaolin and 2 g of sodium 5-sulfonate isophthalic acid are mixed in 400 mL of methanol for 2 h, and then dried to obtain modified kaolin.

[0041] Comparative Example 1 The only difference between this comparative example and Example 1 is that the polyvinyl alcohol PVA-CST is replaced by an equal amount of polydimethyldiallylammonium chloride.

[0042] Comparative Example 2 The only difference between this comparative example and Example 1 is that polydimethyldiallylammonium chloride is replaced by an equal amount of polyvinyl alcohol PVA-CST.

[0043] Comparative Example 3 A method for preparing an algae remover for emergency treatment of red tides comprises the following steps: S1, mixing 10 parts of polyaluminium chloride and 10 parts of ferric chloride to obtain an inorganic flocculant; S2. Compound 70 parts of kaolin and an inorganic flocculant to obtain an algae remover.

[0044] Comparative Example 4 A method for preparing an algae remover for emergency treatment of red tides comprises the following steps: 0.02 parts of organic flocculant are added to 350 parts of deionized water to obtain a mixed solution, 70 parts of kaolin are added to the mixed solution and mixed evenly, and then the mixture is aged, dried at 80° C., and ground to obtain an algae remover.

[0045] Experimental Example 1 Prepare the remover suspension: add 1g of remover to 20mL of seawater to prepare 50g / L of remover suspension; Removal rate of red tide organisms: Take the red tide organism algae liquid (conical Scripps algae, microscopic dinoflagellates, algae cell density of 10 750mL of the above-mentioned colorimetric tube was added into a 50mL colorimetric tube, and 1mL of the removal agent suspension was added using a pipette. After being mixed upside down, the tube was allowed to stand for 2h under culture conditions (a blank control group was set up and an equal volume of seawater was added). The upper clear liquid of the colorimetric tube was taken, fixed with Lugo reagent, and shaken well. 0.5mL was extracted using a pipette and placed under a microscope for algal cell counting. Each sample was extracted 3 times, and the average value was taken after counting respectively. The removal rate of red tide organisms was calculated according to the following formula: Red tide organism removal rate = [1-(algae cell density in the experimental group / algae cell density in the control group)] × 100%.

[0046] Laboratory culture method of red tide organisms: Step 1: Take natural seawater, filter it with a 0.45μm fiber filter membrane, and place it in a conical bottle. Seal it with a sealing film and tie it tightly with a rubber band; Step 2: sterilize the conical flask and the pipette tip required for inoculation at 121°C for 20 minutes under high pressure, and transfer to the clean bench in the sterile room after sterilization; Step 3: Use a pipette to transfer the f / 2 culture medium concentrate into sterile seawater and shake well; Step 4: Inoculate the algae species to be cultivated (Scrippyrum conicalum, Prorocentrum microphyllum) into the above-mentioned conical flask, place it in an incubator for cultivation at a temperature of 20±1°C, a light-dark ratio of 12h:12h, and shake the conical flask manually at least three times a day.

[0047] The test results are shown in Table 1.

[0048] Table 1 Algae removal agent removal rate test results

[0049] Compared with Comparative Examples 1 to 4, the algae removers prepared in Examples 1 to 10 have higher removal rates for Scripps cone-shaped algae and Prorocentrum microphyllum than those in Comparative Examples 1 to 4, indicating that the organic composite clay obtained by compounding clay and sodium 5-sulfonate isophthalic acid, and compounding with inorganic and organic flocculants, wherein the organic flocculant is composed of polydimethyldiallylammonium chloride and polyvinyl alcohol, can improve the removal rate of the algae remover for red tide organisms.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An algae remover for emergency treatment of red tide, characterized in that: The raw materials include the following components in parts by weight: 70-90 parts of clay, 10-40 parts of inorganic flocculant, and 0.02-1 part of organic flocculant; the organic flocculant includes polydimethyldiallyl ammonium chloride and polyvinyl alcohol; the mass ratio of the polydimethyldiallyl ammonium chloride to the polyvinyl alcohol is 10:1-8.

2. The algae remover for emergency treatment of red tide according to claim 1, characterized in that: The mass ratio of the polydimethyldiallylammonium chloride to the polyvinyl alcohol is 10:2-5.

3. The algae remover for emergency treatment of red tide according to claim 1, characterized in that: The alcoholysis degree of the polyvinyl alcohol is 87-94.5 mol%.

4. The algae remover for emergency treatment of red tide according to claim 1, characterized in that: The clay is an organic composite clay, which is obtained by compounding clay and sodium 5-sulfoisophthalic acid.

5. The algae remover for emergency treatment of red tide according to claim 4, characterized in that: The addition amount of the sodium 5-sulfoisophthalate is 2% to 5% of the mass of the clay.

6. The algae remover for emergency treatment of red tide according to claim 1, characterized in that: The inorganic flocculant is composed of the following components in parts by weight: 10 to 30 parts of an aluminum-containing inorganic flocculant and 0 to 10 parts of an iron-containing inorganic flocculant.

7. The algae remover for emergency treatment of red tide according to claim 6, characterized in that: The aluminum-containing inorganic flocculant includes one or more of polyaluminum chloride, polyaluminum sulfate, aluminum sulfate, and aluminum chloride.

8. The algae remover for emergency treatment of red tide according to claim 6, characterized in that: The iron-containing inorganic flocculant includes one or both of polymerized ferric sulfate and ferric chloride.

9. The algae remover for emergency treatment of red tide according to claim 1, characterized in that: The clay includes one or more of kaolin, bentonite, coal gangue and fly ash.

10. The method for preparing an algae remover for emergency treatment of red tide according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, dissolving an organic flocculant in a solvent to obtain a mixed solution, adding clay to the mixed solution, stirring, aging, and drying to obtain a solid mixture; S2. Compounding the solid mixture and an inorganic flocculant to obtain an algae remover.

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