Preparation method and application of algicide for synchronously removing water bloom algae cells and algal toxin

Abstract

The invention belongs to the technical field of chemical agents, and provides a preparation method and application of an algicide for synchronously removing water bloom algae cells and algal toxins, the algicide is composed of calcium hypochlorite and natural clay, and the mass ratio of calcium hypochlorite to clay is 1: 1-5; the natural clay is at least one of bentonite, kaolin or diatomite; natural clay is used as a flocculating agent to prepare the algaecide, the algaecide is basically free of pollution to the ecological environment of a water body, calcium hypochlorite breaks the surface charge balance of algae cells by damaging the algae cells, rapid flocculation and sedimentation of the algae cells under the action of clay are facilitated, the removal rate reaches up to 80% or above, and the flocculation and sedimentation efficiency of the natural clay on the algae cells is far higher than the flocculation and sedimentation efficiency of the natural clay on the algae cells; after the algaecide is used for treatment, algaecide cells are broken, algaecide toxins in the cells are released, but calcium hypochlorite can quickly oxidize the toxins, so that the algaecide can synchronously remove algaecide toxins in water while removing water bloom algaecide cells, and the removal rate is up to 90% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical agents, and in particular relates to a preparation method and application of an algaecide for synchronously removing algae bloom cells and algal toxins. Background Art

[0002] The intensification of eutrophication of water bodies causes abnormal reproduction of algae cells, leading to the outbreak of "water blooms" in lakes and reservoirs, destroying the freshwater ecosystem. At the same time, many algae (such as Microcystis, Anabaena, etc.) will produce algae toxins. Scientific experiments have shown that this toxin is a precursor to liver cancer. This toxin can enter the human body through drinking water or enrichment in the food chain, thus threatening human health.

[0003] At present, directly applying chemical agents and flocculation precipitation methods to water bodies have become common methods for controlling algae blooms. However, general chemical algaecides (e.g., copper sulfate) not only kill harmful algae, but also harm other aquatic organisms. For example, heavy metals such as copper can be transmitted and enriched through the food chain and ultimately threaten human health. Using flocculants such as aluminum sulfate, iron sulfate, polyaluminum chloride, and modified clay to flocculate and remove algae is convenient and can achieve good results. However, the flocculants generally used have the disadvantages of high dosage, high cost, poor flocculation effect, and narrow addition range. Iron salt flocculants are also prone to increase the chromaticity of water bodies. Polyaluminum chloride has a good flocculation effect on algae cells, but aluminum is easily bio-enriched and produces secondary hazards. Although modified clay has a good sedimentation effect on algae cells, the modifier is easy to cause secondary pollution to the treated water body and cannot effectively remove algal toxins.

[0004] Among the algaecide patents disclosed in various applications, for example, Publication No. CN20071065054.6 discloses a water algaecide composed of various metal ions such as copper, zinc, aluminum, iron, calcium, etc. loaded on clay, which has the functions of algae removal, flocculation, precipitation, and phosphorus fixation. In addition, Publication No. CN201610850434.X also discloses a chemical algaecide for algae in eutrophic water bodies, which is composed of trichloroisocyanuric acid and alum. Although these algaecides have good algae removal effects, they generally contain heavy metals in their ingredients. The use of these algaecides will cause secondary pollution to the water body. Patent publication number CN201510562535.2 discloses a chitosan composite illite algaecide, which has no heavy metal pollution, but can only cause the algae to settle quickly. The algaecide in the above patent has little effect on removing algal toxins, especially soluble algal toxins in water. Therefore, it is urgent to develop a new safe and effective composite algaecide that can simultaneously achieve efficient removal of algal cells and algal toxins.

[0005] To this end, those skilled in the art have proposed a method for preparing and applying an algaecide for simultaneously removing algal bloom cells and algal toxins to solve the problems raised by the background art. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of existing algaecides such as high cost, secondary pollution and inability to simultaneously remove algal toxins, and to provide an algaecide for simultaneously removing water bloom algal cells and algal toxins, a method for preparing the algaecide and the use of the algaecide in water blooms.

[0007] In order to achieve the above-mentioned object, the present invention proposes an algaecide for simultaneously removing algal bloom cells and algal toxins, wherein the algaecide is composed of calcium hypochlorite and natural clay (bentonite, kaolin or diatomaceous earth), and the mass ratio of calcium hypochlorite to clay is 1:1-5.

[0008] The present invention also provides a method for preparing an algaecide, wherein the method comprises orderly mixing calcium hypochlorite, clay and water, wherein the amount of calcium hypochlorite is 2 parts by weight and the amount of clay is 2-10 parts by weight relative to 100 parts by weight of water.

[0009] The present invention also provides the use of the algaecide in the process of controlling algal bloom water bodies; preferably, the volume ratio of the water body to be treated to the amount of the algaecide is 1000:0.5-2, more preferably 1000:1-1.5.

[0010] The present invention uses calcium hypochlorite and clay with little impact on the environment as raw materials to prepare an effective and safe algae removal agent; the agent can remove algae cells and algae toxins with high efficiency, has low cost, little impact on the ecological environment, no secondary pollution, and is easy to administer.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. The algaecide of the present invention is simple to prepare and easy to use. The raw materials calcium hypochlorite and clay are non-toxic and easy to purchase at a low price, so the total cost is lower than that of other algaecides;

[0013] 2. The algaecide of the present invention uses calcium hypochlorite and clay as raw materials, which have little impact on the environment. It is very environmentally friendly and will not increase secondary pollution of water bodies. It can be widely used in various water bodies with algal blooms, including drinking water sources, urban landscape water bodies, etc.

[0014] 3. When the algaecide of the present invention is used to treat algal bloom water bodies, the hypochlorite generated by calcium hypochlorite can destroy algal cells, promote the adsorption of algal cells and clay, and facilitate the rapid sedimentation of algal cells. After the algaecide is used to treat small water bodies, most of the algae can be sedimented within two hours, and the algae will be completely settled and the water body will be clear again within 24 hours;

[0015] 4. When the algaecide of the present invention is used to treat algal bloom water bodies, the hypochlorite generated by calcium hypochlorite has a strong oxidation ability for algal toxins, and can quickly and synchronously remove algal toxins in the water body, with a removal rate of more than 90%, which effectively solves the problem that existing algaecides cannot synchronously remove algal toxins. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the reaction principle diagram of the algaecide of the present invention;

[0017] Figure 2 The algaecide preparation process flow chart of the present invention;

[0018] Figure 3 The effect diagram of the algaecide A1-A9 of the present invention after adding the suspension of Microcystis aeruginosa to react for 2h and 12h;

[0019] Figure 4 Schematic diagram of algae cell removal rate after algaecides A1-A9 of the present invention are added to a suspension of Microcystis aeruginosa for 2 hours and 12 hours;

[0020] Figure 5 This is a schematic diagram of the algae toxin removal rate after the algaecides A1-A9 of the present invention are added to the suspension of Microcystis aeruginosa for 1 hour;

[0021] Figure 6 This is a schematic diagram of a small landscape water body with cyanobacteria as the dominant species in the present invention;

[0022] Figure 7 This is a schematic diagram of the effect of treating a small landscape water body with the algaecide of Example 11 of the present invention for 12 hours and 24 hours;

[0023] Figure 8 This is a schematic diagram of the removal rate of algal cells and algal toxins after treating a small landscape water body with the algaecide of Example 11 of the present invention for 2 hours. DETAILED DESCRIPTION

[0024] The invention provides an algaecide for simultaneously removing algal bloom cells and algal toxins. The algaecide consists of calcium hypochlorite and natural clay, wherein the mass ratio of the calcium hypochlorite to the clay is 1:1-5; and the natural clay is at least one of bentonite, kaolin or diatomaceous earth.

[0025] A method for preparing an algaecide for simultaneously removing algae bloom cells and algae toxins, using the algaecide for simultaneously removing algae bloom cells and algae toxins, such as Figure 2 As shown, the method comprises orderly mixing calcium hypochlorite, clay and water, wherein the amount of calcium hypochlorite is 2 parts by weight and the amount of clay is 2-10 parts by weight relative to 100 parts by weight of water; in the mixing step, the mixing order of calcium hypochlorite, clay and water is to first dissolve calcium hypochlorite in water, then add clay powder and mix thoroughly.

[0026] An application of an algaecide in the process of controlling algal bloom water bodies, using the algaecide for simultaneously removing algal bloom cells and algal toxins, the volume ratio of the water body to be treated to the algaecide is 1000:0.5-2; the volume ratio of the water body to be treated to the algaecide is more preferably 1000:1-1.5.

[0027] From the above, it can be seen that the invention provides a chemical algaecide that can simultaneously remove algal cells and algal toxins, which contains calcium hypochlorite and clay. First, a certain amount of calcium hypochlorite is dissolved in water, and then clay powder in a corresponding mass ratio is added, mixed thoroughly, and then applied to the actual water body in a certain volume ratio.

[0028] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0029] Example 1

[0030] The algaecide of this embodiment is prepared by sequentially mixing calcium hypochlorite, bentonite and water. With respect to 100 parts by weight of water, the amount of calcium hypochlorite is 2 parts by weight, and the amount of bentonite is 10 parts by weight, to obtain algaecide A1.

[0031] Example 2

[0032] The algaecide of this embodiment is prepared by mixing calcium hypochlorite, bentonite and water in an orderly manner. With respect to 100 parts by weight of water, the amount of calcium hypochlorite is 2 parts by weight, and the amount of bentonite is 5 parts by weight, to obtain algaecide A2.

[0033] Example 3

[0034] The algaecide of this embodiment is prepared by mixing calcium hypochlorite, bentonite and water in an orderly manner. With respect to 100 parts by weight of water, the amount of calcium hypochlorite is 2 parts by weight, and the amount of bentonite is 2 parts by weight, to obtain algaecide A3.

[0035] Example 4

[0036] The algaecide of this embodiment is prepared by mixing calcium hypochlorite, kaolin and water in an orderly manner. With respect to 100 parts by weight of water, the amount of calcium hypochlorite is 2 parts by weight, and the amount of kaolin is 10 parts by weight, to obtain algaecide A4.

[0037] Example 5

[0038] The algaecide of this embodiment is prepared by sequentially mixing calcium hypochlorite, kaolin and water. With respect to 100 parts by weight of water, the amount of calcium hypochlorite is 2 parts by weight, and the amount of kaolin is 5 parts by weight, to obtain algaecide A5.

[0039] Example 6

[0040] The algaecide of this embodiment is prepared by mixing calcium hypochlorite, kaolin and water in an orderly manner. With respect to 100 parts by weight of water, the amount of calcium hypochlorite used is 2 parts by weight, and the amount of kaolin used is 2 parts by weight, to obtain algaecide A6.

[0041] Example 7

[0042] The algaecide of this embodiment is prepared by mixing calcium hypochlorite, diatomaceous earth and water in an orderly manner. With respect to 100 parts by weight of water, the amount of calcium hypochlorite is 2 parts by weight, and the amount of diatomaceous earth is 10 parts by weight, to obtain algaecide A7.

[0043] Example 8

[0044] The algaecide of this embodiment is prepared by mixing calcium hypochlorite, diatomaceous earth and water in an orderly manner. With respect to 100 parts by weight of water, the amount of calcium hypochlorite is 2 parts by weight and the amount of clay is 5 parts by weight, to obtain algaecide A8.

[0045] Example 9

[0046] The algaecide of this embodiment is prepared by mixing calcium hypochlorite, diatomaceous earth and water in an orderly manner. With respect to 100 parts by weight of water, the amount of calcium hypochlorite used is 2 parts by weight, and the amount of diatomaceous earth used is 2 parts by weight, to obtain algaecide A9.

[0047] Example 10

[0048] This embodiment is the application of the algaecides A1-A9 of the present invention in removing algae cells and their toxins using the most common Microcystis aeruginosa algae cell suspension. Figure 1 , Figures 3 to 5 In the process of simultaneously removing algae cells and toxins, the volume ratio of the water to be treated to the amount of algaecide is 1000:1, and the algae removal effects are:

[0049] 1) Algae cell removal: within 2 hours, the algae cells are flocculated and settled to the bottom of the water by the algaecide, with a removal rate of up to 80%. After the algaecide is treated, the rupture of the algae cells will lead to the release of algae toxins in the cells, but calcium hypochlorite can quickly oxidize the toxins, so that the algaecide can remove algae toxins in the water while removing the algae cells in the water, with a removal rate of more than 90%;

[0050] 2) Algal toxin removal: after 1 hour, the algal toxins in the water are completely oxidized and the concentration drops below the detection limit.

[0051] Embodiment 11

[0052] This embodiment is an application of the algaecide of the present invention in algae removal in a small landscape water body with cyanobacteria as the dominant species, such as Figure 1 , Figures 6 to 8As shown, when the present invention is used in the process of purifying algae-contaminated water, the volume ratio of the water to be treated to the amount of algaecide A1 is 1000:1, and the algae removal effects are:

[0053] 1) Algae cell removal rate: after 12 hours, the algae cells are flocculated by the algaecide and settle to the bottom of the water, the water is clear, and calcium hypochlorite can quickly oxidize the toxins, so that the algaecide can remove algae cells in the water while also removing algal toxins in the water, with a removal rate of more than 90%;

[0054] 2) Algal toxin removal: After 2 hours, the algal toxins in the water are completely oxidized and the concentration drops below the detection limit.

[0055] The present invention uses natural clay as a flocculant to prepare an algaecide, which is basically pollution-free to the ecological environment of the water body. Calcium hypochlorite breaks the surface charge balance of algae cells by destroying algae cells, which is conducive to the rapid flocculation and precipitation of algae cells under the action of clay, and the removal rate is as high as more than 80%, which is much higher than the flocculation and precipitation efficiency of natural clay on algae cells. After the algaecide is treated, the rupture of algae cells will lead to the release of algae toxins in the cells, but calcium hypochlorite can quickly oxidize the toxins, so that the algaecide can remove algae toxins in the water while removing water bloom algae cells, and the removal rate is as high as more than 90%.

[0056] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An algaecide for simultaneously removing algal bloom cells and algal toxins, characterized in that: The algaecide consists of calcium hypochlorite and natural clay, and the mass ratio of the calcium hypochlorite to the clay is 1:1-5.

2. The algaecide for simultaneously removing algal bloom cells and algal toxins as claimed in claim 1, characterized in that: The natural clay is at least one of bentonite, kaolin or diatomaceous earth.

3. A method for preparing an algaecide for simultaneously removing algal bloom cells and algal toxins, characterized in that: Using the algaecide for simultaneously removing algal bloom cells and algal toxins according to any one of claims 1-2, the method comprises orderly mixing calcium hypochlorite, clay and water, with the amount of calcium hypochlorite being 2 parts by weight and the amount of clay being 2-10 parts by weight relative to 100 parts by weight of water.

4. A method for preparing an algaecide for simultaneously removing algal bloom cells and algal toxins as claimed in claim 3, characterized in that: In the mixing step, the mixing order of calcium hypochlorite, clay and water is to first dissolve calcium hypochlorite in water, then add clay powder and mix thoroughly.

5. An application of an algaecide in the process of controlling algal blooms in water bodies, characterized in that: The algaecide for simultaneously removing algal bloom cells and algal toxins according to any one of claims 1-2 is used, and the volume ratio of the water to be treated to the algaecide is 1000:0.5-2.

6. The use of an algaecide in the process of controlling algal bloom water bodies as claimed in claim 5, characterized in that: The volume ratio of the water to be treated to the algaecide is more preferably 1000:1-1.5.

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