A method for removing algae by spore transfer

Abstract

The present application relates to a kind of spore transfer removes algae method, belong to air floatation algae removal technical field, the present application includes two main steps of air floatation algae removal and flocculation algae removal, by first adding rhamnose lipid and dodecyl dimethyl benzyl ammonium chloride in air floatation process, then adding alkyl glycoside and quaternary ammonium salt type surfactant can obtain good algae removal effect;The present application is realized by the structure design of air floatation tank, and the addition of reagent in another air floatation tank is realized in time period, and continuous air floatation algae removal can be realized, so that the algae removal efficiency of active agent can be fully exerted, the combination ability and combination effect of algal cell and bubble are enhanced, and good water algae separation effect can be obtained after flocculation.Especially by the segmented addition of two kinds of active agents, the combination ability of bubble and algal cell is fully improved, and the water algae separation effect is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of air flotation algae removal, and in particular relates to a spore transfer algae removal method. Background Art

[0002] Nutrientation of water causes algae to multiply. Excessive algae in the water reduces the water's appearance and oxygen content. Traditional water treatment facilities struggle to remove excessive algae, which can lead to problems such as clogging filters and water pipes, and corroding reservoirs.

[0003] Spore transfer technology has been successfully applied in wastewater treatment. It utilizes dissolved air flotation (DAF) to reduce water pollution and remove algae. DAF is widely used for algae removal due to its high algae removal effectiveness, low release of algal toxins, and economical efficiency. However, algae cells are small and have a high negative surface potential (-7 to -17 MV). This creates electrostatic repulsion with similarly negatively charged bubbles on their surfaces, hindering their collision and adhesion. Furthermore, the small diameter of algae cells significantly differs from the size of bubbles produced by DAF, preventing them from colliding and forming flocculent particles, making further improvement in removal effectiveness difficult. Summary of the Invention

[0004] To overcome the problems of the prior art, the present invention provides a spore transfer algae removal method that enhances the binding ability and effectiveness of algal cells and air bubbles, achieving excellent algae separation after flocculation. In particular, the staged addition of two active agents significantly increases the binding ability of air bubbles and algal cells, improving algae separation efficiency.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions:

[0006] The spore transfer algae removal method comprises the following steps:

[0007] (1) Intermittent flotation algae removal

[0008] When removing algae by flotation, rhamnolipid and dodecyldimethylbenzyl ammonium chloride are first added to the sewage and fully mixed, and then alkyl glycoside and quaternary ammonium salt surfactant are added to continue flotation to remove algae.

[0009] (2) Flocculation and algae removal

[0010] Add flocculants to separate the algae.

[0011] Furthermore, the present invention first adds rhamnolipid and dodecyldimethylbenzylammonium chloride, and then adds alkyl glucoside and quaternary ammonium salt surfactant to continue flotation algae removal through the flotation tank designed by the present invention. The flotation tank is divided into a primary active agent addition area and a secondary active agent addition area, wherein a partition with a height less than the outer wall of the flotation tank is provided between the primary active agent addition area and the secondary active agent addition area; rhamnolipid and dodecyldimethylbenzylammonium chloride are added to the flotation tank from the primary active agent addition area; and alkyl glucoside and quaternary ammonium salt surfactant are added from the secondary active agent addition area.

[0012] Furthermore, both the primary active agent addition area and the secondary active agent addition area are provided with aeration pipes, and the sewage enters the flotation tank from below the aeration pipe of the primary active agent addition area through the water inlet pipe; the rhamnolipid and dodecyldimethylbenzyl ammonium chloride addition points are set at the bottom of the water inlet pipe or the aeration pipe of the primary active agent addition area.

[0013] Furthermore, the partition is in the shape of a central cylinder or a partition, dividing the flotation tank into a primary active agent addition area and a secondary active agent addition area.

[0014] Furthermore, the molar ratio of the rhamnolipid to dodecyldimethylbenzyl ammonium chloride is 1:1.01-1.02, and the two are mixed and dissolved before being added into water for flotation to remove algae.

[0015] Furthermore, the total amount of rhamnolipid and dodecyldimethylbenzyl ammonium chloride added is 0.5-0.8 mg / L per cubic meter of water.

[0016] Furthermore, the rhamnolipid is disrhamnolipid.

[0017] Furthermore, the molar ratio of the alkyl glycoside to the quaternary ammonium salt surfactant is 1:1.01-1.02, and the added amount is 0.1-0.3 mg / L.

[0018] Furthermore, the flocculant is any one of PAC, PAFC, AS, FC, PFS or PDM.

[0019] Furthermore, the water after the algae are separated is used in the water ecological restoration system.

[0020] Beneficial effects of the present invention:

[0021] The present invention uses rhamnolipid and dodecyldimethylbenzyl ammonium chloride in combination, which can effectively strengthen the binding effect between bubbles and algae bodies during spore transfer algae removal, improve algae removal efficiency, and shorten algae removal time.

[0022] By adding the active agent into the flotation tank twice, the present invention can make each active agent exert a better algae removal effect, improve the algae removal efficiency and shorten the algae removal time compared with adding all the active agents at one time.

[0023] The flotation tank of the present invention, by providing a partition, positioning the water inlet pipe, positioning the rhamnolipid and dodecyldimethylbenzyl ammonium chloride addition points, and positioning the alkyl glycoside and quaternary ammonium surfactant addition points, allows for the staggered addition of two agents within a single flotation tank. Furthermore, the two agents are continuously added to the flotation tank in staggered time periods, enabling continuous flotation algae removal. The staggered addition of the two active agents maximizes their algae removal efficiency. Furthermore, the partition acts as a buffer for the water, reducing the water flow rate and increasing the time it takes for bubbles and algae cells to bind. This, in particular for continuous flotation tanks, increases the tank's processing capacity.

[0024] The method of the present invention can separate algae quickly and completely during flocculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the first structure of the flotation tank of the present invention;

[0026] Figure 2 This is a second structural schematic diagram of the flotation tank of the present invention;

[0027] In the figure, 1- flotation tank, 2- partition, 3- aeration pipe, 4- grid, 5- water inlet pipe. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and beneficial effects of the present invention more clear, the technical solution of the present invention will be described in detail below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0029] In order to illustrate the present invention more clearly, the following examples are provided for detailed description. Example 1

[0030] A flotation tank capable of adding active agents at different time periods

[0031] A partition 2 is installed within the flotation tank 1. The partition 2 is lower than the tank wall and separates the tank 1 into a primary active agent addition zone and a secondary active agent addition zone. Nano aeration tubes 3 are installed in both zones. A grid 4 is located below the aeration tubes 3 in the primary active agent addition zone. This grid 4 reduces the influent flow rate and prolongs the mixing time of the initial active agent addition with the water.

[0032] The partition 2 has two structural forms:

[0033] (1) The first type of partition structure

[0034] As attached Figure 1 As shown, the partition 2 is cylindrical and is located in the center of the flotation tank 1. The cylindrical area enclosed by the partition 2 is the primary active agent addition area, and the area between the partition 2 and the wall of the flotation tank 1 is the secondary active agent addition area. The grid 4 is located within the cylindrical area enclosed by the partition 2.

[0035] The water inlet pipe 5 passes through the wall of the flotation tank 1 and enters the primary activator addition area. The sewage first enters the primary activator addition area and then overflows from the primary activator addition area into the secondary activator addition area. In this way, the time for the water to overflow from the primary activator addition area to the secondary activator addition area is different, resulting in a time difference. Even if two different activators are added to the primary activator addition area and the secondary activator addition area respectively and continuously, from an overall perspective, the water body will always first contact and mix with the first activator, and only after a certain time interval will it contact and mix with the second activator, so that the two activators are added to the water body at different time periods.

[0036] (2) The second partition structure

[0037] As attached Figure 2 As shown, the partition 2 is a straight plate, which divides the flotation tank 1 into two parts horizontally, wherein the right side of the partition 2 (with the attached Figure 2 The water inlet pipe 5 passes through the outer wall of the flotation tank 1 and enters the primary active agent adding area.

[0038] By adding different active agents into the primary active agent adding zone or the secondary active agent adding zone respectively, this structural approach can also achieve the addition of two active agents into the water body at different time periods.

[0039] In both of the above configurations, the active agent addition point must be located below the aeration tube 3. In the primary active agent addition zone, the active agent can be added through the water inlet pipe 5, or the active agent addition pipe can be directly inserted below the grid 4. When sewage is added, the flow of the water and the floating of the bubbles ensure thorough mixing of the active agent and the water.

[0040] Experimental verification shows that, under the same baffle 2 height, the first baffle structure has a longer dosing time interval for the two active agents and the active agents are more evenly dispersed in the water. In the following embodiments, the first baffle structure is adopted. Example 2

[0041] A spore transfer algae removal method (continuous method)

[0042] (1) Flotation algae removal

[0043] Rhamnolipid and dodecyldimethylbenzyl ammonium chloride were dissolved in water at a molar ratio of 1:1.01, and then added to the primary active agent addition area of ​​the flotation tank at a volume of 0.5 mg / L (100% equivalent, unless otherwise specified below, the amount of active agent added is the 100% equivalent amount of one or two active agents). At the same time, alkyl glycoside and quaternary ammonium salt surfactant were dissolved in water at a molar ratio of 1:1.01, and then added to the secondary active agent addition area of ​​the flotation tank at a volume of 0.1 mg / L (100% equivalent).

[0044] (2) Flocculation and algae removal

[0045] The water coming out of the flotation tank is transported through pipes or overflows into the flocculation tank, and flocculants are added to separate the algae. Example 3

[0046] A spore transfer algae removal method comprises the following steps:

[0047] (1) Flotation algae removal

[0048] Rhamnolipid and dodecyldimethylbenzyl ammonium chloride were dissolved in water at a molar ratio of 1:1.01, and then added to the primary surfactant addition area of ​​the flotation tank at a volume of 0.5 mg / L (100% off). At the same time, alkyl glycoside and quaternary ammonium salt surfactant were dissolved in water at a molar ratio of 1:1.01, and then added to the secondary surfactant addition area of ​​the flotation tank at a volume of 0.1 mg / L (100% off).

[0049] (2) Flocculation and algae removal

[0050] After 25-35 minutes of flotation algae removal, stop aeration and add flocculants into the flotation tank to separate the algae cells from the water.

[0051] If intermittent algae removal is used, a scraper for scraping off the floating layer of algae cells can be set on the flotation tank. The algae layer is removed by the scraper, and then the water body after algae removal is discharged.

[0052] Note: The flotation tank of the present invention only requires one tank to achieve the staggered addition of the two agents. The two active agents are added continuously to the tank, enabling continuous flotation algae removal while maintaining mixing and contact between the two active agents and the water at different time intervals. However, to facilitate the collection of algae removal data, intermittent algae removal was used in all subsequent examples and comparative examples.

[0053] Experiments have shown that flotation algae removal can achieve good algae removal effects when the time is between 25 and 35 minutes, and the algae removal effect is not greatly affected by the algae removal time. Example 4

[0054] A method for removing algae by spore transfer, comprising the following steps:

[0055] (1) Algae removal by air floatation

[0056] Dissolve rhamnolipid and dodecyl dimethyl benzyl ammonium chloride in water in a molar ratio of 1:1.02, and add to the primary active agent addition zone of the air floatation tank at a dosage of 0.5 mg / L (fold 100); meanwhile, dissolve alkyl glycoside and quaternary ammonium salt surfactant in water in a molar ratio of 1:1.02, and add to the secondary active agent addition zone of the air floatation tank at a dosage of 0.1 mg / L (fold 100).

[0057] (2) Algae removal by flocculation

[0058] After 25-35 min of algae removal by air floatation, stop aeration, add flocculant to the air floatation tank to separate the algae cells from the water body. Remove the algae layer by scraper, and then discharge the water body after algae removal.

[0059] Comparative Example 1 (one-time addition of four active agents)

[0060] A method for removing algae by spore transfer, comprising the following steps:

[0061] (1) Algae removal by air floatation

[0062] Dissolve rhamnolipid and dodecyl dimethyl benzyl ammonium chloride in water in a molar ratio of 1:1.01, and dissolve alkyl glycoside and quaternary ammonium salt surfactant in water in a molar ratio of 1:1.01, and add to the primary active agent addition zone of the air floatation tank at a dosage of 0.5 mg / L (fold 100) and 0.1 mg / L (fold 100), respectively, for algae removal by air floatation.

[0063] (2) Algae removal by flocculation

[0064] After 25-35 min of algae removal by air floatation, stop aeration, add flocculant to the air floatation tank to separate the algae cells from the water body. Remove the algae layer by scraper, and then discharge the water body after algae removal.

[0065] Comparative Example 2 (no addition of rhamnolipid)

[0066] A method for removing algae by spore transfer, comprising the following steps:

[0067] (1) Algae removal by air floatation

[0068] Dissolve dodecyl dimethyl benzyl ammonium chloride in water, and add to the primary active agent addition zone of the air floatation tank at a dosage of 0.5 mg / L (fold 100); meanwhile, dissolve alkyl glycoside and quaternary ammonium salt surfactant in water in a molar ratio of 1:1.01, and add to the secondary active agent addition zone of the air floatation tank at a dosage of 0.1 mg / L (fold 100).

[0069] (2) Flocculation and algae removal

[0070] After 25-35 minutes of flotation algae removal, aeration is stopped and flocculants are added to the flotation tank to separate the algae cells from the water. The algae layer is removed by scraping, and the algae-free water is then discharged.

[0071] Comparative Example 3 (without adding dodecyldimethylbenzyl ammonium chloride)

[0072] A spore transfer algae removal method comprises the following steps:

[0073] (1) Flotation algae removal

[0074] After rhamnolipid is dissolved in water, it is added to the primary surfactant addition area of ​​the flotation tank at a volume of 0.5 mg / L (100% off); at the same time, alkyl glycoside and quaternary ammonium salt surfactant are dissolved in water at a molar ratio of 1:1.01, and then added to the secondary surfactant addition area of ​​the flotation tank at a volume of 0.1 mg / L (100% off).

[0075] (2) Flocculation and algae removal

[0076] After 25-35 minutes of flotation algae removal, aeration is stopped and flocculants are added to the flotation tank to separate the algae cells from the water. The algae layer is removed by scraping, and the algae-free water is then discharged.

[0077] Comparative Example 4 (rhamnolipid not added, three active agents added at once)

[0078] A spore transfer algae removal method comprises the following steps:

[0079] (1) Flotation algae removal

[0080] Dodecyldimethylbenzyl ammonium chloride, alkyl glycoside and quaternary ammonium surfactant with a molar ratio of 1:1.01, wherein dodecyldimethylbenzyl ammonium chloride is dissolved in an amount of 0.5 mg / L (percentage), and alkyl glycoside and quaternary ammonium surfactant are dissolved in an amount of 0.1 mg / L (percentage) and added to the primary surfactant addition area of ​​the flotation tank at one time.

[0081] (2) Flocculation and algae removal

[0082] After 25-35 minutes of flotation algae removal, aeration is stopped and flocculants are added to the flotation tank to separate the algae cells from the water. The algae layer is removed by scraping, and the algae-free water is then discharged. Example 5

[0083] A spore transfer algae removal method comprises the following steps:

[0084] (1) Flotation algae removal

[0085] Rhamnolipid and dodecyldimethylbenzyl ammonium chloride were dissolved in water at a molar ratio of 1:1.01, and then added to the primary surfactant addition area of ​​the flotation tank at a volume of 0.8 mg / L (100% off). At the same time, alkyl glycoside and quaternary ammonium salt surfactant were dissolved in water at a molar ratio of 1:1.01, and then added to the secondary surfactant addition area of ​​the flotation tank at a volume of 0.3 mg / L (100% off).

[0086] (2) Flocculation and algae removal

[0087] After 25-35 minutes of flotation algae removal, aeration is stopped and flocculants are added to the flotation tank to separate the algae cells from the water. The algae layer is removed by scraping, and the algae-free water is then discharged.

[0088] Comparison of algae removal effects in the above examples

[0089] Note: The chlorophyll a test method is based on the industry standard HJ 897-2017; the algae cell count is based on DB37T 4163-2020; the water turbidity test method is based on the national standard GB 13200-91.

[0090] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A spore transfer algae removal method, characterized in that: The following steps are involved: (1) Flotation algae removal When removing algae by flotation, rhamnolipid and dodecyldimethylbenzyl ammonium chloride are first added to the sewage and mixed thoroughly, and then alkyl glycoside and quaternary ammonium salt surfactant are added; The molar ratio of the rhamnolipid to dodecyldimethylbenzyl ammonium chloride is 1:1.01-1.

02. After the two are mixed and dissolved, they are added to water for flotation to remove algae; the total amount of rhamnolipid and dodecyldimethylbenzyl ammonium chloride added is 0.5-0.8 mg / L water; The molar ratio of alkyl glycoside to quaternary ammonium salt surfactant is 1:1.01-1.02, and the addition amount is 0.1-0.3 mg / L water; (2) Flocculation and algae removal Add flocculants to separate the algae.

2. The spore transfer algae removal method according to claim 1, characterized in that: Using an air flotation tank including a primary active agent addition area and a secondary active agent addition area to perform air flotation algae removal; A partition whose height is less than the outer wall of the flotation tank is set between the primary active agent addition area and the secondary active agent addition area; rhamnolipid and dodecyldimethylbenzyl ammonium chloride are added to the flotation tank from the primary active agent addition area; alkyl glucoside and quaternary ammonium salt surfactant are added to the flotation tank from the secondary active agent addition area.

3. The spore transfer algae removal method according to claim 2, characterized in that: Both the primary activator addition area and the secondary activator addition area are provided with aeration pipes, and the sewage enters the flotation tank from the bottom of the aeration pipe in the primary activator addition area; the addition points of rhamnolipid and dodecyldimethylbenzyl ammonium chloride are set below the water inlet pipe or the aeration pipe in the primary activator addition area.

4. The spore transfer algae removal method according to claim 3, characterized in that: The partition is in the shape of a central cylinder or a partition, and divides the flotation tank into a primary active agent adding area and a secondary active agent adding area.

5. The spore transfer algae removal method according to claim 1, characterized in that: The rhamnolipid is dirhamnolipid.

6. The spore transfer algae removal method according to claim 1, characterized in that: The flocculant is any one of PAC, PAFC, AS, FC, PFS or PDM.

7. The spore transfer algae removal method according to any one of claims 1 to 4, characterized in that: The water after algae separation is used in the water ecological restoration system.

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